Added MesaLib-7.6

1 files changed, 2825 insertions, 0 deletions

diff --git a/mesalib/src/mesa/shader/slang/slang_compile.c b/mesalib/src/mesa/shader/slang/slang_compile.c
new file mode 100644
index 000000000..c1b97c7cb
--- /dev/null
+++ b/mesalib/src/mesa/shader/slang/slang_compile.c
@@ -0,0 +1,2825 @@
+/*
+ * Mesa 3-D graphics library
+ *
+ * Copyright (C) 2005-2006  Brian Paul   All Rights Reserved.
+ * Copyright (C) 2008 VMware, Inc.  All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+/**
+ * \file slang_compile.c
+ * slang front-end compiler
+ * \author Michal Krol
+ */
+
+#include "main/imports.h"
+#include "main/context.h"
+#include "shader/program.h"
+#include "shader/programopt.h"
+#include "shader/prog_optimize.h"
+#include "shader/prog_print.h"
+#include "shader/prog_parameter.h"
+#include "shader/grammar/grammar_mesa.h"
+#include "slang_codegen.h"
+#include "slang_compile.h"
+#include "slang_preprocess.h"
+#include "slang_storage.h"
+#include "slang_emit.h"
+#include "slang_log.h"
+#include "slang_mem.h"
+#include "slang_vartable.h"
+#include "slang_simplify.h"
+
+#include "slang_print.h"
+
+/*
+ * This is a straightforward implementation of the slang front-end
+ * compiler.  Lots of error-checking functionality is missing but
+ * every well-formed shader source should compile successfully and
+ * execute as expected. However, some semantically ill-formed shaders
+ * may be accepted resulting in undefined behaviour.
+ */
+
+
+/** re-defined below, should be the same though */
+#define TYPE_SPECIFIER_COUNT 32
+
+
+/**
+ * Check if the given identifier is legal.
+ */
+static GLboolean
+legal_identifier(slang_atom name)
+{
+   /* "gl_" is a reserved prefix */
+   if (_mesa_strncmp((char *) name, "gl_", 3) == 0) {
+      return GL_FALSE;
+   }
+   return GL_TRUE;
+}
+
+
+/*
+ * slang_code_unit
+ */
+
+GLvoid
+_slang_code_unit_ctr(slang_code_unit * self,
+                     struct slang_code_object_ * object)
+{
+   _slang_variable_scope_ctr(&self->vars);
+   _slang_function_scope_ctr(&self->funs);
+   _slang_struct_scope_ctr(&self->structs);
+   self->object = object;
+}
+
+GLvoid
+_slang_code_unit_dtr(slang_code_unit * self)
+{
+   slang_variable_scope_destruct(&self->vars);
+   slang_function_scope_destruct(&self->funs);
+   slang_struct_scope_destruct(&self->structs);
+}
+
+/*
+ * slang_code_object
+ */
+
+GLvoid
+_slang_code_object_ctr(slang_code_object * self)
+{
+   GLuint i;
+
+   for (i = 0; i < SLANG_BUILTIN_TOTAL; i++)
+      _slang_code_unit_ctr(&self->builtin[i], self);
+   _slang_code_unit_ctr(&self->unit, self);
+   slang_atom_pool_construct(&self->atompool);
+}
+
+GLvoid
+_slang_code_object_dtr(slang_code_object * self)
+{
+   GLuint i;
+
+   for (i = 0; i < SLANG_BUILTIN_TOTAL; i++)
+      _slang_code_unit_dtr(&self->builtin[i]);
+   _slang_code_unit_dtr(&self->unit);
+   slang_atom_pool_destruct(&self->atompool);
+}
+
+
+/* slang_parse_ctx */
+
+typedef struct slang_parse_ctx_
+{
+   const byte *I;
+   slang_info_log *L;
+   int parsing_builtin;
+   GLboolean global_scope;   /**< Is object being declared a global? */
+   slang_atom_pool *atoms;
+   slang_unit_type type;     /**< Vertex vs. Fragment */
+   GLuint version;           /**< user-specified (or default) #version */
+} slang_parse_ctx;
+
+/* slang_output_ctx */
+
+typedef struct slang_output_ctx_
+{
+   slang_variable_scope *vars;
+   slang_function_scope *funs;
+   slang_struct_scope *structs;
+   struct gl_program *program;
+   struct gl_sl_pragmas *pragmas;
+   slang_var_table *vartable;
+   GLuint default_precision[TYPE_SPECIFIER_COUNT];
+   GLboolean allow_precision;
+   GLboolean allow_invariant;
+   GLboolean allow_centroid;
+   GLboolean allow_array_types;  /* float[] syntax */
+} slang_output_ctx;
+
+/* _slang_compile() */
+
+
+/* Debugging aid, print file/line where parsing error is detected */
+#define RETURN0 \
+   do { \
+      if (0) \
+         printf("slang error at %s:%d\n", __FILE__, __LINE__); \
+      return 0; \
+   } while (0)
+
+
+static void
+parse_identifier_str(slang_parse_ctx * C, char **id)
+{
+   *id = (char *) C->I;
+   C->I += _mesa_strlen(*id) + 1;
+}
+
+static slang_atom
+parse_identifier(slang_parse_ctx * C)
+{
+   const char *id;
+
+   id = (const char *) C->I;
+   C->I += _mesa_strlen(id) + 1;
+   return slang_atom_pool_atom(C->atoms, id);
+}
+
+static int
+parse_number(slang_parse_ctx * C, int *number)
+{
+   const int radix = (int) (*C->I++);
+   *number = 0;
+   while (*C->I != '\0') {
+      int digit;
+      if (*C->I >= '0' && *C->I <= '9')
+         digit = (int) (*C->I - '0');
+      else if (*C->I >= 'A' && *C->I <= 'Z')
+         digit = (int) (*C->I - 'A') + 10;
+      else
+         digit = (int) (*C->I - 'a') + 10;
+      *number = *number * radix + digit;
+      C->I++;
+   }
+   C->I++;
+   if (*number > 65535)
+      slang_info_log_warning(C->L, "%d: literal integer overflow.", *number);
+   return 1;
+}
+
+static int
+parse_float(slang_parse_ctx * C, float *number)
+{
+   char *integral = NULL;
+   char *fractional = NULL;
+   char *exponent = NULL;
+   char *whole = NULL;
+
+   parse_identifier_str(C, &integral);
+   parse_identifier_str(C, &fractional);
+   parse_identifier_str(C, &exponent);
+
+   whole = (char *) _slang_alloc((_mesa_strlen(integral) +
+                                  _mesa_strlen(fractional) +
+                                  _mesa_strlen(exponent) + 3) * sizeof(char));
+   if (whole == NULL) {
+      slang_info_log_memory(C->L);
+      RETURN0;
+   }
+
+   slang_string_copy(whole, integral);
+   slang_string_concat(whole, ".");
+   slang_string_concat(whole, fractional);
+   slang_string_concat(whole, "E");
+   slang_string_concat(whole, exponent);
+
+   *number = (float) (_mesa_strtod(whole, (char **) NULL));
+
+   _slang_free(whole);
+
+   return 1;
+}
+
+/* revision number - increment after each change affecting emitted output */
+#define REVISION 5
+
+static int
+check_revision(slang_parse_ctx * C)
+{
+   if (*C->I != REVISION) {
+      slang_info_log_error(C->L, "Internal compiler error.");
+      RETURN0;
+   }
+   C->I++;
+   return 1;
+}
+
+static int parse_statement(slang_parse_ctx *, slang_output_ctx *,
+                           slang_operation *);
+static int parse_expression(slang_parse_ctx *, slang_output_ctx *,
+                            slang_operation *);
+static int parse_type_specifier(slang_parse_ctx *, slang_output_ctx *,
+                                slang_type_specifier *);
+static int
+parse_type_array_size(slang_parse_ctx *C,
+                      slang_output_ctx *O,
+                      GLint *array_len);
+
+static GLboolean
+parse_array_len(slang_parse_ctx * C, slang_output_ctx * O, GLuint * len)
+{
+   slang_operation array_size;
+   slang_name_space space;
+   GLboolean result;
+
+   if (!slang_operation_construct(&array_size))
+      return GL_FALSE;
+   if (!parse_expression(C, O, &array_size)) {
+      slang_operation_destruct(&array_size);
+      return GL_FALSE;
+   }
+
+   space.funcs = O->funs;
+   space.structs = O->structs;
+   space.vars = O->vars;
+
+   /* evaluate compile-time expression which is array size */
+   _slang_simplify(&array_size, &space, C->atoms);
+
+   if (array_size.type == SLANG_OPER_LITERAL_INT) {
+      result = GL_TRUE;
+      *len = (GLint) array_size.literal[0];
+   } else if (array_size.type == SLANG_OPER_IDENTIFIER) {
+      slang_variable *var = _slang_variable_locate(array_size.locals, array_size.a_id, GL_TRUE);
+      if (!var) {
+         slang_info_log_error(C->L, "undefined variable '%s'",
+                              (char *) array_size.a_id);
+         result = GL_FALSE;
+      } else if (var->type.qualifier == SLANG_QUAL_CONST &&
+                 var->type.specifier.type == SLANG_SPEC_INT) {
+         if (var->initializer &&
+             var->initializer->type == SLANG_OPER_LITERAL_INT) {
+            *len = (GLint) var->initializer->literal[0];
+            result = GL_TRUE;
+         } else {
+            slang_info_log_error(C->L, "unable to parse array size declaration");
+            result = GL_FALSE;
+         }
+      } else {
+         slang_info_log_error(C->L, "unable to parse array size declaration");
+         result = GL_FALSE;
+      }
+   } else {
+      result = GL_FALSE;
+   }
+
+   slang_operation_destruct(&array_size);
+   return result;
+}
+
+static GLboolean
+calculate_var_size(slang_parse_ctx * C, slang_output_ctx * O,
+                   slang_variable * var)
+{
+   slang_storage_aggregate agg;
+
+   if (!slang_storage_aggregate_construct(&agg))
+      return GL_FALSE;
+   if (!_slang_aggregate_variable(&agg, &var->type.specifier, var->array_len,
+                                  O->funs, O->structs, O->vars, C->atoms)) {
+      slang_storage_aggregate_destruct(&agg);
+      return GL_FALSE;
+   }
+   var->size = _slang_sizeof_aggregate(&agg);
+   slang_storage_aggregate_destruct(&agg);
+   return GL_TRUE;
+}
+
+static void
+promote_type_to_array(slang_parse_ctx *C,
+                      slang_fully_specified_type *type,
+                      GLint array_len)
+{
+   slang_type_specifier *baseType =
+      slang_type_specifier_new(type->specifier.type, NULL, NULL);
+
+   type->specifier.type = SLANG_SPEC_ARRAY;
+   type->specifier._array = baseType;
+   type->array_len = array_len;
+}
+
+
+static GLboolean
+convert_to_array(slang_parse_ctx * C, slang_variable * var,
+                 const slang_type_specifier * sp)
+{
+   /* sized array - mark it as array, copy the specifier to the array element
+    * and parse the expression */
+   var->type.specifier.type = SLANG_SPEC_ARRAY;
+   var->type.specifier._array = (slang_type_specifier *)
+      _slang_alloc(sizeof(slang_type_specifier));
+   if (var->type.specifier._array == NULL) {
+      slang_info_log_memory(C->L);
+      return GL_FALSE;
+   }
+   slang_type_specifier_ctr(var->type.specifier._array);
+   return slang_type_specifier_copy(var->type.specifier._array, sp);
+}
+
+/* structure field */
+#define FIELD_NONE 0
+#define FIELD_NEXT 1
+#define FIELD_ARRAY 2
+
+static GLboolean
+parse_struct_field_var(slang_parse_ctx * C, slang_output_ctx * O,
+                       slang_variable * var, slang_atom a_name,
+                       const slang_type_specifier * sp,
+                       GLuint array_len)
+{
+   var->a_name = a_name;
+   if (var->a_name == SLANG_ATOM_NULL)
+      return GL_FALSE;
+
+   switch (*C->I++) {
+   case FIELD_NONE:
+      if (array_len != -1) {
+         if (!convert_to_array(C, var, sp))
+            return GL_FALSE;
+         var->array_len = array_len;
+      }
+      else {
+         if (!slang_type_specifier_copy(&var->type.specifier, sp))
+            return GL_FALSE;
+      }
+      break;
+   case FIELD_ARRAY:
+      if (array_len != -1)
+         return GL_FALSE;
+      if (!convert_to_array(C, var, sp))
+         return GL_FALSE;
+      if (!parse_array_len(C, O, &var->array_len))
+         return GL_FALSE;
+      break;
+   default:
+      return GL_FALSE;
+   }
+
+   return calculate_var_size(C, O, var);
+}
+
+static int
+parse_struct_field(slang_parse_ctx * C, slang_output_ctx * O,
+                   slang_struct * st, slang_type_specifier * sp)
+{
+   slang_output_ctx o = *O;
+   GLint array_len;
+
+   o.structs = st->structs;
+   if (!parse_type_specifier(C, &o, sp))
+      RETURN0;
+   if (!parse_type_array_size(C, &o, &array_len))
+      RETURN0;
+
+   do {
+      slang_atom a_name;
+      slang_variable *var = slang_variable_scope_grow(st->fields);
+      if (!var) {
+         slang_info_log_memory(C->L);
+         RETURN0;
+      }
+      a_name = parse_identifier(C);
+      if (_slang_variable_locate(st->fields, a_name, GL_FALSE)) {
+         slang_info_log_error(C->L, "duplicate field '%s'", (char *) a_name);
+         RETURN0;
+      }
+
+      if (!parse_struct_field_var(C, &o, var, a_name, sp, array_len))
+         RETURN0;
+   }
+   while (*C->I++ != FIELD_NONE);
+
+   return 1;
+}
+
+static int
+parse_struct(slang_parse_ctx * C, slang_output_ctx * O, slang_struct ** st)
+{
+   slang_atom a_name;
+   const char *name;
+
+   /* parse struct name (if any) and make sure it is unique in current scope */
+   a_name = parse_identifier(C);
+   if (a_name == SLANG_ATOM_NULL)
+      RETURN0;
+
+   name = slang_atom_pool_id(C->atoms, a_name);
+   if (name[0] != '\0'
+       && slang_struct_scope_find(O->structs, a_name, 0) != NULL) {
+      slang_info_log_error(C->L, "%s: duplicate type name.", name);
+      RETURN0;
+   }
+
+   /* set-up a new struct */
+   *st = (slang_struct *) _slang_alloc(sizeof(slang_struct));
+   if (*st == NULL) {
+      slang_info_log_memory(C->L);
+      RETURN0;
+   }
+   if (!slang_struct_construct(*st)) {
+      _slang_free(*st);
+      *st = NULL;
+      slang_info_log_memory(C->L);
+      RETURN0;
+   }
+   (**st).a_name = a_name;
+   (**st).structs->outer_scope = O->structs;
+
+   /* parse individual struct fields */
+   do {
+      slang_type_specifier sp;
+
+      slang_type_specifier_ctr(&sp);
+      if (!parse_struct_field(C, O, *st, &sp)) {
+         slang_type_specifier_dtr(&sp);
+         RETURN0;
+      }
+      slang_type_specifier_dtr(&sp);
+   }
+   while (*C->I++ != FIELD_NONE);
+
+   /* if named struct, copy it to current scope */
+   if (name[0] != '\0') {
+      slang_struct *s;
+
+      O->structs->structs =
+         (slang_struct *) _slang_realloc(O->structs->structs,
+                                         O->structs->num_structs
+                                         * sizeof(slang_struct),
+                                         (O->structs->num_structs + 1)
+                                         * sizeof(slang_struct));
+      if (O->structs->structs == NULL) {
+         slang_info_log_memory(C->L);
+         RETURN0;
+      }
+      s = &O->structs->structs[O->structs->num_structs];
+      if (!slang_struct_construct(s))
+         RETURN0;
+      O->structs->num_structs++;
+      if (!slang_struct_copy(s, *st))
+         RETURN0;
+   }
+
+   return 1;
+}
+
+
+/* invariant qualifer */
+#define TYPE_VARIANT    90
+#define TYPE_INVARIANT  91
+
+static int
+parse_type_variant(slang_parse_ctx * C, slang_type_variant *variant)
+{
+   GLuint invariant = *C->I++;
+   switch (invariant) {
+   case TYPE_VARIANT:
+      *variant = SLANG_VARIANT;
+      return 1;
+   case TYPE_INVARIANT:
+      *variant = SLANG_INVARIANT;
+      return 1;
+   default:
+      RETURN0;
+   }
+}
+
+
+/* centroid qualifer */
+#define TYPE_CENTER    95
+#define TYPE_CENTROID  96
+
+static int
+parse_type_centroid(slang_parse_ctx * C, slang_type_centroid *centroid)
+{
+   GLuint c = *C->I++;
+   switch (c) {
+   case TYPE_CENTER:
+      *centroid = SLANG_CENTER;
+      return 1;
+   case TYPE_CENTROID:
+      *centroid = SLANG_CENTROID;
+      return 1;
+   default:
+      RETURN0;
+   }
+}
+
+
+/* type qualifier */
+#define TYPE_QUALIFIER_NONE 0
+#define TYPE_QUALIFIER_CONST 1
+#define TYPE_QUALIFIER_ATTRIBUTE 2
+#define TYPE_QUALIFIER_VARYING 3
+#define TYPE_QUALIFIER_UNIFORM 4
+#define TYPE_QUALIFIER_FIXEDOUTPUT 5
+#define TYPE_QUALIFIER_FIXEDINPUT 6
+
+static int
+parse_type_qualifier(slang_parse_ctx * C, slang_type_qualifier * qual)
+{
+   GLuint qualifier = *C->I++;
+   switch (qualifier) {
+   case TYPE_QUALIFIER_NONE:
+      *qual = SLANG_QUAL_NONE;
+      break;
+   case TYPE_QUALIFIER_CONST:
+      *qual = SLANG_QUAL_CONST;
+      break;
+   case TYPE_QUALIFIER_ATTRIBUTE:
+      *qual = SLANG_QUAL_ATTRIBUTE;
+      break;
+   case TYPE_QUALIFIER_VARYING:
+      *qual = SLANG_QUAL_VARYING;
+      break;
+   case TYPE_QUALIFIER_UNIFORM:
+      *qual = SLANG_QUAL_UNIFORM;
+      break;
+   case TYPE_QUALIFIER_FIXEDOUTPUT:
+      *qual = SLANG_QUAL_FIXEDOUTPUT;
+      break;
+   case TYPE_QUALIFIER_FIXEDINPUT:
+      *qual = SLANG_QUAL_FIXEDINPUT;
+      break;
+   default:
+      RETURN0;
+   }
+   return 1;
+}
+
+/* type specifier */
+#define TYPE_SPECIFIER_VOID 0
+#define TYPE_SPECIFIER_BOOL 1
+#define TYPE_SPECIFIER_BVEC2 2
+#define TYPE_SPECIFIER_BVEC3 3
+#define TYPE_SPECIFIER_BVEC4 4
+#define TYPE_SPECIFIER_INT 5
+#define TYPE_SPECIFIER_IVEC2 6
+#define TYPE_SPECIFIER_IVEC3 7
+#define TYPE_SPECIFIER_IVEC4 8
+#define TYPE_SPECIFIER_FLOAT 9
+#define TYPE_SPECIFIER_VEC2 10
+#define TYPE_SPECIFIER_VEC3 11
+#define TYPE_SPECIFIER_VEC4 12
+#define TYPE_SPECIFIER_MAT2 13
+#define TYPE_SPECIFIER_MAT3 14
+#define TYPE_SPECIFIER_MAT4 15
+#define TYPE_SPECIFIER_SAMPLER1D 16
+#define TYPE_SPECIFIER_SAMPLER2D 17
+#define TYPE_SPECIFIER_SAMPLER3D 18
+#define TYPE_SPECIFIER_SAMPLERCUBE 19
+#define TYPE_SPECIFIER_SAMPLER1DSHADOW 20
+#define TYPE_SPECIFIER_SAMPLER2DSHADOW 21
+#define TYPE_SPECIFIER_SAMPLER2DRECT 22
+#define TYPE_SPECIFIER_SAMPLER2DRECTSHADOW 23
+#define TYPE_SPECIFIER_STRUCT 24
+#define TYPE_SPECIFIER_TYPENAME 25
+#define TYPE_SPECIFIER_MAT23 26
+#define TYPE_SPECIFIER_MAT32 27
+#define TYPE_SPECIFIER_MAT24 28
+#define TYPE_SPECIFIER_MAT42 29
+#define TYPE_SPECIFIER_MAT34 30
+#define TYPE_SPECIFIER_MAT43 31
+#define TYPE_SPECIFIER_COUNT 32
+
+static int
+parse_type_specifier(slang_parse_ctx * C, slang_output_ctx * O,
+                     slang_type_specifier * spec)
+{
+   switch (*C->I++) {
+   case TYPE_SPECIFIER_VOID:
+      spec->type = SLANG_SPEC_VOID;
+      break;
+   case TYPE_SPECIFIER_BOOL:
+      spec->type = SLANG_SPEC_BOOL;
+      break;
+   case TYPE_SPECIFIER_BVEC2:
+      spec->type = SLANG_SPEC_BVEC2;
+      break;
+   case TYPE_SPECIFIER_BVEC3:
+      spec->type = SLANG_SPEC_BVEC3;
+      break;
+   case TYPE_SPECIFIER_BVEC4:
+      spec->type = SLANG_SPEC_BVEC4;
+      break;
+   case TYPE_SPECIFIER_INT:
+      spec->type = SLANG_SPEC_INT;
+      break;
+   case TYPE_SPECIFIER_IVEC2:
+      spec->type = SLANG_SPEC_IVEC2;
+      break;
+   case TYPE_SPECIFIER_IVEC3:
+      spec->type = SLANG_SPEC_IVEC3;
+      break;
+   case TYPE_SPECIFIER_IVEC4:
+      spec->type = SLANG_SPEC_IVEC4;
+      break;
+   case TYPE_SPECIFIER_FLOAT:
+      spec->type = SLANG_SPEC_FLOAT;
+      break;
+   case TYPE_SPECIFIER_VEC2:
+      spec->type = SLANG_SPEC_VEC2;
+      break;
+   case TYPE_SPECIFIER_VEC3:
+      spec->type = SLANG_SPEC_VEC3;
+      break;
+   case TYPE_SPECIFIER_VEC4:
+      spec->type = SLANG_SPEC_VEC4;
+      break;
+   case TYPE_SPECIFIER_MAT2:
+      spec->type = SLANG_SPEC_MAT2;
+      break;
+   case TYPE_SPECIFIER_MAT3:
+      spec->type = SLANG_SPEC_MAT3;
+      break;
+   case TYPE_SPECIFIER_MAT4:
+      spec->type = SLANG_SPEC_MAT4;
+      break;
+   case TYPE_SPECIFIER_MAT23:
+      spec->type = SLANG_SPEC_MAT23;
+      break;
+   case TYPE_SPECIFIER_MAT32:
+      spec->type = SLANG_SPEC_MAT32;
+      break;
+   case TYPE_SPECIFIER_MAT24:
+      spec->type = SLANG_SPEC_MAT24;
+      break;
+   case TYPE_SPECIFIER_MAT42:
+      spec->type = SLANG_SPEC_MAT42;
+      break;
+   case TYPE_SPECIFIER_MAT34:
+      spec->type = SLANG_SPEC_MAT34;
+      break;
+   case TYPE_SPECIFIER_MAT43:
+      spec->type = SLANG_SPEC_MAT43;
+      break;
+   case TYPE_SPECIFIER_SAMPLER1D:
+      spec->type = SLANG_SPEC_SAMPLER1D;
+      break;
+   case TYPE_SPECIFIER_SAMPLER2D:
+      spec->type = SLANG_SPEC_SAMPLER2D;
+      break;
+   case TYPE_SPECIFIER_SAMPLER3D:
+      spec->type = SLANG_SPEC_SAMPLER3D;
+      break;
+   case TYPE_SPECIFIER_SAMPLERCUBE:
+      spec->type = SLANG_SPEC_SAMPLERCUBE;
+      break;
+   case TYPE_SPECIFIER_SAMPLER2DRECT:
+      spec->type = SLANG_SPEC_SAMPLER2DRECT;
+      break;
+   case TYPE_SPECIFIER_SAMPLER1DSHADOW:
+      spec->type = SLANG_SPEC_SAMPLER1DSHADOW;
+      break;
+   case TYPE_SPECIFIER_SAMPLER2DSHADOW:
+      spec->type = SLANG_SPEC_SAMPLER2DSHADOW;
+      break;
+   case TYPE_SPECIFIER_SAMPLER2DRECTSHADOW:
+      spec->type = SLANG_SPEC_SAMPLER2DRECTSHADOW;
+      break;
+   case TYPE_SPECIFIER_STRUCT:
+      spec->type = SLANG_SPEC_STRUCT;
+      if (!parse_struct(C, O, &spec->_struct))
+         RETURN0;
+      break;
+   case TYPE_SPECIFIER_TYPENAME:
+      spec->type = SLANG_SPEC_STRUCT;
+      {
+         slang_atom a_name;
+         slang_struct *stru;
+
+         a_name = parse_identifier(C);
+         if (a_name == NULL)
+            RETURN0;
+
+         stru = slang_struct_scope_find(O->structs, a_name, 1);
+         if (stru == NULL) {
+            slang_info_log_error(C->L, "undeclared type name '%s'",
+                                 slang_atom_pool_id(C->atoms, a_name));
+            RETURN0;
+         }
+
+         spec->_struct = (slang_struct *) _slang_alloc(sizeof(slang_struct));
+         if (spec->_struct == NULL) {
+            slang_info_log_memory(C->L);
+            RETURN0;
+         }
+         if (!slang_struct_construct(spec->_struct)) {
+            _slang_free(spec->_struct);
+            spec->_struct = NULL;
+            RETURN0;
+         }
+         if (!slang_struct_copy(spec->_struct, stru))
+            RETURN0;
+      }
+      break;
+   default:
+      RETURN0;
+   }
+   return 1;
+}
+
+#define TYPE_SPECIFIER_NONARRAY 0
+#define TYPE_SPECIFIER_ARRAY    1
+
+static int
+parse_type_array_size(slang_parse_ctx *C,
+                      slang_output_ctx *O,
+                      GLint *array_len)
+{
+   GLuint size;
+
+   switch (*C->I++) {
+   case TYPE_SPECIFIER_NONARRAY:
+      *array_len = -1; /* -1 = not an array */
+      break;
+   case TYPE_SPECIFIER_ARRAY:
+      if (!parse_array_len(C, O, &size))
+         RETURN0;
+      *array_len = (GLint) size;
+      break;
+   default:
+      assert(0);
+      RETURN0;
+   }
+   return 1;
+}
+
+#define PRECISION_DEFAULT 0
+#define PRECISION_LOW     1
+#define PRECISION_MEDIUM  2
+#define PRECISION_HIGH    3
+
+static int
+parse_type_precision(slang_parse_ctx *C,
+                     slang_type_precision *precision)
+{
+   GLint prec = *C->I++;
+   switch (prec) {
+   case PRECISION_DEFAULT:
+      *precision = SLANG_PREC_DEFAULT;
+      return 1;
+   case PRECISION_LOW:
+      *precision = SLANG_PREC_LOW;
+      return 1;
+   case PRECISION_MEDIUM:
+      *precision = SLANG_PREC_MEDIUM;
+      return 1;
+   case PRECISION_HIGH:
+      *precision = SLANG_PREC_HIGH;
+      return 1;
+   default:
+      RETURN0;
+   }
+}
+
+static int
+parse_fully_specified_type(slang_parse_ctx * C, slang_output_ctx * O,
+                           slang_fully_specified_type * type)
+{
+   if (!parse_type_variant(C, &type->variant))
+      RETURN0;
+  
+   if (!parse_type_centroid(C, &type->centroid))
+      RETURN0;
+
+   if (!parse_type_qualifier(C, &type->qualifier))
+      RETURN0;
+
+   if (!parse_type_precision(C, &type->precision))
+      RETURN0;
+
+   if (!parse_type_specifier(C, O, &type->specifier))
+      RETURN0;
+
+   if (!parse_type_array_size(C, O, &type->array_len))
+      RETURN0;
+
+   if (!O->allow_invariant && type->variant == SLANG_INVARIANT) {
+      slang_info_log_error(C->L,
+         "'invariant' keyword not allowed (perhaps set #version 120)");
+      RETURN0;
+   }
+
+   if (!O->allow_centroid && type->centroid == SLANG_CENTROID) {
+      slang_info_log_error(C->L,
+         "'centroid' keyword not allowed (perhaps set #version 120)");
+      RETURN0;
+   }
+   else if (type->centroid == SLANG_CENTROID &&
+            type->qualifier != SLANG_QUAL_VARYING) {
+      slang_info_log_error(C->L,
+         "'centroid' keyword only allowed for varying vars");
+      RETURN0;
+   }
+
+
+   /* need this?
+   if (type->qualifier != SLANG_QUAL_VARYING &&
+       type->variant == SLANG_INVARIANT) {
+      slang_info_log_error(C->L,
+                           "invariant qualifer only allowed for varying vars");
+      RETURN0;
+   }
+   */
+
+   if (O->allow_precision) {
+      if (type->precision == SLANG_PREC_DEFAULT) {
+         assert(type->specifier.type < TYPE_SPECIFIER_COUNT);
+         /* use the default precision for this datatype */
+         type->precision = O->default_precision[type->specifier.type];
+      }
+   }
+   else {
+      /* only default is allowed */
+      if (type->precision != SLANG_PREC_DEFAULT) {
+         slang_info_log_error(C->L, "precision qualifiers not allowed");
+         RETURN0;
+      }
+   }
+
+   if (!O->allow_array_types && type->array_len >= 0) {
+      slang_info_log_error(C->L, "first-class array types not allowed");
+      RETURN0;
+   }
+
+   if (type->array_len >= 0) {
+      /* convert type to array type (ex: convert "int" to "array of int" */
+      promote_type_to_array(C, type, type->array_len);
+   }
+
+   return 1;
+}
+
+/* operation */
+#define OP_END 0
+#define OP_BLOCK_BEGIN_NO_NEW_SCOPE 1
+#define OP_BLOCK_BEGIN_NEW_SCOPE 2
+#define OP_DECLARE 3
+#define OP_ASM 4
+#define OP_BREAK 5
+#define OP_CONTINUE 6
+#define OP_DISCARD 7
+#define OP_RETURN 8
+#define OP_EXPRESSION 9
+#define OP_IF 10
+#define OP_WHILE 11
+#define OP_DO 12
+#define OP_FOR 13
+#define OP_PUSH_VOID 14
+#define OP_PUSH_BOOL 15
+#define OP_PUSH_INT 16
+#define OP_PUSH_FLOAT 17
+#define OP_PUSH_IDENTIFIER 18
+#define OP_SEQUENCE 19
+#define OP_ASSIGN 20
+#define OP_ADDASSIGN 21
+#define OP_SUBASSIGN 22
+#define OP_MULASSIGN 23
+#define OP_DIVASSIGN 24
+/*#define OP_MODASSIGN 25*/
+/*#define OP_LSHASSIGN 26*/
+/*#define OP_RSHASSIGN 27*/
+/*#define OP_ORASSIGN 28*/
+/*#define OP_XORASSIGN 29*/
+/*#define OP_ANDASSIGN 30*/
+#define OP_SELECT 31
+#define OP_LOGICALOR 32
+#define OP_LOGICALXOR 33
+#define OP_LOGICALAND 34
+/*#define OP_BITOR 35*/
+/*#define OP_BITXOR 36*/
+/*#define OP_BITAND 37*/
+#define OP_EQUAL 38
+#define OP_NOTEQUAL 39
+#define OP_LESS 40
+#define OP_GREATER 41
+#define OP_LESSEQUAL 42
+#define OP_GREATEREQUAL 43
+/*#define OP_LSHIFT 44*/
+/*#define OP_RSHIFT 45*/
+#define OP_ADD 46
+#define OP_SUBTRACT 47
+#define OP_MULTIPLY 48
+#define OP_DIVIDE 49
+/*#define OP_MODULUS 50*/
+#define OP_PREINCREMENT 51
+#define OP_PREDECREMENT 52
+#define OP_PLUS 53
+#define OP_MINUS 54
+/*#define OP_COMPLEMENT 55*/
+#define OP_NOT 56
+#define OP_SUBSCRIPT 57
+#define OP_CALL 58
+#define OP_FIELD 59
+#define OP_POSTINCREMENT 60
+#define OP_POSTDECREMENT 61
+#define OP_PRECISION 62
+#define OP_METHOD 63
+
+
+/**
+ * When parsing a compound production, this function is used to parse the
+ * children.
+ * For example, a while-loop compound will have two children, the
+ * while condition expression and the loop body.  So, this function will
+ * be called twice to parse those two sub-expressions.
+ * \param C  the parsing context
+ * \param O  the output context
+ * \param oper  the operation we're parsing
+ * \param statement  indicates whether parsing a statement, or expression
+ * \return 1 if success, 0 if error
+ */
+static int
+parse_child_operation(slang_parse_ctx * C, slang_output_ctx * O,
+                      slang_operation * oper, GLboolean statement)
+{
+   slang_operation *ch;
+
+   /* grow child array */
+   ch = slang_operation_grow(&oper->num_children, &oper->children);
+   if (statement)
+      return parse_statement(C, O, ch);
+   return parse_expression(C, O, ch);
+}
+
+static int parse_declaration(slang_parse_ctx * C, slang_output_ctx * O);
+
+static int
+parse_statement(slang_parse_ctx * C, slang_output_ctx * O,
+                slang_operation * oper)
+{
+   int op;
+
+   oper->locals->outer_scope = O->vars;
+
+   op = *C->I++;
+   switch (op) {
+   case OP_BLOCK_BEGIN_NO_NEW_SCOPE:
+      /* parse child statements, do not create new variable scope */
+      oper->type = SLANG_OPER_BLOCK_NO_NEW_SCOPE;
+      while (*C->I != OP_END)
+         if (!parse_child_operation(C, O, oper, GL_TRUE))
+            RETURN0;
+      C->I++;
+      break;
+   case OP_BLOCK_BEGIN_NEW_SCOPE:
+      /* parse child statements, create new variable scope */
+      {
+         slang_output_ctx o = *O;
+
+         oper->type = SLANG_OPER_BLOCK_NEW_SCOPE;
+         o.vars = oper->locals;
+         while (*C->I != OP_END)
+            if (!parse_child_operation(C, &o, oper, GL_TRUE))
+               RETURN0;
+         C->I++;
+      }
+      break;
+   case OP_DECLARE:
+      /* local variable declaration, individual declarators are stored as
+       * children identifiers
+       */
+      oper->type = SLANG_OPER_BLOCK_NO_NEW_SCOPE;
+      {
+         const unsigned int first_var = O->vars->num_variables;
+
+         /* parse the declaration, note that there can be zero or more
+          * than one declarators
+          */
+         if (!parse_declaration(C, O))
+            RETURN0;
+         if (first_var < O->vars->num_variables) {
+            const unsigned int num_vars = O->vars->num_variables - first_var;
+            unsigned int i;
+            assert(oper->num_children == 0);
+            oper->num_children = num_vars;
+            oper->children = slang_operation_new(num_vars);
+            if (oper->children == NULL) {
+               slang_info_log_memory(C->L);
+               RETURN0;
+            }
+            for (i = first_var; i < O->vars->num_variables; i++) {
+               slang_operation *o = &oper->children[i - first_var];
+               slang_variable *var = O->vars->variables[i];
+               o->type = SLANG_OPER_VARIABLE_DECL;
+               o->locals->outer_scope = O->vars;
+               o->a_id = var->a_name;
+
+               /* new/someday...
+               calculate_var_size(C, O, var);
+               */
+
+               if (!legal_identifier(o->a_id)) {
+                  slang_info_log_error(C->L, "illegal variable name '%s'",
+                                       (char *) o->a_id);
+                  RETURN0;
+               }
+            }
+         }
+      }
+      break;
+   case OP_ASM:
+      /* the __asm statement, parse the mnemonic and all its arguments
+       * as expressions
+       */
+      oper->type = SLANG_OPER_ASM;
+      oper->a_id = parse_identifier(C);
+      if (oper->a_id == SLANG_ATOM_NULL)
+         RETURN0;
+      while (*C->I != OP_END) {
+         if (!parse_child_operation(C, O, oper, GL_FALSE))
+            RETURN0;
+      }
+      C->I++;
+      break;
+   case OP_BREAK:
+      oper->type = SLANG_OPER_BREAK;
+      break;
+   case OP_CONTINUE:
+      oper->type = SLANG_OPER_CONTINUE;
+      break;
+   case OP_DISCARD:
+      oper->type = SLANG_OPER_DISCARD;
+      break;
+   case OP_RETURN:
+      oper->type = SLANG_OPER_RETURN;
+      if (!parse_child_operation(C, O, oper, GL_FALSE))
+         RETURN0;
+      break;
+   case OP_EXPRESSION:
+      oper->type = SLANG_OPER_EXPRESSION;
+      if (!parse_child_operation(C, O, oper, GL_FALSE))
+         RETURN0;
+      break;
+   case OP_IF:
+      oper->type = SLANG_OPER_IF;
+      if (!parse_child_operation(C, O, oper, GL_FALSE))
+         RETURN0;
+      if (!parse_child_operation(C, O, oper, GL_TRUE))
+         RETURN0;
+      if (!parse_child_operation(C, O, oper, GL_TRUE))
+         RETURN0;
+      break;
+   case OP_WHILE:
+      {
+         slang_output_ctx o = *O;
+
+         oper->type = SLANG_OPER_WHILE;
+         o.vars = oper->locals;
+         if (!parse_child_operation(C, &o, oper, GL_TRUE))
+            RETURN0;
+         if (!parse_child_operation(C, &o, oper, GL_TRUE))
+            RETURN0;
+      }
+      break;
+   case OP_DO:
+      oper->type = SLANG_OPER_DO;
+      if (!parse_child_operation(C, O, oper, GL_TRUE))
+         RETURN0;
+      if (!parse_child_operation(C, O, oper, GL_FALSE))
+         RETURN0;
+      break;
+   case OP_FOR:
+      {
+         slang_output_ctx o = *O;
+
+         oper->type = SLANG_OPER_FOR;
+         o.vars = oper->locals;
+         if (!parse_child_operation(C, &o, oper, GL_TRUE))
+            RETURN0;
+         if (!parse_child_operation(C, &o, oper, GL_TRUE))
+            RETURN0;
+         if (!parse_child_operation(C, &o, oper, GL_FALSE))
+            RETURN0;
+         if (!parse_child_operation(C, &o, oper, GL_TRUE))
+            RETURN0;
+      }
+      break;
+   case OP_PRECISION:
+      {
+         /* set default precision for a type in this scope */
+         /* ignored at this time */
+         int prec_qual = *C->I++;
+         int datatype = *C->I++;
+         (void) prec_qual;
+         (void) datatype;
+      }
+      break;
+   default:
+      /*printf("Unexpected operation %d\n", op);*/
+      RETURN0;
+   }
+   return 1;
+}
+
+static int
+handle_nary_expression(slang_parse_ctx * C, slang_operation * op,
+                       slang_operation ** ops, unsigned int *total_ops,
+                       unsigned int n)
+{
+   unsigned int i;
+
+   op->children = slang_operation_new(n);
+   if (op->children == NULL) {
+      slang_info_log_memory(C->L);
+      RETURN0;
+   }
+   op->num_children = n;
+
+   for (i = 0; i < n; i++) {
+      slang_operation_destruct(&op->children[i]);
+      op->children[i] = (*ops)[*total_ops - (n + 1 - i)];
+   }
+
+   (*ops)[*total_ops - (n + 1)] = (*ops)[*total_ops - 1];
+   *total_ops -= n;
+
+   *ops = (slang_operation *)
+      _slang_realloc(*ops,
+                     (*total_ops + n) * sizeof(slang_operation),
+                     *total_ops * sizeof(slang_operation));
+   if (*ops == NULL) {
+      slang_info_log_memory(C->L);
+      RETURN0;
+   }
+   return 1;
+}
+
+static int
+is_constructor_name(const char *name, slang_atom a_name,
+                    slang_struct_scope * structs)
+{
+   if (slang_type_specifier_type_from_string(name) != SLANG_SPEC_VOID)
+      return 1;
+   return slang_struct_scope_find(structs, a_name, 1) != NULL;
+}
+
+#define FUNCTION_CALL_NONARRAY 0
+#define FUNCTION_CALL_ARRAY    1
+
+static int
+parse_expression(slang_parse_ctx * C, slang_output_ctx * O,
+                 slang_operation * oper)
+{
+   slang_operation *ops = NULL;
+   unsigned int num_ops = 0;
+   int number;
+
+   while (*C->I != OP_END) {
+      slang_operation *op;
+      const unsigned int op_code = *C->I++;
+
+      /* allocate default operation, becomes a no-op if not used  */
+      ops = (slang_operation *)
+         _slang_realloc(ops,
+                        num_ops * sizeof(slang_operation),
+                        (num_ops + 1) * sizeof(slang_operation));
+      if (ops == NULL) {
+         slang_info_log_memory(C->L);
+         RETURN0;
+      }
+      op = &ops[num_ops];
+      if (!slang_operation_construct(op)) {
+         slang_info_log_memory(C->L);
+         RETURN0;
+      }
+      num_ops++;
+      op->locals->outer_scope = O->vars;
+
+      switch (op_code) {
+      case OP_PUSH_VOID:
+         op->type = SLANG_OPER_VOID;
+         break;
+      case OP_PUSH_BOOL:
+         op->type = SLANG_OPER_LITERAL_BOOL;
+         if (!parse_number(C, &number))
+            RETURN0;
+         op->literal[0] =
+         op->literal[1] =
+         op->literal[2] =
+         op->literal[3] = (GLfloat) number;
+         op->literal_size = 1;
+         break;
+      case OP_PUSH_INT:
+         op->type = SLANG_OPER_LITERAL_INT;
+         if (!parse_number(C, &number))
+            RETURN0;
+         op->literal[0] =
+         op->literal[1] =
+         op->literal[2] =
+         op->literal[3] = (GLfloat) number;
+         op->literal_size = 1;
+         break;
+      case OP_PUSH_FLOAT:
+         op->type = SLANG_OPER_LITERAL_FLOAT;
+         if (!parse_float(C, &op->literal[0]))
+            RETURN0;
+         op->literal[1] =
+         op->literal[2] =
+         op->literal[3] = op->literal[0];
+         op->literal_size = 1;
+         break;
+      case OP_PUSH_IDENTIFIER:
+         op->type = SLANG_OPER_IDENTIFIER;
+         op->a_id = parse_identifier(C);
+         if (op->a_id == SLANG_ATOM_NULL)
+            RETURN0;
+         break;
+      case OP_SEQUENCE:
+         op->type = SLANG_OPER_SEQUENCE;
+         if (!handle_nary_expression(C, op, &ops, &num_ops, 2))
+            RETURN0;
+         break;
+      case OP_ASSIGN:
+         op->type = SLANG_OPER_ASSIGN;
+         if (!handle_nary_expression(C, op, &ops, &num_ops, 2))
+            RETURN0;
+         break;
+      case OP_ADDASSIGN:
+         op->type = SLANG_OPER_ADDASSIGN;
+         if (!handle_nary_expression(C, op, &ops, &num_ops, 2))
+            RETURN0;
+         break;
+      case OP_SUBASSIGN:
+         op->type = SLANG_OPER_SUBASSIGN;
+         if (!handle_nary_expression(C, op, &ops, &num_ops, 2))
+            RETURN0;
+         break;
+      case OP_MULASSIGN:
+         op->type = SLANG_OPER_MULASSIGN;
+         if (!handle_nary_expression(C, op, &ops, &num_ops, 2))
+            RETURN0;
+         break;
+      case OP_DIVASSIGN:
+         op->type = SLANG_OPER_DIVASSIGN;
+         if (!handle_nary_expression(C, op, &ops, &num_ops, 2))
+            RETURN0;
+         break;
+         /*case OP_MODASSIGN: */
+         /*case OP_LSHASSIGN: */
+         /*case OP_RSHASSIGN: */
+         /*case OP_ORASSIGN: */
+         /*case OP_XORASSIGN: */
+         /*case OP_ANDASSIGN: */
+      case OP_SELECT:
+         op->type = SLANG_OPER_SELECT;
+         if (!handle_nary_expression(C, op, &ops, &num_ops, 3))
+            RETURN0;
+         break;
+      case OP_LOGICALOR:
+         op->type = SLANG_OPER_LOGICALOR;
+         if (!handle_nary_expression(C, op, &ops, &num_ops, 2))
+            RETURN0;
+         break;
+      case OP_LOGICALXOR:
+         op->type = SLANG_OPER_LOGICALXOR;
+         if (!handle_nary_expression(C, op, &ops, &num_ops, 2))
+            RETURN0;
+         break;
+      case OP_LOGICALAND:
+         op->type = SLANG_OPER_LOGICALAND;
+         if (!handle_nary_expression(C, op, &ops, &num_ops, 2))
+            RETURN0;
+         break;
+         /*case OP_BITOR: */
+         /*case OP_BITXOR: */
+         /*case OP_BITAND: */
+      case OP_EQUAL:
+         op->type = SLANG_OPER_EQUAL;
+         if (!handle_nary_expression(C, op, &ops, &num_ops, 2))
+            RETURN0;
+         break;
+      case OP_NOTEQUAL:
+         op->type = SLANG_OPER_NOTEQUAL;
+         if (!handle_nary_expression(C, op, &ops, &num_ops, 2))
+            RETURN0;
+         break;
+      case OP_LESS:
+         op->type = SLANG_OPER_LESS;
+         if (!handle_nary_expression(C, op, &ops, &num_ops, 2))
+            RETURN0;
+         break;
+      case OP_GREATER:
+         op->type = SLANG_OPER_GREATER;
+         if (!handle_nary_expression(C, op, &ops, &num_ops, 2))
+            RETURN0;
+         break;
+      case OP_LESSEQUAL:
+         op->type = SLANG_OPER_LESSEQUAL;
+         if (!handle_nary_expression(C, op, &ops, &num_ops, 2))
+            RETURN0;
+         break;
+      case OP_GREATEREQUAL:
+         op->type = SLANG_OPER_GREATEREQUAL;
+         if (!handle_nary_expression(C, op, &ops, &num_ops, 2))
+            RETURN0;
+         break;
+         /*case OP_LSHIFT: */
+         /*case OP_RSHIFT: */
+      case OP_ADD:
+         op->type = SLANG_OPER_ADD;
+         if (!handle_nary_expression(C, op, &ops, &num_ops, 2))
+            RETURN0;
+         break;
+      case OP_SUBTRACT:
+         op->type = SLANG_OPER_SUBTRACT;
+         if (!handle_nary_expression(C, op, &ops, &num_ops, 2))
+            RETURN0;
+         break;
+      case OP_MULTIPLY:
+         op->type = SLANG_OPER_MULTIPLY;
+         if (!handle_nary_expression(C, op, &ops, &num_ops, 2))
+            RETURN0;
+         break;
+      case OP_DIVIDE:
+         op->type = SLANG_OPER_DIVIDE;
+         if (!handle_nary_expression(C, op, &ops, &num_ops, 2))
+            RETURN0;
+         break;
+         /*case OP_MODULUS: */
+      case OP_PREINCREMENT:
+         op->type = SLANG_OPER_PREINCREMENT;
+         if (!handle_nary_expression(C, op, &ops, &num_ops, 1))
+            RETURN0;
+         break;
+      case OP_PREDECREMENT:
+         op->type = SLANG_OPER_PREDECREMENT;
+         if (!handle_nary_expression(C, op, &ops, &num_ops, 1))
+            RETURN0;
+         break;
+      case OP_PLUS:
+         op->type = SLANG_OPER_PLUS;
+         if (!handle_nary_expression(C, op, &ops, &num_ops, 1))
+            RETURN0;
+         break;
+      case OP_MINUS:
+         op->type = SLANG_OPER_MINUS;
+         if (!handle_nary_expression(C, op, &ops, &num_ops, 1))
+            RETURN0;
+         break;
+      case OP_NOT:
+         op->type = SLANG_OPER_NOT;
+         if (!handle_nary_expression(C, op, &ops, &num_ops, 1))
+            RETURN0;
+         break;
+         /*case OP_COMPLEMENT: */
+      case OP_SUBSCRIPT:
+         op->type = SLANG_OPER_SUBSCRIPT;
+         if (!handle_nary_expression(C, op, &ops, &num_ops, 2))
+            RETURN0;
+         break;
+      case OP_METHOD:
+         op->type = SLANG_OPER_METHOD;
+         op->a_obj = parse_identifier(C);
+         if (op->a_obj == SLANG_ATOM_NULL)
+            RETURN0;
+
+         op->a_id = parse_identifier(C);
+         if (op->a_id == SLANG_ATOM_NULL)
+            RETURN0;
+
+         assert(*C->I == OP_END);
+         C->I++;
+
+         while (*C->I != OP_END)
+            if (!parse_child_operation(C, O, op, GL_FALSE))
+               RETURN0;
+         C->I++;
+#if 0
+         /* don't lookup the method (not yet anyway) */
+         if (!C->parsing_builtin
+             && !slang_function_scope_find_by_name(O->funs, op->a_id, 1)) {
+            const char *id;
+
+            id = slang_atom_pool_id(C->atoms, op->a_id);
+            if (!is_constructor_name(id, op->a_id, O->structs)) {
+               slang_info_log_error(C->L, "%s: undeclared function name.", id);
+               RETURN0;
+            }
+         }
+#endif
+         break;
+      case OP_CALL:
+         {
+            GLboolean array_constructor = GL_FALSE;
+            GLint array_constructor_size = 0;
+
+            op->type = SLANG_OPER_CALL;
+            op->a_id = parse_identifier(C);
+            if (op->a_id == SLANG_ATOM_NULL)
+               RETURN0;
+            switch (*C->I++) {
+            case FUNCTION_CALL_NONARRAY:
+               /* Nothing to do. */
+               break;
+            case FUNCTION_CALL_ARRAY:
+               /* Calling an array constructor. For example:
+                *   float[3](1.1, 2.2, 3.3);
+                */
+               if (!O->allow_array_types) {
+                  slang_info_log_error(C->L,
+                                       "array constructors not allowed "
+                                       "in this GLSL version");
+                  RETURN0;
+               }
+               else {
+                  /* parse the array constructor size */
+                  slang_operation array_size;
+                  array_constructor = GL_TRUE;
+                  slang_operation_construct(&array_size);
+                  if (!parse_expression(C, O, &array_size)) {
+                     slang_operation_destruct(&array_size);
+                     return GL_FALSE;
+                  }
+                  if (array_size.type != SLANG_OPER_LITERAL_INT) {
+                     slang_info_log_error(C->L,
+                        "constructor array size is not an integer");
+                     slang_operation_destruct(&array_size);
+                     RETURN0;
+                  }
+                  array_constructor_size = (int) array_size.literal[0];
+                  op->array_constructor = GL_TRUE;
+                  slang_operation_destruct(&array_size);
+               }
+               break;
+            default:
+               assert(0);
+               RETURN0;
+            }
+            while (*C->I != OP_END)
+               if (!parse_child_operation(C, O, op, GL_FALSE))
+                  RETURN0;
+            C->I++;
+
+            if (array_constructor &&
+                array_constructor_size != op->num_children) {
+               slang_info_log_error(C->L, "number of parameters to array"
+                                    " constructor does not match array size");
+               RETURN0;
+            }
+
+            if (!C->parsing_builtin
+                && !slang_function_scope_find_by_name(O->funs, op->a_id, 1)) {
+               const char *id;
+
+               id = slang_atom_pool_id(C->atoms, op->a_id);
+               if (!is_constructor_name(id, op->a_id, O->structs)) {
+                  slang_info_log_error(C->L, "%s: undeclared function name.", id);
+                  RETURN0;
+               }
+            }
+         }
+         break;
+      case OP_FIELD:
+         op->type = SLANG_OPER_FIELD;
+         op->a_id = parse_identifier(C);
+         if (op->a_id == SLANG_ATOM_NULL)
+            RETURN0;
+         if (!handle_nary_expression(C, op, &ops, &num_ops, 1))
+            RETURN0;
+         break;
+      case OP_POSTINCREMENT:
+         op->type = SLANG_OPER_POSTINCREMENT;
+         if (!handle_nary_expression(C, op, &ops, &num_ops, 1))
+            RETURN0;
+         break;
+      case OP_POSTDECREMENT:
+         op->type = SLANG_OPER_POSTDECREMENT;
+         if (!handle_nary_expression(C, op, &ops, &num_ops, 1))
+            RETURN0;
+         break;
+      default:
+         RETURN0;
+      }
+   }
+   C->I++;
+
+   slang_operation_destruct(oper);
+   *oper = *ops; /* struct copy */
+   _slang_free(ops);
+
+   return 1;
+}
+
+/* parameter qualifier */
+#define PARAM_QUALIFIER_IN 0
+#define PARAM_QUALIFIER_OUT 1
+#define PARAM_QUALIFIER_INOUT 2
+
+/* function parameter array presence */
+#define PARAMETER_ARRAY_NOT_PRESENT 0
+#define PARAMETER_ARRAY_PRESENT 1
+
+static int
+parse_parameter_declaration(slang_parse_ctx * C, slang_output_ctx * O,
+                            slang_variable * param)
+{
+   int param_qual, precision_qual;
+
+   /* parse and validate the parameter's type qualifiers (there can be
+    * two at most) because not all combinations are valid
+    */
+   if (!parse_type_qualifier(C, &param->type.qualifier))
+      RETURN0;
+
+   param_qual = *C->I++;
+   switch (param_qual) {
+   case PARAM_QUALIFIER_IN:
+      if (param->type.qualifier != SLANG_QUAL_CONST
+          && param->type.qualifier != SLANG_QUAL_NONE) {
+         slang_info_log_error(C->L, "Invalid type qualifier.");
+         RETURN0;
+      }
+      break;
+   case PARAM_QUALIFIER_OUT:
+      if (param->type.qualifier == SLANG_QUAL_NONE)
+         param->type.qualifier = SLANG_QUAL_OUT;
+      else {
+         slang_info_log_error(C->L, "Invalid type qualifier.");
+         RETURN0;
+      }
+      break;
+   case PARAM_QUALIFIER_INOUT:
+      if (param->type.qualifier == SLANG_QUAL_NONE)
+         param->type.qualifier = SLANG_QUAL_INOUT;
+      else {
+         slang_info_log_error(C->L, "Invalid type qualifier.");
+         RETURN0;
+      }
+      break;
+   default:
+      RETURN0;
+   }
+
+   /* parse precision qualifier (lowp, mediump, highp */
+   precision_qual = *C->I++;
+   /* ignored at this time */
+   (void) precision_qual;
+
+   /* parse parameter's type specifier and name */
+   if (!parse_type_specifier(C, O, &param->type.specifier))
+      RETURN0;
+   if (!parse_type_array_size(C, O, &param->type.array_len))
+      RETURN0;
+   param->a_name = parse_identifier(C);
+   if (param->a_name == SLANG_ATOM_NULL)
+      RETURN0;
+
+   /* first-class array
+    */
+   if (param->type.array_len >= 0) {
+      slang_type_specifier p;
+
+      slang_type_specifier_ctr(&p);
+      if (!slang_type_specifier_copy(&p, &param->type.specifier)) {
+         slang_type_specifier_dtr(&p);
+         RETURN0;
+      }
+      if (!convert_to_array(C, param, &p)) {
+         slang_type_specifier_dtr(&p);
+         RETURN0;
+      }
+      slang_type_specifier_dtr(&p);
+      param->array_len = param->type.array_len;
+   }
+
+   /* if the parameter is an array, parse its size (the size must be
+    * explicitly defined
+    */
+   if (*C->I++ == PARAMETER_ARRAY_PRESENT) {
+      slang_type_specifier p;
+
+      if (param->type.array_len >= 0) {
+         slang_info_log_error(C->L, "multi-dimensional arrays not allowed");
+         RETURN0;
+      }
+      slang_type_specifier_ctr(&p);
+      if (!slang_type_specifier_copy(&p, &param->type.specifier)) {
+         slang_type_specifier_dtr(&p);
+         RETURN0;
+      }
+      if (!convert_to_array(C, param, &p)) {
+         slang_type_specifier_dtr(&p);
+         RETURN0;
+      }
+      slang_type_specifier_dtr(&p);
+      if (!parse_array_len(C, O, &param->array_len))
+         RETURN0;
+   }
+
+#if 0
+   /* calculate the parameter size */
+   if (!calculate_var_size(C, O, param))
+      RETURN0;
+#endif
+   /* TODO: allocate the local address here? */
+   return 1;
+}
+
+/* function type */
+#define FUNCTION_ORDINARY 0
+#define FUNCTION_CONSTRUCTOR 1
+#define FUNCTION_OPERATOR 2
+
+/* function parameter */
+#define PARAMETER_NONE 0
+#define PARAMETER_NEXT 1
+
+/* operator type */
+#define OPERATOR_ADDASSIGN 1
+#define OPERATOR_SUBASSIGN 2
+#define OPERATOR_MULASSIGN 3
+#define OPERATOR_DIVASSIGN 4
+/*#define OPERATOR_MODASSIGN 5*/
+/*#define OPERATOR_LSHASSIGN 6*/
+/*#define OPERATOR_RSHASSIGN 7*/
+/*#define OPERATOR_ANDASSIGN 8*/
+/*#define OPERATOR_XORASSIGN 9*/
+/*#define OPERATOR_ORASSIGN 10*/
+#define OPERATOR_LOGICALXOR 11
+/*#define OPERATOR_BITOR 12*/
+/*#define OPERATOR_BITXOR 13*/
+/*#define OPERATOR_BITAND 14*/
+#define OPERATOR_LESS 15
+#define OPERATOR_GREATER 16
+#define OPERATOR_LESSEQUAL 17
+#define OPERATOR_GREATEREQUAL 18
+/*#define OPERATOR_LSHIFT 19*/
+/*#define OPERATOR_RSHIFT 20*/
+#define OPERATOR_MULTIPLY 21
+#define OPERATOR_DIVIDE 22
+/*#define OPERATOR_MODULUS 23*/
+#define OPERATOR_INCREMENT 24
+#define OPERATOR_DECREMENT 25
+#define OPERATOR_PLUS 26
+#define OPERATOR_MINUS 27
+/*#define OPERATOR_COMPLEMENT 28*/
+#define OPERATOR_NOT 29
+
+static const struct
+{
+   unsigned int o_code;
+   const char *o_name;
+} operator_names[] = {
+   {OPERATOR_INCREMENT, "++"},
+   {OPERATOR_ADDASSIGN, "+="},
+   {OPERATOR_PLUS, "+"},
+   {OPERATOR_DECREMENT, "--"},
+   {OPERATOR_SUBASSIGN, "-="},
+   {OPERATOR_MINUS, "-"},
+   {OPERATOR_NOT, "!"},
+   {OPERATOR_MULASSIGN, "*="},
+   {OPERATOR_MULTIPLY, "*"},
+   {OPERATOR_DIVASSIGN, "/="},
+   {OPERATOR_DIVIDE, "/"},
+   {OPERATOR_LESSEQUAL, "<="},
+   /*{ OPERATOR_LSHASSIGN, "<<=" }, */
+   /*{ OPERATOR_LSHIFT, "<<" }, */
+   {OPERATOR_LESS, "<"},
+   {OPERATOR_GREATEREQUAL, ">="},
+   /*{ OPERATOR_RSHASSIGN, ">>=" }, */
+   /*{ OPERATOR_RSHIFT, ">>" }, */
+   {OPERATOR_GREATER, ">"},
+   /*{ OPERATOR_MODASSIGN, "%=" }, */
+   /*{ OPERATOR_MODULUS, "%" }, */
+   /*{ OPERATOR_ANDASSIGN, "&=" }, */
+   /*{ OPERATOR_BITAND, "&" }, */
+   /*{ OPERATOR_ORASSIGN, "|=" }, */
+   /*{ OPERATOR_BITOR, "|" }, */
+   /*{ OPERATOR_COMPLEMENT, "~" }, */
+   /*{ OPERATOR_XORASSIGN, "^=" }, */
+   {OPERATOR_LOGICALXOR, "^^"},
+   /*{ OPERATOR_BITXOR, "^" } */
+};
+
+static slang_atom
+parse_operator_name(slang_parse_ctx * C)
+{
+   unsigned int i;
+
+   for (i = 0; i < sizeof(operator_names) / sizeof(*operator_names); i++) {
+      if (operator_names[i].o_code == (unsigned int) (*C->I)) {
+         slang_atom atom =
+            slang_atom_pool_atom(C->atoms, operator_names[i].o_name);
+         if (atom == SLANG_ATOM_NULL) {
+            slang_info_log_memory(C->L);
+            RETURN0;
+         }
+         C->I++;
+         return atom;
+      }
+   }
+   RETURN0;
+}
+
+
+static int
+parse_function_prototype(slang_parse_ctx * C, slang_output_ctx * O,
+                         slang_function * func)
+{
+   GLuint functype;
+   /* parse function type and name */
+   if (!parse_fully_specified_type(C, O, &func->header.type))
+      RETURN0;
+
+   functype = *C->I++;
+   switch (functype) {
+   case FUNCTION_ORDINARY:
+      func->kind = SLANG_FUNC_ORDINARY;
+      func->header.a_name = parse_identifier(C);
+      if (func->header.a_name == SLANG_ATOM_NULL)
+         RETURN0;
+      break;
+   case FUNCTION_CONSTRUCTOR:
+      func->kind = SLANG_FUNC_CONSTRUCTOR;
+      if (func->header.type.specifier.type == SLANG_SPEC_STRUCT)
+         RETURN0;
+      func->header.a_name =
+         slang_atom_pool_atom(C->atoms,
+                              slang_type_specifier_type_to_string
+                              (func->header.type.specifier.type));
+      if (func->header.a_name == SLANG_ATOM_NULL) {
+         slang_info_log_memory(C->L);
+         RETURN0;
+      }
+      break;
+   case FUNCTION_OPERATOR:
+      func->kind = SLANG_FUNC_OPERATOR;
+      func->header.a_name = parse_operator_name(C);
+      if (func->header.a_name == SLANG_ATOM_NULL)
+         RETURN0;
+      break;
+   default:
+      RETURN0;
+   }
+
+   if (!legal_identifier(func->header.a_name)) {
+      slang_info_log_error(C->L, "illegal function name '%s'",
+                           (char *) func->header.a_name);
+      RETURN0;
+   }
+
+   /* parse function parameters */
+   while (*C->I++ == PARAMETER_NEXT) {
+      slang_variable *p = slang_variable_scope_grow(func->parameters);
+      if (!p) {
+         slang_info_log_memory(C->L);
+         RETURN0;
+      }
+      if (!parse_parameter_declaration(C, O, p))
+         RETURN0;
+   }
+
+   /* if the function returns a value, append a hidden __retVal 'out'
+    * parameter that corresponds to the return value.
+    */
+   if (_slang_function_has_return_value(func)) {
+      slang_variable *p = slang_variable_scope_grow(func->parameters);
+      slang_atom a_retVal = slang_atom_pool_atom(C->atoms, "__retVal");
+      assert(a_retVal);
+      p->a_name = a_retVal;
+      p->type = func->header.type;
+      p->type.qualifier = SLANG_QUAL_OUT;
+   }
+
+   /* function formal parameters and local variables share the same
+    * scope, so save the information about param count in a seperate
+    * place also link the scope to the global variable scope so when a
+    * given identifier is not found here, the search process continues
+    * in the global space
+    */
+   func->param_count = func->parameters->num_variables;
+   func->parameters->outer_scope = O->vars;
+
+   return 1;
+}
+
+static int
+parse_function_definition(slang_parse_ctx * C, slang_output_ctx * O,
+                          slang_function * func)
+{
+   slang_output_ctx o = *O;
+
+   if (!parse_function_prototype(C, O, func))
+      RETURN0;
+
+   /* create function's body operation */
+   func->body = (slang_operation *) _slang_alloc(sizeof(slang_operation));
+   if (func->body == NULL) {
+      slang_info_log_memory(C->L);
+      RETURN0;
+   }
+   if (!slang_operation_construct(func->body)) {
+      _slang_free(func->body);
+      func->body = NULL;
+      slang_info_log_memory(C->L);
+      RETURN0;
+   }
+
+   /* to parse the body the parse context is modified in order to
+    * capture parsed variables into function's local variable scope
+    */
+   C->global_scope = GL_FALSE;
+   o.vars = func->parameters;
+   if (!parse_statement(C, &o, func->body))
+      RETURN0;
+
+   C->global_scope = GL_TRUE;
+   return 1;
+}
+
+static GLboolean
+initialize_global(slang_assemble_ctx * A, slang_variable * var)
+{
+   slang_operation op_id, op_assign;
+   GLboolean result;
+
+   /* construct the left side of assignment */
+   if (!slang_operation_construct(&op_id))
+      return GL_FALSE;
+   op_id.type = SLANG_OPER_IDENTIFIER;
+   op_id.a_id = var->a_name;
+
+   /* put the variable into operation's scope */
+   op_id.locals->variables =
+      (slang_variable **) _slang_alloc(sizeof(slang_variable *));
+   if (op_id.locals->variables == NULL) {
+      slang_operation_destruct(&op_id);
+      return GL_FALSE;
+   }
+   op_id.locals->num_variables = 1;
+   op_id.locals->variables[0] = var;
+
+   /* construct the assignment expression */
+   if (!slang_operation_construct(&op_assign)) {
+      op_id.locals->num_variables = 0;
+      slang_operation_destruct(&op_id);
+      return GL_FALSE;
+   }
+   op_assign.type = SLANG_OPER_ASSIGN;
+   op_assign.children =
+      (slang_operation *) _slang_alloc(2 * sizeof(slang_operation));
+   if (op_assign.children == NULL) {
+      slang_operation_destruct(&op_assign);
+      op_id.locals->num_variables = 0;
+      slang_operation_destruct(&op_id);
+      return GL_FALSE;
+   }
+   op_assign.num_children = 2;
+   op_assign.children[0] = op_id;
+   op_assign.children[1] = *var->initializer;
+
+   result = 1;
+
+   /* carefully destroy the operations */
+   op_assign.num_children = 0;
+   _slang_free(op_assign.children);
+   op_assign.children = NULL;
+   slang_operation_destruct(&op_assign);
+   op_id.locals->num_variables = 0;
+   slang_operation_destruct(&op_id);
+
+   if (!result)
+      return GL_FALSE;
+
+   return GL_TRUE;
+}
+
+/* init declarator list */
+#define DECLARATOR_NONE 0
+#define DECLARATOR_NEXT 1
+
+/* variable declaration */
+#define VARIABLE_NONE 0
+#define VARIABLE_IDENTIFIER 1
+#define VARIABLE_INITIALIZER 2
+#define VARIABLE_ARRAY_EXPLICIT 3
+#define VARIABLE_ARRAY_UNKNOWN 4
+
+
+/**
+ * Parse the initializer for a variable declaration.
+ */
+static int
+parse_init_declarator(slang_parse_ctx * C, slang_output_ctx * O,
+                      const slang_fully_specified_type * type)
+{
+   GET_CURRENT_CONTEXT(ctx); /* a hack */
+   slang_variable *var;
+   slang_atom a_name;
+
+   /* empty init declatator (without name, e.g. "float ;") */
+   if (*C->I++ == VARIABLE_NONE)
+      return 1;
+
+   a_name = parse_identifier(C);
+
+   /* check if name is already in this scope */
+   if (_slang_variable_locate(O->vars, a_name, GL_FALSE)) {
+      slang_info_log_error(C->L,
+                   "declaration of '%s' conflicts with previous declaration",
+                   (char *) a_name);
+      RETURN0;
+   }
+
+   /* make room for the new variable and initialize it */
+   var = slang_variable_scope_grow(O->vars);
+   if (!var) {
+      slang_info_log_memory(C->L);
+      RETURN0;
+   }
+
+   /* copy the declarator type qualifier/etc info, parse the identifier */
+   var->type.qualifier = type->qualifier;
+   var->type.centroid = type->centroid;
+   var->type.precision = type->precision;
+   var->type.variant = type->variant;
+   var->type.array_len = type->array_len;
+   var->a_name = a_name;
+   if (var->a_name == SLANG_ATOM_NULL)
+      RETURN0;
+
+   switch (*C->I++) {
+   case VARIABLE_NONE:
+      /* simple variable declarator - just copy the specifier */
+      if (!slang_type_specifier_copy(&var->type.specifier, &type->specifier))
+         RETURN0;
+      break;
+   case VARIABLE_INITIALIZER:
+      /* initialized variable - copy the specifier and parse the expression */
+      if (0 && type->array_len >= 0) {
+         /* The type was something like "float[4]" */
+         convert_to_array(C, var, &type->specifier);
+         var->array_len = type->array_len;
+      }
+      else {
+         if (!slang_type_specifier_copy(&var->type.specifier, &type->specifier))
+            RETURN0;
+      }
+      var->initializer =
+         (slang_operation *) _slang_alloc(sizeof(slang_operation));
+      if (var->initializer == NULL) {
+         slang_info_log_memory(C->L);
+         RETURN0;
+      }
+      if (!slang_operation_construct(var->initializer)) {
+         _slang_free(var->initializer);
+         var->initializer = NULL;
+         slang_info_log_memory(C->L);
+         RETURN0;
+      }
+      if (!parse_expression(C, O, var->initializer))
+         RETURN0;
+      break;
+   case VARIABLE_ARRAY_UNKNOWN:
+      /* unsized array - mark it as array and copy the specifier to
+       * the array element
+       */
+      if (type->array_len >= 0) {
+         slang_info_log_error(C->L, "multi-dimensional arrays not allowed");
+         RETURN0;
+      }
+      if (!convert_to_array(C, var, &type->specifier))
+         return GL_FALSE;
+      break;
+   case VARIABLE_ARRAY_EXPLICIT:
+      if (type->array_len >= 0) {
+         /* the user is trying to do something like: float[2] x[3]; */
+         slang_info_log_error(C->L, "multi-dimensional arrays not allowed");
+         RETURN0;
+      }
+      if (!convert_to_array(C, var, &type->specifier))
+         return GL_FALSE;
+      if (!parse_array_len(C, O, &var->array_len))
+         return GL_FALSE;
+      break;
+   default:
+      RETURN0;
+   }
+
+   /* allocate global address space for a variable with a known size */
+   if (C->global_scope
+       && !(var->type.specifier.type == SLANG_SPEC_ARRAY
+            && var->array_len == 0)) {
+      if (!calculate_var_size(C, O, var))
+         return GL_FALSE;
+   }
+
+   /* emit code for global var decl */
+   if (C->global_scope) {
+      slang_assemble_ctx A;
+      memset(&A, 0, sizeof(slang_assemble_ctx));
+      A.atoms = C->atoms;
+      A.space.funcs = O->funs;
+      A.space.structs = O->structs;
+      A.space.vars = O->vars;
+      A.program = O->program;
+      A.pragmas = O->pragmas;
+      A.vartable = O->vartable;
+      A.log = C->L;
+      A.curFuncEndLabel = NULL;
+      A.EmitContReturn = ctx->Shader.EmitContReturn;
+      if (!_slang_codegen_global_variable(&A, var, C->type))
+         RETURN0;
+   }
+
+   /* initialize global variable */
+   if (C->global_scope) {
+      if (var->initializer != NULL) {
+         slang_assemble_ctx A;
+         memset(&A, 0, sizeof(slang_assemble_ctx));
+         A.atoms = C->atoms;
+         A.space.funcs = O->funs;
+         A.space.structs = O->structs;
+         A.space.vars = O->vars;
+         if (!initialize_global(&A, var))
+            RETURN0;
+      }
+   }
+   return 1;
+}
+
+/**
+ * Parse a list of variable declarations.  Each variable may have an
+ * initializer.
+ */
+static int
+parse_init_declarator_list(slang_parse_ctx * C, slang_output_ctx * O)
+{
+   slang_fully_specified_type type;
+
+   /* parse the fully specified type, common to all declarators */
+   if (!slang_fully_specified_type_construct(&type))
+      RETURN0;
+   if (!parse_fully_specified_type(C, O, &type)) {
+      slang_fully_specified_type_destruct(&type);
+      RETURN0;
+   }
+
+   /* parse declarators, pass-in the parsed type */
+   do {
+      if (!parse_init_declarator(C, O, &type)) {
+         slang_fully_specified_type_destruct(&type);
+         RETURN0;
+      }
+   }
+   while (*C->I++ == DECLARATOR_NEXT);
+
+   slang_fully_specified_type_destruct(&type);
+   return 1;
+}
+
+
+/**
+ * Parse a function definition or declaration.
+ * \param C  parsing context
+ * \param O  output context
+ * \param definition if non-zero expect a definition, else a declaration
+ * \param parsed_func_ret  returns the parsed function
+ * \return GL_TRUE if success, GL_FALSE if failure
+ */
+static GLboolean
+parse_function(slang_parse_ctx * C, slang_output_ctx * O, int definition,
+               slang_function ** parsed_func_ret)
+{
+   slang_function parsed_func, *found_func;
+
+   /* parse function definition/declaration */
+   if (!slang_function_construct(&parsed_func))
+      return GL_FALSE;
+   if (definition) {
+      if (!parse_function_definition(C, O, &parsed_func)) {
+         slang_function_destruct(&parsed_func);
+         return GL_FALSE;
+      }
+   }
+   else {
+      if (!parse_function_prototype(C, O, &parsed_func)) {
+         slang_function_destruct(&parsed_func);
+         return GL_FALSE;
+      }
+   }
+
+   /* find a function with a prototype matching the parsed one - only
+    * the current scope is being searched to allow built-in function
+    * overriding
+    */
+   found_func = slang_function_scope_find(O->funs, &parsed_func, 0);
+   if (found_func == NULL) {
+      /* New function, add it to the function list */
+      O->funs->functions =
+         (slang_function *) _slang_realloc(O->funs->functions,
+                                           O->funs->num_functions
+                                           * sizeof(slang_function),
+                                           (O->funs->num_functions + 1)
+                                           * sizeof(slang_function));
+      if (O->funs->functions == NULL) {
+         /* Make sure that there are no functions marked, as the
+          * allocation is currently NULL, in order to avoid
+          * a potental segfault as we clean up later.
+          */
+         O->funs->num_functions = 0;
+
+         slang_info_log_memory(C->L);
+         slang_function_destruct(&parsed_func);
+         return GL_FALSE;
+      }
+      O->funs->functions[O->funs->num_functions] = parsed_func;
+      O->funs->num_functions++;
+
+      /* return the newly parsed function */
+      *parsed_func_ret = &O->funs->functions[O->funs->num_functions - 1];
+   }
+   else {
+      /* previously defined or declared */
+      /* TODO: check function return type qualifiers and specifiers */
+      if (definition) {
+         if (found_func->body != NULL) {
+            slang_info_log_error(C->L, "%s: function already has a body.",
+                                 slang_atom_pool_id(C->atoms,
+                                                    parsed_func.header.
+                                                    a_name));
+            slang_function_destruct(&parsed_func);
+            return GL_FALSE;
+         }
+
+         /* destroy the existing function declaration and replace it
+          * with the new one
+          */
+         slang_function_destruct(found_func);
+         *found_func = parsed_func;
+      }
+      else {
+         /* another declaration of the same function prototype - ignore it */
+         slang_function_destruct(&parsed_func);
+      }
+
+      /* return the found function */
+      *parsed_func_ret = found_func;
+   }
+
+   return GL_TRUE;
+}
+
+/* declaration */
+#define DECLARATION_FUNCTION_PROTOTYPE 1
+#define DECLARATION_INIT_DECLARATOR_LIST 2
+
+static int
+parse_declaration(slang_parse_ctx * C, slang_output_ctx * O)
+{
+   switch (*C->I++) {
+   case DECLARATION_INIT_DECLARATOR_LIST:
+      if (!parse_init_declarator_list(C, O))
+         RETURN0;
+      break;
+   case DECLARATION_FUNCTION_PROTOTYPE:
+      {
+         slang_function *dummy_func;
+
+         if (!parse_function(C, O, 0, &dummy_func))
+            RETURN0;
+      }
+      break;
+   default:
+      RETURN0;
+   }
+   return 1;
+}
+
+static int
+parse_default_precision(slang_parse_ctx * C, slang_output_ctx * O)
+{
+   int precision, type;
+
+   if (!O->allow_precision) {
+      slang_info_log_error(C->L, "syntax error at \"precision\"");
+      RETURN0;
+   }
+
+   precision = *C->I++;
+   switch (precision) {
+   case PRECISION_LOW:
+   case PRECISION_MEDIUM:
+   case PRECISION_HIGH:
+      /* OK */
+      break;
+   default:
+      _mesa_problem(NULL, "unexpected precision %d at %s:%d\n",
+                    precision, __FILE__, __LINE__);
+      RETURN0;
+   }
+
+   type = *C->I++;
+   switch (type) {
+   case TYPE_SPECIFIER_FLOAT:
+   case TYPE_SPECIFIER_INT:
+   case TYPE_SPECIFIER_SAMPLER1D:
+   case TYPE_SPECIFIER_SAMPLER2D:
+   case TYPE_SPECIFIER_SAMPLER3D:
+   case TYPE_SPECIFIER_SAMPLERCUBE:
+   case TYPE_SPECIFIER_SAMPLER1DSHADOW:
+   case TYPE_SPECIFIER_SAMPLER2DSHADOW:
+   case TYPE_SPECIFIER_SAMPLER2DRECT:
+   case TYPE_SPECIFIER_SAMPLER2DRECTSHADOW:
+      /* OK */
+      break;
+   default:
+      _mesa_problem(NULL, "unexpected type %d at %s:%d\n",
+                    type, __FILE__, __LINE__);
+      RETURN0;
+   }
+
+   assert(type < TYPE_SPECIFIER_COUNT);
+   O->default_precision[type] = precision;
+
+   return 1;
+}
+
+
+/**
+ * Initialize the default precision for all types.
+ * XXX this info isn't used yet.
+ */
+static void
+init_default_precision(slang_output_ctx *O, slang_unit_type type)
+{
+   GLuint i;
+   for (i = 0; i < TYPE_SPECIFIER_COUNT; i++) {
+#if FEATURE_es2_glsl
+      O->default_precision[i] = PRECISION_LOW;
+#else
+      O->default_precision[i] = PRECISION_HIGH;
+#endif
+   }
+
+   if (type == SLANG_UNIT_VERTEX_SHADER) {
+      O->default_precision[TYPE_SPECIFIER_FLOAT] = PRECISION_HIGH;
+      O->default_precision[TYPE_SPECIFIER_INT] = PRECISION_HIGH;
+   }
+   else {
+      O->default_precision[TYPE_SPECIFIER_INT] = PRECISION_MEDIUM;
+   }
+}
+
+
+static int
+parse_invariant(slang_parse_ctx * C, slang_output_ctx * O)
+{
+   if (O->allow_invariant) {
+      slang_atom *a = parse_identifier(C);
+      /* XXX not doing anything with this var yet */
+      /*printf("ID: %s\n", (char*) a);*/
+      return a ? 1 : 0;
+   }
+   else {
+      slang_info_log_error(C->L, "syntax error at \"invariant\"");
+      RETURN0;
+   }
+}
+      
+
+/* external declaration or default precision specifier */
+#define EXTERNAL_NULL 0
+#define EXTERNAL_FUNCTION_DEFINITION 1
+#define EXTERNAL_DECLARATION 2
+#define DEFAULT_PRECISION 3
+#define INVARIANT_STMT 4
+
+
+static GLboolean
+parse_code_unit(slang_parse_ctx * C, slang_code_unit * unit,
+                struct gl_shader *shader)
+{
+   GET_CURRENT_CONTEXT(ctx);
+   slang_output_ctx o;
+   GLboolean success;
+   GLuint maxRegs;
+   slang_function *mainFunc = NULL;
+
+   if (unit->type == SLANG_UNIT_FRAGMENT_BUILTIN ||
+       unit->type == SLANG_UNIT_FRAGMENT_SHADER) {
+      maxRegs = ctx->Const.FragmentProgram.MaxTemps;
+   }
+   else {
+      assert(unit->type == SLANG_UNIT_VERTEX_BUILTIN ||
+             unit->type == SLANG_UNIT_VERTEX_SHADER);
+      maxRegs = ctx->Const.VertexProgram.MaxTemps;
+   }
+
+   /* setup output context */
+   o.funs = &unit->funs;
+   o.structs = &unit->structs;
+   o.vars = &unit->vars;
+   o.program = shader ? shader->Program : NULL;
+   o.pragmas = shader ? &shader->Pragmas : NULL;
+   o.vartable = _slang_new_var_table(maxRegs);
+   _slang_push_var_table(o.vartable);
+
+   /* allow 'invariant' keyword? */
+#if FEATURE_es2_glsl
+   o.allow_invariant = GL_TRUE;
+#else
+   o.allow_invariant = (C->version >= 120) ? GL_TRUE : GL_FALSE;
+#endif
+
+   /* allow 'centroid' keyword? */
+   o.allow_centroid = (C->version >= 120) ? GL_TRUE : GL_FALSE;
+
+   /* allow 'lowp/mediump/highp' keywords? */
+#if FEATURE_es2_glsl
+   o.allow_precision = GL_TRUE;
+#else
+   o.allow_precision = (C->version >= 120) ? GL_TRUE : GL_FALSE;
+#endif
+   init_default_precision(&o, unit->type);
+
+   /* allow 'float[]' keyword? */
+   o.allow_array_types = (C->version >= 120) ? GL_TRUE : GL_FALSE;
+
+   /* parse individual functions and declarations */
+   while (*C->I != EXTERNAL_NULL) {
+      switch (*C->I++) {
+      case EXTERNAL_FUNCTION_DEFINITION:
+         {
+            slang_function *func;
+            success = parse_function(C, &o, 1, &func);
+            if (success &&
+                _mesa_strcmp((char *) func->header.a_name, "main") == 0) {
+               /* found main() */
+               mainFunc = func;
+            }
+         }
+         break;
+      case EXTERNAL_DECLARATION:
+         success = parse_declaration(C, &o);
+         break;
+      case DEFAULT_PRECISION:
+         success = parse_default_precision(C, &o);
+         break;
+      case INVARIANT_STMT:
+         success = parse_invariant(C, &o);
+         break;
+      default:
+         success = GL_FALSE;
+      }
+
+      if (!success) {
+         /* xxx free codegen */
+         _slang_pop_var_table(o.vartable);
+         return GL_FALSE;
+      }
+   }
+   C->I++;
+
+   if (mainFunc) {
+      /* assemble (generate code) for main() */
+      slang_assemble_ctx A;
+      memset(&A, 0, sizeof(slang_assemble_ctx));
+      A.atoms = C->atoms;
+      A.space.funcs = o.funs;
+      A.space.structs = o.structs;
+      A.space.vars = o.vars;
+      A.program = o.program;
+      A.pragmas = &shader->Pragmas;
+      A.vartable = o.vartable;
+      A.EmitContReturn = ctx->Shader.EmitContReturn;
+      A.log = C->L;
+
+      /* main() takes no parameters */
+      if (mainFunc->param_count > 0) {
+         slang_info_log_error(A.log, "main() takes no arguments");
+         return GL_FALSE;
+      }
+
+      _slang_codegen_function(&A, mainFunc);
+
+      shader->Main = GL_TRUE; /* this shader defines main() */
+
+      shader->UnresolvedRefs = A.UnresolvedRefs;
+   }
+
+   _slang_pop_var_table(o.vartable);
+   _slang_delete_var_table(o.vartable);
+
+   return GL_TRUE;
+}
+
+static GLboolean
+compile_binary(const byte * prod, slang_code_unit * unit,
+               GLuint version,
+               slang_unit_type type, slang_info_log * infolog,
+               slang_code_unit * builtin, slang_code_unit * downlink,
+               struct gl_shader *shader)
+{
+   slang_parse_ctx C;
+
+   unit->type = type;
+
+   /* setup parse context */
+   C.I = prod;
+   C.L = infolog;
+   C.parsing_builtin = (builtin == NULL);
+   C.global_scope = GL_TRUE;
+   C.atoms = &unit->object->atompool;
+   C.type = type;
+   C.version = version;
+
+   if (!check_revision(&C))
+      return GL_FALSE;
+
+   if (downlink != NULL) {
+      unit->vars.outer_scope = &downlink->vars;
+      unit->funs.outer_scope = &downlink->funs;
+      unit->structs.outer_scope = &downlink->structs;
+   }
+
+   /* parse translation unit */
+   return parse_code_unit(&C, unit, shader);
+}
+
+static GLboolean
+compile_with_grammar(grammar id, const char *source, slang_code_unit * unit,
+                     slang_unit_type type, slang_info_log * infolog,
+                     slang_code_unit * builtin,
+                     struct gl_shader *shader,
+                     const struct gl_extensions *extensions,
+                     struct gl_sl_pragmas *pragmas)
+{
+   byte *prod;
+   GLuint size, start, version;
+   slang_string preprocessed;
+   GLuint maxVersion;
+
+#if FEATURE_ARB_shading_language_120
+   maxVersion = 120;
+#elif FEATURE_es2_glsl
+   maxVersion = 100;
+#else
+   maxVersion = 110;
+#endif
+
+   /* First retrieve the version number. */
+   if (!_slang_preprocess_version(source, &version, &start, infolog))
+      return GL_FALSE;
+
+   if (version > maxVersion) {
+      slang_info_log_error(infolog,
+                           "language version %.2f is not supported.",
+                           version * 0.01);
+      return GL_FALSE;
+   }
+
+   /* Now preprocess the source string. */
+   slang_string_init(&preprocessed);
+   if (!_slang_preprocess_directives(&preprocessed, &source[start],
+                                     infolog, extensions, pragmas)) {
+      slang_string_free(&preprocessed);
+      slang_info_log_error(infolog, "failed to preprocess the source.");
+      return GL_FALSE;
+   }
+
+   /* Finally check the syntax and generate its binary representation. */
+   if (!grammar_fast_check(id,
+                           (const byte *) (slang_string_cstr(&preprocessed)),
+                           &prod, &size, 65536)) {
+      char buf[1024];
+      GLint pos;
+
+      slang_string_free(&preprocessed);
+      grammar_get_last_error((byte *) (buf), sizeof(buf), &pos);
+      slang_info_log_error(infolog, buf);
+      /* syntax error (possibly in library code) */
+#if 0
+      {
+         int line, col;
+         char *s;
+         s = (char *) _mesa_find_line_column((const GLubyte *) source,
+                                             (const GLubyte *) source + pos,
+                                             &line, &col);
+         printf("Error on line %d, col %d: %s\n", line, col, s);
+      }
+#endif
+      return GL_FALSE;
+   }
+   slang_string_free(&preprocessed);
+
+   /* Syntax is okay - translate it to internal representation. */
+   if (!compile_binary(prod, unit, version, type, infolog, builtin,
+                       &builtin[SLANG_BUILTIN_TOTAL - 1],
+                       shader)) {
+      grammar_alloc_free(prod);
+      return GL_FALSE;
+   }
+   grammar_alloc_free(prod);
+   return GL_TRUE;
+}
+
+LONGSTRING static const char *slang_shader_syn =
+#include "library/slang_shader_syn.h"
+   ;
+
+static const byte slang_core_gc[] = {
+#include "library/slang_core_gc.h"
+};
+
+static const byte slang_120_core_gc[] = {
+#include "library/slang_120_core_gc.h"
+};
+
+static const byte slang_120_fragment_gc[] = {
+#include "library/slang_builtin_120_fragment_gc.h"
+};
+
+static const byte slang_common_builtin_gc[] = {
+#include "library/slang_common_builtin_gc.h"
+};
+
+static const byte slang_fragment_builtin_gc[] = {
+#include "library/slang_fragment_builtin_gc.h"
+};
+
+static const byte slang_vertex_builtin_gc[] = {
+#include "library/slang_vertex_builtin_gc.h"
+};
+
+static GLboolean
+compile_object(grammar * id, const char *source, slang_code_object * object,
+               slang_unit_type type, slang_info_log * infolog,
+               struct gl_shader *shader,
+               const struct gl_extensions *extensions,
+               struct gl_sl_pragmas *pragmas)
+{
+   slang_code_unit *builtins = NULL;
+   GLuint base_version = 110;
+
+   /* load GLSL grammar */
+   *id = grammar_load_from_text((const byte *) (slang_shader_syn));
+   if (*id == 0) {
+      byte buf[1024];
+      int pos;
+
+      grammar_get_last_error(buf, 1024, &pos);
+      slang_info_log_error(infolog, (const char *) (buf));
+      return GL_FALSE;
+   }
+
+   /* set shader type - the syntax is slightly different for different shaders */
+   if (type == SLANG_UNIT_FRAGMENT_SHADER
+       || type == SLANG_UNIT_FRAGMENT_BUILTIN)
+      grammar_set_reg8(*id, (const byte *) "shader_type", 1);
+   else
+      grammar_set_reg8(*id, (const byte *) "shader_type", 2);
+
+   /* enable language extensions */
+   grammar_set_reg8(*id, (const byte *) "parsing_builtin", 1);
+
+   /* if parsing user-specified shader, load built-in library */
+   if (type == SLANG_UNIT_FRAGMENT_SHADER || type == SLANG_UNIT_VERTEX_SHADER) {
+      /* compile core functionality first */
+      if (!compile_binary(slang_core_gc,
+                          &object->builtin[SLANG_BUILTIN_CORE],
+                          base_version,
+                          SLANG_UNIT_FRAGMENT_BUILTIN, infolog,
+                          NULL, NULL, NULL))
+         return GL_FALSE;
+
+#if FEATURE_ARB_shading_language_120
+      if (!compile_binary(slang_120_core_gc,
+                          &object->builtin[SLANG_BUILTIN_120_CORE],
+                          120,
+                          SLANG_UNIT_FRAGMENT_BUILTIN, infolog,
+                          NULL, &object->builtin[SLANG_BUILTIN_CORE], NULL))
+         return GL_FALSE;
+#endif
+
+      /* compile common functions and variables, link to core */
+      if (!compile_binary(slang_common_builtin_gc,
+                          &object->builtin[SLANG_BUILTIN_COMMON],
+#if FEATURE_ARB_shading_language_120
+                          120,
+#else
+                          base_version,
+#endif
+                          SLANG_UNIT_FRAGMENT_BUILTIN, infolog, NULL,
+#if FEATURE_ARB_shading_language_120
+                          &object->builtin[SLANG_BUILTIN_120_CORE],
+#else
+                          &object->builtin[SLANG_BUILTIN_CORE],
+#endif
+                          NULL))
+         return GL_FALSE;
+
+      /* compile target-specific functions and variables, link to common */
+      if (type == SLANG_UNIT_FRAGMENT_SHADER) {
+         if (!compile_binary(slang_fragment_builtin_gc,
+                             &object->builtin[SLANG_BUILTIN_TARGET],
+                             base_version,
+                             SLANG_UNIT_FRAGMENT_BUILTIN, infolog, NULL,
+                             &object->builtin[SLANG_BUILTIN_COMMON], NULL))
+            return GL_FALSE;
+#if FEATURE_ARB_shading_language_120
+         if (!compile_binary(slang_120_fragment_gc,
+                             &object->builtin[SLANG_BUILTIN_TARGET],
+                             120,
+                             SLANG_UNIT_FRAGMENT_BUILTIN, infolog, NULL,
+                             &object->builtin[SLANG_BUILTIN_COMMON], NULL))
+            return GL_FALSE;
+#endif
+      }
+      else if (type == SLANG_UNIT_VERTEX_SHADER) {
+         if (!compile_binary(slang_vertex_builtin_gc,
+                             &object->builtin[SLANG_BUILTIN_TARGET],
+                             base_version,
+                             SLANG_UNIT_VERTEX_BUILTIN, infolog, NULL,
+                             &object->builtin[SLANG_BUILTIN_COMMON], NULL))
+            return GL_FALSE;
+      }
+
+      /* disable language extensions */
+#if NEW_SLANG /* allow-built-ins */
+      grammar_set_reg8(*id, (const byte *) "parsing_builtin", 1);
+#else
+      grammar_set_reg8(*id, (const byte *) "parsing_builtin", 0);
+#endif
+      builtins = object->builtin;
+   }
+
+   /* compile the actual shader - pass-in built-in library for external shader */
+   return compile_with_grammar(*id, source, &object->unit, type, infolog,
+                               builtins, shader, extensions, pragmas);
+}
+
+
+static GLboolean
+compile_shader(GLcontext *ctx, slang_code_object * object,
+               slang_unit_type type, slang_info_log * infolog,
+               struct gl_shader *shader)
+{
+   GLboolean success;
+   grammar id = 0;
+
+#if 0 /* for debug */
+   _mesa_printf("********* COMPILE SHADER ***********\n");
+   _mesa_printf("%s\n", shader->Source);
+   _mesa_printf("************************************\n");
+#endif
+
+   assert(shader->Program);
+
+   _slang_code_object_dtr(object);
+   _slang_code_object_ctr(object);
+
+   success = compile_object(&id, shader->Source, object, type, infolog, shader,
+                            &ctx->Extensions, &shader->Pragmas);
+   if (id != 0)
+      grammar_destroy(id);
+   if (!success)
+      return GL_FALSE;
+
+   return GL_TRUE;
+}
+
+
+
+GLboolean
+_slang_compile(GLcontext *ctx, struct gl_shader *shader)
+{
+   GLboolean success;
+   slang_info_log info_log;
+   slang_code_object obj;
+   slang_unit_type type;
+
+   if (shader->Type == GL_VERTEX_SHADER) {
+      type = SLANG_UNIT_VERTEX_SHADER;
+   }
+   else {
+      assert(shader->Type == GL_FRAGMENT_SHADER);
+      type = SLANG_UNIT_FRAGMENT_SHADER;
+   }
+
+   if (!shader->Source)
+      return GL_FALSE;
+
+   ctx->Shader.MemPool = _slang_new_mempool(1024*1024);
+
+   shader->Main = GL_FALSE;
+
+   if (!shader->Program) {
+      GLenum progTarget;
+      if (shader->Type == GL_VERTEX_SHADER)
+         progTarget = GL_VERTEX_PROGRAM_ARB;
+      else
+         progTarget = GL_FRAGMENT_PROGRAM_ARB;
+      shader->Program = ctx->Driver.NewProgram(ctx, progTarget, 1);
+      shader->Program->Parameters = _mesa_new_parameter_list();
+      shader->Program->Varying = _mesa_new_parameter_list();
+      shader->Program->Attributes = _mesa_new_parameter_list();
+   }
+
+   slang_info_log_construct(&info_log);
+   _slang_code_object_ctr(&obj);
+
+   success = compile_shader(ctx, &obj, type, &info_log, shader);
+
+   /* free shader's prev info log */
+   if (shader->InfoLog) {
+      _mesa_free(shader->InfoLog);
+      shader->InfoLog = NULL;
+   }
+
+   if (info_log.text) {
+      /* copy info-log string to shader object */
+      shader->InfoLog = _mesa_strdup(info_log.text);
+   }
+
+   if (info_log.error_flag) {
+      success = GL_FALSE;
+   }
+
+   slang_info_log_destruct(&info_log);
+   _slang_code_object_dtr(&obj);
+
+   _slang_delete_mempool((slang_mempool *) ctx->Shader.MemPool);
+   ctx->Shader.MemPool = NULL;
+
+   /* remove any reads of output registers */
+#if 0
+   printf("Pre-remove output reads:\n");
+   _mesa_print_program(shader->Program);
+#endif
+   _mesa_remove_output_reads(shader->Program, PROGRAM_OUTPUT);
+   if (shader->Type == GL_VERTEX_SHADER) {
+      /* and remove writes to varying vars in vertex programs */
+      _mesa_remove_output_reads(shader->Program, PROGRAM_VARYING);
+   }
+#if 0
+   printf("Post-remove output reads:\n");
+   _mesa_print_program(shader->Program);
+#endif
+
+   shader->CompileStatus = success;
+
+   if (success) {
+      if (shader->Pragmas.Optimize &&
+          (ctx->Shader.Flags & GLSL_NO_OPT) == 0) {
+         _mesa_optimize_program(ctx, shader->Program);
+      }
+   }
+
+   if (ctx->Shader.Flags & GLSL_LOG) {
+      _mesa_write_shader_to_file(shader);
+   }
+
+   return success;
+}
+