svn merge ^/branches/released .

4 files changed, 237 insertions, 207 deletions

diff --git a/mesalib/scons/crossmingw.py b/mesalib/scons/crossmingw.py
index bac51de07..cc046229e 100644
--- a/mesalib/scons/crossmingw.py
+++ b/mesalib/scons/crossmingw.py
@@ -1,198 +1,201 @@
-"""SCons.Tool.gcc

-

-Tool-specific initialization for MinGW (http://www.mingw.org/)

-

-There normally shouldn't be any need to import this module directly.

-It will usually be imported through the generic SCons.Tool.Tool()

-selection method.

-

-See also http://www.scons.org/wiki/CrossCompilingMingw

-"""

-

-#

-# Copyright (c) 2001, 2002, 2003, 2004 The SCons Foundation

-#

-# 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 THE AUTHORS OR COPYRIGHT HOLDERS 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.

-#

-

-import os

-import os.path

-import string

-

-import SCons.Action

-import SCons.Builder

-import SCons.Tool

-import SCons.Util

-

-# This is what we search for to find mingw:

-prefixes32 = SCons.Util.Split("""

-    mingw32-

-    mingw32msvc-

-    i386-mingw32-

-    i486-mingw32-

-    i586-mingw32-

-    i686-mingw32-

-    i386-mingw32msvc-

-    i486-mingw32msvc-

-    i586-mingw32msvc-

-    i686-mingw32msvc-

-    i686-pc-mingw32-

-    i686-w64-mingw32-

-""")

-prefixes64 = SCons.Util.Split("""

-    amd64-mingw32-

-    amd64-mingw32msvc-

-    amd64-pc-mingw32-

-    x86_64-w64-mingw32-

-""")

-

-def find(env):

-    if env['machine'] == 'x86_64':

-        prefixes = prefixes64

-    else:

-        prefixes = prefixes32

-    for prefix in prefixes:

-        # First search in the SCons path and then the OS path:

-        if env.WhereIs(prefix + 'gcc') or SCons.Util.WhereIs(prefix + 'gcc'):

-            return prefix

-

-    return ''

-

-def shlib_generator(target, source, env, for_signature):

-    cmd = SCons.Util.CLVar(['$SHLINK', '$SHLINKFLAGS']) 

-

-    dll = env.FindIxes(target, 'SHLIBPREFIX', 'SHLIBSUFFIX')

-    if dll: cmd.extend(['-o', dll])

-

-    cmd.extend(['$SOURCES', '$_LIBDIRFLAGS', '$_LIBFLAGS'])

-

-    implib = env.FindIxes(target, 'LIBPREFIX', 'LIBSUFFIX')

-    if implib: cmd.append('-Wl,--out-implib,'+implib.get_string(for_signature))

-

-    def_target = env.FindIxes(target, 'WIN32DEFPREFIX', 'WIN32DEFSUFFIX')

-    if def_target: cmd.append('-Wl,--output-def,'+def_target.get_string(for_signature))

-

-    return [cmd]

-

-def shlib_emitter(target, source, env):

-    dll = env.FindIxes(target, 'SHLIBPREFIX', 'SHLIBSUFFIX')

-    no_import_lib = env.get('no_import_lib', 0)

-

-    if not dll:

-        raise SCons.Errors.UserError, "A shared library should have exactly one target with the suffix: %s" % env.subst("$SHLIBSUFFIX")

-    

-    if not no_import_lib and \

-       not env.FindIxes(target, 'LIBPREFIX', 'LIBSUFFIX'):

-

-        # Append an import library to the list of targets.

-        target.append(env.ReplaceIxes(dll,  

-                                      'SHLIBPREFIX', 'SHLIBSUFFIX',

-                                      'LIBPREFIX', 'LIBSUFFIX'))

-

-    # Append a def file target if there isn't already a def file target

-    # or a def file source. There is no option to disable def file

-    # target emitting, because I can't figure out why someone would ever

-    # want to turn it off.

-    def_source = env.FindIxes(source, 'WIN32DEFPREFIX', 'WIN32DEFSUFFIX')

-    def_target = env.FindIxes(target, 'WIN32DEFPREFIX', 'WIN32DEFSUFFIX')

-    if not def_source and not def_target:

-        target.append(env.ReplaceIxes(dll,  

-                                      'SHLIBPREFIX', 'SHLIBSUFFIX',

-                                      'WIN32DEFPREFIX', 'WIN32DEFSUFFIX'))

-    

-    return (target, source)

-                         

-

-shlib_action = SCons.Action.Action(shlib_generator, '$SHLINKCOMSTR', generator=1)

-

-res_action = SCons.Action.Action('$RCCOM', '$RCCOMSTR')

-

-res_builder = SCons.Builder.Builder(action=res_action, suffix='.o',

-                                    source_scanner=SCons.Tool.SourceFileScanner)

-SCons.Tool.SourceFileScanner.add_scanner('.rc', SCons.Defaults.CScan)

-

-def generate(env):

-    mingw_prefix = find(env)

-

-    if mingw_prefix:

-        dir = os.path.dirname(env.WhereIs(mingw_prefix + 'gcc') or SCons.Util.WhereIs(mingw_prefix + 'gcc'))

-

-        # The mingw bin directory must be added to the path:

-        path = env['ENV'].get('PATH', [])

-        if not path: 

-            path = []

-        if SCons.Util.is_String(path):

-            path = string.split(path, os.pathsep)

-

-        env['ENV']['PATH'] = string.join([dir] + path, os.pathsep)

-

-    # Most of mingw is the same as gcc and friends...

-    gnu_tools = ['gcc', 'g++', 'gnulink', 'ar', 'gas']

-    for tool in gnu_tools:

-        SCons.Tool.Tool(tool)(env)

-

-    #... but a few things differ:

-    env['CC'] = mingw_prefix + 'gcc'

-    env['SHCCFLAGS'] = SCons.Util.CLVar('$CCFLAGS')

-    env['CXX'] = mingw_prefix + 'g++'

-    env['SHCXXFLAGS'] = SCons.Util.CLVar('$CXXFLAGS')

-    env['SHLINKFLAGS'] = SCons.Util.CLVar('$LINKFLAGS -shared')

-    env['SHLINKCOM']   = shlib_action

-    env.Append(SHLIBEMITTER = [shlib_emitter])

-    env['LINK'] = mingw_prefix + 'g++'

-    env['AR'] = mingw_prefix + 'ar'

-    env['RANLIB'] = mingw_prefix + 'ranlib'

-    env['LINK'] = mingw_prefix + 'g++'

-    env['AS'] = mingw_prefix + 'as'

-    env['WIN32DEFPREFIX']        = ''

-    env['WIN32DEFSUFFIX']        = '.def'

-    env['SHOBJSUFFIX'] = '.o'

-    env['STATIC_AND_SHARED_OBJECTS_ARE_THE_SAME'] = 1

-

-    env['RC'] = mingw_prefix + 'windres'

-    env['RCFLAGS'] = SCons.Util.CLVar('')

-    env['RCCOM'] = '$RC $_CPPDEFFLAGS $_CPPINCFLAGS ${INCPREFIX}${SOURCE.dir} $RCFLAGS -i $SOURCE -o $TARGET'

-    env['BUILDERS']['RES'] = res_builder

-    

-    # Some setting from the platform also have to be overridden:

-    env['OBJPREFIX']      = ''

-    env['OBJSUFFIX']      = '.o'

-    env['SHOBJPREFIX']    = '$OBJPREFIX'

-    env['SHOBJSUFFIX']    = '$OBJSUFFIX'

-    env['PROGPREFIX']     = ''

-    env['PROGSUFFIX']     = '.exe'

-    env['LIBPREFIX']      = 'lib'

-    env['LIBSUFFIX']      = '.a'

-    env['SHLIBPREFIX']    = ''

-    env['SHLIBSUFFIX']    = '.dll'

-    env['LIBPREFIXES']    = [ 'lib', '' ]

-    env['LIBSUFFIXES']    = [ '.a', '.lib' ]

-

-    # MinGW port of gdb does not handle well dwarf debug info which is the

-    # default in recent gcc versions

-    env.AppendUnique(CCFLAGS = ['-gstabs'])

-

-    env.AppendUnique(CPPDEFINES = [('__MSVCRT_VERSION__', '0x0700')])

-    #env.AppendUnique(LIBS = ['iberty'])

-    env.AppendUnique(SHLINKFLAGS = ['-Wl,--enable-stdcall-fixup'])

-    #env.AppendUnique(SHLINKFLAGS = ['-Wl,--kill-at'])

-

-def exists(env):

-    return find(env)

+"""SCons.Tool.gcc
+
+Tool-specific initialization for MinGW (http://www.mingw.org/)
+
+There normally shouldn't be any need to import this module directly.
+It will usually be imported through the generic SCons.Tool.Tool()
+selection method.
+
+See also http://www.scons.org/wiki/CrossCompilingMingw
+"""
+
+#
+# Copyright (c) 2001, 2002, 2003, 2004 The SCons Foundation
+#
+# 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 THE AUTHORS OR COPYRIGHT HOLDERS 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.
+#
+
+import os
+import os.path
+import string
+
+import SCons.Action
+import SCons.Builder
+import SCons.Tool
+import SCons.Util
+
+# This is what we search for to find mingw:
+prefixes32 = SCons.Util.Split("""
+    mingw32-
+    mingw32msvc-
+    i386-mingw32-
+    i486-mingw32-
+    i586-mingw32-
+    i686-mingw32-
+    i386-mingw32msvc-
+    i486-mingw32msvc-
+    i586-mingw32msvc-
+    i686-mingw32msvc-
+    i686-pc-mingw32-
+    i686-w64-mingw32-
+""")
+prefixes64 = SCons.Util.Split("""
+    amd64-mingw32-
+    amd64-mingw32msvc-
+    amd64-pc-mingw32-
+    x86_64-w64-mingw32-
+""")
+
+def find(env):
+    if env['machine'] == 'x86_64':
+        prefixes = prefixes64
+    else:
+        prefixes = prefixes32
+    for prefix in prefixes:
+        # First search in the SCons path and then the OS path:
+        if env.WhereIs(prefix + 'gcc') or SCons.Util.WhereIs(prefix + 'gcc'):
+            return prefix
+
+    return ''
+
+def shlib_generator(target, source, env, for_signature):
+    cmd = SCons.Util.CLVar(['$SHLINK', '$SHLINKFLAGS']) 
+
+    dll = env.FindIxes(target, 'SHLIBPREFIX', 'SHLIBSUFFIX')
+    if dll: cmd.extend(['-o', dll])
+
+    cmd.extend(['$SOURCES', '$_LIBDIRFLAGS', '$_LIBFLAGS'])
+
+    implib = env.FindIxes(target, 'LIBPREFIX', 'LIBSUFFIX')
+    if implib: cmd.append('-Wl,--out-implib,'+implib.get_string(for_signature))
+
+    def_target = env.FindIxes(target, 'WIN32DEFPREFIX', 'WIN32DEFSUFFIX')
+    if def_target: cmd.append('-Wl,--output-def,'+def_target.get_string(for_signature))
+
+    return [cmd]
+
+def shlib_emitter(target, source, env):
+    dll = env.FindIxes(target, 'SHLIBPREFIX', 'SHLIBSUFFIX')
+    no_import_lib = env.get('no_import_lib', 0)
+
+    if not dll:
+        raise SCons.Errors.UserError, "A shared library should have exactly one target with the suffix: %s" % env.subst("$SHLIBSUFFIX")
+    
+    if not no_import_lib and \
+       not env.FindIxes(target, 'LIBPREFIX', 'LIBSUFFIX'):
+
+        # Append an import library to the list of targets.
+        target.append(env.ReplaceIxes(dll,  
+                                      'SHLIBPREFIX', 'SHLIBSUFFIX',
+                                      'LIBPREFIX', 'LIBSUFFIX'))
+
+    # Append a def file target if there isn't already a def file target
+    # or a def file source. There is no option to disable def file
+    # target emitting, because I can't figure out why someone would ever
+    # want to turn it off.
+    def_source = env.FindIxes(source, 'WIN32DEFPREFIX', 'WIN32DEFSUFFIX')
+    def_target = env.FindIxes(target, 'WIN32DEFPREFIX', 'WIN32DEFSUFFIX')
+    if not def_source and not def_target:
+        target.append(env.ReplaceIxes(dll,  
+                                      'SHLIBPREFIX', 'SHLIBSUFFIX',
+                                      'WIN32DEFPREFIX', 'WIN32DEFSUFFIX'))
+    
+    return (target, source)
+                         
+
+shlib_action = SCons.Action.Action(shlib_generator, '$SHLINKCOMSTR', generator=1)
+
+res_action = SCons.Action.Action('$RCCOM', '$RCCOMSTR')
+
+res_builder = SCons.Builder.Builder(action=res_action, suffix='.o',
+                                    source_scanner=SCons.Tool.SourceFileScanner)
+SCons.Tool.SourceFileScanner.add_scanner('.rc', SCons.Defaults.CScan)
+
+def generate(env):
+    mingw_prefix = find(env)
+
+    if mingw_prefix:
+        dir = os.path.dirname(env.WhereIs(mingw_prefix + 'gcc') or SCons.Util.WhereIs(mingw_prefix + 'gcc'))
+
+        # The mingw bin directory must be added to the path:
+        path = env['ENV'].get('PATH', [])
+        if not path: 
+            path = []
+        if SCons.Util.is_String(path):
+            path = string.split(path, os.pathsep)
+
+        env['ENV']['PATH'] = string.join([dir] + path, os.pathsep)
+
+    # Most of mingw is the same as gcc and friends...
+    gnu_tools = ['gcc', 'g++', 'gnulink', 'ar', 'gas']
+    for tool in gnu_tools:
+        SCons.Tool.Tool(tool)(env)
+
+    #... but a few things differ:
+    env['CC'] = mingw_prefix + 'gcc'
+    env['SHCCFLAGS'] = SCons.Util.CLVar('$CCFLAGS')
+    env['CXX'] = mingw_prefix + 'g++'
+    env['SHCXXFLAGS'] = SCons.Util.CLVar('$CXXFLAGS')
+    env['SHLINKFLAGS'] = SCons.Util.CLVar('$LINKFLAGS -shared')
+    env['SHLINKCOM']   = shlib_action
+    env.Append(SHLIBEMITTER = [shlib_emitter])
+    env['LINK'] = mingw_prefix + 'g++'
+    env['AR'] = mingw_prefix + 'ar'
+    env['RANLIB'] = mingw_prefix + 'ranlib'
+    env['LINK'] = mingw_prefix + 'g++'
+    env['AS'] = mingw_prefix + 'as'
+    env['WIN32DEFPREFIX']        = ''
+    env['WIN32DEFSUFFIX']        = '.def'
+    env['SHOBJSUFFIX'] = '.o'
+    env['STATIC_AND_SHARED_OBJECTS_ARE_THE_SAME'] = 1
+
+    env['RC'] = mingw_prefix + 'windres'
+    env['RCFLAGS'] = SCons.Util.CLVar('')
+    env['RCCOM'] = '$RC $_CPPDEFFLAGS $_CPPINCFLAGS ${INCPREFIX}${SOURCE.dir} $RCFLAGS -i $SOURCE -o $TARGET'
+    env['BUILDERS']['RES'] = res_builder
+    
+    # Some setting from the platform also have to be overridden:
+    env['OBJPREFIX']      = ''
+    env['OBJSUFFIX']      = '.o'
+    env['SHOBJPREFIX']    = '$OBJPREFIX'
+    env['SHOBJSUFFIX']    = '$OBJSUFFIX'
+    env['PROGPREFIX']     = ''
+    env['PROGSUFFIX']     = '.exe'
+    env['LIBPREFIX']      = 'lib'
+    env['LIBSUFFIX']      = '.a'
+    env['SHLIBPREFIX']    = ''
+    env['SHLIBSUFFIX']    = '.dll'
+    env['LIBPREFIXES']    = [ 'lib', '' ]
+    env['LIBSUFFIXES']    = [ '.a', '.lib' ]
+
+    # MinGW port of gdb does not handle well dwarf debug info which is the
+    # default in recent gcc versions
+    env.AppendUnique(CCFLAGS = ['-gstabs'])
+
+    env.AppendUnique(CPPDEFINES = [('__MSVCRT_VERSION__', '0x0700')])
+    #env.AppendUnique(LIBS = ['iberty'])
+    env.AppendUnique(SHLINKFLAGS = ['-Wl,--enable-stdcall-fixup'])
+    #env.AppendUnique(SHLINKFLAGS = ['-Wl,--kill-at'])
+
+    # Avoid depending on gcc runtime DLLs
+    env.AppendUnique(LINKFLAGS = ['-static-libgcc'])
+
+def exists(env):
+    return find(env)
diff --git a/mesalib/src/glsl/ast_function.cpp b/mesalib/src/glsl/ast_function.cpp
index 28d49ee0d..7611617df 100644
--- a/mesalib/src/glsl/ast_function.cpp
+++ b/mesalib/src/glsl/ast_function.cpp
@@ -75,7 +75,7 @@ prototype_string(const glsl_type *return_type, const char *name,
    char *str = NULL;
 
    if (return_type != NULL)
-      ralloc_asprintf(&str, "%s ", return_type->name);
+      str = ralloc_asprintf(NULL, "%s ", return_type->name);
 
    ralloc_asprintf_append(&str, "%s(", name);
 
diff --git a/mesalib/src/glsl/glcpp/glcpp-parse.y b/mesalib/src/glsl/glcpp/glcpp-parse.y
index aa5a0c4f2..1f6e67fa0 100644
--- a/mesalib/src/glsl/glcpp/glcpp-parse.y
+++ b/mesalib/src/glsl/glcpp/glcpp-parse.y
@@ -388,7 +388,12 @@ expression:
 		$$ = $1 + $3;
 	}
 |	expression '%' expression {
-		$$ = $1 % $3;
+		if ($3 == 0) {
+			yyerror (& @1, parser,
+				 "zero modulus in preprocessor directive");
+		} else {
+			$$ = $1 % $3;
+		}
 	}
 |	expression '/' expression {
 		if ($3 == 0) {
diff --git a/mesalib/src/glsl/ir_constant_expression.cpp b/mesalib/src/glsl/ir_constant_expression.cpp
index cf958aa7a..2841fb350 100644
--- a/mesalib/src/glsl/ir_constant_expression.cpp
+++ b/mesalib/src/glsl/ir_constant_expression.cpp
@@ -288,20 +288,24 @@ ir_expression::constant_expression_value()
       break;
 
    case ir_unop_rcp:
+      /* FINISHME: Emit warning when division-by-zero is detected. */
       assert(op[0]->type->base_type == GLSL_TYPE_FLOAT);
       for (unsigned c = 0; c < op[0]->type->components(); c++) {
 	 switch (this->type->base_type) {
 	 case GLSL_TYPE_UINT:
-	    if (op[0]->value.u[c] != 0.0)
-	       data.u[c] = 1 / op[0]->value.u[c];
+	    if (op[0]->value.u[c] == 0.0)
+	       return NULL;
+	    data.u[c] = 1 / op[0]->value.u[c];
 	    break;
 	 case GLSL_TYPE_INT:
-	    if (op[0]->value.i[c] != 0.0)
-	       data.i[c] = 1 / op[0]->value.i[c];
+	    if (op[0]->value.i[c] == 0.0)
+	       return NULL;
+	    data.i[c] = 1 / op[0]->value.i[c];
 	    break;
 	 case GLSL_TYPE_FLOAT:
-	    if (op[0]->value.f[c] != 0.0)
-	       data.f[c] = 1.0F / op[0]->value.f[c];
+	    if (op[0]->value.f[c] == 0.0)
+	       return NULL;
+	    data.f[c] = 1.0F / op[0]->value.f[c];
 	    break;
 	 default:
 	    assert(0);
@@ -310,9 +314,13 @@ ir_expression::constant_expression_value()
       break;
 
    case ir_unop_rsq:
+      /* FINISHME: Emit warning when division-by-zero is detected. */
       assert(op[0]->type->base_type == GLSL_TYPE_FLOAT);
       for (unsigned c = 0; c < op[0]->type->components(); c++) {
-	 data.f[c] = 1.0F / sqrtf(op[0]->value.f[c]);
+	 float s = sqrtf(op[0]->value.f[c]);
+	 if (s == 0)
+	    return NULL;
+	 data.f[c] = 1.0F / s;
       }
       break;
 
@@ -507,6 +515,7 @@ ir_expression::constant_expression_value()
 
       break;
    case ir_binop_div:
+      /* FINISHME: Emit warning when division-by-zero is detected. */
       assert(op[0]->type == op[1]->type || op0_scalar || op1_scalar);
       for (unsigned c = 0, c0 = 0, c1 = 0;
 	   c < components;
@@ -514,12 +523,18 @@ ir_expression::constant_expression_value()
 
 	 switch (op[0]->type->base_type) {
 	 case GLSL_TYPE_UINT:
+	    if (op[1]->value.u[c1] == 0)
+	       return NULL;
 	    data.u[c] = op[0]->value.u[c0] / op[1]->value.u[c1];
 	    break;
 	 case GLSL_TYPE_INT:
+	    if (op[1]->value.i[c1] == 0)
+	       return NULL;
 	    data.i[c] = op[0]->value.i[c0] / op[1]->value.i[c1];
 	    break;
 	 case GLSL_TYPE_FLOAT:
+	    if (op[1]->value.f[c1] == 0)
+	       return NULL;
 	    data.f[c] = op[0]->value.f[c0] / op[1]->value.f[c1];
 	    break;
 	 default:
@@ -529,6 +544,7 @@ ir_expression::constant_expression_value()
 
       break;
    case ir_binop_mod:
+      /* FINISHME: Emit warning when division-by-zero is detected. */
       assert(op[0]->type == op[1]->type || op0_scalar || op1_scalar);
       for (unsigned c = 0, c0 = 0, c1 = 0;
 	   c < components;
@@ -536,12 +552,18 @@ ir_expression::constant_expression_value()
 
 	 switch (op[0]->type->base_type) {
 	 case GLSL_TYPE_UINT:
+	    if (op[1]->value.u[c1] == 0)
+	       return NULL;
 	    data.u[c] = op[0]->value.u[c0] % op[1]->value.u[c1];
 	    break;
 	 case GLSL_TYPE_INT:
+	    if (op[1]->value.i[c1] == 0)
+	       return NULL;
 	    data.i[c] = op[0]->value.i[c0] % op[1]->value.i[c1];
 	    break;
 	 case GLSL_TYPE_FLOAT:
+	    if (op[1]->value.f[c1] == 0)
+	       return NULL;
 	    /* We don't use fmod because it rounds toward zero; GLSL specifies
 	     * the use of floor.
 	     */