diff options
Diffstat (limited to 'mesalib/src/glsl/linker.cpp')
| -rw-r--r-- | mesalib/src/glsl/linker.cpp | 190 |
1 files changed, 170 insertions, 20 deletions
diff --git a/mesalib/src/glsl/linker.cpp b/mesalib/src/glsl/linker.cpp index c2f7f4863..a43d23082 100644 --- a/mesalib/src/glsl/linker.cpp +++ b/mesalib/src/glsl/linker.cpp @@ -1195,6 +1195,83 @@ private: }; /** + * Performs the cross-validation of layout qualifiers specified in + * redeclaration of gl_FragCoord for the attached fragment shaders, + * and propagates them to the linked FS and linked shader program. + */ +static void +link_fs_input_layout_qualifiers(struct gl_shader_program *prog, + struct gl_shader *linked_shader, + struct gl_shader **shader_list, + unsigned num_shaders) +{ + linked_shader->redeclares_gl_fragcoord = false; + linked_shader->uses_gl_fragcoord = false; + linked_shader->origin_upper_left = false; + linked_shader->pixel_center_integer = false; + + if (linked_shader->Stage != MESA_SHADER_FRAGMENT || + (prog->Version < 150 && !prog->ARB_fragment_coord_conventions_enable)) + return; + + for (unsigned i = 0; i < num_shaders; i++) { + struct gl_shader *shader = shader_list[i]; + /* From the GLSL 1.50 spec, page 39: + * + * "If gl_FragCoord is redeclared in any fragment shader in a program, + * it must be redeclared in all the fragment shaders in that program + * that have a static use gl_FragCoord." + * + * Exclude the case when one of the 'linked_shader' or 'shader' redeclares + * gl_FragCoord with no layout qualifiers but the other one doesn't + * redeclare it. If we strictly follow GLSL 1.50 spec's language, it + * should be a link error. But, generating link error for this case will + * be a wrong behaviour which spec didn't intend to do and it could also + * break some applications. + */ + if ((linked_shader->redeclares_gl_fragcoord + && !shader->redeclares_gl_fragcoord + && shader->uses_gl_fragcoord + && (linked_shader->origin_upper_left + || linked_shader->pixel_center_integer)) + || (shader->redeclares_gl_fragcoord + && !linked_shader->redeclares_gl_fragcoord + && linked_shader->uses_gl_fragcoord + && (shader->origin_upper_left + || shader->pixel_center_integer))) { + linker_error(prog, "fragment shader defined with conflicting " + "layout qualifiers for gl_FragCoord\n"); + } + + /* From the GLSL 1.50 spec, page 39: + * + * "All redeclarations of gl_FragCoord in all fragment shaders in a + * single program must have the same set of qualifiers." + */ + if (linked_shader->redeclares_gl_fragcoord && shader->redeclares_gl_fragcoord + && (shader->origin_upper_left != linked_shader->origin_upper_left + || shader->pixel_center_integer != linked_shader->pixel_center_integer)) { + linker_error(prog, "fragment shader defined with conflicting " + "layout qualifiers for gl_FragCoord\n"); + } + + /* Update the linked shader state. Note that uses_gl_fragcoord should + * accumulate the results. The other values should replace. If there + * are multiple redeclarations, all the fields except uses_gl_fragcoord + * are already known to be the same. + */ + if (shader->redeclares_gl_fragcoord || shader->uses_gl_fragcoord) { + linked_shader->redeclares_gl_fragcoord = + shader->redeclares_gl_fragcoord; + linked_shader->uses_gl_fragcoord = linked_shader->uses_gl_fragcoord + || shader->uses_gl_fragcoord; + linked_shader->origin_upper_left = shader->origin_upper_left; + linked_shader->pixel_center_integer = shader->pixel_center_integer; + } + } +} + +/** * Performs the cross-validation of geometry shader max_vertices and * primitive type layout qualifiers for the attached geometry shaders, * and propagates them to the linked GS and linked shader program. @@ -1471,6 +1548,7 @@ link_intrastage_shaders(void *mem_ctx, linked->NumUniformBlocks = num_uniform_blocks; ralloc_steal(linked, linked->UniformBlocks); + link_fs_input_layout_qualifiers(prog, linked, shader_list, num_shaders); link_gs_inout_layout_qualifiers(prog, linked, shader_list, num_shaders); link_cs_input_layout_qualifiers(prog, linked, shader_list, num_shaders); @@ -1798,10 +1876,12 @@ assign_attribute_or_color_locations(gl_shader_program *prog, * active attribute array, both of which require multiple * contiguous generic attributes." * - * Previous versions of the spec contain similar language but omit - * the bit about attribute arrays. + * I think above text prohibits the aliasing of explicit and + * automatic assignments. But, aliasing is allowed in manual + * assignments of attribute locations. See below comments for + * the details. * - * Page 61 of the OpenGL 4.0 spec also says: + * From OpenGL 4.0 spec, page 61: * * "It is possible for an application to bind more than one * attribute name to the same location. This is referred to as @@ -1814,29 +1894,84 @@ assign_attribute_or_color_locations(gl_shader_program *prog, * but implementations are not required to generate an error * in this case." * - * These two paragraphs are either somewhat contradictory, or I - * don't fully understand one or both of them. - */ - /* FINISHME: The code as currently written does not support - * FINISHME: attribute location aliasing (see comment above). + * From GLSL 4.30 spec, page 54: + * + * "A program will fail to link if any two non-vertex shader + * input variables are assigned to the same location. For + * vertex shaders, multiple input variables may be assigned + * to the same location using either layout qualifiers or via + * the OpenGL API. However, such aliasing is intended only to + * support vertex shaders where each execution path accesses + * at most one input per each location. Implementations are + * permitted, but not required, to generate link-time errors + * if they detect that every path through the vertex shader + * executable accesses multiple inputs assigned to any single + * location. For all shader types, a program will fail to link + * if explicit location assignments leave the linker unable + * to find space for other variables without explicit + * assignments." + * + * From OpenGL ES 3.0 spec, page 56: + * + * "Binding more than one attribute name to the same location + * is referred to as aliasing, and is not permitted in OpenGL + * ES Shading Language 3.00 vertex shaders. LinkProgram will + * fail when this condition exists. However, aliasing is + * possible in OpenGL ES Shading Language 1.00 vertex shaders. + * This will only work if only one of the aliased attributes + * is active in the executable program, or if no path through + * the shader consumes more than one attribute of a set of + * attributes aliased to the same location. A link error can + * occur if the linker determines that every path through the + * shader consumes multiple aliased attributes, but implemen- + * tations are not required to generate an error in this case." + * + * After looking at above references from OpenGL, OpenGL ES and + * GLSL specifications, we allow aliasing of vertex input variables + * in: OpenGL 2.0 (and above) and OpenGL ES 2.0. + * + * NOTE: This is not required by the spec but its worth mentioning + * here that we're not doing anything to make sure that no path + * through the vertex shader executable accesses multiple inputs + * assigned to any single location. */ + /* Mask representing the contiguous slots that will be used by * this attribute. */ const unsigned attr = var->data.location - generic_base; const unsigned use_mask = (1 << slots) - 1; + const char *const string = (target_index == MESA_SHADER_VERTEX) + ? "vertex shader input" : "fragment shader output"; + + /* Generate a link error if the requested locations for this + * attribute exceed the maximum allowed attribute location. + */ + if (attr + slots > max_index) { + linker_error(prog, + "insufficient contiguous locations " + "available for %s `%s' %d %d %d", string, + var->name, used_locations, use_mask, attr); + return false; + } /* Generate a link error if the set of bits requested for this * attribute overlaps any previously allocated bits. */ if ((~(use_mask << attr) & used_locations) != used_locations) { - const char *const string = (target_index == MESA_SHADER_VERTEX) - ? "vertex shader input" : "fragment shader output"; - linker_error(prog, - "insufficient contiguous locations " - "available for %s `%s' %d %d %d", string, - var->name, used_locations, use_mask, attr); - return false; + if (target_index == MESA_SHADER_FRAGMENT || + (prog->IsES && prog->Version >= 300)) { + linker_error(prog, + "overlapping location is assigned " + "to %s `%s' %d %d %d\n", string, + var->name, used_locations, use_mask, attr); + return false; + } else { + linker_warning(prog, + "overlapping location is assigned " + "to %s `%s' %d %d %d\n", string, + var->name, used_locations, use_mask, attr); + } } used_locations |= (use_mask << attr); @@ -2115,6 +2250,7 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog) ralloc_free(prog->AtomicBuffers); prog->AtomicBuffers = NULL; prog->NumAtomicBuffers = 0; + prog->ARB_fragment_coord_conventions_enable = false; /* Separate the shaders into groups based on their type. */ @@ -2141,6 +2277,9 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog) goto done; } + prog->ARB_fragment_coord_conventions_enable |= + prog->Shaders[i]->ARB_fragment_coord_conventions_enable; + gl_shader_stage shader_type = prog->Shaders[i]->Stage; shader_list[shader_type][num_shaders[shader_type]] = prog->Shaders[i]; num_shaders[shader_type]++; @@ -2161,7 +2300,8 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog) /* Geometry shaders have to be linked with vertex shaders. */ if (num_shaders[MESA_SHADER_GEOMETRY] > 0 && - num_shaders[MESA_SHADER_VERTEX] == 0) { + num_shaders[MESA_SHADER_VERTEX] == 0 && + !prog->SeparateShader) { linker_error(prog, "Geometry shader must be linked with " "vertex shader\n"); goto done; @@ -2363,7 +2503,7 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog) if (last >= 0 && last < MESA_SHADER_FRAGMENT) { gl_shader *const sh = prog->_LinkedShaders[last]; - if (num_tfeedback_decls != 0) { + if (num_tfeedback_decls != 0 || prog->SeparateShader) { /* There was no fragment shader, but we still have to assign varying * locations for use by transform feedback. */ @@ -2377,7 +2517,8 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog) do_dead_builtin_varyings(ctx, sh, NULL, num_tfeedback_decls, tfeedback_decls); - demote_shader_inputs_and_outputs(sh, ir_var_shader_out); + if (!prog->SeparateShader) + demote_shader_inputs_and_outputs(sh, ir_var_shader_out); /* Eliminate code that is now dead due to unused outputs being demoted. */ @@ -2392,7 +2533,16 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog) do_dead_builtin_varyings(ctx, NULL, sh, num_tfeedback_decls, tfeedback_decls); - demote_shader_inputs_and_outputs(sh, ir_var_shader_in); + if (prog->SeparateShader) { + if (!assign_varying_locations(ctx, mem_ctx, prog, + NULL /* producer */, + sh /* consumer */, + 0 /* num_tfeedback_decls */, + NULL /* tfeedback_decls */, + 0 /* gs_input_vertices */)) + goto done; + } else + demote_shader_inputs_and_outputs(sh, ir_var_shader_in); while (do_dead_code(sh->ir, false)) ; @@ -2457,7 +2607,7 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog) * fragment shader) is absent. So, the extension shouldn't change the * behavior specified in GLSL specification. */ - if (!prog->InternalSeparateShader && ctx->API == API_OPENGLES2) { + if (!prog->SeparateShader && ctx->API == API_OPENGLES2) { if (prog->_LinkedShaders[MESA_SHADER_VERTEX] == NULL) { linker_error(prog, "program lacks a vertex shader\n"); } else if (prog->_LinkedShaders[MESA_SHADER_FRAGMENT] == NULL) { |