diff options
Diffstat (limited to 'src/glsl')
| -rw-r--r-- | src/glsl/linker.cpp | 37 |
1 files changed, 30 insertions, 7 deletions
diff --git a/src/glsl/linker.cpp b/src/glsl/linker.cpp index ec3cc01d40..fa4fb493f2 100644 --- a/src/glsl/linker.cpp +++ b/src/glsl/linker.cpp @@ -1061,7 +1061,8 @@ assign_attribute_locations(gl_shader_program *prog, unsigned max_attribute_index void -assign_varying_locations(gl_shader *producer, gl_shader *consumer) +assign_varying_locations(struct gl_shader_program *prog, + gl_shader *producer, gl_shader *consumer) { /* FINISHME: Set dynamically when geometry shader support is added. */ unsigned output_index = VERT_RESULT_VAR0; @@ -1128,11 +1129,32 @@ assign_varying_locations(gl_shader *producer, gl_shader *consumer) if ((var == NULL) || (var->mode != ir_var_in)) continue; - /* An 'in' variable is only really a shader input if its value is written - * by the previous stage. - */ - var->shader_in = (var->location != -1); - var->mode = ir_var_auto; + if (var->location == -1) { + if (prog->Version <= 120) { + /* On page 25 (page 31 of the PDF) of the GLSL 1.20 spec: + * + * Only those varying variables used (i.e. read) in + * the fragment shader executable must be written to + * by the vertex shader executable; declaring + * superfluous varying variables in a vertex shader is + * permissible. + * + * We interpret this text as meaning that the VS must + * write the variable for the FS to read it. See + * "glsl1-varying read but not written" in piglit. + */ + + linker_error_printf(prog, "fragment shader varying %s not written " + "by vertex shader\n.", var->name); + prog->LinkStatus = false; + } + + /* An 'in' variable is only really a shader input if its + * value is written by the previous stage. + */ + var->shader_in = false; + var->mode = ir_var_auto; + } } } @@ -1294,7 +1316,8 @@ link_shaders(struct gl_shader_program *prog) goto done; for (unsigned i = 1; i < prog->_NumLinkedShaders; i++) - assign_varying_locations(prog->_LinkedShaders[i - 1], + assign_varying_locations(prog, + prog->_LinkedShaders[i - 1], prog->_LinkedShaders[i]); /* FINISHME: Assign fragment shader output locations. */ |