Uniforms and attributes name conflicts should cause link failure

BUG=286538
TEST=gpu_unittests, webgl conformance tests

Review URL: https://chromiumcodereview.appspot.com/23819037

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@222128 0039d316-1c4b-4281-b951-d872f2087c98

gpu/command_buffer/service/program_manager.cc

@@ -558,6 +558,10 @@ bool Program::Link(ShaderManager* manager,
                  "declared in vertex shader");
     return false;
   }
+  if (DetectGlobalNameConflicts()) {
+    set_log_info("Name conflicts between an uniform and an attribute");
+    return false;
+  }
   if (!CheckVaryingsPacking()) {
     set_log_info("Varyings over maximum register limit");
     return false;
@@ -1072,6 +1076,27 @@ bool Program::DetectVaryingsMismatch() const {
   return false;
 }
 
+bool Program::DetectGlobalNameConflicts() const {
+  DCHECK(attached_shaders_[0] &&
+         attached_shaders_[0]->shader_type() == GL_VERTEX_SHADER &&
+         attached_shaders_[1] &&
+         attached_shaders_[1]->shader_type() == GL_FRAGMENT_SHADER);
+  const ShaderTranslator::VariableMap* uniforms[2];
+  uniforms[0] = &(attached_shaders_[0]->uniform_map());
+  uniforms[1] = &(attached_shaders_[1]->uniform_map());
+  const ShaderTranslator::VariableMap* attribs =
+      &(attached_shaders_[0]->attrib_map());
+
+  for (ShaderTranslator::VariableMap::const_iterator iter =
+           attribs->begin(); iter != attribs->end(); ++iter) {
+    for (int ii = 0; ii < 2; ++ii) {
+      if (uniforms[ii]->find(iter->first) != uniforms[ii]->end())
+        return true;
+    }
+  }
+  return false;
+}
+
 bool Program::CheckVaryingsPacking() const {
   DCHECK(attached_shaders_[0] &&
          attached_shaders_[0]->shader_type() == GL_VERTEX_SHADER &&

gpu/command_buffer/service/program_manager.h

@@ -195,6 +195,9 @@ class GPU_EXPORT Program : public base::RefCounted<Program> {
   // is not declared in vertex shader.
   bool DetectVaryingsMismatch() const;
 
+  // Return true if an uniform and an attribute share the same name.
+  bool DetectGlobalNameConflicts() const;
+
   // Return false if varyings can't be packed into the max available
   // varying registers.
   bool CheckVaryingsPacking() const;