Restore flatten invariant behavior

src/compiler/translator/Compiler.cpp

@@ -364,8 +364,8 @@ TIntermBlock *TCompiler::compileTreeImpl(const char *const shaderStrings[],
         ++firstSource;
     }
 
-    TParseContext parseContext(mSymbolTable, mExtensionBehavior, mShaderType, mShaderSpec, true,
-                               &mDiagnostics, getResources());
+    TParseContext parseContext(mSymbolTable, mExtensionBehavior, mShaderType, mShaderSpec,
+                               compileOptions, true, &mDiagnostics, getResources());
 
     parseContext.setFragmentPrecisionHighOnESSL1(mResources.FragmentPrecisionHigh == 1);
 

src/compiler/translator/ParseContext.cpp

@@ -166,6 +166,7 @@ TParseContext::TParseContext(TSymbolTable &symt,
                              TExtensionBehavior &ext,
                              sh::GLenum type,
                              ShShaderSpec spec,
+                             ShCompileOptions options,
                              bool checksPrecErrors,
                              TDiagnostics *diagnostics,
                              const ShBuiltInResources &resources)
@@ -173,6 +174,7 @@ TParseContext::TParseContext(TSymbolTable &symt,
       mDeferredNonEmptyDeclarationErrorCheck(false),
       mShaderType(type),
       mShaderSpec(spec),
+      mCompileOptions(options),
       mShaderVersion(100),
       mTreeRoot(nullptr),
       mLoopNestingLevel(0),
@@ -2447,6 +2449,28 @@ TIntermDeclaration *TParseContext::parseSingleDeclaration(
     const ImmutableString &identifier)
 {
     TType *type = new TType(publicType);
+    if ((mCompileOptions & SH_FLATTEN_PRAGMA_STDGL_INVARIANT_ALL) &&
+        mDirectiveHandler.pragma().stdgl.invariantAll)
+    {
+        TQualifier qualifier = type->getQualifier();
+
+        // The directive handler has already taken care of rejecting invalid uses of this pragma
+        // (for example, in ESSL 3.00 fragment shaders), so at this point, flatten it into all
+        // affected variable declarations:
+        //
+        // 1. Built-in special variables which are inputs to the fragment shader. (These are handled
+        // elsewhere, in TranslatorGLSL.)
+        //
+        // 2. Outputs from vertex shaders in ESSL 1.00 and 3.00 (EvqVaryingOut and EvqVertexOut). It
+        // is actually less likely that there will be bugs in the handling of ESSL 3.00 shaders, but
+        // the way this is currently implemented we have to enable this compiler option before
+        // parsing the shader and determining the shading language version it uses. If this were
+        // implemented as a post-pass, the workaround could be more targeted.
+        if (qualifier == EvqVaryingOut || qualifier == EvqVertexOut)
+        {
+            type->setInvariant(true);
+        }
+    }
 
     checkGeometryShaderInputAndSetArraySize(identifierOrTypeLocation, identifier, type);
 

src/compiler/translator/ParseContext.h

@@ -37,6 +37,7 @@ class TParseContext : angle::NonCopyable
                   TExtensionBehavior &ext,
                   sh::GLenum type,
                   ShShaderSpec spec,
+                  ShCompileOptions options,
                   bool checksPrecErrors,
                   TDiagnostics *diagnostics,
                   const ShBuiltInResources &resources);
@@ -597,6 +598,7 @@ class TParseContext : angle::NonCopyable
 
     sh::GLenum mShaderType;    // vertex or fragment language (future: pack or unpack)
     ShShaderSpec mShaderSpec;  // The language specification compiler conforms to - GLES2 or WebGL.
+    ShCompileOptions mCompileOptions;  // Options passed to TCompiler
     int mShaderVersion;
     TIntermBlock *mTreeRoot;  // root of parse tree being created
     int mLoopNestingLevel;    // 0 if outside all loops