GLSL parser: Fix empty declaration qualifier checks

src/compiler/translator/ParseContext.h

@@ -136,9 +136,17 @@ class TParseContext : angle::NonCopyable
                                         const TTypeQualifierBuilder &typeQualifierBuilder,
                                         TType *type);
     bool checkCanUseExtension(const TSourceLoc &line, const TString &extension);
-    void singleDeclarationErrorCheck(const TPublicType &publicType,
-                                     const TSourceLoc &identifierLocation);
+
+    // Done for all declarations, whether empty or not.
+    void declarationQualifierErrorCheck(const sh::TQualifier qualifier,
+                                        const sh::TLayoutQualifier &layoutQualifier,
+                                        const TSourceLoc &location);
+    // Done for the first non-empty declarator in a declaration.
+    void nonEmptyDeclarationErrorCheck(const TPublicType &publicType,
+                                       const TSourceLoc &identifierLocation);
+    // Done only for empty declarations.
     void emptyDeclarationErrorCheck(const TPublicType &publicType, const TSourceLoc &location);
+
     void checkLayoutQualifierSupported(const TSourceLoc &location,
                                        const TString &layoutQualifierName,
                                        int versionRequired);
@@ -433,8 +441,10 @@ class TParseContext : angle::NonCopyable
                                                               const TSourceLoc &location,
                                                               bool insertParametersToSymbolTable);
 
-    // Set to true when the last/current declarator list was started with an empty declaration.
-    bool mDeferredSingleDeclarationErrorCheck;
+    // Set to true when the last/current declarator list was started with an empty declaration. The
+    // non-empty declaration error check will need to be performed if the empty declaration is
+    // followed by a declarator.
+    bool mDeferredNonEmptyDeclarationErrorCheck;
 
     sh::GLenum mShaderType;    // vertex or fragment language (future: pack or unpack)
     ShShaderSpec mShaderSpec;  // The language specification compiler conforms to - GLES2 or WebGL.

src/tests/compiler_tests/ShaderValidation_test.cpp

@@ -2345,6 +2345,22 @@ TEST_F(FragmentShaderValidationTest, InvariantNonOuput)
     }
 }
 
+// Invariant cannot be used with a non-output variable in ESSL3.
+// ESSL 3.00.6 section 4.8: This applies even if the declaration is empty.
+TEST_F(FragmentShaderValidationTest, InvariantNonOuputEmptyDeclaration)
+{
+    const std::string &shaderString =
+        "#version 300 es\n"
+        "precision mediump float;\n"
+        "invariant in float;\n"
+        "void main() {}\n";
+
+    if (compile(shaderString))
+    {
+        FAIL() << "Shader compilation succeeded, expecting failure:\n" << mInfoLog;
+    }
+}
+
 // Invariant declaration should follow the following format "invariant <out variable name>".
 // Test having an incorrect qualifier in the invariant declaration.
 TEST_F(FragmentShaderValidationTest, InvariantDeclarationWithStorageQualifier)
@@ -3729,3 +3745,20 @@ TEST_F(FragmentShaderValidationTest, ConstructStructContainingVoidArray)
         FAIL() << "Shader compilation succeeded, expecting failure " << mInfoLog;
     }
 }
+
+// Uniforms can't have location in ESSL 3.00.
+// Test this with an empty declaration (ESSL 3.00.6 section 4.8: The combinations of qualifiers that
+// cause compile-time or link-time errors are the same whether or not the declaration is empty).
+TEST_F(FragmentShaderValidationTest, UniformLocationEmptyDeclaration)
+{
+    const std::string &shaderString =
+        "#version 300 es\n"
+        "precision mediump float;\n"
+        "layout(location=0) uniform float;\n"
+        "void main() {}\n";
+
+    if (compile(shaderString))
+    {
+        FAIL() << "Shader compilation succeeded, expecting failure:\n" << mInfoLog;
+    }
+}