Disallow multiple function prototypes in ESSL 1.00

src/compiler/translator/ParseContext.cpp

@@ -1928,6 +1928,20 @@ void TParseContext::parseGlobalLayoutQualifier(const TPublicType &typeQualifier)
 TIntermAggregate *TParseContext::addFunctionPrototypeDeclaration(const TFunction &function,
                                                                  const TSourceLoc &location)
 {
+    // Note: symbolTableFunction could be the same as function if this is the first declaration.
+    // Either way the instance in the symbol table is used to track whether the function is declared
+    // multiple times.
+    TFunction *symbolTableFunction =
+        static_cast<TFunction *>(symbolTable.find(function.getMangledName(), getShaderVersion()));
+    if (symbolTableFunction->hasPrototypeDeclaration() && mShaderVersion == 100)
+    {
+        // ESSL 1.00.17 section 4.2.7.
+        // Doesn't apply to ESSL 3.00.4: see section 4.2.3.
+        error(location, "duplicate function prototype declarations are not allowed", "function");
+        recover();
+    }
+    symbolTableFunction->setHasPrototypeDeclaration();
+
     TIntermAggregate *prototype = new TIntermAggregate;
     prototype->setType(function.getReturnType());
     prototype->setName(function.getMangledName());
@@ -2086,12 +2100,12 @@ void TParseContext::parseFunctionPrototype(const TSourceLoc &location,
 TFunction *TParseContext::parseFunctionDeclarator(const TSourceLoc &location, TFunction *function)
 {
     //
-    // Multiple declarations of the same function are allowed.
-    //
-    // If this is a definition, the definition production code will check for redefinitions
-    // (we don't know at this point if it's a definition or not).
+    // We don't know at this point whether this is a function definition or a prototype.
+    // The definition production code will check for redefinitions.
+    // In the case of ESSL 1.00 the prototype production code will also check for redeclarations.
     //
-    // Redeclarations are allowed.  But, return types and parameter qualifiers must match.
+    // Return types and parameter qualifiers must match in all redeclarations, so those are checked
+    // here.
     //
     TFunction *prevDec =
         static_cast<TFunction *>(symbolTable.find(function->getMangledName(), getShaderVersion()));

src/compiler/translator/SymbolTable.h

@@ -197,12 +197,16 @@ struct TParameter
 class TFunction : public TSymbol
 {
   public:
-    TFunction(const TString *name, const TType *retType, TOperator tOp = EOpNull, const char *ext = "")
+    TFunction(const TString *name,
+              const TType *retType,
+              TOperator tOp   = EOpNull,
+              const char *ext = "")
         : TSymbol(name),
           returnType(retType),
           mangledName(nullptr),
           op(tOp),
-          defined(false)
+          defined(false),
+          mHasPrototypeDeclaration(false)
     {
         relateToExtension(ext);
     }
@@ -242,14 +246,10 @@ class TFunction : public TSymbol
         return op;
     }
 
-    void setDefined()
-    {
-        defined = true;
-    }
-    bool isDefined()
-    {
-        return defined;
-    }
+    void setDefined() { defined = true; }
+    bool isDefined() { return defined; }
+    void setHasPrototypeDeclaration() { mHasPrototypeDeclaration = true; }
+    bool hasPrototypeDeclaration() const { return mHasPrototypeDeclaration; }
 
     size_t getParamCount() const
     {
@@ -269,6 +269,7 @@ class TFunction : public TSymbol
     mutable const TString *mangledName;
     TOperator op;
     bool defined;
+    bool mHasPrototypeDeclaration;
 };
 
 // Interface block name sub-symbol

src/tests/compiler_tests/MalformedShader_test.cpp

@@ -1454,3 +1454,43 @@ TEST_F(MalformedShaderTest, NonIntegerIndex)
         FAIL() << "Shader compilation succeeded, expecting failure " << mInfoLog;
     }
 }
+
+// ESSL1 shaders with a duplicate function prototype should be rejected.
+// ESSL 1.00.17 section 4.2.7.
+TEST_F(MalformedShaderTest, DuplicatePrototypeESSL1)
+{
+    const std::string &shaderString =
+        "precision mediump float;\n"
+        "void foo();\n"
+        "void foo();\n"
+        "void foo() {}\n"
+        "void main()\n"
+        "{\n"
+        "    gl_FragColor = vec4(0.0);\n"
+        "}\n";
+    if (compile(shaderString))
+    {
+        FAIL() << "Shader compilation succeeded, expecting failure " << mInfoLog;
+    }
+}
+
+// ESSL3 shaders with a duplicate function prototype should be allowed.
+// ESSL 3.00.4 section 4.2.3.
+TEST_F(MalformedShaderTest, DuplicatePrototypeESSL3)
+{
+    const std::string &shaderString =
+        "#version 300 es\n"
+        "precision mediump float;\n"
+        "out vec4 my_FragColor;\n"
+        "void foo();\n"
+        "void foo();\n"
+        "void foo() {}\n"
+        "void main()\n"
+        "{\n"
+        "    my_FragColor = vec4(0.0);\n"
+        "}\n";
+    if (!compile(shaderString))
+    {
+        FAIL() << "Shader compilation failed, expecting success " << mInfoLog;
+    }
+}

src/tests/deqp_support/deqp_gles2_test_expectations.txt

@@ -256,8 +256,6 @@
 989 WIN LINUX MAC : dEQP-GLES2.functional.shaders.preprocessor.extensions.after_non_preprocessing_tokens_fragment = FAIL
 1015 WIN LINUX MAC : dEQP-GLES2.functional.shaders.functions.invalid.return_array_in_struct_vertex = FAIL
 1015 WIN LINUX MAC : dEQP-GLES2.functional.shaders.functions.invalid.return_array_in_struct_fragment = FAIL
-996 WIN LINUX MAC : dEQP-GLES2.functional.shaders.functions.invalid.double_declare_vertex = FAIL
-996 WIN LINUX MAC : dEQP-GLES2.functional.shaders.functions.invalid.double_declare_fragment = FAIL
 1016 WIN LINUX MAC : dEQP-GLES2.functional.shaders.scoping.valid.local_variable_hides_function_parameter_vertex = FAIL
 1016 WIN LINUX MAC : dEQP-GLES2.functional.shaders.scoping.valid.local_variable_hides_function_parameter_fragment = FAIL
 1016 WIN LINUX MAC : dEQP-GLES2.functional.shaders.scoping.invalid.redeclare_function_vertex = FAIL