Check that texture offset is constant and valid

src/compiler/translator/Compiler.cpp

@@ -213,11 +213,9 @@ TIntermNode *TCompiler::compileTreeImpl(const char *const shaderStrings[],
         ++firstSource;
     }
 
-    bool debugShaderPrecision = getResources().WEBGL_debug_shader_precision == 1;
     TIntermediate intermediate(infoSink);
-    TParseContext parseContext(symbolTable, extensionBehavior, intermediate,
-                               shaderType, shaderSpec, compileOptions, true,
-                               infoSink, debugShaderPrecision);
+    TParseContext parseContext(symbolTable, extensionBehavior, intermediate, shaderType, shaderSpec,
+                               compileOptions, true, infoSink, getResources());
 
     parseContext.setFragmentPrecisionHighOnESSL1(fragmentPrecisionHigh);
     SetGlobalParseContext(&parseContext);

src/compiler/translator/ParseContext.cpp

@@ -3767,6 +3767,59 @@ TIntermBranch *TParseContext::addBranch(TOperator op,
     return intermediate.addBranch(op, returnValue, loc);
 }
 
+void TParseContext::checkTextureOffsetConst(TIntermAggregate *functionCall)
+{
+    ASSERT(!functionCall->isUserDefined());
+    const TString &name        = functionCall->getName();
+    TIntermNode *offset        = nullptr;
+    TIntermSequence *arguments = functionCall->getSequence();
+    if (name.compare(0, 16, "texelFetchOffset") == 0 ||
+        name.compare(0, 16, "textureLodOffset") == 0 ||
+        name.compare(0, 20, "textureProjLodOffset") == 0 ||
+        name.compare(0, 17, "textureGradOffset") == 0 ||
+        name.compare(0, 21, "textureProjGradOffset") == 0)
+    {
+        offset = arguments->back();
+    }
+    else if (name.compare(0, 13, "textureOffset") == 0 ||
+             name.compare(0, 17, "textureProjOffset") == 0)
+    {
+        // A bias parameter might follow the offset parameter.
+        ASSERT(arguments->size() >= 3);
+        offset = (*arguments)[2];
+    }
+    if (offset != nullptr)
+    {
+        TIntermConstantUnion *offsetConstantUnion = offset->getAsConstantUnion();
+        if (offset->getAsTyped()->getQualifier() != EvqConst || !offsetConstantUnion)
+        {
+            TString unmangledName = TFunction::unmangleName(name);
+            error(functionCall->getLine(), "Texture offset must be a constant expression",
+                  unmangledName.c_str());
+            recover();
+        }
+        else
+        {
+            ASSERT(offsetConstantUnion->getBasicType() == EbtInt);
+            size_t size                  = offsetConstantUnion->getType().getObjectSize();
+            const TConstantUnion *values = offsetConstantUnion->getUnionArrayPointer();
+            for (size_t i = 0u; i < size; ++i)
+            {
+                int offsetValue = values[i].getIConst();
+                if (offsetValue > mMaxProgramTexelOffset || offsetValue < mMinProgramTexelOffset)
+                {
+                    std::stringstream tokenStream;
+                    tokenStream << offsetValue;
+                    std::string token = tokenStream.str();
+                    error(offset->getLine(), "Texture offset value out of valid range",
+                          token.c_str());
+                    recover();
+                }
+            }
+        }
+    }
+}
+
 TIntermTyped *TParseContext::addFunctionCallOrMethod(TFunction *fnCall,
                                                      TIntermNode *paramNode,
                                                      TIntermNode *thisNode,
@@ -3935,8 +3988,12 @@ TIntermTyped *TParseContext::addFunctionCallOrMethod(TFunction *fnCall,
 
                 // This needs to happen after the name is set
                 if (builtIn)
+                {
                     aggregate->setBuiltInFunctionPrecision();
 
+                    checkTextureOffsetConst(aggregate);
+                }
+
                 callNode = aggregate;
 
                 functionCallLValueErrorCheck(fnCandidate, aggregate);

src/compiler/translator/ParseContext.h

@@ -36,7 +36,7 @@ class TParseContext : angle::NonCopyable
                   int options,
                   bool checksPrecErrors,
                   TInfoSink &is,
-                  bool debugShaderPrecisionSupported)
+                  const ShBuiltInResources &resources)
         : intermediate(interm),
           symbolTable(symt),
           mDeferredSingleDeclarationErrorCheck(false),
@@ -54,12 +54,17 @@ class TParseContext : angle::NonCopyable
           mDefaultMatrixPacking(EmpColumnMajor),
           mDefaultBlockStorage(EbsShared),
           mDiagnostics(is),
-          mDirectiveHandler(ext, mDiagnostics, mShaderVersion, debugShaderPrecisionSupported),
+          mDirectiveHandler(ext,
+                            mDiagnostics,
+                            mShaderVersion,
+                            resources.WEBGL_debug_shader_precision == 1),
           mPreprocessor(&mDiagnostics, &mDirectiveHandler),
           mScanner(nullptr),
           mUsesFragData(false),
           mUsesFragColor(false),
-          mUsesSecondaryOutputs(false)
+          mUsesSecondaryOutputs(false),
+          mMinProgramTexelOffset(resources.MinProgramTexelOffset),
+          mMaxProgramTexelOffset(resources.MaxProgramTexelOffset)
     {
     }
 
@@ -324,6 +329,7 @@ class TParseContext : angle::NonCopyable
     TIntermBranch *addBranch(TOperator op, const TSourceLoc &loc);
     TIntermBranch *addBranch(TOperator op, TIntermTyped *returnValue, const TSourceLoc &loc);
 
+    void checkTextureOffsetConst(TIntermAggregate *functionCall);
     TIntermTyped *addFunctionCallOrMethod(TFunction *fnCall,
                                           TIntermNode *paramNode,
                                           TIntermNode *thisNode,
@@ -381,6 +387,8 @@ class TParseContext : angle::NonCopyable
     bool mUsesFragColor;
     bool mUsesSecondaryOutputs;  // Track if we are using either gl_SecondaryFragData or
                                  // gl_Secondary FragColor or both.
+    int mMinProgramTexelOffset;
+    int mMaxProgramTexelOffset;
 };
 
 int PaParseStrings(

src/tests/compiler_tests/MalformedShader_test.cpp

@@ -1253,3 +1253,65 @@ TEST_F(MalformedWebGL2ShaderTest, IndexFragDataWithNonConstant)
         FAIL() << "Shader compilation succeeded, expecting failure " << mInfoLog;
     }
 }
+
+// Test that a non-constant texture offset is not accepted for textureOffset.
+// ESSL 3.00 section 8.8
+TEST_F(MalformedShaderTest, TextureOffsetNonConst)
+{
+    const std::string &shaderString =
+        "#version 300 es\n"
+        "precision mediump float;\n"
+        "out vec4 my_FragColor;\n"
+        "uniform vec3 u_texCoord;\n"
+        "uniform mediump sampler3D u_sampler;\n"
+        "uniform int x;\n"
+        "void main()\n"
+        "{\n"
+        "   my_FragColor = textureOffset(u_sampler, u_texCoord, ivec3(x, 3, -8));\n"
+        "}\n";
+    if (compile(shaderString))
+    {
+        FAIL() << "Shader compilation succeeded, expecting failure " << mInfoLog;
+    }
+}
+
+// Test that a non-constant texture offset is not accepted for textureProjOffset with bias.
+// ESSL 3.00 section 8.8
+TEST_F(MalformedShaderTest, TextureProjOffsetNonConst)
+{
+    const std::string &shaderString =
+        "#version 300 es\n"
+        "precision mediump float;\n"
+        "out vec4 my_FragColor;\n"
+        "uniform vec4 u_texCoord;\n"
+        "uniform mediump sampler3D u_sampler;\n"
+        "uniform int x;\n"
+        "void main()\n"
+        "{\n"
+        "   my_FragColor = textureProjOffset(u_sampler, u_texCoord, ivec3(x, 3, -8), 0.0);\n"
+        "}\n";
+    if (compile(shaderString))
+    {
+        FAIL() << "Shader compilation succeeded, expecting failure " << mInfoLog;
+    }
+}
+
+// Test that an out-of-range texture offset is not accepted.
+// GLES 3.0.4 section 3.8.10 specifies that out-of-range offset has undefined behavior.
+TEST_F(MalformedShaderTest, TextureLodOffsetOutOfRange)
+{
+    const std::string &shaderString =
+        "#version 300 es\n"
+        "precision mediump float;\n"
+        "out vec4 my_FragColor;\n"
+        "uniform vec3 u_texCoord;\n"
+        "uniform mediump sampler3D u_sampler;\n"
+        "void main()\n"
+        "{\n"
+        "   my_FragColor = textureLodOffset(u_sampler, u_texCoord, 0.0, ivec3(0, 0, 8));\n"
+        "}\n";
+    if (compile(shaderString))
+    {
+        FAIL() << "Shader compilation succeeded, expecting failure " << mInfoLog;
+    }
+}