Translator: Validate precision for function args

In fragment shaders, float does not have a default precision.  Any
declaration of this type must therefore specify the precision if a
default one is not provided.

This was not validated for function arguments.

Bug: chromium:1255089
Change-Id: I0d17e226ec88610692ec7dd18793cf4d471f12e7
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3226314
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Tim Van Patten <timvp@google.com>
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>

src/compiler/translator/ParseContext.cpp

@@ -3959,17 +3959,20 @@ TFunction *TParseContext::parseFunctionDeclarator(const TSourceLoc &location, TF
     for (size_t i = 0u; i < function->getParamCount(); ++i)
     {
         const TVariable *param = function->getParam(i);
-        if (param->getType().isStructSpecifier())
+        const TType &paramType = param->getType();
+
+        if (paramType.isStructSpecifier())
         {
             // ESSL 3.00.6 section 12.10.
             error(location, "Function parameter type cannot be a structure definition",
                   function->name());
         }
+
+        checkPrecisionSpecified(location, paramType.getPrecision(), paramType.getBasicType());
     }
 
     if (getShaderVersion() >= 300)
     {
-
         if (symbolTable.isUnmangledBuiltInName(function->name(), getShaderVersion(),
                                                extensionBehavior()))
         {

src/tests/compiler_tests/ShaderValidation_test.cpp

@@ -3334,6 +3334,25 @@ TEST_F(FragmentShaderValidationTest, FloatDeclarationNoQualifiersNoPrecision)
     }
 }
 
+// Precision must be specified for floats. Test this with a function argument no qualifiers.
+TEST_F(FragmentShaderValidationTest, FloatDeclarationNoQualifiersNoPrecisionFunctionArg)
+{
+    const std::string &shaderString = R"(
+int c(float x)
+{
+    return int(x);
+}
+void main()
+{
+    c(5.0);
+})";
+
+    if (compile(shaderString))
+    {
+        FAIL() << "Shader compilation succeeded, expecting failure:\n" << mInfoLog;
+    }
+}
+
 // Check compiler doesn't crash on incorrect unsized array declarations.
 TEST_F(FragmentShaderValidationTest, IncorrectUnsizedArray)
 {

src/tests/gl_tests/GLSLTest.cpp

@@ -4611,7 +4611,7 @@ layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;
 layout(binding = 0, r32f) uniform highp image2D image1[2][3];
 layout(binding = 6, r32f) uniform highp image2D image2;
 
-void testFunction(image2D imageOut[2][3])
+void testFunction(highp image2D imageOut[2][3])
 {
     // image1 is an array of 1x1 images.
     // image2 is a 1x4 image with the following data:
@@ -5079,8 +5079,8 @@ TEST_P(GLSLTest_ES31, ParameterArraysOfArraysSampler)
         "uniform mediump isampler2D test[2][3];\n"
         "const vec2 ZERO = vec2(0.0, 0.0);\n"
         "\n"
-        "bool check(isampler2D data[2][3]);\n"
-        "bool check(isampler2D data[2][3]) {\n"
+        "bool check(mediump isampler2D data[2][3]);\n"
+        "bool check(mediump isampler2D data[2][3]) {\n"
         "#define DO_CHECK(i,j) \\\n"
         "    if (texture(data[i][j], ZERO) != ivec4(i+1, j+1, 0, 1)) { \\\n"
         "        return false; \\\n"
@@ -5284,20 +5284,20 @@ TEST_P(GLSLTest_ES31, ParameterArrayArrayArraySampler)
         "uniform mediump isampler2D test2[4];\n"
         "const vec2 ZERO = vec2(0.0, 0.0);\n"
         "\n"
-        "bool check1D(isampler2D arr[4], int x, int y) {\n"
+        "bool check1D(mediump isampler2D arr[4], int x, int y) {\n"
         "    if (texture(arr[0], ZERO) != ivec4(x, y, 0, 0)+1) return false;\n"
         "    if (texture(arr[1], ZERO) != ivec4(x, y, 1, 0)+1) return false;\n"
         "    if (texture(arr[2], ZERO) != ivec4(x, y, 2, 0)+1) return false;\n"
         "    if (texture(arr[3], ZERO) != ivec4(x, y, 3, 0)+1) return false;\n"
         "    return true;\n"
         "}\n"
-        "bool check2D(isampler2D arr[3][4], int x) {\n"
+        "bool check2D(mediump isampler2D arr[3][4], int x) {\n"
         "    if (!check1D(arr[0], x, 0)) return false;\n"
         "    if (!check1D(arr[1], x, 1)) return false;\n"
         "    if (!check1D(arr[2], x, 2)) return false;\n"
         "    return true;\n"
         "}\n"
-        "bool check3D(isampler2D arr[2][3][4]) {\n"
+        "bool check3D(mediump isampler2D arr[2][3][4]) {\n"
         "    if (!check2D(arr[0], 0)) return false;\n"
         "    if (!check2D(arr[1], 1)) return false;\n"
         "    return true;\n"

src/tests/gl_tests/WEBGLVideoTextureTest.cpp

@@ -106,7 +106,7 @@ precision mediump float;
 varying mediump vec2 texCoord;
 uniform mediump samplerVideoWEBGL s;
 
-vec4 wrapTextureVideoWEBGL(samplerVideoWEBGL sampler, vec2 coord)
+vec4 wrapTextureVideoWEBGL(mediump samplerVideoWEBGL sampler, vec2 coord)
 {
     return textureVideoWEBGL(sampler, coord);
 }