ShaderVars: add isSameInterfaceBlockFieldAtLinkTime

include/GLSLANG/ShaderLang.h

@@ -48,7 +48,7 @@ typedef unsigned int GLenum;
 
 // Version number for shader translation API.
 // It is incremented every time the API changes.
-#define ANGLE_SH_VERSION 146
+#define ANGLE_SH_VERSION 147
 
 typedef enum {
   SH_GLES2_SPEC = 0x8B40,

include/GLSLANG/ShaderVars.h

@@ -203,6 +203,9 @@ struct COMPILER_EXPORT InterfaceBlock
     // Fields from blocks with non-empty instance names are prefixed with the block name.
     std::string fieldPrefix() const;
 
+    // Decide whether two interface blocks are the same at shader link time.
+    bool isSameInterfaceBlockAtLinkTime(const InterfaceBlock &other) const;
+
     std::string name;
     std::string mappedName;
     std::string instanceName;

src/compiler/translator/ShaderVars.cpp

@@ -355,7 +355,7 @@ bool Varying::isSameVaryingAtLinkTime(const Varying &other) const
 bool Varying::isSameVaryingAtLinkTime(const Varying &other, int shaderVersion) const
 {
     return (ShaderVariable::isSameVariableAtLinkTime(other, false) &&
-            interpolation == other.interpolation &&
+            InterpolationTypesMatch(interpolation, other.interpolation) &&
             (shaderVersion >= 300 || isInvariant == other.isInvariant));
 }
 
@@ -398,4 +398,24 @@ std::string InterfaceBlock::fieldPrefix() const
     return instanceName.empty() ? "" : name;
 }
 
+bool InterfaceBlock::isSameInterfaceBlockAtLinkTime(const InterfaceBlock &other) const
+{
+    if (name != other.name || mappedName != other.mappedName || arraySize != other.arraySize ||
+        layout != other.layout || isRowMajorLayout != other.isRowMajorLayout ||
+        fields.size() != other.fields.size())
+    {
+        return false;
+    }
+
+    for (size_t fieldIndex = 0; fieldIndex < fields.size(); ++fieldIndex)
+    {
+        if (!fields[fieldIndex].isSameInterfaceBlockFieldAtLinkTime(other.fields[fieldIndex]))
+        {
+            return false;
+        }
+    }
+
+    return true;
+}
+
 }  // namespace sh