[clang][bytecode] Use PredefinedExpr as base for its variable (llvm#111956)

This fixes the error message generated.

Author: tbaederr

clang/lib/AST/ByteCode/Compiler.cpp

@@ -2869,6 +2869,11 @@ bool Compiler<Emitter>::VisitPredefinedExpr(const PredefinedExpr *E) {
   if (DiscardResult)
     return true;
 
+  if (!Initializing) {
+    unsigned StringIndex = P.createGlobalString(E->getFunctionName(), E);
+    return this->emitGetPtrGlobal(StringIndex, E);
+  }
+
   return this->delegate(E->getFunctionName());
 }
 

clang/lib/AST/ByteCode/Program.cpp

@@ -33,7 +33,7 @@ const void *Program::getNativePointer(unsigned Idx) {
   return NativePointers[Idx];
 }
 
-unsigned Program::createGlobalString(const StringLiteral *S) {
+unsigned Program::createGlobalString(const StringLiteral *S, const Expr *Base) {
   const size_t CharWidth = S->getCharByteWidth();
   const size_t BitWidth = CharWidth * Ctx.getCharBit();
 
@@ -52,12 +52,15 @@ unsigned Program::createGlobalString(const StringLiteral *S) {
     llvm_unreachable("unsupported character width");
   }
 
+  if (!Base)
+    Base = S;
+
   // Create a descriptor for the string.
-  Descriptor *Desc =
-      allocateDescriptor(S, CharType, Descriptor::GlobalMD, S->getLength() + 1,
-                         /*isConst=*/true,
-                         /*isTemporary=*/false,
-                         /*isMutable=*/false);
+  Descriptor *Desc = allocateDescriptor(Base, CharType, Descriptor::GlobalMD,
+                                        S->getLength() + 1,
+                                        /*isConst=*/true,
+                                        /*isTemporary=*/false,
+                                        /*isMutable=*/false);
 
   // Allocate storage for the string.
   // The byte length does not include the null terminator.

clang/lib/AST/ByteCode/Program.h

@@ -64,7 +64,8 @@ class Program final {
   const void *getNativePointer(unsigned Idx);
 
   /// Emits a string literal among global data.
-  unsigned createGlobalString(const StringLiteral *S);
+  unsigned createGlobalString(const StringLiteral *S,
+                              const Expr *Base = nullptr);
 
   /// Returns a pointer to a global.
   Pointer getPtrGlobal(unsigned Idx) const;

clang/test/AST/ByteCode/cxx1z.cpp

@@ -13,3 +13,7 @@ namespace Temp {
 
 char arr[3];
 A<const char*, &arr[1]> d; // both-error {{refers to subobject '&arr[1]'}}
+
+void Func() {
+  A<const char*, __func__> a; // both-error {{pointer to subobject of predefined '__func__' variable}}
+}