fix horrible assumptions in clang codegen

Author: jacobly0

clang/include/clang/Basic/TargetInfo.h

@@ -429,6 +429,11 @@ class TargetInfo : public virtual TransferrableTargetInfo,
     return PointerWidth;
   }
 
+  /// Return the maximum width of pointers on this target.
+  virtual uint64_t getMaxPointerAlign() const {
+    return PointerAlign;
+  }
+
   /// Get integer value for null pointer.
   /// \param AddrSpace address space of pointee in source language.
   virtual uint64_t getNullPointerValue(LangAS AddrSpace) const { return 0; }

clang/lib/CodeGen/CodeGenModule.cpp

@@ -121,8 +121,14 @@ CodeGenModule::CodeGenModule(ASTContext &C, const HeaderSearchOptions &HSO,
   PointerWidthInBits = C.getTargetInfo().getPointerWidth(0);
   PointerAlignInBytes =
     C.toCharUnitsFromBits(C.getTargetInfo().getPointerAlign(0)).getQuantity();
+  PointerSizeInBytes =
+    C.toCharUnitsFromBits(C.getTargetInfo().getPointerWidth(0)).getQuantity();
   SizeSizeInBytes =
     C.toCharUnitsFromBits(C.getTargetInfo().getMaxPointerWidth()).getQuantity();
+  SizeAlignInBytes =
+    C.toCharUnitsFromBits(C.getTargetInfo().getMaxPointerAlign()).getQuantity();
+  IntSizeInBytes =
+    C.toCharUnitsFromBits(C.getTargetInfo().getIntWidth()).getQuantity();
   IntAlignInBytes =
     C.toCharUnitsFromBits(C.getTargetInfo().getIntAlign()).getQuantity();
   CharTy =

clang/lib/CodeGen/CodeGenTypeCache.h

@@ -77,10 +77,8 @@ struct CodeGenTypeCache {
 
   /// The size and alignment of the builtin C type 'int'.  This comes
   /// up enough in various ABI lowering tasks to be worth pre-computing.
-  union {
-    unsigned char IntSizeInBytes;
-    unsigned char IntAlignInBytes;
-  };
+  unsigned char IntSizeInBytes;
+  unsigned char IntAlignInBytes;
   CharUnits getIntSize() const {
     return CharUnits::fromQuantity(IntSizeInBytes);
   }
@@ -92,16 +90,12 @@ struct CodeGenTypeCache {
   unsigned char PointerWidthInBits;
 
   /// The size and alignment of a pointer into the generic address space.
-  union {
-    unsigned char PointerAlignInBytes;
-    unsigned char PointerSizeInBytes;
-  };
+  unsigned char PointerAlignInBytes;
+  unsigned char PointerSizeInBytes;
 
   /// The size and alignment of size_t.
-  union {
-    unsigned char SizeSizeInBytes; // sizeof(size_t)
-    unsigned char SizeAlignInBytes;
-  };
+  unsigned char SizeSizeInBytes; // sizeof(size_t)
+  unsigned char SizeAlignInBytes;
 
   LangAS ASTAllocaAddressSpace;