Verify that clang's max alignment is <= LLVM's max alignment

davezarzycki · davezarzycki · commit 0d61cd25a692 · 2020-01-24T12:37:05.000-05:00
Reviewers: lebedev.ri Reviewed By: lebedev.ri Subscribers: cfe-commits Tags: #llvm, #clang Differential Revision: https://reviews.llvm.org/D73363
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
@@ -372,16 +372,17 @@ class Sema final {
                                       QualType ResultTy,
                                       ArrayRef<QualType> Args);
 
+public:
   /// The maximum alignment, same as in llvm::Value. We duplicate them here
   /// because that allows us not to duplicate the constants in clang code,
   /// which we must to since we can't directly use the llvm constants.
+  /// The value is verified against llvm here: lib/CodeGen/CGValue.h
   ///
   /// This is the greatest alignment value supported by load, store, and alloca
   /// instructions, and global values.
   static const unsigned MaxAlignmentExponent = 29;
   static const unsigned MaximumAlignment = 1u << MaxAlignmentExponent;
 
-public:
   typedef OpaquePtr<DeclGroupRef> DeclGroupPtrTy;
   typedef OpaquePtr<TemplateName> TemplateTy;
   typedef OpaquePtr<QualType> TypeTy;
diff --git a/clang/lib/CodeGen/CGValue.h b/clang/lib/CodeGen/CGValue.h
@@ -15,12 +15,16 @@
 #define LLVM_CLANG_LIB_CODEGEN_CGVALUE_H
 
 #include "clang/AST/ASTContext.h"
+#include "clang/Sema/Sema.h"
 #include "clang/AST/Type.h"
 #include "llvm/IR/Value.h"
 #include "llvm/IR/Type.h"
 #include "Address.h"
 #include "CodeGenTBAA.h"
 
+static_assert(clang::Sema::MaximumAlignment <= llvm::Value::MaximumAlignment,
+              "Clang max alignment greater than what LLVM supports?");
+
 namespace llvm {
   class Constant;
   class MDNode;
