[clang-repl] Fix RuntimeInterfaceBuilder for 32-bit systems

[weliveindetail]

When generating runtime interface bindings, extend integral types to the native register size rather than 64-bit per se

[llvmbot]

@llvm/pr-subscribers-clang

Author: Stefan Gränitz (weliveindetail)

Changes

When generating runtime interface bindings, extend integral types to the native register size rather than 64-bit per se

---

Full diff: https://github.com/llvm/llvm-project/pull/97071.diff

1 Files Affected:

• (modified) clang/lib/Interpreter/Interpreter.cpp (+5-3)

diff --git a/clang/lib/Interpreter/Interpreter.cpp b/clang/lib/Interpreter/Interpreter.cpp
index 7a95278914276..e6d6ab6024bb8 100644
--- a/clang/lib/Interpreter/Interpreter.cpp
+++ b/clang/lib/Interpreter/Interpreter.cpp
@@ -673,10 +673,12 @@ class InterfaceKindVisitor
   }
 
 private:
-  // Force cast these types to uint64 to reduce the number of overloads of
-  // `__clang_Interpreter_SetValueNoAlloc`.
+  // Force cast these types to the uint that fits the register size. That way we
+  // reduce the number of overloads of `__clang_Interpreter_SetValueNoAlloc`.
   void HandleIntegralOrEnumType(const Type *Ty) {
-    TypeSourceInfo *TSI = Ctx.getTrivialTypeSourceInfo(Ctx.UnsignedLongLongTy);
+    uint64_t PtrBits = Ctx.getTypeSize(Ctx.VoidPtrTy);
+    QualType UIntTy = Ctx.getBitIntType(true, PtrBits);
+    TypeSourceInfo *TSI = Ctx.getTrivialTypeSourceInfo(UIntTy);
     ExprResult CastedExpr =
         S.BuildCStyleCastExpr(SourceLocation(), TSI, SourceLocation(), E);
     assert(!CastedExpr.isInvalid() && "Cannot create cstyle cast expr");

[vgvassilev]

Oh, that's a good catch. Any chance of adding a test case? Maybe something like:

enum X : short {...}?

[weliveindetail]

Any chance of adding a test case?

We could add a lot more tests in general, but I don't think this specific detail requires a dedicated one. It's a fix for an existing bug, so we have coverage already.

[vgvassilev]

LGTM!

[eymay]

Great work, I can imagine how hard it would be to uncover it!

Small note: I think you may also want to remove the Arm macro guards that mask the unittest in the same commit, as you did in the previous PR

[DavidSpickett]

Also remove the comment that links to #94994 and add Fixes #94994 to the commit message.

I checked locally, the test now passes.