[PATCH] D54055: CXXNameMangler::mangleFunctionParam: fix assertion

[JF Bastien via Phabricator via cfe-commits]

jfb created this revision.
jfb added a reviewer: rjmccall.
Herald added subscribers: cfe-commits, dexonsmith.
jfb added a comment.

I'm not sure this is the right fix because mangling confuses me. It fixes the assertion I'm encountering in my patch, and I don't think I can create a repro without the patch (since I'm asking to mangle a local in a way we don't seem to right now).


The assertion seemed to be trying to avoid subtracting from zero, but was missing a case. I have a patch which was trying to mangle a local (to promote to a global and keep a nice name to it), and it was triggering the assertion.


Repository:
  rC Clang

https://reviews.llvm.org/D54055

Files:
  lib/AST/ItaniumMangle.cpp


Index: lib/AST/ItaniumMangle.cpp
===================================================================
--- lib/AST/ItaniumMangle.cpp
+++ lib/AST/ItaniumMangle.cpp
@@ -4300,7 +4300,9 @@
   // Compute 'L'.
   // parmDepth does not include the declaring function prototype.
   // FunctionTypeDepth does account for that.
-  assert(parmDepth < FunctionTypeDepth.getDepth());
+  assert(parmDepth < FunctionTypeDepth.getDepth() ||
+         (parmDepth == FunctionTypeDepth.getDepth() &&
+          !FunctionTypeDepth.isInResultType()));
   unsigned nestingDepth = FunctionTypeDepth.getDepth() - parmDepth;
   if (FunctionTypeDepth.isInResultType())
     nestingDepth--;


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