Give external linkage and mangling to lambdas inside inline variables and variable templates.

This implements the proposed approach in https://github.com/itanium-cxx-abi/cxx-abi/issues/33

This reinstates r313827, reverted in r313856, with a fix for the 'out-of-bounds
enumeration value' ubsan error in that change.

llvm-svn: 313955

1 files changed, 7 insertions, 1 deletions

diff --git a/clang/lib/AST/ItaniumMangle.cpp b/clang/lib/AST/ItaniumMangle.cpp
index a9c5ab2cc1dc..ef54ad5ec852 100644
--- a/clang/lib/AST/ItaniumMangle.cpp
+++ b/clang/lib/AST/ItaniumMangle.cpp
@@ -1691,10 +1691,16 @@ void CXXNameMangler::mangleLambda(const CXXRecordDecl *Lambda) {
   // to emit that last part of the prefix here.
   if (Decl *Context = Lambda->getLambdaContextDecl()) {
     if ((isa<VarDecl>(Context) || isa<FieldDecl>(Context)) &&
-        Context->getDeclContext()->isRecord()) {
+        !isa<ParmVarDecl>(Context)) {
+      // FIXME: 'inline auto [a, b] = []{ return ... };' does not get a
+      // reasonable mangling here.
       if (const IdentifierInfo *Name
             = cast<NamedDecl>(Context)->getIdentifier()) {
         mangleSourceName(Name);
+        const TemplateArgumentList *TemplateArgs = nullptr;
+        if (const TemplateDecl *TD =
+                isTemplate(cast<NamedDecl>(Context), TemplateArgs))
+          mangleTemplateArgs(*TemplateArgs);
         Out << 'M';
       }
     }