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.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@313955 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 37 insertions, 29 deletions

diff --git a/lib/Parse/ParseDecl.cpp b/lib/Parse/ParseDecl.cpp
index ad16d2c5bb..8bca7badea 100644
--- a/lib/Parse/ParseDecl.cpp
+++ b/lib/Parse/ParseDecl.cpp
@@ -2131,6 +2131,37 @@ Decl *Parser::ParseDeclarationAfterDeclarator(
 
 Decl *Parser::ParseDeclarationAfterDeclaratorAndAttributes(
     Declarator &D, const ParsedTemplateInfo &TemplateInfo, ForRangeInit *FRI) {
+  // RAII type used to track whether we're inside an initializer.
+  struct InitializerScopeRAII {
+    Parser &P;
+    Declarator &D;
+    Decl *ThisDecl;
+
+    InitializerScopeRAII(Parser &P, Declarator &D, Decl *ThisDecl)
+        : P(P), D(D), ThisDecl(ThisDecl) {
+      if (ThisDecl && P.getLangOpts().CPlusPlus) {
+        Scope *S = nullptr;
+        if (D.getCXXScopeSpec().isSet()) {
+          P.EnterScope(0);
+          S = P.getCurScope();
+        }
+        P.Actions.ActOnCXXEnterDeclInitializer(S, ThisDecl);
+      }
+    }
+    ~InitializerScopeRAII() { pop(); }
+    void pop() {
+      if (ThisDecl && P.getLangOpts().CPlusPlus) {
+        Scope *S = nullptr;
+        if (D.getCXXScopeSpec().isSet())
+          S = P.getCurScope();
+        P.Actions.ActOnCXXExitDeclInitializer(S, ThisDecl);
+        if (S)
+          P.ExitScope();
+      }
+      ThisDecl = nullptr;
+    }
+  };
+
   // Inform the current actions module that we just parsed this declarator.
   Decl *ThisDecl = nullptr;
   switch (TemplateInfo.Kind) {
@@ -2208,10 +2239,7 @@ Decl *Parser::ParseDeclarationAfterDeclaratorAndAttributes(
       else
         Diag(ConsumeToken(), diag::err_default_special_members);
     } else {
-      if (getLangOpts().CPlusPlus && D.getCXXScopeSpec().isSet()) {
-        EnterScope(0);
-        Actions.ActOnCXXEnterDeclInitializer(getCurScope(), ThisDecl);
-      }
+      InitializerScopeRAII InitScope(*this, D, ThisDecl);
 
       if (Tok.is(tok::code_completion)) {
         Actions.CodeCompleteInitializer(getCurScope(), ThisDecl);
@@ -2234,10 +2262,7 @@ Decl *Parser::ParseDeclarationAfterDeclaratorAndAttributes(
         FRI->RangeExpr = Init;
       }
 
-      if (getLangOpts().CPlusPlus && D.getCXXScopeSpec().isSet()) {
-        Actions.ActOnCXXExitDeclInitializer(getCurScope(), ThisDecl);
-        ExitScope();
-      }
+      InitScope.pop();
 
       if (Init.isInvalid()) {
         SmallVector<tok::TokenKind, 2> StopTokens;
@@ -2259,10 +2284,7 @@ Decl *Parser::ParseDeclarationAfterDeclaratorAndAttributes(
     ExprVector Exprs;
     CommaLocsTy CommaLocs;
 
-    if (getLangOpts().CPlusPlus && D.getCXXScopeSpec().isSet()) {
-      EnterScope(0);
-      Actions.ActOnCXXEnterDeclInitializer(getCurScope(), ThisDecl);
-    }
+    InitializerScopeRAII InitScope(*this, D, ThisDecl);
 
     llvm::function_ref<void()> ExprListCompleter;
     auto ThisVarDecl = dyn_cast_or_null<VarDecl>(ThisDecl);
@@ -2283,11 +2305,6 @@ Decl *Parser::ParseDeclarationAfterDeclaratorAndAttributes(
     if (ParseExpressionList(Exprs, CommaLocs, ExprListCompleter)) {
       Actions.ActOnInitializerError(ThisDecl);
       SkipUntil(tok::r_paren, StopAtSemi);
-
-      if (getLangOpts().CPlusPlus && D.getCXXScopeSpec().isSet()) {
-        Actions.ActOnCXXExitDeclInitializer(getCurScope(), ThisDecl);
-        ExitScope();
-      }
     } else {
       // Match the ')'.
       T.consumeClose();
@@ -2295,10 +2312,7 @@ Decl *Parser::ParseDeclarationAfterDeclaratorAndAttributes(
       assert(!Exprs.empty() && Exprs.size()-1 == CommaLocs.size() &&
              "Unexpected number of commas!");
 
-      if (getLangOpts().CPlusPlus && D.getCXXScopeSpec().isSet()) {
-        Actions.ActOnCXXExitDeclInitializer(getCurScope(), ThisDecl);
-        ExitScope();
-      }
+      InitScope.pop();
 
       ExprResult Initializer = Actions.ActOnParenListExpr(T.getOpenLocation(),
                                                           T.getCloseLocation(),
@@ -2311,17 +2325,11 @@ Decl *Parser::ParseDeclarationAfterDeclaratorAndAttributes(
     // Parse C++0x braced-init-list.
     Diag(Tok, diag::warn_cxx98_compat_generalized_initializer_lists);
 
-    if (D.getCXXScopeSpec().isSet()) {
-      EnterScope(0);
-      Actions.ActOnCXXEnterDeclInitializer(getCurScope(), ThisDecl);
-    }
+    InitializerScopeRAII InitScope(*this, D, ThisDecl);
 
     ExprResult Init(ParseBraceInitializer());
 
-    if (D.getCXXScopeSpec().isSet()) {
-      Actions.ActOnCXXExitDeclInitializer(getCurScope(), ThisDecl);
-      ExitScope();
-    }
+    InitScope.pop();
 
     if (Init.isInvalid()) {
       Actions.ActOnInitializerError(ThisDecl);