[clang] 8c98c88 - PR47176: Don't read from an inactive union member if a friend function

[Richard Smith via cfe-commits]

Author: Richard Smith
Date: 2020-09-24T19:02:27-07:00
New Revision: 8c98c8803430804010da06a07cfb291dab59067c

URL: https://github.com/llvm/llvm-project/commit/8c98c8803430804010da06a07cfb291dab59067c
DIFF: https://github.com/llvm/llvm-project/commit/8c98c8803430804010da06a07cfb291dab59067c.diff

LOG: PR47176: Don't read from an inactive union member if a friend function
has default arguments and an exception specification.

Added: 
    

Modified: 
    clang/include/clang/Parse/Parser.h
    clang/lib/Parse/ParseDecl.cpp
    clang/lib/Parse/ParseDeclCXX.cpp
    clang/test/Parser/cxx0x-decl.cpp

Removed: 
    


################################################################################
diff  --git a/clang/include/clang/Parse/Parser.h b/clang/include/clang/Parse/Parser.h
index 570f60fb9479..ee08cfc589e1 100644
--- a/clang/include/clang/Parse/Parser.h
+++ b/clang/include/clang/Parse/Parser.h
@@ -1367,7 +1367,7 @@ class Parser : public CodeCompletionHandler {
 
     void ParseLexedMethodDeclarations() override;
 
-    Parser* Self;
+    Parser *Self;
 
     /// Method - The method declaration.
     Decl *Method;

diff  --git a/clang/lib/Parse/ParseDecl.cpp b/clang/lib/Parse/ParseDecl.cpp
index d6b2eb8a9877..79628cfed1b2 100644
--- a/clang/lib/Parse/ParseDecl.cpp
+++ b/clang/lib/Parse/ParseDecl.cpp
@@ -6486,6 +6486,10 @@ void Parser::ParseFunctionDeclarator(Declarator &D,
       InitCXXThisScopeForDeclaratorIfRelevant(D, DS, ThisScope);
 
       // Parse exception-specification[opt].
+      // FIXME: Per [class.mem]p6, all exception-specifications at class scope
+      // should be delayed, including those for non-members (eg, friend
+      // declarations). But only applying this to member declarations is
+      // consistent with what other implementations do.
       bool Delayed = D.isFirstDeclarationOfMember() &&
                      D.isFunctionDeclaratorAFunctionDeclaration();
       if (Delayed && Actions.isLibstdcxxEagerExceptionSpecHack(D) &&

diff  --git a/clang/lib/Parse/ParseDeclCXX.cpp b/clang/lib/Parse/ParseDeclCXX.cpp
index 290b3c5df959..059d875d683d 100644
--- a/clang/lib/Parse/ParseDeclCXX.cpp
+++ b/clang/lib/Parse/ParseDeclCXX.cpp
@@ -2186,17 +2186,20 @@ void Parser::HandleMemberFunctionDeclDelays(Declarator& DeclaratorInfo,
     auto LateMethod = new LateParsedMethodDeclaration(this, ThisDecl);
     getCurrentClass().LateParsedDeclarations.push_back(LateMethod);
 
-    // Stash the exception-specification tokens in the late-pased method.
-    LateMethod->ExceptionSpecTokens = FTI.ExceptionSpecTokens;
-    FTI.ExceptionSpecTokens = nullptr;
-
-    // Push tokens for each parameter.  Those that do not have
-    // defaults will be NULL.
+    // Push tokens for each parameter. Those that do not have defaults will be
+    // NULL. We need to track all the parameters so that we can push them into
+    // scope for later parameters and perhaps for the exception specification.
     LateMethod->DefaultArgs.reserve(FTI.NumParams);
     for (unsigned ParamIdx = 0; ParamIdx < FTI.NumParams; ++ParamIdx)
       LateMethod->DefaultArgs.push_back(LateParsedDefaultArgument(
           FTI.Params[ParamIdx].Param,
           std::move(FTI.Params[ParamIdx].DefaultArgTokens)));
+
+    // Stash the exception-specification tokens in the late-pased method.
+    if (FTI.getExceptionSpecType() == EST_Unparsed) {
+      LateMethod->ExceptionSpecTokens = FTI.ExceptionSpecTokens;
+      FTI.ExceptionSpecTokens = nullptr;
+    }
   }
 }
 

diff  --git a/clang/test/Parser/cxx0x-decl.cpp b/clang/test/Parser/cxx0x-decl.cpp
index 4ddcb8ccfd0f..8be98d6ef299 100644
--- a/clang/test/Parser/cxx0x-decl.cpp
+++ b/clang/test/Parser/cxx0x-decl.cpp
@@ -199,6 +199,11 @@ namespace AliasDeclEndLocation {
   B something_else;
 }
 
+class PR47176 {
+  friend void f(PR47176, int = 0) noexcept(true) {}
+};
+static_assert(noexcept(f(PR47176())), "");
+
 struct Base { virtual void f() = 0; virtual void g() = 0; virtual void h() = 0; };
 struct MemberComponentOrder : Base {
   void f() override __asm__("foobar") __attribute__(( )) {}