When disambiguating an expression-statement from a declaraton-statement, if the
statement starts with an identifier for which name lookup will fail either way,
look at later tokens to disambiguate in order to improve error recovery.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@162464 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Parse/ParseTentative.cpp b/lib/Parse/ParseTentative.cpp
index 653f6c2..01ab0e4 100644
--- a/lib/Parse/ParseTentative.cpp
+++ b/lib/Parse/ParseTentative.cpp
@@ -104,16 +104,27 @@
// isCXXDeclarationSpecifier will return TPResult::Ambiguous() only in such
// a case.
- TPResult TPR = isCXXDeclarationSpecifier();
+ bool InvalidAsDeclaration = false;
+ TPResult TPR = isCXXDeclarationSpecifier(TPResult::False(),
+ &InvalidAsDeclaration);
if (TPR != TPResult::Ambiguous())
return TPR != TPResult::False(); // Returns true for TPResult::True() or
// TPResult::Error().
+ // FIXME: TryParseSimpleDeclaration doesn't look past the first initializer,
+ // and so gets some cases wrong. We can't carry on if we've already seen
+ // something which makes this statement invalid as a declaration in this case,
+ // since it can cause us to misparse valid code. Revisit this once
+ // TryParseInitDeclaratorList is fixed.
+ if (InvalidAsDeclaration)
+ return false;
+
// FIXME: Add statistics about the number of ambiguous statements encountered
// and how they were resolved (number of declarations+number of expressions).
- // Ok, we have a simple-type-specifier/typename-specifier followed by a '('.
- // We need tentative parsing...
+ // Ok, we have a simple-type-specifier/typename-specifier followed by a '(',
+ // or an identifier which doesn't resolve as anything. We need tentative
+ // parsing...
TentativeParsingAction PA(*this);
TPR = TryParseSimpleDeclaration(AllowForRangeDecl);
@@ -140,20 +151,28 @@
/// attribute-specifier-seqopt type-specifier-seq declarator
///
Parser::TPResult Parser::TryParseSimpleDeclaration(bool AllowForRangeDecl) {
- // We know that we have a simple-type-specifier/typename-specifier followed
- // by a '('.
- assert(isCXXDeclarationSpecifier() == TPResult::Ambiguous());
-
if (Tok.is(tok::kw_typeof))
TryParseTypeofSpecifier();
else {
+ if (Tok.is(tok::annot_cxxscope))
+ ConsumeToken();
ConsumeToken();
-
+
if (getLangOpts().ObjC1 && Tok.is(tok::less))
TryParseProtocolQualifiers();
}
-
- assert(Tok.is(tok::l_paren) && "Expected '('");
+
+ // Two decl-specifiers in a row conclusively disambiguate this as being a
+ // simple-declaration. Don't bother calling isCXXDeclarationSpecifier in the
+ // overwhelmingly common case that the next token is a '('.
+ if (Tok.isNot(tok::l_paren)) {
+ TPResult TPR = isCXXDeclarationSpecifier();
+ if (TPR == TPResult::Ambiguous())
+ return TPResult::True();
+ if (TPR == TPResult::True() || TPR == TPResult::Error())
+ return TPR;
+ assert(TPR == TPResult::False());
+ }
TPResult TPR = TryParseInitDeclaratorList();
if (TPR != TPResult::Ambiguous())