From d9da6e9994507d48a41708a26d3e8494a538152c Mon Sep 17 00:00:00 2001 From: Reid Kleckner Date: Fri, 9 Dec 2016 21:10:43 +0000 Subject: [PATCH] Remove special error recovery for ::(id) The code pattern used to implement the token rewriting hack doesn't interact well with token caching in the pre-processor. As a result, clang would crash on 'int f(::(id));' while doing a tenative parse of the contents of the outer parentheses. The original code from PR11852 still doesn't crash the compiler. This error recovery also often does the wrong thing with member function pointers. The test case from the original PR doesn't recover the right way either: void S::(*pf)() = S::f; // should be 'void (S::*pf)()' Instead we were recovering as 'void S::*pf()', which is still wrong. If we still think that users mistakenly parenthesize identifiers in nested name specifiers, we should change clang to intentionally parse that form with an error, rather than doing a token rewrite. Fixes PR26623, but I think there will be many more bugs like this around token rewriting in the parser. Reviewers: rsmith, rtrieu Differential Revision: https://reviews.llvm.org/D25882 git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@289273 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/clang/Basic/DiagnosticParseKinds.td | 2 - include/clang/Parse/Parser.h | 2 - lib/Parse/ParseExprCXX.cpp | 46 --------------------- test/Parser/colon-colon-parentheses.cpp | 34 ++++++++------- 4 files changed, 20 insertions(+), 64 deletions(-) diff --git a/include/clang/Basic/DiagnosticParseKinds.td b/include/clang/Basic/DiagnosticParseKinds.td index ecebda9924..8aa3e1ccb3 100644 --- a/include/clang/Basic/DiagnosticParseKinds.td +++ b/include/clang/Basic/DiagnosticParseKinds.td @@ -347,8 +347,6 @@ def ext_c11_static_assert : Extension< def warn_cxx98_compat_static_assert : Warning< "static_assert declarations are incompatible with C++98">, InGroup, DefaultIgnore; -def err_paren_after_colon_colon : Error< - "unexpected parenthesis after '::'">; def err_function_definition_not_allowed : Error< "function definition is not allowed here">; def err_expected_end_of_enumerator : Error< diff --git a/include/clang/Parse/Parser.h b/include/clang/Parse/Parser.h index 40eb579be4..c956aaeffc 100644 --- a/include/clang/Parse/Parser.h +++ b/include/clang/Parse/Parser.h @@ -1530,8 +1530,6 @@ private: bool IsTypename = false, IdentifierInfo **LastII = nullptr); - void CheckForLParenAfterColonColon(); - //===--------------------------------------------------------------------===// // C++0x 5.1.2: Lambda expressions diff --git a/lib/Parse/ParseExprCXX.cpp b/lib/Parse/ParseExprCXX.cpp index cabc7b5266..3f335747a4 100644 --- a/lib/Parse/ParseExprCXX.cpp +++ b/lib/Parse/ParseExprCXX.cpp @@ -100,48 +100,6 @@ void Parser::CheckForTemplateAndDigraph(Token &Next, ParsedType ObjectType, /*AtDigraph*/false); } -/// \brief Emits an error for a left parentheses after a double colon. -/// -/// When a '(' is found after a '::', emit an error. Attempt to fix the token -/// stream by removing the '(', and the matching ')' if found. -void Parser::CheckForLParenAfterColonColon() { - if (!Tok.is(tok::l_paren)) - return; - - Token LParen = Tok; - Token NextTok = GetLookAheadToken(1); - Token StarTok = NextTok; - // Check for (identifier or (*identifier - Token IdentifierTok = StarTok.is(tok::star) ? GetLookAheadToken(2) : StarTok; - if (IdentifierTok.isNot(tok::identifier)) - return; - // Eat the '('. - ConsumeParen(); - Token RParen; - RParen.setLocation(SourceLocation()); - // Do we have a ')' ? - NextTok = StarTok.is(tok::star) ? GetLookAheadToken(2) : GetLookAheadToken(1); - if (NextTok.is(tok::r_paren)) { - RParen = NextTok; - // Eat the '*' if it is present. - if (StarTok.is(tok::star)) - ConsumeToken(); - // Eat the identifier. - ConsumeToken(); - // Add the identifier token back. - PP.EnterToken(IdentifierTok); - // Add the '*' back if it was present. - if (StarTok.is(tok::star)) - PP.EnterToken(StarTok); - // Eat the ')'. - ConsumeParen(); - } - - Diag(LParen.getLocation(), diag::err_paren_after_colon_colon) - << FixItHint::CreateRemoval(LParen.getLocation()) - << FixItHint::CreateRemoval(RParen.getLocation()); -} - /// \brief Parse global scope or nested-name-specifier if present. /// /// Parses a C++ global scope specifier ('::') or nested-name-specifier (which @@ -237,8 +195,6 @@ bool Parser::ParseOptionalCXXScopeSpecifier(CXXScopeSpec &SS, if (Actions.ActOnCXXGlobalScopeSpecifier(ConsumeToken(), SS)) return true; - CheckForLParenAfterColonColon(); - HasScopeSpecifier = true; } } @@ -491,8 +447,6 @@ bool Parser::ParseOptionalCXXScopeSpecifier(CXXScopeSpec &SS, Token ColonColon = Tok; SourceLocation CCLoc = ConsumeToken(); - CheckForLParenAfterColonColon(); - bool IsCorrectedToColon = false; bool *CorrectionFlagPtr = ColonIsSacred ? &IsCorrectedToColon : nullptr; if (Actions.ActOnCXXNestedNameSpecifier(getCurScope(), IdInfo, diff --git a/test/Parser/colon-colon-parentheses.cpp b/test/Parser/colon-colon-parentheses.cpp index b3db4fbed2..804e4f785e 100644 --- a/test/Parser/colon-colon-parentheses.cpp +++ b/test/Parser/colon-colon-parentheses.cpp @@ -1,30 +1,36 @@ -// RUN: %clang_cc1 %s -fsyntax-only -verify -DPR21815 -// RUN: cp %s %t -// RUN: not %clang_cc1 -x c++ -fixit %t -// RUN: %clang_cc1 -x c++ %t +// RUN: %clang_cc1 %s -verify -fno-spell-checking struct S { static int a,b,c;}; -int S::(a); // expected-error{{unexpected parenthesis after '::'}} -int S::(b; // expected-error{{unexpected parenthesis after '::'}} +int S::(a); // expected-error{{expected unqualified-id}} +int S::(b; // expected-error{{expected unqualified-id}} + ); int S::c; -int S::(*d); // expected-error{{unexpected parenthesis after '::'}} -int S::(*e; // expected-error{{unexpected parenthesis after '::'}} +int S::(*d); // expected-error{{expected unqualified-id}} +int S::(*e; // expected-error{{expected unqualified-id}} + ); int S::*f; -int g = S::(a); // expected-error{{unexpected parenthesis after '::'}} -int h = S::(b; // expected-error{{unexpected parenthesis after '::'}} +int g = S::(a); // expected-error {{expected unqualified-id}} expected-error {{use of undeclared identifier 'a'}} +int h = S::(b; // expected-error {{expected unqualified-id}} expected-error {{use of undeclared identifier 'b'}} + ); int i = S::c; void foo() { int a; - a = ::(g); // expected-error{{unexpected parenthesis after '::'}} - a = ::(h; // expected-error{{unexpected parenthesis after '::'}} + a = ::(g); // expected-error{{expected unqualified-id}} + a = ::(h; // expected-error{{expected unqualified-id}} a = ::i; } -#ifdef PR21815 +// The following tests used to be crash bugs. + +// PR21815 // expected-error@+2{{C++ requires a type specifier for all declarations}} // expected-error@+1{{expected unqualified-id}} a (::( )); ::((c )); // expected-error{{expected unqualified-id}} -#endif + +// PR26623 +int f1(::(B) p); // expected-error {{expected unqualified-id}} expected-error {{use of undeclared identifier 'B'}} + +int f2(::S::(C) p); // expected-error {{expected unqualified-id}} expected-error {{use of undeclared identifier 'C'}} -- 2.40.0