r222471 - PR21565: Further refine the conditions for enabling eager parsing of
Richard Smith
richard-llvm at metafoo.co.uk
Thu Nov 20 14:32:11 PST 2014
Author: rsmith
Date: Thu Nov 20 16:32:11 2014
New Revision: 222471
URL: http://llvm.org/viewvc/llvm-project?rev=222471&view=rev
Log:
PR21565: Further refine the conditions for enabling eager parsing of
std::X::swap exception specifications (allowing parsing of non-conforming code
in libstdc++). The old conditions also matched the functions in MSVC's STL,
which were relying on deferred parsing here.
Modified:
cfe/trunk/lib/Parse/ParseCXXInlineMethods.cpp
cfe/trunk/lib/Parse/ParseDecl.cpp
cfe/trunk/test/SemaCXX/libstdcxx_pair_swap_hack.cpp
Modified: cfe/trunk/lib/Parse/ParseCXXInlineMethods.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Parse/ParseCXXInlineMethods.cpp?rev=222471&r1=222470&r2=222471&view=diff
==============================================================================
--- cfe/trunk/lib/Parse/ParseCXXInlineMethods.cpp (original)
+++ cfe/trunk/lib/Parse/ParseCXXInlineMethods.cpp Thu Nov 20 16:32:11 2014
@@ -416,13 +416,12 @@ void Parser::ParseLexedMethodDeclaration
Diag(Tok.getLocation(), diag::err_except_spec_unparsed);
// Attach the exception-specification to the method.
- if (EST != EST_None)
- Actions.actOnDelayedExceptionSpecification(LM.Method, EST,
- SpecificationRange,
- DynamicExceptions,
- DynamicExceptionRanges,
- NoexceptExpr.isUsable()?
- NoexceptExpr.get() : nullptr);
+ Actions.actOnDelayedExceptionSpecification(LM.Method, EST,
+ SpecificationRange,
+ DynamicExceptions,
+ DynamicExceptionRanges,
+ NoexceptExpr.isUsable()?
+ NoexceptExpr.get() : nullptr);
assert(!PP.getSourceManager().isBeforeInTranslationUnit(origLoc,
Tok.getLocation()) &&
Modified: cfe/trunk/lib/Parse/ParseDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Parse/ParseDecl.cpp?rev=222471&r1=222470&r2=222471&view=diff
==============================================================================
--- cfe/trunk/lib/Parse/ParseDecl.cpp (original)
+++ cfe/trunk/lib/Parse/ParseDecl.cpp Thu Nov 20 16:32:11 2014
@@ -5282,8 +5282,24 @@ void Parser::ParseFunctionDeclarator(Dec
// Parse exception-specification[opt].
bool Delayed = D.isFirstDeclarationOfMember() &&
- D.isFunctionDeclaratorAFunctionDeclaration() &&
- !Actions.isLibstdcxxEagerExceptionSpecHack(D);
+ D.isFunctionDeclaratorAFunctionDeclaration();
+ if (Delayed && Actions.isLibstdcxxEagerExceptionSpecHack(D) &&
+ GetLookAheadToken(0).is(tok::kw_noexcept) &&
+ GetLookAheadToken(1).is(tok::l_paren) &&
+ GetLookAheadToken(2).is(tok::kw_noexcept) &&
+ GetLookAheadToken(3).is(tok::l_paren) &&
+ GetLookAheadToken(4).is(tok::identifier) &&
+ GetLookAheadToken(4).getIdentifierInfo()->isStr("swap")) {
+ // HACK: We've got an exception-specification
+ // noexcept(noexcept(swap(...)))
+ // or
+ // noexcept(noexcept(swap(...)) && noexcept(swap(...)))
+ // on a 'swap' member function. This is a libstdc++ bug; the lookup
+ // for 'swap' will only find the function we're currently declaring,
+ // whereas it expects to find a non-member swap through ADL. Turn off
+ // delayed parsing to give it a chance to find what it expects.
+ Delayed = false;
+ }
ESpecType = tryParseExceptionSpecification(Delayed,
ESpecRange,
DynamicExceptions,
Modified: cfe/trunk/test/SemaCXX/libstdcxx_pair_swap_hack.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/libstdcxx_pair_swap_hack.cpp?rev=222471&r1=222470&r2=222471&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/libstdcxx_pair_swap_hack.cpp (original)
+++ cfe/trunk/test/SemaCXX/libstdcxx_pair_swap_hack.cpp Thu Nov 20 16:32:11 2014
@@ -1,20 +1,47 @@
-// RUN: %clang_cc1 -fsyntax-only %s -std=c++11 -verify -fexceptions -fcxx-exceptions
-
// This is a test for an egregious hack in Clang that works around
// an issue with GCC's <utility> implementation. std::pair::swap
// has an exception specification that makes an unqualified call to
// swap. This is invalid, because it ends up calling itself with
// the wrong number of arguments.
+//
+// The same problem afflicts a bunch of other class templates. Those
+// affected are array, pair, priority_queue, stack, and queue.
+
+// RUN: %clang_cc1 -fsyntax-only %s -std=c++11 -verify -fexceptions -fcxx-exceptions -DCLASS=array
+// RUN: %clang_cc1 -fsyntax-only %s -std=c++11 -verify -fexceptions -fcxx-exceptions -DCLASS=pair
+// RUN: %clang_cc1 -fsyntax-only %s -std=c++11 -verify -fexceptions -fcxx-exceptions -DCLASS=priority_queue
+// RUN: %clang_cc1 -fsyntax-only %s -std=c++11 -verify -fexceptions -fcxx-exceptions -DCLASS=stack
+// RUN: %clang_cc1 -fsyntax-only %s -std=c++11 -verify -fexceptions -fcxx-exceptions -DCLASS=queue
+
+// MSVC's standard library uses a very similar pattern that relies on delayed
+// parsing of exception specifications.
+//
+// RUN: %clang_cc1 -fsyntax-only %s -std=c++11 -verify -fexceptions -fcxx-exceptions -DCLASS=array -DMSVC
#ifdef BE_THE_HEADER
#pragma GCC system_header
namespace std {
template<typename T> void swap(T &, T &);
-
- template<typename A, typename B> struct pair {
- void swap(pair &other) noexcept(noexcept(swap(*this, other)));
+ template<typename T> void do_swap(T &a, T &b) noexcept(noexcept(swap(a, b))) {
+ swap(a, b);
+ }
+
+ template<typename A, typename B> struct CLASS {
+#ifdef MSVC
+ void swap(CLASS &other) noexcept(noexcept(do_swap(member, other.member)));
+#endif
+ A member;
+#ifndef MSVC
+ void swap(CLASS &other) noexcept(noexcept(swap(member, other.member)));
+#endif
};
+
+// template<typename T> void do_swap(T &, T &);
+// template<typename A> struct vector {
+// void swap(vector &other) noexcept(noexcept(do_swap(member, other.member)));
+// A member;
+// };
}
#else
@@ -23,9 +50,9 @@ namespace std {
#include __FILE__
struct X {};
-using PX = std::pair<X, X>;
-using PI = std::pair<int, int>;
-void swap(PX &, PX &) noexcept;
+using PX = std::CLASS<X, X>;
+using PI = std::CLASS<int, int>;
+void swap(X &, X &) noexcept;
PX px;
PI pi;
@@ -35,11 +62,11 @@ static_assert(!noexcept(pi.swap(pi)), ""
namespace sad {
template<typename T> void swap(T &, T &);
- template<typename A, typename B> struct pair {
- void swap(pair &other) noexcept(noexcept(swap(*this, other))); // expected-error {{too many arguments}} expected-note {{declared here}}
+ template<typename A, typename B> struct CLASS {
+ void swap(CLASS &other) noexcept(noexcept(swap(*this, other))); // expected-error {{too many arguments}} expected-note {{declared here}}
};
- pair<int, int> pi;
+ CLASS<int, int> pi;
static_assert(!noexcept(pi.swap(pi)), ""); // expected-note {{in instantiation of}}
}
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