diff mbox

libstdc++/69386 Ensure C++ language linkage in cmath and cstdlib

Message ID 20160120123440.GO15084@redhat.com
State New
Headers show

Commit Message

Jonathan Wakely Jan. 20, 2016, 12:34 p.m. UTC 
On 19/01/16 21:43 +0000, Jonathan Wakely wrote:
>On 08/01/16 19:18 +0000, Jonathan Wakely wrote:
>>This resolves the longstanding issue that #include <math.h> uses the C
>>library header, which on most targets doesn't declare the additional
>>overloads required by C++11 26.8 [c.math], and similarly for
>><stdlib.h>.
>>
>>With this patch libstdc++ provides its own <math.h> and <stdlib.h>
>>wrappers, which are equivalent to <cmath> or <cstdlib> followed by
>>using-directives for all standard names. This means there are no more
>>inconsistencies in the contents of the <cxxx> and <xxx.h> headers.

The new wrappers might get included as:

extern "C" {
#include <stdlib.h>
}

which then includes <cstdlib> inside the extern "C" block, so we need
to ensure that the definitions in <cstdlib> get the right language
linkage.

Tested powerpc64le-linux, committed to trunk.

Comments

Jonathan Wakely Jan. 21, 2016, 1:39 p.m. UTC | #1 
On 20/01/16 12:34 +0000, Jonathan Wakely wrote:
>--- a/libstdc++-v3/include/c_global/ccomplex
>+++ b/libstdc++-v3/include/c_global/ccomplex
>@@ -35,6 +35,8 @@
> # include <bits/c++0x_warning.h>
> #endif
> 
>+extern "C++" {
> #include <complex>
>+}

P.S. I would have preferred not to do this around <complex> and add
the linkage specification inside <complex>, but that would also mean
adding it inside <sstream>, which includes the entire iostream
hierarchy and <string> and bits/stl_algobase.h and lots of other
headers. Maybe I'll clean that up in stage 1 but it's a big patch.
diff mbox

Patch

commit d5175d037f6d1a5951d3a023dca71bed16ec0434
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Wed Jan 20 11:41:47 2016 +0000

    Ensure C++ language linkage in cmath and cstdlib
    
    	PR libstdc++/69386
    	* include/c_global/ccomplex: Ensure C++ language linkage.
    	* include/c_global/cmath: Likewise.
    	* include/c_global/cstdlib: Likewise.
    	* include/c_global/ctgmath: Likewise.
    	* testsuite/17_intro/headers/c++2011/linkage.cc: New.

diff --git a/libstdc++-v3/include/c_global/ccomplex b/libstdc++-v3/include/c_global/ccomplex
index 8879e20..df2e413 100644
--- a/libstdc++-v3/include/c_global/ccomplex
+++ b/libstdc++-v3/include/c_global/ccomplex
@@ -35,6 +35,8 @@ 
 # include <bits/c++0x_warning.h>
 #endif
 
+extern "C++" {
 #include <complex>
+}
 
 #endif
diff --git a/libstdc++-v3/include/c_global/cmath b/libstdc++-v3/include/c_global/cmath
index 45e40ab3..c4ee3f5 100644
--- a/libstdc++-v3/include/c_global/cmath
+++ b/libstdc++-v3/include/c_global/cmath
@@ -74,6 +74,8 @@ 
 #undef tan
 #undef tanh
 
+extern "C++"
+{
 namespace std _GLIBCXX_VISIBILITY(default)
 {
 _GLIBCXX_BEGIN_NAMESPACE_VERSION
@@ -1790,4 +1792,6 @@  _GLIBCXX_END_NAMESPACE_VERSION
 #  include <bits/specfun.h>
 #endif
 
+} // extern "C++"
+
 #endif
diff --git a/libstdc++-v3/include/c_global/cstdlib b/libstdc++-v3/include/c_global/cstdlib
index 44b6e5c..1ba5fb7 100644
--- a/libstdc++-v3/include/c_global/cstdlib
+++ b/libstdc++-v3/include/c_global/cstdlib
@@ -115,6 +115,8 @@  namespace std
 #undef wcstombs
 #undef wctomb
 
+extern "C++"
+{
 namespace std _GLIBCXX_VISIBILITY(default)
 {
 _GLIBCXX_BEGIN_NAMESPACE_VERSION
@@ -272,6 +274,8 @@  namespace std
 
 #endif // _GLIBCXX_USE_C99_STDLIB
 
+} // extern "C++"
+
 #endif // !_GLIBCXX_HOSTED
 
 #endif
diff --git a/libstdc++-v3/include/c_global/ctgmath b/libstdc++-v3/include/c_global/ctgmath
index 2fee958..4314516 100644
--- a/libstdc++-v3/include/c_global/ctgmath
+++ b/libstdc++-v3/include/c_global/ctgmath
@@ -35,7 +35,9 @@ 
 #  include <bits/c++0x_warning.h>
 #else
 #  include <cmath>
+extern "C++" {
 #  include <complex>
+}
 #endif
 
 #endif 
diff --git a/libstdc++-v3/testsuite/17_intro/headers/c++2011/linkage.cc b/libstdc++-v3/testsuite/17_intro/headers/c++2011/linkage.cc
new file mode 100644
index 0000000..33e7053
--- /dev/null
+++ b/libstdc++-v3/testsuite/17_intro/headers/c++2011/linkage.cc
@@ -0,0 +1,50 @@ 
+// Copyright (C) 2016 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++11" }
+// { dg-do compile }
+
+// libstdc++/69386
+
+extern "C"
+{
+#include <assert.h>
+#include <complex.h>
+#include <ctype.h>
+#include <errno.h>
+#include <fenv.h>
+#include <float.h>
+#include <inttypes.h>
+#include <iso646.h>
+#include <limits.h>
+#include <locale.h>
+#include <math.h>
+#include <setjmp.h>
+#include <signal.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <tgmath.h>
+#include <time.h>
+#include <uchar.h>
+#include <wchar.h>
+#include <wctype.h>
+}