[Bug build/25731] New: Build failure on Darwin/macOS: error: no member named 'abs' in namespace 'std'

[Bug build/25731] New: Build failure on Darwin/macOS: error: no member named 'abs' in namespace 'std'

[alexey.brodkin at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=25731

            Bug ID: 25731
           Summary: Build failure on Darwin/macOS: error: no member named
                    'abs' in namespace 'std'
           Product: gdb
           Version: HEAD
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: build
          Assignee: unassigned at sourceware dot org
          Reporter: alexey.brodkin at gmail dot com
                CC: andrew.burgess at embecosm dot com, shahab.vahedi at gmail dot com
  Target Milestone: ---
              Host: Darwin

On current HEAD compilation fails in Darwin/macOS this way:
--------------------------------->8--------------------------------
$ ../binutils-gdb/configure --disable-binutils --disable-ld --disable-gold
--disable-gas --disable-sim --disable-gprof --disable-werror

$ make

  CXX    gdbtypes.o
In file included from ../../binutils-gdb/gdb/gdbtypes.c:22:
In file included from ../../binutils-gdb/gdb/defs.h:630:
In file included from ../../binutils-gdb/gdb/utils.h:24:
In file included from ../../binutils-gdb/gdb/exceptions.h:23:
../../binutils-gdb/gdb/ui-out.h:113:11: warning: returning address of local
temporary object [-Wreturn-stack-address]
  return &tmp;
          ^~~
../../binutils-gdb/gdb/ui-out.h:108:25: note: binding reference variable 'tmp'
here
              signed_field_s &&tmp = {})
                               ^   ~~~~
../../binutils-gdb/gdb/ui-out.h:134:11: warning: returning address of local
temporary object [-Wreturn-stack-address]
  return &tmp;
          ^~~
../../binutils-gdb/gdb/ui-out.h:129:25: note: binding reference variable 'tmp'
here
              string_field_s &&tmp = {})
                               ^   ~~~~
../../binutils-gdb/gdb/ui-out.h:158:11: warning: returning address of local
temporary object [-Wreturn-stack-address]
  return &tmp;
          ^~~
../../binutils-gdb/gdb/ui-out.h:154:27: note: binding reference variable 'tmp'
here
               styled_string_s &&tmp = {})
                                 ^     ~~
../../binutils-gdb/gdb/gdbtypes.c:1252:28: error: no member named 'abs' in
namespace 'std'; did you mean simply 'abs'?
          LONGEST element_count = std::abs (high_bound - low_bound + 1);
                                  ^~~~~~~~
                                  abs
/usr/include/stdlib.h:129:6: note: 'abs' declared here
int      abs(int) __pure2;
         ^
../../binutils-gdb/gdb/gdbtypes.c:1254:10: error: no member named 'abs' in
namespace 'std'; did you mean simply 'abs'?
            = ((std::abs (stride) * element_count) + 7) / 8;
                ^~~~~~~~
                abs
/usr/include/stdlib.h:129:6: note: 'abs' declared here
int      abs(int) __pure2;
         ^
3 warnings and 2 errors generated.
make[2]: *** [gdbtypes.o] Error 1
make[1]: *** [all-gdb] Error 2
make: *** [all] Error 2
--------------------------------->8--------------------------------

I guess it started to happen after commit 3104d9ee2231 ("gdb: Use std::abs
instead of abs on LONGEST types"), see
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=commit;h=3104d9ee223133b9f5be4ec96b3f986e4fbc893e

The following fixes that failure:
--------------------------------->8--------------------------------
diff --git a/gdb/gdbtypes.c b/gdb/gdbtypes.c
index d89df9f7409..a6ef14c2e4c 100644
--- a/gdb/gdbtypes.c
+++ b/gdb/gdbtypes.c
@@ -40,6 +40,8 @@
 #include "gdbcore.h"
 #include "floatformat.h"
+#include <cstdlib>
+
 /* Initialize BADNESS constants.  */
 const struct rank LENGTH_MISMATCH_BADNESS = {100,0};
--------------------------------->8--------------------------------

FWIW:
--------------------------------->8--------------------------------
$ gcc -v
Apple LLVM version 8.0.0 (clang-800.0.42.1)
Target: x86_64-apple-darwin15.6.0
Thread model: posix
InstalledDir: /Library/Developer/CommandLineTools/usr/bin
--------------------------------->8--------------------------------

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[Bug build/25731] Build failure on Darwin/macOS: error: no member named 'abs' in namespace 'std'

[alexey.brodkin at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=25731

Alexey Brodkin <alexey.brodkin at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |alexey.brodkin at gmail dot com

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[Bug build/25731] Build failure on Darwin/macOS: error: no member named 'abs' in namespace 'std'

[simark at simark dot ca]

https://sourceware.org/bugzilla/show_bug.cgi?id=25731

Simon Marchi <simark at simark dot ca> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |simark at simark dot ca

--- Comment #1 from Simon Marchi <simark at simark dot ca> ---
Thanks for reporting.  I'll push a patch directly, since this is obvious, but
next time don't hesitate to send your patch to the gdb-patches mailing list, as
described here:

https://sourceware.org/gdb/wiki/ContributionChecklist

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[Bug build/25731] Build failure on Darwin/macOS: error: no member named 'abs' in namespace 'std'

[simark at simark dot ca]

https://sourceware.org/bugzilla/show_bug.cgi?id=25731

--- Comment #2 from Simon Marchi <simark at simark dot ca> ---
Hmm, in fact I can't reproduce locally.  Here's how this file is built for me:

$ gdb gnumake gdbtypes.o V=1
g++ -x c++ -std=gnu++11 -g3 -O0   -I. -I../../binutils-gdb/gdb
-I../../binutils-gdb/gdb/config -DLOCALEDIR="\"/usr/local/share/locale\""
-DHAVE_CONFIG_H -I../../binutils-gdb/gdb/../include/opcode
-I../../binutils-gdb/gdb/../readline/readline/..
-I../../binutils-gdb/gdb/../zlib -I../bfd -I../../binutils-gdb/gdb/../bfd
-I../../binutils-gdb/gdb/../include -I../libdecnumber
-I../../binutils-gdb/gdb/../libdecnumber -I./../intl
-I../../binutils-gdb/gdb/../gnulib/import -I../gnulib/import
-I../../binutils-gdb/gdb/.. -I..  -DTUI=1   
-I/System/Library/Frameworks/Python.framework/Versions/2.7/include/python2.7
-I/System/Library/Frameworks/Python.framework/Versions/2.7/include/python2.7 
-I../../binutils-gdb/gdb/.. -pthread -Wall -Wpointer-arith -Wno-unused
-Wunused-value -Wunused-function -Wno-switch -Wno-char-subscripts -Wempty-body
-Wno-sign-compare -Wno-mismatched-tags -Wno-error=deprecated-register
-Wredundant-move -Wmissing-declarations -Wmissing-prototypes -Wformat
-Wformat-nonliteral -Werror -c -o gdbtypes.o -MT gdbtypes.o -MMD -MP -MF
./.deps/gdbtypes.Tpo ../../binutils-gdb/gdb/gdbtypes.c
$ gdb which g++
/usr/bin/g++
$ gdb g++ --version
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr
--with-gxx-include-dir=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/4.2.1
Apple clang version 11.0.0 (clang-1100.0.33.17)
Target: x86_64-apple-darwin19.3.0
Thread model: posix
InstalledDir:
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin

Do you have any idea why I don't see the same failure as you?

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[Bug build/25731] Build failure on Darwin/macOS: error: no member named 'abs' in namespace 'std'

[simark at simark dot ca]

https://sourceware.org/bugzilla/show_bug.cgi?id=25731

--- Comment #3 from Simon Marchi <simark at simark dot ca> ---
(In reply to Simon Marchi from comment #2)
> Hmm, in fact I can't reproduce locally.  Here's how this file is built for
> me:
> 
> $ gdb gnumake gdbtypes.o V=1
> ...
> $ gdb which g++
> ...
> $ gdb g++ --version

Err, ignore the leading "gdb" in those commands, that was part of my prompt.

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[Bug build/25731] Build failure on Darwin/macOS: error: no member named 'abs' in namespace 'std'

[simark at simark dot ca]

https://sourceware.org/bugzilla/show_bug.cgi?id=25731

--- Comment #4 from Simon Marchi <simark at simark dot ca> ---
I noticed that we already include stdlib.h in common-defs.h:

https://sourceware.org/git/?p=binutils-gdb.git;a=blob;f=gdbsupport/common-defs.h;h=e42d2b80c045361cfa19f52cb146ae32c58f61b3;hb=HEAD#l87

However, according to [1], C++ standard library implementations are not
mandated to make stdlib.h populate the std namespace.  I guess your C++ library
doesn't.

[1] https://en.cppreference.com/w/cpp/header

So since we use std::abs, the correct thing to do would indeed be to include
cstdlib.  I tried to swap stdlib.h for cstdlib in common-defs.h, I just
stumbled on some old hack in ada-exp.y that can probably be removed.  But
otherwise it builds for me.

Can you see if the patch below builds fine for you on macOS?


>From 8ca602f1a6b05cb431b663c8ed0c09537fe31960 Mon Sep 17 00:00:00 2001
From: Simon Marchi <simon.marchi@efficios.com>
Date: Thu, 26 Mar 2020 13:27:07 -0400
Subject: [PATCH] allo

---
 gdb/ada-exp.y            | 3 ---
 gdbsupport/common-defs.h | 2 +-
 2 files changed, 1 insertion(+), 4 deletions(-)

diff --git a/gdb/ada-exp.y b/gdb/ada-exp.y
index c5e1e14299e..6e65b212e24 100644
--- a/gdb/ada-exp.y
+++ b/gdb/ada-exp.y
@@ -720,9 +720,6 @@ primary     :       '*' primary             %prec '.'

 static struct obstack temp_parse_space;

-/* The following kludge was found necessary to prevent conflicts between */
-/* defs.h and non-standard stdlib.h files.  */
-#define qsort __qsort__dummy
 #include "ada-lex.c"

 int
diff --git a/gdbsupport/common-defs.h b/gdbsupport/common-defs.h
index e42d2b80c04..e1a431c6939 100644
--- a/gdbsupport/common-defs.h
+++ b/gdbsupport/common-defs.h
@@ -84,7 +84,7 @@

 #include <stdarg.h>
 #include <stdio.h>
-#include <stdlib.h>
+#include <cstdlib>
 #include <stddef.h>
 #include <stdint.h>
 #include <string.h>
-- 
2.25.1

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[Bug build/25731] Build failure on Darwin/macOS: error: no member named 'abs' in namespace 'std'

[alexey.brodkin at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=25731

--- Comment #5 from Alexey Brodkin <alexey.brodkin at gmail dot com> ---
Indeed with proposed patch it builds perfectly fine.
Though I don't have an answer to your question why the same problem is not
reproduced on your side, sorry.

And thanks a lot for the prompt fix!

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[Bug build/25731] Build failure on Darwin/macOS: error: no member named 'abs' in namespace 'std'

[alexey.brodkin at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=25731

--- Comment #6 from Alexey Brodkin <alexey.brodkin at gmail dot com> ---
Hi Simon,

Do you still have any doubts about your fix from comment #4?
Otherwise it would be good to get it merged so it won't slip through the
cracks.

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[Bug build/25731] Build failure on Darwin/macOS: error: no member named 'abs' in namespace 'std'

[tromey at sourceware dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=25731

Tom Tromey <tromey at sourceware dot org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |tromey at sourceware dot org

--- Comment #7 from Tom Tromey <tromey at sourceware dot org> ---
FWIW it looks fine to me.

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[Bug build/25731] Build failure on Darwin/macOS: error: no member named 'abs' in namespace 'std'

[alexey.brodkin at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=25731

--- Comment #8 from Alexey Brodkin <alexey.brodkin at gmail dot com> ---
Sorry for bugging you but is there a chance to get proposed fix committed
sometime soon?

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[Bug build/25731] Build failure on Darwin/macOS: error: no member named 'abs' in namespace 'std'

[simark at simark dot ca]

https://sourceware.org/bugzilla/show_bug.cgi?id=25731

--- Comment #9 from Simon Marchi <simark at simark dot ca> ---
I'll send something on the list.

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[Bug build/25731] Build failure on Darwin/macOS: error: no member named 'abs' in namespace 'std'

[simark at simark dot ca]

https://sourceware.org/bugzilla/show_bug.cgi?id=25731

Simon Marchi <simark at simark dot ca> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2020-04-09
     Ever confirmed|0                           |1

--- Comment #10 from Simon Marchi <simark at simark dot ca> ---
Patch posted here:
https://sourceware.org/pipermail/gdb-patches/2020-April/167501.html

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[Bug build/25731] Build failure on Darwin/macOS: error: no member named 'abs' in namespace 'std'

[alexey.brodkin at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=25731

Alexey Brodkin <alexey.brodkin at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |cbiesinger at google dot com

--- Comment #11 from Alexey Brodkin <alexey.brodkin at gmail dot com> ---
Yet another gentle reminder :)
There seems to be a discussion on the mailing list which stops here:
https://sourceware.org/pipermail/gdb-patches/2020-April/167520.html

Do we need a re-spin or it might be fixed-up by the committer?

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[Bug build/25731] Build failure on Darwin/macOS: error: no member named 'abs' in namespace 'std'

[simark at simark dot ca]

https://sourceware.org/bugzilla/show_bug.cgi?id=25731

--- Comment #12 from Simon Marchi <simark at simark dot ca> ---
Thanks for the reminder, I'm not very good at tracking my own patches... I'll
push it, as nobody opposed, we'll see if it breaks something somewhere.

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[Bug build/25731] Build failure on Darwin/macOS: error: no member named 'abs' in namespace 'std'

[cvs-commit at gcc dot gnu.org]

https://sourceware.org/bugzilla/show_bug.cgi?id=25731

--- Comment #13 from cvs-commit at gcc dot gnu.org <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Simon Marchi <simark@sourceware.org>:

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=ff8885c3be6f42ed90a7b0ec0028fad26861cd94

commit ff8885c3be6f42ed90a7b0ec0028fad26861cd94
Author: Simon Marchi <simon.marchi@polymtl.ca>
Date:   Mon Apr 27 09:19:48 2020 -0400

    gdbsupport: include cstdlib in common-defs.h

    In PR 25731 [1], the following build failure was reported:

        ../../binutils-gdb/gdb/gdbtypes.c:1254:10: error: no member named 'abs'
in namespace 'std'; did you mean simply 'abs'?
                    = ((std::abs (stride) * element_count) + 7) / 8;
                        ^~~~~~~~
                        abs
        /usr/include/stdlib.h:129:6: note: 'abs' declared here
        int      abs(int) __pure2;
                 ^
    The original report was using:

        $ gcc -v
        Apple LLVM version 8.0.0 (clang-800.0.42.1)
        Target: x86_64-apple-darwin15.6.0

    Note that I was _not_ able to reproduce using:

        $ g++ --version
        Configured with:
--prefix=/Applications/Xcode.app/Contents/Developer/usr
--with-gxx-include-dir=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/usr/include/c++/4.2.1
        Apple clang version 11.0.0 (clang-1100.0.33.17)
        Target: x86_64-apple-darwin19.3.0

    The proposed fix is to include <cstdlib> in addition to <stdlib.h>.

    Here's an excerpt of [2] relevant to this problem:

        These headers [speaking of the .h form] are allowed to also declare
        the same names in the std namespace, and the corresponding cxxx
        headers are allowed to also declare the same names in the global
        namespace: including <cstdlib> definitely provides std::malloc and
        may also provide ::malloc.  Including <stdlib.h> definitely provides
        ::malloc and may also provide std::malloc

    Since we use std::abs, we should not assume that our include of stdlib.h
    declares an `abs` function in the `std` namespace.

    If we replace the include of stdlib.h with cstdlib, then we fall in the
    opposite situation.  A standard C++ library may decide to only put the
    declarations in the std namespace, requiring us to prefix all standard
    functions with `std::`.  I'm not against that, but for the moment I think
the
    safest way forward is to just include both.

    Note that I don't know what effect this patch can have on any stdlib.h fix
    provided by gnulib.

    [1] https://sourceware.org/bugzilla/show_bug.cgi?id=25731
    [2] https://en.cppreference.com/w/cpp/header#C_compatibility_headers

    gdbsupport/ChangeLog:

            * common-defs.h: Include cstdlib.h.

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[Bug build/25731] Build failure on Darwin/macOS: error: no member named 'abs' in namespace 'std'

[simark at simark dot ca]

https://sourceware.org/bugzilla/show_bug.cgi?id=25731

Simon Marchi <simark at simark dot ca> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |FIXED

--- Comment #14 from Simon Marchi <simark at simark dot ca> ---
Fixed.

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[Bug build/25731] Build failure on Darwin/macOS: error: no member named 'abs' in namespace 'std'

[tromey at sourceware dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=25731

Tom Tromey <tromey at sourceware dot org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |10.1

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