[Bug c++/58824] New: Lambda trigger internal compiler error

[Bug c++/58824] New: Lambda trigger internal compiler error

[thomas.sanchz at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58824

            Bug ID: 58824
           Summary: Lambda trigger internal compiler error
           Product: gcc
           Version: 4.8.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: thomas.sanchz at gmail dot com

Created attachment 31058
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=31058&action=edit
Source file + ii + s

Hi,

Please see in attached file the source triggering an internal error in gcc.

The source file is compiled like this:

$> g++ -std=c++11 -W -Wall -Wextra test.cpp 
test.cpp: In instantiation of ‘struct test<dummy>::__lambda0’:
test.cpp:5:8:   required from here
test.cpp:8:20: internal compiler error: in tsubst_copy, at cp/pt.c:12116
         { "test", [this]{} }

The bug is triggered when `this` is captured from a template class and the
lambda is assigned directly from the class definition.

The platform tested is an ubuntu 13.10 with default shipped compiler:

$gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.8/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro
4.8.1-10ubuntu8' --with-bugurl=file:///usr/share/doc/gcc-4.8/README.Bugs
--enable-languages=c,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr
--program-suffix=-4.8 --enable-shared --enable-linker-build-id
--libexecdir=/usr/lib --without-included-gettext --enable-threads=posix
--with-gxx-include-dir=/usr/include/c++/4.8 --libdir=/usr/lib --enable-nls
--with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug
--enable-libstdcxx-time=yes --enable-gnu-unique-object --enable-plugin
--with-system-zlib --disable-browser-plugin --enable-java-awt=gtk
--enable-gtk-cairo --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-4.8-amd64/jre
--enable-java-home --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-4.8-amd64
--with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-4.8-amd64
--with-arch-directory=amd64 --with-ecj-jar=/usr/share/java/eclipse-ecj.jar
--enable-objc-gc --enable-multiarch --disable-werror --with-arch-32=i686
--with-abi=m64 --with-multilib-list=m32,m64,mx32 --with-tune=generic
--enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu
--target=x86_64-linux-gnu
Thread model: posix
gcc version 4.8.1 (Ubuntu/Linaro 4.8.1-10ubuntu8) 

The bug is still present in gcc4.9 (tested via: http://gcc.godbolt.org/).
I joined the *i files even if I doubt that they'll be helpful in this
particular bug.
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Subject: [Bug middle-end/58742] [4.7/4.8/4.9 Regression] pointer arithmetic simplification
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http://gcc.gnu.org/bugzilla/show_bug.cgi?idX742

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|tree-optimization           |middle-end
      Known to work|                            |4.1.2
   Target Milestone|---                         |4.7.4
            Summary|pointer arithmetic          |[4.7/4.8/4.9 Regression]
                   |simplification              |pointer arithmetic
                   |                            |simplification
      Known to fail|                            |4.2.0

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
This case is a signed exact division followed by an unsigned multiply.  We do
that to avoid introducing undefined signed overflow.

signed exact division and unsigned multiply still cancel out though, handling
of these is in extract_muldiv (ugh).  I'm not going to enhance that but
pattern match this case.  Testing

Index: gcc/fold-const.c
==================================================================--- gcc/fold-const.c    (revision 203885)
+++ gcc/fold-const.c    (working copy)
@@ -11002,6 +11002,13 @@ fold_binary_loc (location_t loc,
                                fold_build2_loc (loc, MULT_EXPR, type,
                                             build_int_cst (type, 2) , arg1));

+         /* ((T) (X /[ex] C)) * C cancels out if the conversion is
+            sign-changing only.  */
+         if (TREE_CODE (arg1) == INTEGER_CST
+             && TREE_CODE (arg0) == EXACT_DIV_EXPR
+             && operand_equal_p (arg1, TREE_OPERAND (arg0, 1), 0))
+           return fold_convert_loc (loc, type, TREE_OPERAND (arg0, 0));
+
          strict_overflow_p = false;
          if (TREE_CODE (arg1) == INTEGER_CST
              && 0 != (tem = extract_muldiv (op0, arg1, code, NULL_TREE,

note that this simplification worked in 4.1.2 but stopped working in 4.2.0.
Likely a wrong-code fix for extract_muldiv disabled this case (the way
that function works makes special casing a pattern like above impossible).

[Bug c++/58824] Lambda trigger internal compiler error

[thomas.sanchz at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58824

Thomas Sanchez <thomas.sanchz at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
  Attachment #31058|0                           |1
        is obsolete|                            |

--- Comment #1 from Thomas Sanchez <thomas.sanchz at gmail dot com> ---
Created attachment 31059
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=31059&action=edit
Only source file

Sorry for the archive...

[Bug c++/58824] Lambda trigger internal compiler error

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58824

Paolo Carlini <paolo.carlini at oracle dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2013-10-21
             Blocks|                            |54367
     Ever confirmed|0                           |1

--- Comment #2 from Paolo Carlini <paolo.carlini at oracle dot com> ---
Please do your best to simplify the testcase to a few lines with no includes,
to speed up the debugging. In my experience, less than 100 lines are almost
always enough.

[Bug c++/58824] Lambda trigger internal compiler error

[thomas.sanchz at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58824

--- Comment #3 from Thomas Sanchez <thomas.sanchz at gmail dot com> ---
The code is 21 lines... I can't reproduce the bug otherwise...

[Bug c++/58824] Lambda trigger internal compiler error

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58824

Paolo Carlini <paolo.carlini at oracle dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|thomas.sanchz at gmail dot com     |

--- Comment #4 from Paolo Carlini <paolo.carlini at oracle dot com> ---
Almost certainly Dup of PR58761

[Bug c++/58824] Lambda trigger internal compiler error

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58824

--- Comment #5 from Paolo Carlini <paolo.carlini at oracle dot com> ---
I said *without includes* ;)

[Bug c++/58824] Lambda trigger internal compiler error

[thomas.sanchz at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58824

Thomas Sanchez <thomas.sanchz at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
  Attachment #31059|0                           |1
        is obsolete|                            |
                 CC|                            |thomas.sanchz at gmail dot com

--- Comment #6 from Thomas Sanchez <thomas.sanchz at gmail dot com> ---
Created attachment 31060
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=31060&action=edit
Source file

Source file without any include added.

[Bug c++/58824] Lambda trigger internal compiler error

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58824

--- Comment #7 from Paolo Carlini <paolo.carlini at oracle dot com> ---
Great, thanks a lot!

[Bug c++/58824] Lambda trigger internal compiler error

[thomas.sanchz at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58824

--- Comment #8 from Thomas Sanchez <thomas.sanchz at gmail dot com> ---
You're welcome, good luck !

[Bug c++/58824] Lambda trigger internal compiler error

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58824

Paolo Carlini <paolo.carlini at oracle dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
                 CC|thomas.sanchz at gmail dot com     |
         Resolution|---                         |DUPLICATE

--- Comment #9 from Paolo Carlini <paolo.carlini at oracle dot com> ---
Dup.

*** This bug has been marked as a duplicate of bug 58761 ***