[Bug c++/43856] New: [C++0x] gcc-4.5.0 fails to transform id-expression into class member access in lambda compound-statement

[Bug c++/43856] New: [C++0x] gcc-4.5.0 fails to transform id-expression into class member access in lambda compound-statement

[paul dot bibbings at gmail dot com]

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When attempting to compile the following code taken directly from
[expr.prim.lambda] 5.1.2/7 (n3092, FCD):

19:56:28 Paul Bibbings@JIJOU
/cygdrive/d/CPPProjects/nano/gcc_bugs $cat _5_1_2_7.cpp
// file: _5_1_2_7.cpp

struct S1 {
   int x, y;
   int operator()(int);
   void f() {
      [=]()->int {
         return operator()(this->x + y);
      };
   }
};

gcc-4.5.0 fails to apply all aspects of the clause correctly:

5.1.2/7: "The lambda-expression’s compound-statement yields the function-body
(8.4) of the function call operator, but for purposes of name lookup (3.4),
determining the type and value of this (9.3.2) and transforming id-expressions
referring to non-static class members into class member access expressions
using (*this) (9.3.1), the compound-statement is considered in the context of
the lambda-expression."

Specifically, it fails in transforming operator()(this->x + y) into
(*this).operator()(this->x + y).

19:56:37 Paul Bibbings@JIJOU
/cygdrive/d/CPPProjects/nano/gcc_bugs $i686-pc-cygwin-gcc-4.5.0 -v -save-temps
-Wall -std=c++0x -pedantic -c _5_1_2_7.cpp
Using built-in specs.
COLLECT_GCC=i686-pc-cygwin-gcc-4.5.0
COLLECT_LTO_WRAPPER=/opt/gcc-4.5.0/libexec/gcc/i686-pc-cygwin/4.5.0/lto-wrapper.exe
Target: i686-pc-cygwin
Configured with: ./configure --prefix=/opt/gcc-4.5.0 --enable-bootstrap
--enable-version-specific-runtime-libs --enable-static --enable-shared
--enable-shared-libgcc --disable-__cxa_atexit --with-gnu-ld --with-gnu-as
--with-dwarf2 --disable-sjlj-exceptions --enable-languages=c,c++
--disable-symvers --enable-libgomp --enable-libssp --enable-threads=posix
--with-arch-i686 --with-tune=generic
Thread model: posix
gcc version 4.5.0 (GCC)
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-Wall' '-std=c++0x' '-pedantic' '-c'
'-mtune=generic' '-march=pentiumpro'
 /opt/gcc-4.5.0/libexec/gcc/i686-pc-cygwin/4.5.0/cc1plus.exe -E -quiet -v
-D__CYGWIN32__ -D__CYGWIN__ -Dunix -D__unix__ -D__unix -idirafter
/usr/lib/../include/w32api -idirafter ../../include/w32api _5_1_2_7.cpp
-mtune=generic -march=pentiumpro -std=c++0x -Wall -pedantic -fpch-preprocess -o
_5_1_2_7.ii
ignoring nonexistent directory
"/opt/gcc-4.5.0/lib/gcc/i686-pc-cygwin/4.5.0/../../../../i686-pc-cygwin/include"
ignoring nonexistent directory "../../include/w32api"
#include "..." search starts here:
#include <...> search starts here:
 /opt/gcc-4.5.0/lib/gcc/i686-pc-cygwin/4.5.0/include/c++
 /opt/gcc-4.5.0/lib/gcc/i686-pc-cygwin/4.5.0/include/c++/i686-pc-cygwin
 /opt/gcc-4.5.0/lib/gcc/i686-pc-cygwin/4.5.0/include/c++/backward
 /usr/local/include
 /opt/gcc-4.5.0/include
 /opt/gcc-4.5.0/lib/gcc/i686-pc-cygwin/4.5.0/include
 /opt/gcc-4.5.0/lib/gcc/i686-pc-cygwin/4.5.0/include-fixed
 /usr/include
 /usr/lib/../include/w32api
End of search list.
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-Wall' '-std=c++0x' '-pedantic' '-c'
'-mtune=generic' '-march=pentiumpro'
 /opt/gcc-4.5.0/libexec/gcc/i686-pc-cygwin/4.5.0/cc1plus.exe -fpreprocessed
_5_1_2_7.ii -quiet -dumpbase _5_1_2_7.cpp -mtune=generic -march=pentiumpro
-auxbase _5_1_2_7 -Wall -pedantic -std=c++0x -version -o _5_1_2_7.s
GNU C++ (GCC) version 4.5.0 (i686-pc-cygwin)
        compiled by GNU C version 4.5.0, GMP version 4.3.2, MPFR version 2.4.1,
MPC version 0.8.1
GGC heuristics: --param ggc-min-expand=99 --param ggc-min-heapsize=129712
GNU C++ (GCC) version 4.5.0 (i686-pc-cygwin)
Compiler executable checksum: 81a7a49c1fa28713ff621b6b856147c0
_5_1_2_7.cpp: In lambda function:
_5_1_2_7.cpp:7:14: error: ‘this’ has incomplete type
_5_1_2_7.cpp:7:9: error: forward declaration of ‘struct S1::f()::<lambda()>’
_5_1_2_7.cpp:7:14: note: candidate is: S1::f()::<lambda()>


If the given code is augmented to include an explicit reference to (*this) on
the invocation of op() in the return statement, as:

struct S1 {
   int x, y;
   int operator()(int);
   void f() {
      [=]()->int {
         return (*this).operator()(this->x + y);
      };
   }
};

then compilation succeeds.


20:08:51 Paul Bibbings@JIJOU
/cygdrive/d/CPPProjects/nano/gcc_bugs $cat _5_1_2_7.ii
# 1 "_5_1_2_7.cpp"
# 1 "<built-in>"
# 1 "<command-line>"
# 1 "_5_1_2_7.cpp"


struct S1 {
   int x, y;
   int operator()(int);
   void f() {
      [=]()->int {
         return operator()(this->x + y);
      };
   }
};


-- 
           Summary: [C++0x] gcc-4.5.0 fails to transform id-expression into
                    class member access in lambda compound-statement
           Product: gcc
           Version: 4.5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: paul dot bibbings at gmail dot com
  GCC host triplet: i686-pc-cygwin


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43856

[Bug c++/43856] [C++0x] gcc-4.5.0 fails to transform id-expression into class member access in lambda compound-statement

[paolo dot carlini at oracle dot com]

------- Comment #1 from paolo dot carlini at oracle dot com  2010-04-22 20:04 -------
Let's CC Jason.


-- 

paolo dot carlini at oracle dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|paul dot bibbings at gmail  |jason at gcc dot gnu dot org
                   |dot com                     |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43856

[Bug c++/43856] [C++0x] gcc-4.5.0 fails to transform id-expression into class member access in lambda compound-statement

[jason at gcc dot gnu dot org]

------- Comment #2 from jason at gcc dot gnu dot org  2010-04-27 21:26 -------
Subject: Bug 43856

Author: jason
Date: Tue Apr 27 21:26:25 2010
New Revision: 158807

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=158807
Log:
        PR c++/43856
        * name-lookup.c (qualify_lookup): Disqualify lambda op().
        * class.c (current_nonlambda_class_type): New fn.
        * semantics.c (nonlambda_method_basetype): New.
        * cp-tree.h: Declare them.
        * tree.c (maybe_dummy_object): Handle implicit 'this' capture.

Added:
    trunk/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-this2.C
Modified:
    trunk/gcc/cp/ChangeLog
    trunk/gcc/cp/class.c
    trunk/gcc/cp/cp-tree.h
    trunk/gcc/cp/name-lookup.c
    trunk/gcc/cp/semantics.c
    trunk/gcc/cp/tree.c
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43856

[Bug c++/43856] [C++0x] gcc-4.5.0 fails to transform id-expression into class member access in lambda compound-statement

[jason at gcc dot gnu dot org]

------- Comment #3 from jason at gcc dot gnu dot org  2010-04-27 23:03 -------
Subject: Bug 43856

Author: jason
Date: Tue Apr 27 23:03:06 2010
New Revision: 158815

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=158815
Log:
        PR c++/43856
        * name-lookup.c (qualify_lookup): Disqualify lambda op().
        * semantics.c (nonlambda_method_basetype): New.
        * cp-tree.h: Declare it.
        * tree.c (maybe_dummy_object): Handle implicit 'this' capture.

Added:
    branches/gcc-4_5-branch/gcc/testsuite/g++.dg/cpp0x/lambda/lambda-this2.C
Modified:
    branches/gcc-4_5-branch/gcc/cp/ChangeLog
    branches/gcc-4_5-branch/gcc/cp/cp-tree.h
    branches/gcc-4_5-branch/gcc/cp/name-lookup.c
    branches/gcc-4_5-branch/gcc/cp/semantics.c
    branches/gcc-4_5-branch/gcc/cp/tree.c
    branches/gcc-4_5-branch/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43856

[Bug c++/43856] [C++0x] gcc-4.5.0 fails to transform id-expression into class member access in lambda compound-statement

[jason at gcc dot gnu dot org]

------- Comment #4 from jason at gcc dot gnu dot org  2010-05-06 16:49 -------
Fixed for 4.5.1.


-- 

jason at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.5.1
            Version|4.5.0                       |4.4.5


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43856

[Bug c++/43856] [C++0x] gcc-4.5.0 fails to transform id-expression into class member access in lambda compound-statement

[jason at gcc dot gnu dot org]

------- Comment #5 from jason at gcc dot gnu dot org  2010-05-06 16:49 -------
.


-- 

jason at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43856