[Bug c++/67584] New: Compilation is fine if an undeclared identifier is used in a for range-based loop, and lsh has the same name as rhs

[Bug c++/67584] New: Compilation is fine if an undeclared identifier is used in a for range-based loop, and lsh has the same name as rhs

[tony at becrux dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67584

            Bug ID: 67584
           Summary: Compilation is fine if an undeclared identifier is
                    used in a for range-based loop, and lsh has the same
                    name as rhs
           Product: gcc
           Version: 5.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: tony at becrux dot com
  Target Milestone: ---

GCC does not fail in compiling the following code:

#include <vector>

class A : public std::vector< int >
{
public:
  A(int x) : std::vector< int >(x) { }
};

int main(int, char **)
{
  for (A v : v)
  {

  }

  return 0;
}

"A" class has been declared just to "trick" the vector behavior (i.e. remove
the explicit constructor) and fool the compiler.

Command-line used for compilation:

g++ -v -save-temps -std=c++11 -Wall -Wextra -pedantic -o for_bug.exe
for_bug.cpp

No warning is generated.

I've tested 5.2 too, and older version of GCC (4.8 and 4.7 series), the result
is always the same (using an online compiler).

Clang and ICC behave correctly, i.e. compilation fails cause "v" is an
undeclared identifier (using an online compiler).

GCC version used for test is 5.1.0, MinGW-w64, Windows 7 64 bit. The produced
executable crashes during execution.

Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=C:/i686-510-win32-sjlj-rt_v4/bin/../libexec/gcc/i686-w64-mingw32/5.1.0/lto-wrapper.exe
Target: i686-w64-mingw32
Configured with: ../../../src/gcc-5.1.0/configure --host=i686-w64-mingw32
--build=i686-w64-mingw32 --target=i686-w64-mingw32 --prefix=/mingw32
--with-sysroot=/home/Tony/mingw-gcc-5.1.0/i686-510-win32-sjlj-rt_v4/mingw32
--with-gxx-include-dir=/mingw32/i686-w64-mingw32/include/c++ --enable-shared
--enable-static --disable-multilib --enable-languages=c,c++,lto
--enable-libstdcxx-time=yes --enable-threads=win32 --enable-libgomp
--enable-libatomic --enable-lto --enable-graphite --enable-checking=release
--enable-fully-dynamic-string --enable-version-specific-runtime-libs
--enable-sjlj-exceptions --disable-isl-version-check --disable-libstdcxx-pch
--disable-libstdcxx-debug --disable-bootstrap --disable-rpath
--disable-win32-registry --disable-nls --disable-werror --disable-symvers
--with-gnu-as --with-gnu-ld --with-arch=i686 --with-tune=i686 --with-libiconv
--with-system-zlib
--with-gmp=/home/Tony/mingw-gcc-5.1.0/prerequisites/i686-w64-mingw32-static
--with-mpfr=/home/Tony/mingw-gcc-5.1.0/prerequisites/i686-w64-mingw32-static
--with-mpc=/home/Tony/mingw-gcc-5.1.0/prerequisites/i686-w64-mingw32-static
--with-isl=/home/Tony/mingw-gcc-5.1.0/prerequisites/i686-w64-mingw32-static
--with-pkgversion='i686-win32-sjlj, Built by Antonio Di Monaco'
--with-bugurl=http://sourceforge.net/projects/mingw-w64 CFLAGS='-O2 -pipe
-march=i686 -mtune=i686 -mthreads
-I/home/Tony/mingw-gcc-5.1.0/i686-510-win32-sjlj-rt_v4/mingw32/opt/include
-I/home/Tony/mingw-gcc-5.1.0/prerequisites/i686-zlib-static/include
-I/home/Tony/mingw-gcc-5.1.0/prerequisites/i686-w64-mingw32-static/include'
CXXFLAGS='-O2 -pipe -march=i686 -mtune=i686 -mthreads
-I/home/Tony/mingw-gcc-5.1.0/i686-510-win32-sjlj-rt_v4/mingw32/opt/include
-I/home/Tony/mingw-gcc-5.1.0/prerequisites/i686-zlib-static/include
-I/home/Tony/mingw-gcc-5.1.0/prerequisites/i686-w64-mingw32-static/include'
CPPFLAGS= LDFLAGS='-pipe
-L/home/Tony/mingw-gcc-5.1.0/i686-510-win32-sjlj-rt_v4/mingw32/opt/lib
-L/home/Tony/mingw-gcc-5.1.0/prerequisites/i686-zlib-static/lib
-L/home/Tony/mingw-gcc-5.1.0/prerequisites/i686-w64-mingw32-static/lib
-Wl,--large-address-aware'
Thread model: win32
gcc version 5.1.0 (i686-win32-sjlj, Built by Antonio Di Monaco) 
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-std=c++11' '-Wall' '-Wextra'
'-Wpedantic' '-o' 'for_bug.exe' '-shared-libgcc' '-mtune=i686' '-march=i686'

C:/i686-510-win32-sjlj-rt_v4/bin/../libexec/gcc/i686-w64-mingw32/5.1.0/cc1plus.exe
-E -quiet -v -iprefix
C:/i686-510-win32-sjlj-rt_v4/bin/../lib/gcc/i686-w64-mingw32/5.1.0/
-U_REENTRANT for_bug.cpp -mtune=i686 -march=i686 -std=c++11 -Wall -Wextra
-Wpedantic -fpch-preprocess -o for_bug.ii
ignoring duplicate directory
"C:/i686-510-win32-sjlj-rt_v4/lib/gcc/../../lib/gcc/i686-w64-mingw32/5.1.0/include"
ignoring nonexistent directory
"C:/msys32/home/Tony/mingw-gcc-5.1.0/i686-510-win32-sjlj-rt_v4/mingw32C:/msys32/mingw32/lib/gcc/i686-w64-mingw32/5.1.0/../../../../include"
ignoring duplicate directory
"C:/i686-510-win32-sjlj-rt_v4/lib/gcc/../../lib/gcc/i686-w64-mingw32/5.1.0/include-fixed"
ignoring duplicate directory
"C:/i686-510-win32-sjlj-rt_v4/lib/gcc/../../lib/gcc/i686-w64-mingw32/5.1.0/../../../../i686-w64-mingw32/include"
ignoring nonexistent directory
"C:/msys32/home/Tony/mingw-gcc-5.1.0/i686-510-win32-sjlj-rt_v4/mingw32/mingw/include"
#include "..." search starts here:
#include <...> search starts here:
 C:/i686-510-win32-sjlj-rt_v4/bin/../lib/gcc/i686-w64-mingw32/5.1.0/include

C:/i686-510-win32-sjlj-rt_v4/bin/../lib/gcc/i686-w64-mingw32/5.1.0/include-fixed

C:/i686-510-win32-sjlj-rt_v4/bin/../lib/gcc/i686-w64-mingw32/5.1.0/../../../../i686-w64-mingw32/include
 C:/i686-510-win32-sjlj-rt_v4/lib/gcc/../../i686-w64-mingw32/include/c++

C:/i686-510-win32-sjlj-rt_v4/lib/gcc/../../i686-w64-mingw32/include/c++/i686-w64-mingw32

C:/i686-510-win32-sjlj-rt_v4/lib/gcc/../../i686-w64-mingw32/include/c++/backward
End of search list.
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-std=c++11' '-Wall' '-Wextra'
'-Wpedantic' '-o' 'for_bug.exe' '-shared-libgcc' '-mtune=i686' '-march=i686'

C:/i686-510-win32-sjlj-rt_v4/bin/../libexec/gcc/i686-w64-mingw32/5.1.0/cc1plus.exe
-fpreprocessed for_bug.ii -quiet -dumpbase for_bug.cpp -mtune=i686 -march=i686
-auxbase for_bug -Wall -Wextra -Wpedantic -std=c++11 -version -o for_bug.s
GNU C++11 (i686-win32-sjlj, Built by Antonio Di Monaco) version 5.1.0
(i686-w64-mingw32)
        compiled by GNU C version 4.8.4, GMP version 6.0.0, MPFR version
3.1.2-p11, MPC version 1.0.3
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
GNU C++11 (i686-win32-sjlj, Built by Antonio Di Monaco) version 5.1.0
(i686-w64-mingw32)
        compiled by GNU C version 4.8.4, GMP version 6.0.0, MPFR version
3.1.2-p11, MPC version 1.0.3
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: cd26162daf8c5b33311803309ba41a5d
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-std=c++11' '-Wall' '-Wextra'
'-Wpedantic' '-o' 'for_bug.exe' '-shared-libgcc' '-mtune=i686' '-march=i686'

C:/i686-510-win32-sjlj-rt_v4/bin/../lib/gcc/i686-w64-mingw32/5.1.0/../../../../i686-w64-mingw32/bin/as.exe
-v -o for_bug.o for_bug.s
GNU assembler version 2.25 (i686-w64-mingw32) using BFD version (GNU Binutils)
2.25
COMPILER_PATH=C:/i686-510-win32-sjlj-rt_v4/bin/../libexec/gcc/i686-w64-mingw32/5.1.0/;C:/i686-510-win32-sjlj-rt_v4/bin/../libexec/gcc/;C:/i686-510-win32-sjlj-rt_v4/bin/../lib/gcc/i686-w64-mingw32/5.1.0/../../../../i686-w64-mingw32/bin/
LIBRARY_PATH=C:/i686-510-win32-sjlj-rt_v4/bin/../lib/gcc/i686-w64-mingw32/5.1.0/;C:/i686-510-win32-sjlj-rt_v4/bin/../lib/gcc/;C:/i686-510-win32-sjlj-rt_v4/bin/../lib/gcc/i686-w64-mingw32/5.1.0/../../../../i686-w64-mingw32/lib/../lib/;C:/i686-510-win32-sjlj-rt_v4/bin/../lib/gcc/i686-w64-mingw32/5.1.0/../../../../lib/;C:/i686-510-win32-sjlj-rt_v4/bin/../lib/gcc/i686-w64-mingw32/5.1.0/../../../../i686-w64-mingw32/lib/;C:/i686-510-win32-sjlj-rt_v4/bin/../lib/gcc/i686-w64-mingw32/5.1.0/../../../
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-std=c++11' '-Wall' '-Wextra'
'-Wpedantic' '-o' 'for_bug.exe' '-shared-libgcc' '-mtune=i686' '-march=i686'

C:/i686-510-win32-sjlj-rt_v4/bin/../libexec/gcc/i686-w64-mingw32/5.1.0/collect2.exe
-plugin
C:/i686-510-win32-sjlj-rt_v4/bin/../libexec/gcc/i686-w64-mingw32/5.1.0/liblto_plugin-0.dll
-plugin-opt=C:/i686-510-win32-sjlj-rt_v4/bin/../libexec/gcc/i686-w64-mingw32/5.1.0/lto-wrapper.exe
-plugin-opt=-fresolution=for_bug.res -plugin-opt=-pass-through=-lmingw32
-plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lgcc
-plugin-opt=-pass-through=-lmoldname -plugin-opt=-pass-through=-lmingwex
-plugin-opt=-pass-through=-lmsvcrt -plugin-opt=-pass-through=-ladvapi32
-plugin-opt=-pass-through=-lshell32 -plugin-opt=-pass-through=-luser32
-plugin-opt=-pass-through=-lkernel32 -plugin-opt=-pass-through=-liconv
-plugin-opt=-pass-through=-lmingw32 -plugin-opt=-pass-through=-lgcc_s
-plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lmoldname
-plugin-opt=-pass-through=-lmingwex -plugin-opt=-pass-through=-lmsvcrt
--sysroot=C:/msys32/home/Tony/mingw-gcc-5.1.0/i686-510-win32-sjlj-rt_v4/mingw32
-m i386pe -Bdynamic -o for_bug.exe
C:/i686-510-win32-sjlj-rt_v4/bin/../lib/gcc/i686-w64-mingw32/5.1.0/../../../../i686-w64-mingw32/lib/../lib/crt2.o
C:/i686-510-win32-sjlj-rt_v4/bin/../lib/gcc/i686-w64-mingw32/5.1.0/crtbegin.o
-LC:/i686-510-win32-sjlj-rt_v4/bin/../lib/gcc/i686-w64-mingw32/5.1.0
-LC:/i686-510-win32-sjlj-rt_v4/bin/../lib/gcc
-LC:/i686-510-win32-sjlj-rt_v4/bin/../lib/gcc/i686-w64-mingw32/5.1.0/../../../../i686-w64-mingw32/lib/../lib
-LC:/i686-510-win32-sjlj-rt_v4/bin/../lib/gcc/i686-w64-mingw32/5.1.0/../../../../lib
-LC:/i686-510-win32-sjlj-rt_v4/bin/../lib/gcc/i686-w64-mingw32/5.1.0/../../../../i686-w64-mingw32/lib
-LC:/i686-510-win32-sjlj-rt_v4/bin/../lib/gcc/i686-w64-mingw32/5.1.0/../../..
for_bug.o -lstdc++ -lmingw32 -lgcc_s -lgcc -lmoldname -lmingwex -lmsvcrt
-ladvapi32 -lshell32 -luser32 -lkernel32 -liconv -lmingw32 -lgcc_s -lgcc
-lmoldname -lmingwex -lmsvcrt
C:/i686-510-win32-sjlj-rt_v4/bin/../lib/gcc/i686-w64-mingw32/5.1.0/crtend.o

[Bug c++/67584] Compilation is fine if an undeclared identifier is used in a for range-based loop, and lsh has the same name as rhs

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67584

Jonathan Wakely <redi at gcc dot gnu.org> changed:

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

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Probably another symptom of Bug 54430, just a particularly nasty variation of
it.

*** This bug has been marked as a duplicate of bug 54430 ***