From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 8902 invoked by alias); 6 Apr 2009 12:21:14 -0000 Received: (qmail 7489 invoked by uid 48); 6 Apr 2009 12:20:47 -0000 Date: Mon, 06 Apr 2009 12:21:00 -0000 Subject: [Bug c/39662] New: segmentation failed on correctly compiled mixed C and C++ code X-Bugzilla-Reason: CC Message-ID: Reply-To: gcc-bugzilla@gcc.gnu.org To: gcc-bugs@gcc.gnu.org From: "pavel dot petrovic at gmail dot com" Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org X-SW-Source: 2009-04/txt/msg00481.txt.bz2 I understand C is low-level, but I'd love the compiler to refuse to compile or link a mixed C and C++ code that is not mixed correctly. The story is: parts of the program are implemented in C, parts are in C++. The functions in C++ are made callable from C using the "__attribute__((stdcall))" feature, i.e. these are C-type functions implemented in C++. The main program is in C, and attempts to call the C-style C++ function, which only computes a number. The program crashes on exit from the main() function. It does not crash if compiled using gcc/g++ version 3.3. However, removing the obsolete line "int a = 1;" makes the program crash also when compiled using 3.3 version of the compliers. Here are the sources: ------------------------------------------------------------ /* fnc.h - prototype of C++ function with C-style calling style int f2(nt int) */ #ifdef __cplusplus #define EXPORTCALL __attribute__((stdcall)) #else #define EXPORTCALL #endif #ifdef __cplusplus extern "C" { #endif extern int EXPORTCALL f2(int a, int b); #ifdef __cplusplus } #endif --------------------------------------------------------------- /* fnmc.h - main C program that calls a C++ function int f2(int, int) */ #include #include "fnc.h" int main(int argc, char **argv) { int a = 1; printf("f2(2,3)=%d\n", f2(2,3)); printf("exiting...\n"); return; } ------------------------------------------------------------------ /* fnc.cpp - implementation of the C++ function int f2(int, int), using the C-calling semantics */ #include "fnc.h" /* function prototype for f2() */ /* the function only returns the result */ int EXPORTCALL f2(int a, int b) { return a+b; } ------------------------------------------------------------------ # Makefile GCC=gcc GPP=g++ # GCC=gcc-3.3 # GPP=g++-3.3 all: fn3 fn3: fnc.cpp fnmc.c $(GPP) -v -save-temps -c fnc.cpp -g $(GCC) -v -save-temps -c fnmc.c -g $(GPP) -v -save-temps -o fn3 fnc.o fnmc.o -g clean: rm -f *.o *.s *.i *.ii rm -f fn3 ------------------------------------------------------------------------ Here is the what is obtained when running: petrovic@student03:~/pasCPP2$ make clean rm -f *.o *.s *.i *.ii rm -f fn3 petrovic@student03:~/pasCPP2$ make g++ -v -save-temps -c fnc.cpp -g Using built-in specs. Target: i486-linux-gnu Configured with: ../src/configure -v --enable-languages=c,c++,fortran,objc,obj-c++,treelang --prefix=/usr --enable-shared --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --enable-nls --with-gxx-include-dir=/usr/include/c++/4.2 --program-suffix=-4.2 --enable-clocale=gnu --enable-libstdcxx-debug --enable-objc-gc --enable-mpfr --enable-targets=all --enable-checking=release --build=i486-linux-gnu --host=i486-linux-gnu --target=i486-linux-gnu Thread model: posix gcc version 4.2.4 (Ubuntu 4.2.4-1ubuntu3) /usr/lib/gcc/i486-linux-gnu/4.2.4/cc1plus -E -quiet -v -D_GNU_SOURCE fnc.cpp -mtune=generic -fworking-directory -fpch-preprocess -o fnc.ii ignoring nonexistent directory "/usr/local/include/i486-linux-gnu" ignoring nonexistent directory "/usr/lib/gcc/i486-linux-gnu/4.2.4/../../../../i486-linux-gnu/include" ignoring nonexistent directory "/usr/include/i486-linux-gnu" #include "..." search starts here: #include <...> search starts here: /usr/include/c++/4.2 /usr/include/c++/4.2/i486-linux-gnu /usr/include/c++/4.2/backward /usr/local/include /usr/lib/gcc/i486-linux-gnu/4.2.4/include /usr/include End of search list. /usr/lib/gcc/i486-linux-gnu/4.2.4/cc1plus -fpreprocessed fnc.ii -quiet -dumpbase fnc.cpp -mtune=generic -auxbase fnc -g -version -fstack-protector -fstack-protector -o fnc.s GNU C++ version 4.2.4 (Ubuntu 4.2.4-1ubuntu3) (i486-linux-gnu) compiled by GNU C version 4.2.4 (Ubuntu 4.2.4-1ubuntu3). GGC heuristics: --param ggc-min-expand=98 --param ggc-min-heapsize=128358 Compiler executable checksum: cca9b7b48c023363b938f208576b99cc as --traditional-format -V -Qy -o fnc.o fnc.s GNU assembler version 2.18.0 (i486-linux-gnu) using BFD version (GNU Binutils for Ubuntu) 2.18.0.20080103 gcc -v -save-temps -c fnmc.c -g Using built-in specs. Target: i486-linux-gnu Configured with: ../src/configure -v --enable-languages=c,c++,fortran,objc,obj-c++,treelang --prefix=/usr --enable-shared --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --enable-nls --with-gxx-include-dir=/usr/include/c++/4.2 --program-suffix=-4.2 --enable-clocale=gnu --enable-libstdcxx-debug --enable-objc-gc --enable-mpfr --enable-targets=all --enable-checking=release --build=i486-linux-gnu --host=i486-linux-gnu --target=i486-linux-gnu Thread model: posix gcc version 4.2.4 (Ubuntu 4.2.4-1ubuntu3) /usr/lib/gcc/i486-linux-gnu/4.2.4/cc1 -E -quiet -v fnmc.c -mtune=generic -fworking-directory -fpch-preprocess -o fnmc.i ignoring nonexistent directory "/usr/local/include/i486-linux-gnu" ignoring nonexistent directory "/usr/lib/gcc/i486-linux-gnu/4.2.4/../../../../i486-linux-gnu/include" ignoring nonexistent directory "/usr/include/i486-linux-gnu" #include "..." search starts here: #include <...> search starts here: /usr/local/include /usr/lib/gcc/i486-linux-gnu/4.2.4/include /usr/include End of search list. /usr/lib/gcc/i486-linux-gnu/4.2.4/cc1 -fpreprocessed fnmc.i -quiet -dumpbase fnmc.c -mtune=generic -auxbase fnmc -g -version -fstack-protector -fstack-protector -o fnmc.s GNU C version 4.2.4 (Ubuntu 4.2.4-1ubuntu3) (i486-linux-gnu) compiled by GNU C version 4.2.4 (Ubuntu 4.2.4-1ubuntu3). GGC heuristics: --param ggc-min-expand=98 --param ggc-min-heapsize=128358 Compiler executable checksum: e2971cf2189271aeeb10133511ecea3a as --traditional-format -V -Qy -o fnmc.o fnmc.s GNU assembler version 2.18.0 (i486-linux-gnu) using BFD version (GNU Binutils for Ubuntu) 2.18.0.20080103 g++ -v -save-temps -o fn3 fnc.o fnmc.o -g Using built-in specs. Target: i486-linux-gnu Configured with: ../src/configure -v --enable-languages=c,c++,fortran,objc,obj-c++,treelang --prefix=/usr --enable-shared --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --enable-nls --with-gxx-include-dir=/usr/include/c++/4.2 --program-suffix=-4.2 --enable-clocale=gnu --enable-libstdcxx-debug --enable-objc-gc --enable-mpfr --enable-targets=all --enable-checking=release --build=i486-linux-gnu --host=i486-linux-gnu --target=i486-linux-gnu Thread model: posix gcc version 4.2.4 (Ubuntu 4.2.4-1ubuntu3) /usr/lib/gcc/i486-linux-gnu/4.2.4/collect2 --eh-frame-hdr -m elf_i386 --hash-style=both -dynamic-linker /lib/ld-linux.so.2 -o fn3 /usr/lib/gcc/i486-linux-gnu/4.2.4/../../../../lib/crt1.o /usr/lib/gcc/i486-linux-gnu/4.2.4/../../../../lib/crti.o /usr/lib/gcc/i486-linux-gnu/4.2.4/crtbegin.o -L/usr/lib/gcc/i486-linux-gnu/4.2.4 -L/usr/lib/gcc/i486-linux-gnu/4.2.4 -L/usr/lib/gcc/i486-linux-gnu/4.2.4/../../../../lib -L/lib/../lib -L/usr/lib/../lib -L/usr/lib/gcc/i486-linux-gnu/4.2.4/../../.. fnc.o fnmc.o -lstdc++ -lm -lgcc_s -lgcc -lc -lgcc_s -lgcc /usr/lib/gcc/i486-linux-gnu/4.2.4/crtend.o /usr/lib/gcc/i486-linux-gnu/4.2.4/../../../../lib/crtn.o petrovic@student03:~/pasCPP2$ ./fn3 f2(2,3)=5 exiting... Segmentation fault petrovic@student03:~/pasCPP2$ ------------------------------------------------------------------ I understand, I am probably doing the mixing of C and C++ incorrectly, although I am not sure where (hints are welcome!), but still, would it be possible to get the compiler/linker to produce a warning, if it is generating a code that crashes? P.S. sorry for my previous unfinished post (accidentally clicked ENTER before finishing the report) -- Summary: segmentation failed on correctly compiled mixed C and C++ code Product: gcc Version: 4.2.4 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: pavel dot petrovic at gmail dot com GCC build triplet: i486-linux-gnu GCC host triplet: i486-linux-gnu GCC target triplet: i486-linux-gnu http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39662