gcc编译过程涉及到的crt文件

gcc编译过程涉及到的crt*.o文件
crt应该是c runtime 的缩写吧,用于执行进入main之前的初始化和退出main之后的扫尾工作。

1.gcc编译可执行文件中涉及到的crt*.o文件

[root@mail ~]# cat 2.c
#include

int main()
{
printf("Hello World!\n");
return 0;
}
[root@mail ~]# gcc -v 2.c
Reading specs from /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/specs
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --enable-shared --enable-threads=posix --disable-checking --with-system-zlib --enable-__cxa_atexit --host=i386-redhat-linux
Thread model: posix
gcc version 3.2.2 20030222 (Red Hat Linux 3.2.2-5)
 /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/cc1 -lang-c -v -D__GNUC__=3 -D__GNUC_MINOR__=2 -D__GNUC_PATCHLEVEL__=2 -D__GXX_ABI_VERSION=102 -D__ELF__ -Dunix -D__gnu_linux__ -Dlinux -D__ELF__ -D__unix__ -D__gnu_linux__ -D__linux__ -D__unix -D__linux -Asystem=posix -D__NO_INLINE__ -D__STDC_HOSTED__=1 -Acpu=i386 -Amachine=i386 -Di386 -D__i386 -D__i386__ -D__tune_i386__ 2.c -quiet -dumpbase 2.c -version -o /tmp/cclv0EN3.s
GNU CPP version 3.2.2 20030222 (Red Hat Linux 3.2.2-5) (cpplib) (i386 Linux/ELF)
GNU C version 3.2.2 20030222 (Red Hat Linux 3.2.2-5) (i386-redhat-linux)
        compiled by GNU C version 3.2.2 20030222 (Red Hat Linux 3.2.2-5).
ignoring nonexistent directory "/usr/i386-redhat-linux/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/local/include
 /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/include
 /usr/include
End of search list.
 as -V -Qy -o /tmp/cc6Aj5k1.o /tmp/cclv0EN3.s
GNU assembler version 2.18 (i686-pc-linux-gnu) using BFD version (GNU Binutils) 2.18
 /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/collect2 --eh-frame-hdr -m elf_i386 -dynamic-linker /lib/ld-linux.so.2 /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/../../../crt1.o /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/../../../crti.o /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/crtbegin.o -L/usr/lib/gcc-lib/i386-redhat-linux/3.2.2 -L/usr/lib/gcc-lib/i386-redhat-linux/3.2.2/../../.. /tmp/cc6Aj5k1.o -lgcc -lgcc_eh -lc -lgcc -lgcc_eh /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/crtend.o /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/../../../crtn.o
[root@mail ~]#

这里涉及到的.o文件有
/usr/lib/crt1.o
/usr/lib/crti.o
/usr/lib/gcc-lib/i386-redhat-linux/3.2.2/crtbegin.o
/tmp/cc6Aj5k1.o
/usr/lib/gcc-lib/i386-redhat-linux/3.2.2/crtend.o
/usr/lib/crtn.o

[root@mail ~]# rpm -qf /usr/lib/crt1.o    
glibc-devel-2.3.2-11.9
[root@mail ~]# rpm -qf /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/crtbegin.o
gcc-3.2.2-5

可见crt1.o,crti.o,crtn.o属于glibc,crtbegin.o,crtend.o属于gcc

2.gcc编译动态连接库中涉及到crt*.o文件

[root@mail ~]# cat 3.c
int a(int i,int j)
{
return i*j;
}
[root@mail ~]# gcc -c 3.c -o 3.o           
[root@mail ~]# gcc -shared 3.c -v -o 3.o
Reading specs from /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/specs
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --enable-shared --enable-threads=posix --disable-checking --with-system-zlib --enable-__cxa_atexit --host=i386-redhat-linux
Thread model: posix
gcc version 3.2.2 20030222 (Red Hat Linux 3.2.2-5)
 /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/cc1 -lang-c -v -D__GNUC__=3 -D__GNUC_MINOR__=2 -D__GNUC_PATCHLEVEL__=2 -D__GXX_ABI_VERSION=102 -D__ELF__ -Dunix -D__gnu_linux__ -Dlinux -D__ELF__ -D__unix__ -D__gnu_linux__ -D__linux__ -D__unix -D__linux -Asystem=posix -D__NO_INLINE__ -D__STDC_HOSTED__=1 -Acpu=i386 -Amachine=i386 -Di386 -D__i386 -D__i386__ -D__tune_i386__ 3.c -quiet -dumpbase 3.c -version -o /tmp/ccYnvcAN.s
GNU CPP version 3.2.2 20030222 (Red Hat Linux 3.2.2-5) (cpplib) (i386 Linux/ELF)
GNU C version 3.2.2 20030222 (Red Hat Linux 3.2.2-5) (i386-redhat-linux)
        compiled by GNU C version 3.2.2 20030222 (Red Hat Linux 3.2.2-5).
ignoring nonexistent directory "/usr/i386-redhat-linux/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/local/include
 /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/include
 /usr/include
End of search list.
 as -V -Qy -o /tmp/ccak95mp.o /tmp/ccYnvcAN.s
GNU assembler version 2.18 (i686-pc-linux-gnu) using BFD version (GNU Binutils) 2.18
 /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/collect2 --eh-frame-hdr -m elf_i386 -shared -o 3.o /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/../../../crti.o /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/crtbeginS.o -L/usr/lib/gcc-lib/i386-redhat-linux/3.2.2 -L/usr/lib/gcc-lib/i386-redhat-linux/3.2.2/../../.. /tmp/ccak95mp.o -lgcc -lc -lgcc /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/crtendS.o /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/../../../crtn.o
 
这里涉及到的.o文件有
/usr/lib/crti.o
/usr/lib/gcc-lib/i386-redhat-linux/3.2.2/crtbeginS.o
/tmp/ccak95mp.o
/usr/lib/gcc-lib/i386-redhat-linux/3.2.2/crtendS.o
/usr/lib/crtn.o

crtbeginS.o和crtendS.o也属于gcc.

3.gcc编译可进行性能分析程序中涉及到crt*.o文件
[root@mail ~]# cat 2.c
#include

int main()
{
printf("Hello World!\n");
return 0;
}[root@mail ~]# gcc -v -pg 2.c
Reading specs from /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/specs
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --enable-shared --enable-threads=posix --disable-checking --with-system-zlib --enable-__cxa_atexit --host=i386-redhat-linux
Thread model: posix
gcc version 3.2.2 20030222 (Red Hat Linux 3.2.2-5)
 /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/cc1 -lang-c -v -D__GNUC__=3 -D__GNUC_MINOR__=2 -D__GNUC_PATCHLEVEL__=2 -D__GXX_ABI_VERSION=102 -D__ELF__ -Dunix -D__gnu_linux__ -Dlinux -D__ELF__ -D__unix__ -D__gnu_linux__ -D__linux__ -D__unix -D__linux -Asystem=posix -D__NO_INLINE__ -D__STDC_HOSTED__=1 -Acpu=i386 -Amachine=i386 -Di386 -D__i386 -D__i386__ -D__tune_i386__ 2.c -quiet -dumpbase 2.c -version -p -o /tmp/ccyBluwA.s
GNU CPP version 3.2.2 20030222 (Red Hat Linux 3.2.2-5) (cpplib) (i386 Linux/ELF)
GNU C version 3.2.2 20030222 (Red Hat Linux 3.2.2-5) (i386-redhat-linux)
        compiled by GNU C version 3.2.2 20030222 (Red Hat Linux 3.2.2-5).
ignoring nonexistent directory "/usr/i386-redhat-linux/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/local/include
 /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/include
 /usr/include
End of search list.
 as -V -Qy -o /tmp/ccOgYtn4.o /tmp/ccyBluwA.s
GNU assembler version 2.18 (i686-pc-linux-gnu) using BFD version (GNU Binutils) 2.18
 /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/collect2 --eh-frame-hdr -m elf_i386 -dynamic-linker /lib/ld-linux.so.2 /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/../../../gcrt1.o /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/../../../crti.o /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/crtbegin.o -L/usr/lib/gcc-lib/i386-redhat-linux/3.2.2 -L/usr/lib/gcc-lib/i386-redhat-linux/3.2.2/../../.. /tmp/ccOgYtn4.o -lgcc -lgcc_eh -lc -lgcc -lgcc_eh /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/crtend.o /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/../../../crtn.o

对比前面，crt1.o变成了gcrt1.o,这个文件属于glibc.

4.静态链接可执行文件涉及到的crt*.o
[root@mail ~]#  cat 2.c
#include

int main()
{
printf("Hello World!\n");
return 0;
}
[root@mail ~]# gcc -static 2.c -v
Reading specs from /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/specs
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --enable-shared --enable-threads=posix --disable-checking --with-system-zlib --enable-__cxa_atexit --host=i386-redhat-linux
Thread model: posix
gcc version 3.2.2 20030222 (Red Hat Linux 3.2.2-5)
 /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/cc1 -lang-c -v -D__GNUC__=3 -D__GNUC_MINOR__=2 -D__GNUC_PATCHLEVEL__=2 -D__GXX_ABI_VERSION=102 -D__ELF__ -Dunix -D__gnu_linux__ -Dlinux -D__ELF__ -D__unix__ -D__gnu_linux__ -D__linux__ -D__unix -D__linux -Asystem=posix -D__NO_INLINE__ -D__STDC_HOSTED__=1 -Acpu=i386 -Amachine=i386 -Di386 -D__i386 -D__i386__ -D__tune_i386__ 2.c -quiet -dumpbase 2.c -version -o /tmp/ccZlcdoM.s
GNU CPP version 3.2.2 20030222 (Red Hat Linux 3.2.2-5) (cpplib) (i386 Linux/ELF)
GNU C version 3.2.2 20030222 (Red Hat Linux 3.2.2-5) (i386-redhat-linux)
        compiled by GNU C version 3.2.2 20030222 (Red Hat Linux 3.2.2-5).
ignoring nonexistent directory "/usr/i386-redhat-linux/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/local/include
 /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/include
 /usr/include
End of search list.
 as -V -Qy -o /tmp/ccoe335r.o /tmp/ccZlcdoM.s
GNU assembler version 2.18 (i686-pc-linux-gnu) using BFD version (GNU Binutils) 2.18
 /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/collect2 -m elf_i386 -static /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/../../../crt1.o /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/../../../crti.o /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/crtbeginT.o -L/usr/lib/gcc-lib/i386-redhat-linux/3.2.2 -L/usr/lib/gcc-lib/i386-redhat-linux/3.2.2/../../.. /tmp/ccoe335r.o -lgcc -lgcc_eh -lc -lgcc -lgcc_eh /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/crtend.o /usr/lib/gcc-lib/i386-redhat-linux/3.2.2/../../../crtn.o

对比前面crtbegin.o变成了crtbeginT.o
 
5.总结
[root@mail ~]# rpm -ql gcc|grep crt
/usr/lib/gcc-lib/i386-redhat-linux/3.2.2/crtbegin.o
/usr/lib/gcc-lib/i386-redhat-linux/3.2.2/crtbeginS.o
/usr/lib/gcc-lib/i386-redhat-linux/3.2.2/crtbeginT.o
/usr/lib/gcc-lib/i386-redhat-linux/3.2.2/crtend.o
/usr/lib/gcc-lib/i386-redhat-linux/3.2.2/crtendS.o

[root@mail ~]# rpm -ql glibc-devel|grep crt
/usr/lib/Mcrt1.o
/usr/lib/crt1.o
/usr/lib/crti.o
/usr/lib/crtn.o
/usr/lib/gcrt1.o

基本所有的crt都涉及到了，除了Mcrt1.o.Mcrt1.o用途未知。