Compile without generating output file in GCC
$ gcc -c somefile.c
compiles without reference and generates the appropriate one somefile.o
.
Is it possible to compile files in gcc
without creating an output file?
I know there are other ways to achieve this, but I'm wondering if there is a flag to go through the source code that looks for errors / warnings.
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You might like the option -fsyntax-only
. It doesn't write anything to disk, it just checks that the code is valid.
You can check that it is not writing anything to disk with this command:
$ strace -e write -f gcc -fsyntax-only test.c
Process 14033 attached
[pid 14033] +++ exited with 0 +++
--- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=14033, si_status=0, si_utime=0, si_stime=0} ---
+++ exited with 0 +++
Compare to this other command, which uses instead -c -o /dev/null
:
rodrigo@P41CCTX5:/tmp$ strace -e write -f gcc -c -o /dev/null test.c
Process 14182 attached
[pid 14182] write(3, "\t.file\t\"a.c\"\n\t.text\n\t.globl\tfoo\n"..., 353) = 353
[pid 14182] +++ exited with 0 +++
--- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=14182, si_status=0, si_utime=0, si_stime=1} ---
Process 14183 attached
[pid 14183] write(3, "\0a.c\0foo\0", 9) = 9
[pid 14183] write(3, "U\211\345]\303\0GCC: (Ubuntu 4.8.2-19ubunt"..., 42) = 42
[pid 14183] write(3, "\24\0\0\0\0\0\0\0\1zR\0\1|\10\1\33\f\4\4\210\1\0\0\34\0\0\0\34\0\0\0"..., 56) = 56
....
[pid 14183] +++ exited with 0 +++
--- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=14183, si_status=0, si_utime=0, si_stime=0} ---
+++ exited with 0 +++
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