https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116957
Bug ID: 116957
Summary: Creation of pre-compiled header (-x c-header, -x
c++-header) confused by linker options (eg -Wl,-g)
Product: gcc
Version: 12.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: driver
Assignee: unassigned at gcc dot gnu.org
Reporter: earl_chew at yahoo dot com
Target Milestone: ---
Precompiled headers are created from C headers, or C++ headers. For example:
$ gcc -x c-header /dev/null -o /tmp/test.gch && echo Ok
Ok
Surprisingly, passing any option to the linker via -Wl, triggers an attempt to
link the precompiled header file:
$ gcc -x c-header /dev/null -o /tmp/test.gch -Wl,-g && echo Ok
/usr/bin/ld:
/usr/lib/gcc/x86_64-linux-gnu/12/../../../x86_64-linux-gnu/Scrt1.o: in function
`_start':
(.text+0x17): undefined reference to `main'
collect2: error: ld returned 1 exit status
In comparison, object files are created from C source, and passing any option
to the linker via -Wl, does not trigger an attempt to link. For example:
$ gcc -x c /dev/null -c -o /tmp/test.o && echo Ok
Ok
$ gcc -x c /dev/null -c -o /tmp/test.o -Wl,-g && echo Ok
Ok
$ gcc -x c /dev/null -c -o /tmp/test.o -Wl,bar.o && echo Ok
Ok
Options to address this issue include:
* Do nothing, and accept the inconsistency
* Any -Wl option only applies when the linker is run
* All -Wl options that do not specify a linker option (-Wl,-option or
-Wl,--option, for example -Wl,bar.o) will force the linker to run
* Ignore -Wl for -x c-header and -x c++-header
* Something else
