From: Michael Haubenwallner <michael.haubenwallner@ssi-schaefer.com>
To: cygwin@cygwin.com
Subject: linker (binutils ld) is unable to resolve weak symbol, depends on object file order
Date: Fri, 07 Jun 2019 10:04:00 -0000 [thread overview]
Message-ID: <c302ea94-ae7b-f7b1-9d8f-0c2e31dc6bc7@ssi-schaefer.com> (raw)
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Hi,
so I'm encountering a strange problem related to object file order passed to
the linker, with any binutils and gcc version available to setup-x86_64.exe:
$ cat weak-func.c
extern void weakfunc() __attribute__((weak));
void weakfunc() {}
$ cat weak-main.c
extern void weakfunc() __attribute__((weak));
int main() { weakfunc(); }
$ gcc -o weak.exe weak-func.c weak-main.c
SUCCESS
But then, changing the order of input files on the command line does break
(does work on Linux of course):
$ gcc -o weak.exe weak-main.c weak-func.c
/usr/lib/gcc/x86_64-pc-cygwin/8.3.0/../../../../x86_64-pc-cygwin/bin/ld: /tmp/ccIthYHe.o:weak-main.c:(.text+0xe): relocation truncated to fit: R_X86_64_PC32 against undefined symbol `weakfunc'
collect2: error: ld returned 1 exit status
So the difference is that the object providing weakfunc is passed to
the linker after the object requiring weakfunc.
Attached is the weak-func.sh script that does perform these commands.
Thanks!
/haubi/
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next reply other threads:[~2019-06-07 10:04 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-07 10:04 Michael Haubenwallner [this message]
2019-06-07 11:22 ` JonY
2019-06-07 11:58 ` Jon Turney
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