Rich Felker
a6adb2bcd8
previously we detected this bug in configure and issued advice for a workaround, but this turned out not to work. since then gcc 4.9.0 has appeared in several distributions, and now 4.9.1 has been released without a fix despite this being a wrong code generation bug which is supposed to be a release-blocker, per gcc policy. since the scope of the bug seems to affect only data objects (rather than functions) whose definitions are overridable, and there are only a very small number of these in musl, I am just changing them from const to volatile for the time being. simply removing the const would be sufficient to make gcc 4.9.1 work (the non-const case was inadvertently fixed as part of another change in gcc), and this would also be sufficient with 4.9.0 if we forced -O0 on the affected files or on the whole build. however it's cleaner to just remove all the broken compiler detection and use volatile, which will ensure that they are never constant-folded. the quality of a non-broken compiler's output should not be affected except for the fact that these objects are no longer const and thus possibly add a few bytes to data/bss. this change can be reconsidered and possibly reverted at some point in the future when the broken gcc versions are no longer relevant.
50 lines
876 B
C
50 lines
876 B
C
#include "stdio_impl.h"
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static int __fflush_unlocked(FILE *f)
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{
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/* If writing, flush output */
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if (f->wpos > f->wbase) {
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f->write(f, 0, 0);
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if (!f->wpos) return EOF;
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}
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/* If reading, sync position, per POSIX */
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if (f->rpos < f->rend) f->seek(f, f->rpos-f->rend, SEEK_CUR);
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/* Clear read and write modes */
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f->wpos = f->wbase = f->wend = 0;
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f->rpos = f->rend = 0;
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return 0;
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}
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/* stdout.c will override this if linked */
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static FILE *volatile dummy = 0;
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weak_alias(dummy, __stdout_used);
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int fflush(FILE *f)
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{
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int r;
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if (f) {
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FLOCK(f);
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r = __fflush_unlocked(f);
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FUNLOCK(f);
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return r;
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}
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r = __stdout_used ? fflush(__stdout_used) : 0;
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OFLLOCK();
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for (f=libc.ofl_head; f; f=f->next) {
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FLOCK(f);
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if (f->wpos > f->wbase) r |= __fflush_unlocked(f);
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FUNLOCK(f);
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}
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OFLUNLOCK();
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return r;
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}
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weak_alias(__fflush_unlocked, fflush_unlocked);
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