There's some strange bug in glibc that triggers if you combine the

--gc-sections linker flag with static linking.  If this happens, then
the "stdout" variable (used by printf() and such) will only work if stdout
is _not_ redirected.  I.E "./busybox" prints stuff, but "./busybox | cat"
does not produce any output.  (But even when redirected, "write(1,"blah",4);"
continues to work just fine.)

This is clearly a glibc bug, but to avoid triggering it I've moved the
--gc-sections flag so it only gets added when we're not statically linking.
If somebody would like to go poke Ulrich Drepper, you can trivially reproduce
this with a "hello world" program, ala:

  gcc -static -Wl,--gc-sections hello.c &&  (./a.out | cat)
This commit is contained in:
Rob Landley 2006-08-29 21:46:10 +00:00
parent 31e2c00ec3
commit 1fdd83f897

View File

@ -267,8 +267,6 @@ ifeq ($(strip $(CONFIG_DEBUG)),y)
CFLAGS +=-g CFLAGS +=-g
else else
CFLAGS +=-DNDEBUG CFLAGS +=-DNDEBUG
CHECKED_LDFLAGS += $(call check_ld,$(LD),--sort-common,)
CHECKED_LDFLAGS += $(call check_ld,$(LD),--gc-sections,)
endif endif
ifneq ($(strip $(CONFIG_DEBUG_PESSIMIZE)),y) ifneq ($(strip $(CONFIG_DEBUG_PESSIMIZE)),y)
@ -288,6 +286,11 @@ endif
STRIPCMD:=$(call check_strip,$(STRIP),-s --remove-section=.note --remove-section=.comment,$(STRIP)) STRIPCMD:=$(call check_strip,$(STRIP),-s --remove-section=.note --remove-section=.comment,$(STRIP))
ifeq ($(strip $(CONFIG_STATIC)),y) ifeq ($(strip $(CONFIG_STATIC)),y)
PROG_CFLAGS += $(call check_cc,$(CC),-static,) PROG_CFLAGS += $(call check_cc,$(CC),-static,)
else
ifneq ($(strip $(CONFIG_DEBUG)),y)
CHECKED_LDFLAGS += $(call check_ld,$(LD),--sort-common,)
CHECKED_LDFLAGS += $(call check_ld,$(LD),--gc-sections,)
endif
endif endif
CFLAGS_SHARED := $(call check_cc,$(CC),-shared,) CFLAGS_SHARED := $(call check_cc,$(CC),-shared,)
LIB_CFLAGS+=$(CFLAGS_SHARED) LIB_CFLAGS+=$(CFLAGS_SHARED)