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Define GEN_AS_CONST_HEADERS when generating header files [BZ #22792]

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Glibc build generates header files to define constants from special .sym
files.  If a .sym file includes the same header file which it generates,
it leads to circular dependency which may lead to build hang on a
many-core machine.  Define GEN_AS_CONST_HEADERS when generating header
files to avoid circular dependency.

<tcb-offsets.h> is needed for i686 and it isn't needed for x86-64 at
least since glibc 2.23.

Tested on i686 and x86-64.

	[BZ #22792]
	* Makerules ($(common-objpfx)%.h): Pass -DGEN_AS_CONST_HEADERS
	to $(CC).
	* sysdeps/unix/sysv/linux/i386/lowlevellock.h: Include
	<tcb-offsets.h> only if GEN_AS_CONST_HEADERS isn't defined.
	* sysdeps/unix/sysv/linux/x86_64/lowlevellock.h: Don't include
	<tcb-offsets.h>.
This commit is contained in:
H.J. Lu 2018-02-23 11:29:27 -08:00
parent 54412d2061
commit f5d1f629c6
4 changed files with 26 additions and 3 deletions
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10
ChangeLog
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@ -1,3 +1,13 @@
2018-02-23 H.J. Lu <hongjiu.lu@intel.com>
[BZ #22792]
* Makerules ($(common-objpfx)%.h): Pass -DGEN_AS_CONST_HEADERS
to $(CC).
* sysdeps/unix/sysv/linux/i386/lowlevellock.h: Include
<tcb-offsets.h> only if GEN_AS_CONST_HEADERS isn't defined.
* sysdeps/unix/sysv/linux/x86_64/lowlevellock.h: Don't include
<tcb-offsets.h>.
2018-02-23 Joseph Myers <joseph@codesourcery.com>
[BZ #15105]

9
Makerules
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@ -276,10 +276,17 @@ ifdef gen-as-const-headers
# Generating headers for assembly constants.
# We need this defined early to get into before-compile before
# it's used in sysd-rules, below.
# Define GEN_AS_CONST_HEADERS to avoid circular dependency [BZ #22792].
# NB: <tcb-offsets.h> is generated from tcb-offsets.sym to define
# offsets and sizes of types in <tls.h> and maybe <pthread.h> which
# may include <tcb-offsets.h>. Target header files can check if
# GEN_AS_CONST_HEADERS is defined to avoid circular dependency which
# may lead to build hang on a many-core machine.
$(common-objpfx)%.h $(common-objpfx)%.h.d: $(..)scripts/gen-as-const.awk \
%.sym $(common-before-compile)
$(AWK) -f $< $(filter %.sym,$^) \
| $(CC) -S -o $(@:.h.d=.h)T3 $(CFLAGS) $(CPPFLAGS) -x c - \
| $(CC) -S -o $(@:.h.d=.h)T3 $(CFLAGS) $(CPPFLAGS) \
-DGEN_AS_CONST_HEADERS -x c - \
-MD -MP -MF $(@:.h=.h.d)T -MT '$(@:.h=.h.d) $(@:.h.d=.h)'
sed -n 's/^.*@@@name@@@\([^@]*\)@@@value@@@[^0-9Xxa-fA-F-]*\([0-9Xxa-fA-F-][0-9Xxa-fA-F-]*\).*@@@end@@@.*$$/#define \1 \2/p' \
$(@:.h.d=.h)T3 > $(@:.h.d=.h)T

9
sysdeps/unix/sysv/linux/i386/lowlevellock.h
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@ -26,7 +26,14 @@
# include <sys/param.h>
# include <bits/pthreadtypes.h>
# include <kernel-features.h>
# include <tcb-offsets.h>
/* <tcb-offsets.h> is generated from tcb-offsets.sym to define offsets
and sizes of types in <tls.h> as well as <pthread.h> which includes
<lowlevellock.h> via nptl/descr.h. Don't include <tcb-offsets.h>
when generating <tcb-offsets.h> to avoid circular dependency which
may lead to build hang on a many-core machine. */
# ifndef GEN_AS_CONST_HEADERS
# include <tcb-offsets.h>
# endif
# ifndef LOCK_INSTR
# ifdef UP

1
sysdeps/unix/sysv/linux/x86_64/lowlevellock.h
View File

@ -26,7 +26,6 @@
# include <sys/param.h>
# include <bits/pthreadtypes.h>
# include <kernel-features.h>
# include <tcb-offsets.h>
# ifndef LOCK_INSTR
# ifdef UP