fix race when building ada-lex.c
Commit Message
PR build/22873
Prevent a race when building ada-lex.c, and any target of rules .c:.l or .c:.y.
The target should be written only at the last step, else SIGINT (^C)
can leave an inconsistent state. Being .PRECIOUS makes it even worse.
gdb/ChangeLog:
* gdb/Makefile.in: (.c:.l, .c:.y): Write the target only in the
last step, and do it atomically.
[patch attached]
Comments
On 2018-04-28 17:13, John Reiser wrote:
> PR build/22873
> Prevent a race when building ada-lex.c, and any target of rules .c:.l
> or .c:.y.
> The target should be written only at the last step, else SIGINT (^C)
> can leave an inconsistent state. Being .PRECIOUS makes it even worse.
>
> gdb/ChangeLog:
> * gdb/Makefile.in: (.c:.l, .c:.y): Write the target only in the
> last step, and do it atomically.
>
> [patch attached]
Hi John,
Thanks for the patch, it makes sense. I pushed it.
Simon
From 66e71c48037729d3239d2fd30dbb92f31281763b Mon Sep 17 00:00:00 2001
From: John Reiser <jreiser@BitWagon.com>
Date: Sat, 28 Apr 2018 13:38:56 -0700
Subject: [PATCH] Fix race when building ada-lex.c
PR build/22873
Prevent a race when building ada-lex.c, and any target of rules .c:.l or .c:.y.
The target should be written only at the last step, else SIGINT (^C)
can leave an inconsistent state. Being .PRECIOUS makes it even worse.
gdb/ChangeLog:
* gdb/Makefile.in: (.c:.l, .c:.y): Write the target only in the
last step, and do it atomically.
---
gdb/Makefile.in | 18 ++++++++----------
1 file changed, 8 insertions(+), 10 deletions(-)
@@ -2483,9 +2483,8 @@ po/$(PACKAGE).pot: force
# Makefile.in, but that was a pretty big annoyance.
%.c: %.y
- rm -f $@ $@.tmp
- $(SHELL) $(YLWRAP) $< y.tab.c $@ -- $(YACC) $(YFLAGS) && mv $@ $@.tmp \
- || (rm -f $@; false)
+ $(SHELL) $(YLWRAP) $< y.tab.c $@.tmp -- $(YACC) $(YFLAGS) \
+ || (rm -f $@.tmp; false)
sed -e '/extern.*malloc/d' \
-e '/extern.*realloc/d' \
-e '/extern.*free/d' \
@@ -2496,13 +2495,13 @@ po/$(PACKAGE).pot: force
-e 's/\([ \t;,(]\)free$$/\1xfree/g' \
-e '/^#line.*y.tab.c/d' \
-e 's/YY_NULL/YY_NULLPTR/g' \
- < $@.tmp > $@
- rm -f $@.tmp
+ < $@.tmp > $@.new && \
+ rm -f $@.tmp && \
+ mv $@.new $@
%.c: %.l
if [ "$(FLEX)" ] && $(FLEX) --version >/dev/null 2>&1; then \
- $(FLEX) -o$@ $< && \
- rm -f $@.new && \
- sed -e '/extern.*malloc/d' \
+ $(FLEX) --stdout $< \
+ | sed -e '/extern.*malloc/d' \
-e '/extern.*realloc/d' \
-e '/extern.*free/d' \
-e '/include.*malloc.h/d' \
@@ -2511,8 +2510,7 @@ po/$(PACKAGE).pot: force
-e 's/\([ \t;,(]\)free\([ \t]*[&(),]\)/\1xfree\2/g' \
-e 's/\([ \t;,(]\)free$$/\1xfree/g' \
-e 's/yy_flex_xrealloc/yyxrealloc/g' \
- < $@ > $@.new && \
- rm -f $@ && \
+ > $@.new && \
mv $@.new $@; \
elif [ -f $@ ]; then \
echo "Warning: $*.c older than $*.l and flex not available."; \
--
2.9.5