[RFA 04/10] Use a stamp file for init.c

Tom Tromey
2018-07-02T20:18:43Z

This introduces a stamp file for init.c. This prevents constant
rebuilds of init.o, by arranging for init.c to only be modified when
its contents change. (FWIW this is a standard idiom in use by
Automake and by gdb itself for many years.)

2018-07-02 Tom Tromey <tom@tromey.com>

* Makefile.in (init.c): Depend on stamp-init.
(stamp-init): New rule, from init.c rule.
(clean mostlyclean): Remove stamp-init.
---
gdb/ChangeLog | 6 ++++++
gdb/Makefile.in | 9 +++++----
2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index b35ca2e7aef..d14e86727b8 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -1849,7 +1849,8 @@ test-cp-name-parser$(EXEEXT): test-cp-name-parser.o $(LIBIBERTY)
# in sub-directories such as cli/ and mi/.

INIT_FILES = $(COMMON_OBS)
-init.c: $(INIT_FILES)
+init.c: stamp-init; @true
+stamp-init: $(INIT_FILES)
@$(ECHO_INIT_C) echo "Making init.c"
@rm -f init.c-tmp init.l-tmp
@touch init.c-tmp
@@ -1879,8 +1880,8 @@ init.c: $(INIT_FILES)
@echo '{' >>init.c-tmp
@sed -e 's/\(.*\)/ _initialize_\1 ();/' <init.l-tmp >>init.c-tmp
@echo '}' >>init.c-tmp
- @rm init.l-tmp
- @mv init.c-tmp init.c
+ @$(SHELL) $(srcdir)/../move-if-change init.c-tmp init.c
+ @echo stamp > stamp-init

.PRECIOUS: init.c

@@ -1947,7 +1948,7 @@ tags: TAGS
clean mostlyclean: $(CONFIG_CLEAN)
@$(MAKE) $(FLAGS_TO_PASS) DO=clean "DODIRS=$(CLEANDIRS)" subdir_do
rm -f *.o *.a $(ADD_FILES) *~ init.c-tmp init.l-tmp version.c-tmp
- rm -f init.c version.c
+ rm -f init.c stamp-init version.c
rm -f gdb$(EXEEXT) core make.log
rm -f gdb[0-9]$(EXEEXT)
rm -f test-cp-name-parser$(EXEEXT)
--
2.13.6