I am having problems in Bison (current master) to recover from a lost parse-gram.h, generated from parse-gram.y with regular Automake (1.11.3) handling:
> AM_YFLAGS = -d -v --warnings=all,error --report=all > > src_bison_SOURCES = \ > ... > src/output.h \ > src/parse-gram.y \ > src/print-xml.c \ > ... Makefile.in: > src/parse-gram.h: src/parse-gram.c > @if test ! -f $@; then rm -f src/parse-gram.c; else :; fi > @if test ! -f $@; then $(MAKE) $(AM_MAKEFLAGS) src/parse-gram.c; else > :; fi The problem is that src/parse-gram.c is in $(srcdir), so its occurrences in the commands should be prefixed by $(srcdir)/. Actually, I don't understand why we don't simply use $< (lemme guess: it's not portable for non generic recipes, ISTR some horrors in this area that my brains decided to quickly forget :). Also, why two "if"? In case some concurrent execution of Make would already have provided $@ in the meanwhile? The following patch extends a test which is aimed at checking this, but does it in a non-vpath build :) I have a question though. I don't understand how come Make realizes it must provide $@ in srcdir too. The Makefile.in features: > .y.c: > $(AM_V_YACC)$(am__skipyacc) $(SHELL) $(YLWRAP) $< y.tab.c $@ y.tab.h > $*.h y.output $*.output -- $(YACCCOMPILE) and at runtime I have: > /bin/sh ../../build-aux/ylwrap ../../src/parse-gram.y y.tab.c > ../../src/parse-gram.c y.tab.h ../../src/parse-gram.h y.output > ../../src/parse-gram.output -- ./tests/bison -y -d -v --warnings=all,error > --report=all > updating ../../src/parse-gram.h > ../../src/parse-gram.output is unchanged which is what is expected, but I don't understand why it works: that $< is prefixed with $(srcdir), this I understand, but why does it appear on $@? I have to specify $(srcdir)/ by hand on similar patterns, why does it work here? Thanks!
0001-tests-check-yacc-parser-header-recovery-in-vpath-bui.patch
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