From c519609864babf8c9ae8a6500894e2f1a84781dd Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Thu, 20 Aug 2009 09:48:49 -0600 Subject: [PATCH] Import latest m4/m4.m4. * submodules/autoconf: Update to autoconf 2.64. * configure.ac (M4_GNU_OPTION): New define. * src/output.c (output_skeleton): Use it to resolve FIXME. * NEWS: Mention this. Signed-off-by: Eric Blake (cherry picked from commit b9ad39c1fb2482e1513cdf9800b31e71b7986b39) --- ChangeLog | 8 ++++++++ NEWS | 2 ++ configure.ac | 2 ++ src/output.c | 33 ++++++++++++++------------------- submodules/autoconf | 2 +- 5 files changed, 27 insertions(+), 20 deletions(-) diff --git a/ChangeLog b/ChangeLog index 25762bc0..8fd9ffdc 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,11 @@ +2009-08-20 Eric Blake + + Import latest m4/m4.m4. + * submodules/autoconf: Update to autoconf 2.64. + * configure.ac (M4_GNU_OPTION): New define. + * src/output.c (output_skeleton): Use it to resolve FIXME. + * NEWS: Mention this. + 2009-08-19 Joel E. Denny Fix complaints about escape sequences. diff --git a/NEWS b/NEWS index e4bb63f5..d300fbc4 100644 --- a/NEWS +++ b/NEWS @@ -113,6 +113,8 @@ Bison News * Changes in version 2.4.2 (????-??-??): +** Detection of GNU M4 1.4.6 or newer during configure is improved. + ** %code is now a permanent feature. A traditional Yacc prologue directive is written in the form: diff --git a/configure.ac b/configure.ac index c7e4fd84..42308f3f 100644 --- a/configure.ac +++ b/configure.ac @@ -94,6 +94,8 @@ AC_PROG_YACC AC_PROG_RANLIB AC_PROG_GNU_M4 AC_DEFINE_UNQUOTED([M4], ["$M4"], [Define to the GNU M4 executable name.]) +AC_DEFINE_UNQUOTED([M4_GNU_OPTION], ["$M4_GNU"], [Define to "-g" if GNU M4 +supports -g, otherwise to "".]) AM_MISSING_PROG([HELP2MAN], [help2man]) AC_PATH_PROG([XSLTPROC], [xsltproc]) AC_SUBST([XSLTPROC]) diff --git a/src/output.c b/src/output.c index a75a9468..6e9a76fb 100644 --- a/src/output.c +++ b/src/output.c @@ -491,7 +491,7 @@ output_skeleton (void) { FILE *in; int filter_fd[2]; - char const *argv[9]; + char const *argv[10]; pid_t pid; /* Compute the names of the package data dir and skeleton files. */ @@ -542,6 +542,19 @@ output_skeleton (void) { int i = 0; argv[i++] = m4; + + /* When POSIXLY_CORRECT is set, GNU M4 1.6 and later disable GNU + extensions, which Bison's skeletons depend on. With older M4, + it has no effect. M4 1.4.12 added a -g/--gnu command-line + option to make it explicit that a program wants GNU M4 + extensions even when POSIXLY_CORRECT is set. + + See the thread starting at + + for details. */ + if (*M4_GNU_OPTION) + argv[i++] = M4_GNU_OPTION; + argv[i++] = "-I"; argv[i++] = pkgdatadir; if (trace_flag & trace_m4) @@ -552,25 +565,7 @@ output_skeleton (void) argv[i++] = full_skeleton; argv[i++] = NULL; } - /* When POSIXLY_CORRECT is set, some future versions of GNU M4 (most likely - 2.0) may drop some of the GNU extensions that Bison's skeletons depend - upon. So that the next release of Bison is forward compatible with those - future versions of GNU M4, we unset POSIXLY_CORRECT here. - - FIXME: A user might set POSIXLY_CORRECT to affect processes run from - macros like m4_syscmd in a custom skeleton. For now, Bison makes no - promises about the behavior of custom skeletons, so this scenario is not a - concern. However, we eventually want to eliminate this shortcoming. The - next release of GNU M4 (1.4.12 or 1.6) will accept the -g command-line - option as a no-op, and later releases will accept it to indicate that - POSIXLY_CORRECT should be ignored. Once the GNU M4 versions that accept - -g are pervasive, Bison should use -g instead of unsetting - POSIXLY_CORRECT. - See the thread starting at - - for details. */ - unsetenv ("POSIXLY_CORRECT"); init_subpipe (); pid = create_subpipe (argv, filter_fd); free (full_m4sugar); diff --git a/submodules/autoconf b/submodules/autoconf index ef8940d9..936160f7 160000 --- a/submodules/autoconf +++ b/submodules/autoconf @@ -1 +1 @@ -Subproject commit ef8940d9b5a3fe2866027f82a535915da3e78829 +Subproject commit 936160f7619cb7fddbc424bb5cb9a2f997d8e166 -- 2.45.2