[binutils-gdb] gdb/Makefile: rewrite dependencies for config.status target

[Andrew Burgess <aburgess@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=766f411f084bd6c9a224300bf946a1bfd583ab5f

commit 766f411f084bd6c9a224300bf946a1bfd583ab5f
Author: Andrew Burgess <aburgess@redhat.com>
Date:   Fri Apr 5 10:50:27 2024 +0100

    gdb/Makefile: rewrite dependencies for config.status target
    
    I noticed something weird, the rule for the config.status target looks
    like this:
    
      config.status: $(srcdir)/configure configure.nat configure.tgt configure.host ../bfd/development.sh
              $(SHELL) config.status --recheck
    
    What bothered me is that 'configure' is specified as being in
    $(srcdir), while all of the other files are not, even though those
    files are in the same $(srcdir) as the configure script.
    
    However, I tried touching one of those files, and the config.status
    rule does trigger!
    
    This is thanks to the VPATH variable, which is set to $(srcdir), so
    make looks in $(srcdir) for any dependencies.
    
    However, this inconsistency bothers me.  Better, I think, to add the
    $(srcdir) prefix to each of these files.
    
    I also spotted that the configure script also includes the files
    ../bfd/config.bfd, yet that is missing from the include list, so in
    this commit I plan to add this as a dependency.
    
    The configure script also pulls in two TCL and TK related files:
    
            . ${TCL_BIN_DIR}/tclConfig.sh
            . ${TK_BIN_DIR}/tkConfig.sh
    
    However, I don't think ${TCL_BIN_DIR} and ${TK_BIN_DIR} are currently
    visible in GDB's Makefile, so I'm not planning to add these
    dependencies at this time.
    
    In this commit I add a new variable config_status_deps which holds the
    list of all the dependencies for config.status, with the $(srcdir)
    prefix included, and then I use this in the config.status rule.
    
    After this commit config.status will regenerate if config.bfd changes,
    which it wouldn't before, but nothing else changes.
    
    Approved-By: Simon Marchi <simon.marchi@efficios.com>

Diff:
---
 gdb/Makefile.in | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index df044288b5e..9340becbdc9 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -2333,7 +2333,18 @@ nm.h: stamp-nmh ; @true
 stamp-nmh: config.status
 	$(SHELL) config.status nm.h
 
-config.status: $(srcdir)/configure configure.nat configure.tgt configure.host ../bfd/development.sh
+# Files included from config.status or the configure script.  When
+# these change the configure script doesn't need regenerating, but its
+# output (and so that of config.status) might change.
+config_status_deps = \
+	$(srcdir)/configure \
+	$(srcdir)/configure.nat \
+	$(srcdir)/configure.tgt \
+	$(srcdir)/configure.host \
+	$(srcdir)/../bfd/development.sh \
+	$(srcdir)/../bfd/config.bfd
+
+config.status: $(config_status_deps)
 	$(SHELL) config.status --recheck
 
 ACLOCAL = aclocal