[gcc r14-8932] gcc/Makefile.in: Always check info dependencies

[Christophe Lyon <clyon@gcc.gnu.org>]

https://gcc.gnu.org/g:1fcaa3a8225885a93d537025cb071651c13235f7

commit r14-8932-g1fcaa3a8225885a93d537025cb071651c13235f7
Author: Christophe Lyon <christophe.lyon@linaro.org>
Date:   Sat Feb 10 21:17:08 2024 +0000

    gcc/Makefile.in: Always check info dependencies
    
    BUILD_INFO is currently a byproduct of checking makeinfo
    presence/version.  INSTALL_INFO used to be defined similarly, but was
    removed in 2000 (!) by commit 17db658241d18cf6db59d31bc2d6eac96e9257df
    (svn r38141).
    
    In order to save build time, our CI overrides MAKEINFO=echo, which
    works when invoking 'make all' but not for 'make install' in case some
    info files need an update.
    
    I noticed this while testing a patch posted on the gcc-patches list,
    leading to an error at 'make install' time after updating tm.texi (the
    build reported 'new text' in tm.texi and stopped).  This is because
    'install' depends on 'install-info', which depends on
    $(DESTDIR)$(infodir)/gccint.info (among others).
    
    As discussed, it is better to detect this problem during 'make all'
    rather than 'make install', and we still want to detect it even if
    makeinfo is not available.
    
    This patch makes configure set BUILD_INFO=no-info in case makeinfo is
    missing/too old, which effectively makes the build rules no-ops
    (x$(BUILD_INFO) != xinfo), and updates Makefile.in so that 'info'
    dependencies are still checked.
    
    2024-02-10  Christophe Lyon  <christophe.lyon@linaro.org>
    
            gcc/
            * Makefile.in: Add no-info dependency.
            * configure.ac: Set BUILD_INFO=no-info if makeinfo is not
            available.
            * configure: Regenerate.

Diff:
---
 gcc/Makefile.in  | 7 +++++++
 gcc/configure    | 2 +-
 gcc/configure.ac | 2 +-
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/gcc/Makefile.in b/gcc/Makefile.in
index 95caa54a52bd..a74761b7ab32 100644
--- a/gcc/Makefile.in
+++ b/gcc/Makefile.in
@@ -3480,6 +3480,13 @@ install-no-fixedincludes:
 
 doc: $(BUILD_INFO) $(GENERATED_MANPAGES)
 
+# If BUILD_INFO is set to no-info by configure, we still want to check
+# 'info' dependencies even the build rules are no-ops because
+# BUILD_INFO != info (see %.info rule)
+ifeq ($(BUILD_INFO),no-info)
+no-info: info
+endif
+
 INFOFILES = doc/cpp.info doc/gcc.info doc/gccint.info \
             doc/gccinstall.info doc/cppinternals.info
 
diff --git a/gcc/configure b/gcc/configure
index c83e09beea9f..41b978b0380b 100755
--- a/gcc/configure
+++ b/gcc/configure
@@ -8835,7 +8835,7 @@ if test $gcc_cv_prog_makeinfo_modern = no; then
 $as_echo "$as_me: WARNING:
 *** Makeinfo is missing or too old.
 *** Info documentation will not be built." >&2;}
-  BUILD_INFO=
+  BUILD_INFO=no-info
 else
   BUILD_INFO=info
 fi
diff --git a/gcc/configure.ac b/gcc/configure.ac
index 239856a4e202..72012d61e671 100644
--- a/gcc/configure.ac
+++ b/gcc/configure.ac
@@ -1245,7 +1245,7 @@ if test $gcc_cv_prog_makeinfo_modern = no; then
   AC_MSG_WARN([
 *** Makeinfo is missing or too old.
 *** Info documentation will not be built.])
-  BUILD_INFO=
+  BUILD_INFO=no-info
 else
   BUILD_INFO=info
 fi