[binutils-gdb] [gdb/build] Handle deprecation of scm_install_gmp_memory_functions

[binutils-gdb] [gdb/build] Handle deprecation of scm_install_gmp_memory_functions

[Tom de Vries]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=57f8fe908bec51c40ec686294460ec979b140843

commit 57f8fe908bec51c40ec686294460ec979b140843
Author: Ludovic Courtès <ludo@gnu.org>
Date:   Fri Jul 8 16:01:16 2022 +0200

    [gdb/build] Handle deprecation of scm_install_gmp_memory_functions
    
    When building gdb with guile 3.0.8, we run into:
    ...
    gdb/guile/guile.c: In function \
      'void gdbscm_initialize(const extension_language_defn*)':
    gdb/guile/guile.c:680:5: error: 'scm_install_gmp_memory_functions' is \
      deprecated [-Werror=deprecated-declarations]
      680 |     scm_install_gmp_memory_functions = 0;
          |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    In file included from /usr/include/guile/3.0/libguile.h:128,
                     from gdb/guile/guile-internal.h:30,
                     from gdb/guile/guile.c:36:
    /usr/include/guile/3.0/libguile/deprecated.h:164:20: note: declared here
      164 | SCM_DEPRECATED int scm_install_gmp_memory_functions;
          |                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    cc1plus: all warnings being treated as errors
    make[1]: *** [Makefile:1896: guile/guile.o] Error 1
    ...
    
    The variable has been deprecated because it no longer has any effect.
    
    Fix this by disabling the specific deprecation warning.
    
    Also handle upcoming guile versions > 3.0, in which the variable will be
    removed, by limiting the usage of the variable to guile versions <= 3.0.
    
    This does not break anything.  The variable was merely used to address a
    problem present in guile versions <= v3.0.5.
    
    Note that we don't limit the usage of the variable to guile versions <= 3.0.5,
    because we want to support f.i. building against 3.0.6 and then using a shared
    lib with 3.0.5.
    
    Tested on x86_64-linux.
    
    Co-Authored-By: Tom de Vries <tdevries@suse.de>
    
    Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28994

Diff:
---
 gdb/guile/guile.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/gdb/guile/guile.c b/gdb/guile/guile.c
index 14b191ded62..e5565b627d9 100644
--- a/gdb/guile/guile.c
+++ b/gdb/guile/guile.c
@@ -677,7 +677,17 @@ gdbscm_initialize (const struct extension_language_defn *extlang)
        "double free or corruption (out)" error.
        Work around the libguile bug by disabling the installation of the
        libgmp memory functions by guile initialization.  */
+
+    /* The scm_install_gmp_memory_functions variable should be removed after
+       version 3.0, so limit usage to 3.0 and before.  */
+#if SCM_MAJOR_VERSION < 3 || (SCM_MAJOR_VERSION == 3 && SCM_MINOR_VERSION == 0)
+    /* This variable is deprecated in Guile 3.0.8 and later but remains
+       available in the whole 3.0 series.  */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
     scm_install_gmp_memory_functions = 0;
+#pragma GCC diagnostic pop
+#endif
 
     /* scm_with_guile is the most portable way to initialize Guile.  Plus
        we need to initialize the Guile support while in Guile mode (e.g.,