gnu: make-bootstrap: Ensure libm.a provides ‘fmod’ on i686.

Fixes <https://issues.guix.gnu.org/72725>.

* gnu/packages/make-bootstrap.scm (glibc-for-bootstrap)[arguments]: Add
‘apply-libm-patch’ on i686.
* gnu/packages/patches/glibc-2.39-fmod-libm-a.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.

Reported-by: Ricardo Wurmus <rekado@elephly.net>
Change-Id: Iaffba0a9f424d8d80a8a5611df2d285d7d632d99

gnu/local.mk

@@ -1394,6 +1394,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/glib-skip-failing-test.patch		\
   %D%/packages/patches/glibc-2.33-riscv64-miscompilation.patch	\
   %D%/packages/patches/glibc-2.39-git-updates.patch	\
+  %D%/packages/patches/glibc-2.39-fmod-libm-a.patch		\
   %D%/packages/patches/glibc-CVE-2019-7309.patch		\
   %D%/packages/patches/glibc-CVE-2019-9169.patch		\
   %D%/packages/patches/glibc-CVE-2019-19126.patch		\

gnu/packages/make-bootstrap.scm

@@ -85,7 +85,18 @@ (define glibc-for-bootstrap
           ;; and can use statically-linked NSS modules.
           `(cons* "--disable-nscd" "--disable-build-nscd"
                   "--enable-static-nss"
-                  ,flags))))
+                  ,flags))
+         ((#:phases phases #~%standard-phases)
+          ;; Apply i686-linux-specific patch.
+          (if (target-x86-32?)
+              #~(modify-phases #$phases
+                  (add-after 'unpack 'apply-libm-patch
+                    (lambda _
+                      (define patch
+                        #$(local-file
+                           (search-patch "glibc-2.39-fmod-libm-a.patch")))
+                      (invoke "patch" "--force" "-p1" "-i" patch))))
+              phases))))
 
       ;; Remove the 'debug' output to allow bit-reproducible builds (when the
       ;; 'debug' output is used, ELF files end up with a .gnu_debuglink, which

gnu/packages/patches/glibc-2.39-fmod-libm-a.patch

@@ -0,0 +1,98 @@
+Fixes lack of 'fmod' in libm.a on i686-linux:
+
+  https://sourceware.org/bugzilla/show_bug.cgi?id=31488
+  https://issues.guix.gnu.org/72725
+
+commit 0b716305dfb48c2d13ed4f7d06c082b90c1d226f
+Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>
+Date:   Thu Mar 14 14:59:35 2024 -0300
+
+    math: Fix i386 and m68k fmod/fmodf on static build (BZ 31488)
+
+diff --git a/sysdeps/i386/fpu/w_fmod_compat.c b/sysdeps/i386/fpu/w_fmod_compat.c
+index 5ac9995ffd..528bfc2a13 100644
+--- a/sysdeps/i386/fpu/w_fmod_compat.c
++++ b/sysdeps/i386/fpu/w_fmod_compat.c
+@@ -7,8 +7,9 @@
+ # define LIBM_SVID_COMPAT 1
+ # undef compat_symbol
+ # define compat_symbol(a, b, c, d)
+-#endif
+-#include <math/w_fmod_compat.c>
+-#ifdef SHARED
++# include <math/w_fmod_compat.c>
+ libm_alias_double (__fmod_compat, fmod)
++#else
++#include <math-type-macros-double.h>
++#include <w_fmod_template.c>
+ #endif
+diff --git a/sysdeps/i386/fpu/w_fmodf_compat.c b/sysdeps/i386/fpu/w_fmodf_compat.c
+index cc417e07d3..5a61693e51 100644
+--- a/sysdeps/i386/fpu/w_fmodf_compat.c
++++ b/sysdeps/i386/fpu/w_fmodf_compat.c
+@@ -7,8 +7,9 @@
+ # define LIBM_SVID_COMPAT 1
+ # undef compat_symbol
+ # define compat_symbol(a, b, c, d)
+-#endif
+-#include <math/w_fmodf_compat.c>
+-#ifdef SHARED
++# include <math/w_fmodf_compat.c>
+ libm_alias_float (__fmod_compat, fmod)
++#else
++#include <math-type-macros-float.h>
++#include <w_fmod_template.c>
+ #endif
+diff --git a/sysdeps/ieee754/ldbl-opt/s_ldexpl.c b/sysdeps/ieee754/ldbl-opt/s_ldexpl.c
+index 1afbe7d8ad..932cc4341c 100644
+--- a/sysdeps/ieee754/ldbl-opt/s_ldexpl.c
++++ b/sysdeps/ieee754/ldbl-opt/s_ldexpl.c
+@@ -17,13 +17,13 @@
+    License along with the GNU C Library; if not, see
+    <https://www.gnu.org/licenses/>.  */
+ 
+-#if IS_IN (libc)
++#if IS_IN (libc) && defined SHARED
+ # define declare_mgen_alias(f,t)
+ #endif
+ #include <math-type-macros-ldouble.h>
+ #include <s_ldexp_template.c>
+ 
+-#if IS_IN (libc)
++#if IS_IN (libc) && defined SHARED
+ long_double_symbol (libc, __ldexpl, ldexpl);
+ long_double_symbol (libc, __wrap_scalbnl, scalbnl);
+ #endif
+diff --git a/sysdeps/m68k/m680x0/fpu/w_fmod_compat.c b/sysdeps/m68k/m680x0/fpu/w_fmod_compat.c
+index 527d4fbed2..57f38091e6 100644
+--- a/sysdeps/m68k/m680x0/fpu/w_fmod_compat.c
++++ b/sysdeps/m68k/m680x0/fpu/w_fmod_compat.c
+@@ -7,8 +7,9 @@
+ # define LIBM_SVID_COMPAT 1
+ # undef compat_symbol
+ # define compat_symbol(a, b, c, d)
+-#endif
+ #include <math/w_fmod_compat.c>
+-#ifdef SHARED
+ libm_alias_double (__fmod_compat, fmod)
++#else
++#include <math-type-macros-double.h>
++#include <w_fmod_template.c>
+ #endif
+diff --git a/sysdeps/m68k/m680x0/fpu/w_fmodf_compat.c b/sysdeps/m68k/m680x0/fpu/w_fmodf_compat.c
+index 5043586b91..88db07f443 100644
+--- a/sysdeps/m68k/m680x0/fpu/w_fmodf_compat.c
++++ b/sysdeps/m68k/m680x0/fpu/w_fmodf_compat.c
+@@ -7,8 +7,9 @@
+ # define LIBM_SVID_COMPAT 1
+ # undef compat_symbol
+ # define compat_symbol(a, b, c, d)
+-#endif
+-#include <math/w_fmodf_compat.c>
+-#ifdef SHARED
++# include <math/w_fmodf_compat.c>
+ libm_alias_float (__fmod_compat, fmod)
++#else
++#include <math-type-macros-float.h>
++#include <w_fmod_template.c>
+ #endif