tools/elfutils: install a subset of the elfutils binaries

Install binaries that are not common with binutils
instead of none at all. This adds a negligible time to the build.

Building shared libraries is disabled, so the AM_LDFLAGS can be reset
without the rpath-link option which is unrecognized by clang.

Some of the binaries depend on functions that are defined
using a "strong alias" instead of a normal definition,
but this is disabled by our patches in order to work on macOS,
so use the identical function directly instead.

Add fnmatch from gnulib with GNU extensions
which is needed for usage of the FNM_EXTMATCH flag.

Handle a "Wunused-const-variable" error with the same
preprocessor conditional used to include the function
that the variable is used in.

Ref: f64bd4b6c ("tools/elfutils: only build required components")
Tested-by: Georgi Valkov <[email protected]> # macOS
Signed-off-by: Michael Pratt <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/15368
Signed-off-by: Robert Marko <[email protected]>

tools/elfutils/Makefile

@@ -17,6 +17,8 @@ PKG_CPE_ID:=cpe:/a:elfutils_project:elfutils
 PKG_FIXUP:=autoreconf
 PKG_INSTALL:=1
 
+PKG_PROGRAMS:=elflint findtextrel elfcmp unstrip stack elfcompress elfclassify srcfiles
+
 PKG_SUBDIRS := \
 	libgnu \
 	config \
@@ -27,7 +29,8 @@ PKG_SUBDIRS := \
 	libebl \
 	libdwelf \
 	libdwfl \
-	libdw
+	libdw \
+	src
 
 PKG_GNULIB_BASE:=libgnu
 
@@ -41,6 +44,7 @@ PKG_GNULIB_ARGS = \
 
 PKG_GNULIB_MODS = \
 	argp \
+	fnmatch-gnu \
 	fts \
 	obstack \
 	progname \
@@ -49,6 +53,10 @@ PKG_GNULIB_MODS = \
 
 include $(INCLUDE_DIR)/host-build.mk
 
+HOST_MAKE_FLAGS += \
+	AM_LDFLAGS='$$$$(STACK_USAGE_NO_ERROR)' \
+	bin_PROGRAMS='$(PKG_PROGRAMS)' EXEEXT=
+
 ifeq ($(HOST_OS),Darwin)
   HOST_CFLAGS += -I/opt/homebrew/include
 endif

tools/elfutils/patches/100-portability.patch

@@ -898,3 +898,46 @@
  #include <stddef.h>
  
  
+--- a/libebl/eblopenbackend.c
++++ b/libebl/eblopenbackend.c
+@@ -198,8 +198,6 @@ static bool default_object_note (const c
+ 				 uint32_t descsz, const char *desc);
+ static bool default_debugscn_p (const char *name);
+ static bool default_copy_reloc_p (int reloc);
+-static bool default_none_reloc_p (int reloc);
+-static bool default_relative_reloc_p (int reloc);
+ static bool default_check_special_symbol (Elf *elf,
+ 					  const GElf_Sym *sym,
+ 					  const char *name,
+@@ -251,8 +249,8 @@ fill_defaults (Ebl *result)
+   result->object_note = default_object_note;
+   result->debugscn_p = default_debugscn_p;
+   result->copy_reloc_p = default_copy_reloc_p;
+-  result->none_reloc_p = default_none_reloc_p;
+-  result->relative_reloc_p = default_relative_reloc_p;
++  result->none_reloc_p = default_copy_reloc_p;
++  result->relative_reloc_p = default_copy_reloc_p;
+   result->check_special_symbol = default_check_special_symbol;
+   result->data_marker_symbol = default_data_marker_symbol;
+   result->check_st_other_bits = default_check_st_other_bits;
+@@ -634,8 +632,6 @@ default_copy_reloc_p (int reloc __attrib
+ {
+   return false;
+ }
+-strong_alias (default_copy_reloc_p, default_none_reloc_p)
+-strong_alias (default_copy_reloc_p, default_relative_reloc_p)
+ 
+ static bool
+ default_check_special_symbol (Elf *elf __attribute__ ((unused)),
+--- a/src/srcfiles.cxx
++++ b/src/srcfiles.cxx
+@@ -78,7 +78,9 @@ ARGP_PROGRAM_VERSION_HOOK_DEF = print_ve
+ /* Bug report address.  */
+ ARGP_PROGRAM_BUG_ADDRESS_DEF = PACKAGE_BUGREPORT;
+ 
++#ifdef HAVE_LIBARCHIVE
+ constexpr size_t BUFFER_SIZE = 8192;
++#endif
+ 
+ /* Definitions of arguments for argp functions.  */
+ static const struct argp_option options[] =