tools/libelf: remove unneeded host library

This old ELF library dating to 2009 used to be necessary on MacOS but
is not required for building the kernel or tools since [1]. On Linux
systems, libelf is already an OpenWRT build-system prerequisite [2].

Presence of the older library can mask or conflict with the system libelf
and lead to build errors, as seen compiling Linux kernels since v5.8 or
host tools such as dwarves (e.g. pahole).

Remove the unnecessary tools/libelf library and avoid the related issues.

[1] 5f8e587240 ("build: force disable stack validation during kernel build
                 on non-linux systems")
[2] https://openwrt.org/docs/guide-developer/build-system/install-buildsystem#prerequisites

Tested-by: Rosen Penev <rosenp@gmail.com> (Linux)
Tested-by: Georgi Valkov <gvalkov@abv.bg> (MacOS)
Signed-off-by: Tony Ambardar <itugrok@yahoo.com>

3 files changed, 1 insertions, 258 deletions

diff --git a/tools/Makefile b/tools/Makefile
index 1d7da0756d..8752a3e2b5 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -28,7 +28,7 @@ tools-y += mklibs mm-macros mtd-utils mtools padjffs2 patch-image
 tools-y += patchelf pkgconf quilt squashfskit4 sstrip xxd zip zlib zstd
 tools-$(BUILD_B43_TOOLS) += b43-tools
 tools-$(BUILD_ISL) += isl
-tools-$(BUILD_TOOLCHAIN) += expat gmp libelf mpc mpfr
+tools-$(BUILD_TOOLCHAIN) += expat gmp mpc mpfr
 tools-$(CONFIG_TARGET_apm821xx)$(CONFIG_TARGET_gemini) += genext2fs
 tools-$(CONFIG_TARGET_ath79) += lzma-old squashfs
 tools-$(CONFIG_TARGET_mxs) += elftosb sdimage
@@ -53,7 +53,6 @@ $(curdir)/flex/compile := $(curdir)/libtool/compile
 $(curdir)/gengetopt/compile := $(curdir)/libtool/compile
 $(curdir)/gmp/compile := $(curdir)/libtool/compile
 $(curdir)/isl/compile := $(curdir)/gmp/compile
-$(curdir)/libelf/compile := $(curdir)/libtool/compile
 $(curdir)/libressl/compile := $(curdir)/pkgconf/compile
 $(curdir)/libtool/compile := $(curdir)/m4/compile $(curdir)/autoconf/compile $(curdir)/automake/compile $(curdir)/missing-macros/compile
 $(curdir)/lzma-old/compile := $(curdir)/zlib/compile
diff --git a/tools/libelf/Makefile b/tools/libelf/Makefile
deleted file mode 100644
index 726c4776bf..0000000000
--- a/tools/libelf/Makefile
+++ /dev/null
@@ -1,58 +0,0 @@
-#
-# Copyright (C) 2010 OpenWrt.org
-#
-# This is free software, licensed under the GNU General Public License v2.
-# See /LICENSE for more information.
-#
-
-include $(TOPDIR)/rules.mk
-
-PKG_NAME:=libelf
-PKG_VERSION:=0.8.13
-PKG_HASH:=591a9b4ec81c1f2042a97aa60564e0cb79d041c52faa7416acb38bc95bd2c76d
-PKG_RELEASE:=1
-
-PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
-PKG_SOURCE_URL:= \
-	http://distfiles.gentoo.org/distfiles/ \
-	http://distcache.freebsd.org/ports-distfiles/
-HOST_BUILD_PARALLEL:=1
-
-HOST_FIXUP:=autoreconf
-
-include $(INCLUDE_DIR)/host-build.mk
-
-PKG_REMOVE_FILES :=
-
-HOST_CONFIGURE_ARGS += \
-	--disable-shared \
-	--enable-elf64
-
-define Host/Configure
-        (cd $(HOST_BUILD_DIR)/$(3); \
-                $(HOST_CONFIGURE_CMD) \
-                $(HOST_CONFIGURE_ARGS); \
-        )
-endef
-
-
-define Host/Compile
-	+$(MAKE) $(HOST_JOBS) -C $(HOST_BUILD_DIR)/lib/ libelf.a
-endef
-
-define Host/Install
-	$(INSTALL_DIR) $(STAGING_DIR_HOST)/{lib/pkgconfig,include/libelf}
-	$(CP) $(HOST_BUILD_DIR)/lib/{elf_repl.h,gelf.h,libelf.h,nlist.h,sys_elf.h} \
-						$(STAGING_DIR_HOST)/include/libelf/
-	$(CP) $(HOST_BUILD_DIR)/lib/libelf.a $(STAGING_DIR_HOST)/lib/
-	$(CP) $(HOST_BUILD_DIR)/libelf.pc $(STAGING_DIR_HOST)/lib/pkgconfig/
-endef
-
-define Host/Clean
-	rm -rf $(STAGING_DIR_HOST)/include/libelf
-	rm -f $(STAGING_DIR_HOST)/lib/libelf.a
-	rm -f $(STAGING_DIR_HOST)/lib/pkgconfig/libelf.pc
-	$(call Host/Clean/Default)
-endef
-
-$(eval $(call HostBuild))
diff --git a/tools/libelf/patches/900-fix-undefined-macro-access.patch b/tools/libelf/patches/900-fix-undefined-macro-access.patch
deleted file mode 100644
index 21e7d1ba8f..0000000000
--- a/tools/libelf/patches/900-fix-undefined-macro-access.patch
+++ /dev/null
@@ -1,198 +0,0 @@
---- a/lib/elf_repl.h
-+++ b/lib/elf_repl.h
-@@ -45,7 +45,7 @@ typedef __libelf_u32_t		Elf32_Word;
- #define ELF32_FSZ_SWORD		4
- #define ELF32_FSZ_WORD		4
- 
--#if __LIBELF64
-+#if defined(__LIBELF64)
- 
- typedef __libelf_u64_t		Elf64_Addr;
- typedef __libelf_u16_t		Elf64_Half;
-@@ -93,7 +93,7 @@ typedef struct {
-     Elf32_Half		e_shstrndx;
- } Elf32_Ehdr;
- 
--#if __LIBELF64
-+#if defined(__LIBELF64)
- typedef struct {
-     unsigned char	e_ident[EI_NIDENT];
-     Elf64_Half		e_type;
-@@ -307,7 +307,7 @@ typedef struct {
-     Elf32_Word		sh_entsize;
- } Elf32_Shdr;
- 
--#if __LIBELF64
-+#if defined(__LIBELF64)
- typedef struct {
-     Elf64_Word		sh_name;
-     Elf64_Word		sh_type;
-@@ -434,7 +434,7 @@ typedef struct {
-     Elf32_Half		st_shndx;
- } Elf32_Sym;
- 
--#if __LIBELF64
-+#if defined(__LIBELF64)
- typedef struct {
-     Elf64_Word		st_name;
-     unsigned char	st_info;
-@@ -457,7 +457,7 @@ typedef struct {
- #define ELF32_ST_TYPE(i)	((i)&0xf)
- #define ELF32_ST_INFO(b,t)	(((b)<<4)+((t)&0xf))
- 
--#if __LIBELF64
-+#if defined(__LIBELF64)
- #define ELF64_ST_BIND(i)	((i)>>4)
- #define ELF64_ST_TYPE(i)	((i)&0xf)
- #define ELF64_ST_INFO(b,t)	(((b)<<4)+((t)&0xf))
-@@ -495,7 +495,7 @@ typedef struct {
-  * Macros for manipulating st_other
-  */
- #define ELF32_ST_VISIBILITY(o)	((o)&0x3)
--#if __LIBELF64
-+#if defined(__LIBELF64)
- #define ELF64_ST_VISIBILITY(o)	((o)&0x3)
- #endif /* __LIBELF64 */
- 
-@@ -521,7 +521,7 @@ typedef struct {
-     Elf32_Sword		r_addend;
- } Elf32_Rela;
- 
--#if __LIBELF64
-+#if defined(__LIBELF64)
- typedef struct {
-     Elf64_Addr		r_offset;
-     Elf64_Xword		r_info;
-@@ -541,7 +541,7 @@ typedef struct {
- #define ELF32_R_TYPE(i)		((unsigned char)(i))
- #define ELF32_R_INFO(s,t)	(((s)<<8)+(unsigned char)(t))
- 
--#if __LIBELF64
-+#if defined(__LIBELF64)
- #define ELF64_R_SYM(i)		((Elf64_Xword)(i)>>32)
- #define ELF64_R_TYPE(i)		((i)&0xffffffffL)
- #define ELF64_R_INFO(s,t)	(((Elf64_Xword)(s)<<32)+((t)&0xffffffffL))
-@@ -556,7 +556,7 @@ typedef struct {
-     Elf32_Word		n_type;		/* descriptor type */
- } Elf32_Nhdr;
- 
--#if __LIBELF64
-+#if defined(__LIBELF64)
- /* Solaris and GNU use this layout.  Be compatible. */
- /* XXX: Latest ELF specs say it's 64-bit!!! */
- typedef struct {
-@@ -587,7 +587,7 @@ typedef struct {
-     Elf32_Word		p_align;
- } Elf32_Phdr;
- 
--#if __LIBELF64
-+#if defined(__LIBELF64)
- typedef struct {
-     Elf64_Word		p_type;
-     Elf64_Word		p_flags;
-@@ -654,7 +654,7 @@ typedef struct {
-     } d_un;
- } Elf32_Dyn;
- 
--#if __LIBELF64
-+#if defined(__LIBELF64)
- typedef struct {
-     Elf64_Sxword	d_tag;
-     union {
-@@ -798,7 +798,7 @@ typedef struct {
-     Elf32_Half		si_flags;
- } Elf32_Syminfo;
- 
--#if __LIBELF64
-+#if defined(__LIBELF64)
- typedef struct {
-     Elf64_Half		si_boundto;
-     Elf64_Half		si_flags;
-@@ -863,7 +863,7 @@ typedef struct {
- 
- typedef Elf32_Half	Elf32_Versym;
- 
--#if __LIBELF64
-+#if defined(__LIBELF64)
- 
- typedef struct {
-     Elf64_Half		vd_version;
-@@ -933,7 +933,7 @@ typedef Elf64_Half	Elf64_Versym;
- /*
-  * Move section
-  */
--#if __LIBELF64
-+#if defined(__LIBELF64)
- 
- typedef struct {
-     Elf32_Lword		m_value;
-@@ -973,7 +973,7 @@ typedef struct {
-     } c_un;
- } Elf32_Cap;
- 
--#if __LIBELF64
-+#if defined(__LIBELF64)
- 
- typedef struct {
-     Elf64_Xword     	c_tag;
---- a/lib/gelf.h
-+++ b/lib/gelf.h
-@@ -22,15 +22,15 @@
- #ifndef _GELF_H
- #define _GELF_H
- 
--#if __LIBELF_INTERNAL__
-+#if defined(__LIBELF_INTERNAL__)
- #include <libelf.h>
- #else /* __LIBELF_INTERNAL__ */
- #include <libelf/libelf.h>
- #endif /* __LIBELF_INTERNAL__ */
- 
--#if __LIBELF_NEED_LINK_H
-+#if defined(__LIBELF_NEED_LINK_H)
- #include <link.h>
--#elif __LIBELF_NEED_SYS_LINK_H
-+#elif defined(__LIBELF_NEED_SYS_LINK_H)
- #include <sys/link.h>
- #endif /* __LIBELF_NEED_LINK_H */
- 
-@@ -71,7 +71,7 @@ typedef Elf64_Sym	GElf_Sym;
- /*
-  * Symbol versioning
-  */
--#if __LIBELF_SYMBOL_VERSIONS
-+#if defined(__LIBELF_SYMBOL_VERSIONS)
- typedef Elf64_Verdef	GElf_Verdef;
- typedef Elf64_Verneed	GElf_Verneed;
- typedef Elf64_Verdaux	GElf_Verdaux;
---- a/lib/libelf.h
-+++ b/lib/libelf.h
-@@ -25,7 +25,7 @@
- #include <stddef.h>	/* for size_t */
- #include <sys/types.h>
- 
--#if __LIBELF_INTERNAL__
-+#if defined(__LIBELF_INTERNAL__)
- #include <sys_elf.h>
- #else /* __LIBELF_INTERNAL__ */
- #include <libelf/sys_elf.h>
-@@ -224,7 +224,7 @@ extern Elf_Data *elf32_xlatetom __P((Elf
-  */
- extern long elf32_checksum __P((Elf *__elf));
- 
--#if __LIBELF64
-+#if defined(__LIBELF64)
- /*
-  * 64-bit ELF functions
-  * Not available on all platforms
---- a/lib/sys_elf.h.in
-+++ b/lib/sys_elf.h.in
-@@ -116,7 +116,7 @@ Foundation, Inc., 51 Franklin Street, Fi
- #   define ELF64_R_INFO(s,t)	(((Elf64_Xword)(s)<<32)+((t)&0xffffffffL))
- #  endif /* ELF64_R_SYM */
- 
--#  if __LIBELF64_LINUX
-+#  if defined(__LIBELF64_LINUX)
- typedef __libelf_u64_t	Elf64_Addr;
- typedef __libelf_u16_t	Elf64_Half;
- typedef __libelf_u64_t	Elf64_Off;