From d08229790289e2bbf1e285275dd1bf3189cad078 Mon Sep 17 00:00:00 2001
From: nbd <nbd@3c298f89-4303-0410-b956-a3cf2f4a3e73>
Date: Tue, 1 Mar 2011 05:40:38 +0000
Subject: [PATCH] base-files: relink uclibc and libgcc libraries to remove
 leftovers of the statically linked initial libgcc saves a few kb and gets rid
 of unused not exported functions as well should also improve the reliability
 of mklibs

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@25800 3c298f89-4303-0410-b956-a3cf2f4a3e73
---
 package/base-files/Makefile | 64 ++++++++++++++++++++++++++++++++++---
 scripts/relink-lib.sh       | 14 ++++++++
 2 files changed, 73 insertions(+), 5 deletions(-)
 create mode 100755 scripts/relink-lib.sh

diff --git a/package/base-files/Makefile b/package/base-files/Makefile
index 4abbdf7ac..27916f3e6 100644
--- a/package/base-files/Makefile
+++ b/package/base-files/Makefile
@@ -327,8 +327,56 @@ endef
 define Build/Compile/Default
 endef
 
+LIBGCC_A=$(wildcard $(TOOLCHAIN_DIR)/lib/gcc/*/*/libgcc_pic.a)
+LIBGCC_MAP=$(wildcard $(TOOLCHAIN_DIR)/lib/gcc/*/*/libgcc.map)
+
+ifeq ($(CONFIG_EXTERNAL_TOOLCHAIN),)
+  define Build/Compile/uClibc
+	$(SCRIPT_DIR)/relink-lib.sh \
+		"$(TARGET_CROSS)" \
+		"$(wildcard $(TOOLCHAIN_DIR)/lib/libc_so.a)" \
+		"$(wildcard $(TOOLCHAIN_DIR)/lib/libc_so.a)" \
+		"$(patsubst $(TOOLCHAIN_DIR)/lib/%,$(PKG_BUILD_DIR)/%,$(wildcard $(TOOLCHAIN_DIR)/lib/libuClibc-*.so))" \
+		-Wl,-init,__uClibc_init -Wl,-soname=libc.so.0 \
+		$(PKG_BUILD_DIR)/libgcc_s.so.*
+	$(SCRIPT_DIR)/relink-lib.sh \
+		"$(TARGET_CROSS)" \
+		"$(wildcard $(TOOLCHAIN_DIR)/lib/libcrypt-*.so)" \
+		"$(wildcard $(TOOLCHAIN_DIR)/lib/libcrypt_pic.a)" \
+		"$(patsubst $(TOOLCHAIN_DIR)/lib/%,$(PKG_BUILD_DIR)/%,$(wildcard $(TOOLCHAIN_DIR)/lib/libcrypt-*.so))" \
+		$(PKG_BUILD_DIR)/libgcc_s.so.* \
+		-Wl,-soname=libcrypt.so.0
+	$(SCRIPT_DIR)/relink-lib.sh \
+		"$(TARGET_CROSS)" \
+		"$(wildcard $(TOOLCHAIN_DIR)/lib/libm-*.so)" \
+		"$(wildcard $(TOOLCHAIN_DIR)/lib/libm_pic.a)" \
+		"$(patsubst $(TOOLCHAIN_DIR)/lib/%,$(PKG_BUILD_DIR)/%,$(wildcard $(TOOLCHAIN_DIR)/lib/libm-*.so))" \
+		$(PKG_BUILD_DIR)/libgcc_s.so.* \
+		-Wl,-soname=libm.so.0
+	$(SCRIPT_DIR)/relink-lib.sh \
+		"$(TARGET_CROSS)" \
+		"$(wildcard $(TOOLCHAIN_DIR)/lib/libpthread-*.so)" \
+		"$(wildcard $(TOOLCHAIN_DIR)/lib/libpthread_so.a)" \
+		"$(patsubst $(TOOLCHAIN_DIR)/lib/%,$(PKG_BUILD_DIR)/%,$(wildcard $(TOOLCHAIN_DIR)/lib/libpthread-*.so))" \
+		-Wl,-z,nodelete,-z,initfirst,-init=__pthread_initialize_minimal_internal \
+		$(PKG_BUILD_DIR)/libgcc_s.so.* \
+		-Wl,-soname=libpthread.so.0
+  endef
+
+  define Build/Compile/libgcc
+	$(SCRIPT_DIR)/relink-lib.sh \
+		"$(TARGET_CROSS)" \
+		"$(wildcard $(TOOLCHAIN_DIR)/lib/libgcc_s.so.*)" \
+		"$(LIBGCC_A)" \
+		"$(patsubst $(TOOLCHAIN_DIR)/lib/%,$(PKG_BUILD_DIR)/%,$(wildcard $(TOOLCHAIN_DIR)/lib/libgcc_s.so.*))" \
+		-Wl,--version-script=$(LIBGCC_MAP) -Wl,-soname=libgcc_s.so.1
+  endef
+endif
+
 define Build/Compile
 	$(call Build/Compile/Default)
+	$(call Build/Compile/libgcc)
+	$(call Build/Compile/$(LIBC))
 endef
 
 define Package/base-files/install
@@ -398,7 +446,7 @@ ifeq ($(CONFIG_EXTERNAL_TOOLCHAIN),)
 
   define Package/libgcc/install
 	$(INSTALL_DIR) $(1)/lib
-	$(CP) $(TOOLCHAIN_DIR)/lib/libgcc_s.so.* $(1)/lib/
+	$(CP) $(PKG_BUILD_DIR)/libgcc_s.so.* $(1)/lib/
   endef
 
   define Package/libssp/install
@@ -450,6 +498,12 @@ ifeq ($(CONFIG_EXTERNAL_TOOLCHAIN),)
 			$(TOOLCHAIN_DIR)/lib/$$$$file-$(LIBC_SO_VERSION).so \
 			$(1)/lib/; \
 	done
+
+	$(CP) \
+		$(PKG_BUILD_DIR)/libuClibc-* \
+		$(PKG_BUILD_DIR)/libm-* \
+		$(PKG_BUILD_DIR)/libcrypt-* \
+		$(1)/lib/
   endef
 
   define Package/libc/install
@@ -459,9 +513,9 @@ ifeq ($(CONFIG_EXTERNAL_TOOLCHAIN),)
   define Package/libc/install_lib
 	$(CP) $(filter-out %/libdl_pic.a %/libpthread_pic.a %/libresolv_pic.a,$(wildcard $(TOOLCHAIN_DIR)/lib/lib*.a)) $(1)/lib/
 	$(if $(wildcard $(TOOLCHAIN_DIR)/lib/libc_so.a),$(CP) $(TOOLCHAIN_DIR)/lib/libc_so.a $(1)/lib/libc_pic.a)
-	$(if $(wildcard $(TOOLCHAIN_DIR)/lib/gcc/*/*/libgcc.map), \
-		$(CP) $(TOOLCHAIN_DIR)/lib/gcc/*/*/libgcc_pic.a $(1)/lib/libgcc_s_pic.a; \
-		$(CP) $(TOOLCHAIN_DIR)/lib/gcc/*/*/libgcc.map $(1)/lib/libgcc_s_pic.map \
+	$(if $(LIBGCC_MAP), \
+		$(CP) $(LIBGCC_A) $(1)/lib/libgcc_s_pic.a; \
+		$(CP) $(LIBGCC_MAP) $(1)/lib/libgcc_s_pic.map \
 	)
   endef
 
@@ -469,7 +523,7 @@ ifeq ($(CONFIG_EXTERNAL_TOOLCHAIN),)
 	$(INSTALL_DIR) $(1)/lib
 	$(CP) \
 		$(TOOLCHAIN_DIR)/lib/libpthread.so.* \
-		$(TOOLCHAIN_DIR)/lib/libpthread-$(LIBC_SO_VERSION).so \
+		$(PKG_BUILD_DIR)/libpthread-$(LIBC_SO_VERSION).so \
 		$(1)/lib/
   endef
 
diff --git a/scripts/relink-lib.sh b/scripts/relink-lib.sh
new file mode 100755
index 000000000..5367b7093
--- /dev/null
+++ b/scripts/relink-lib.sh
@@ -0,0 +1,14 @@
+#!/bin/sh
+[ $# -lt 4 -o -z "$1" -o -z "$2" -o -z "$3" -o -z "$4" ] && {
+	echo "Usage: $0 <cross> <reference> <pic .a> <destination>"
+	exit 1
+}
+
+cross="$1"; shift
+ref="$1"; shift
+pic="$1"; shift
+dest="$1"; shift
+
+SYMBOLS="$(${cross}nm "$ref" | grep -E '........ [TW] ' | awk '$3 {printf "-u%s ", $3}')"
+set -x
+${cross}gcc -nostdlib -nostartfiles -shared -Wl,--gc-sections -o "$dest" $SYMBOLS "$pic" "$@"