comp-libs: make libelf a companion library

When gcc-4.5 is out, it will require libelf. So better make it a
companion library now rather than postponing the ineluctable.

config/companion_libs.in

@@ -100,6 +100,20 @@ config MPC
       can say 'Y' here, although it is unknown yet if any other component
       can use it.
 
+config LIBELF
+    bool
+#    prompt "libelf"
+    select COMPLIBS
+    select WRAPPER_NEEDED
+    help
+      gcc-4.5.0 and above can also use libelf to enable some optimisation
+      (LTO, Link-Time Optimisation, to be precise).  Although libelf is
+      optional, crosstool-NG requires it and uses it to build gcc >= 4.5.0.
+      
+      This will be automatically selected if you choose gcc>=4.5.0, but you
+      can say 'Y' here, although it is unknown yet if any other component
+      can use it.
+
 config GMP_TARGET
     bool
 
@@ -125,6 +139,9 @@ config MPC_TARGET
     select PPL_TARGET
     select CLOOG_TARGET
 
+config LIBELF_TARGET
+    bool
+
 if GMP || GMP_TARGET
 comment "GMP version needed to build for target"
     depends on !GMP
@@ -150,6 +167,11 @@ comment "MPC version needed to build for target"
     depends on !MPC
 source config/companion_libs/mpc.in
 endif
+if LIBELF || LIBELF_TARGET
+comment "libelf version needed to build for target"
+    depends on !LIBELF
+source config/companion_libs/libelf.in
+endif
 
 config FOO
     bool

config/companion_libs/libelf.in

@@ -1,10 +1,5 @@
 # libelf config file
 
-config TOOL_libelf
-    help
-      libelf lets you read, modify or create ELF files in an
-      architecture-independent way.
-
 choice
     bool
     prompt "libelf version"

config/debug/ltrace.in

@@ -1,7 +1,7 @@
 # ltrace
 
 config DEBUG_ltrace
-    select TOOL_libelf
+    select LIBELF_TARGET
     help
       ltrace is a program that simply runs the specified command until it exits.
       It intercepts and records the dynamic library calls which are called by

scripts/build/companion_libs/libelf.sh

@@ -0,0 +1,91 @@
+# Build script for libelf
+
+do_libelf_get() { :; }
+do_libelf_extract() { :; }
+do_libelf() { :; }
+do_libelf_target() { :; }
+
+if [ "${CT_LIBELF}" = "y" -o "${CT_LIBELF_TARGET}" = "y" ]; then
+
+do_libelf_get() {
+    # The server hosting libelf will return an "HTTP 300 : Multiple Choices"
+    # error code if we try to download a file that does not exists there.
+    # So we have to request the file with an explicit extension.
+    CT_GetFile "libelf-${CT_LIBELF_VERSION}" .tar.gz http://www.mr511.de/software/
+}
+
+do_libelf_extract() {
+    CT_Extract "libelf-${CT_LIBELF_VERSION}"
+    CT_Patch "libelf-${CT_LIBELF_VERSION}"
+}
+
+if [ "${CT_LIBELF}" = "y" ]; then
+
+# Uncomment when we need it for gcc-4.5
+# WARNING! This function is absolutely UNTESTED yet!
+do_libelf() {
+    : # Remove this line!
+#    CT_DoStep INFO "Installing libelf"
+#    mkdir -p "${CT_BUILD_DIR}/build-libelf"
+#    CT_Pushd "${CT_BUILD_DIR}/build-libelf"
+#
+#    CT_DoLog EXTRA "Configuring libelf"
+#    CC="${CT_TARGET}-gcc"                                   \
+#    CT_DoExecLog ALL                                        \
+#    "${CT_SRC_DIR}/libelf-${CT_LIBELF_VERSION}/configure"   \
+#        --build=${CT_BUILD}                                 \
+#        --host=${CT_HOST}                                   \
+#        --target=${CT_TARGET}                               \
+#        --prefix="${CT_PREFIX_DIR}"                         \
+#        --enable-compat                                     \
+#        --enable-elf64                                      \
+#        --enable-static                                     \
+#        --enable-shared                                     \
+#        --enable-extended-format
+#
+#    CT_DoLog EXTRA "Building libelf"
+#    CT_DoExecLog ALL make
+#
+#    CT_DoLog EXTRA "Installing libelf"
+#    CT_DoExecLog ALL make instroot="${CT_SYSROOT_DIR}" install
+#
+#    CT_Popd
+#    CT_EndStep
+}
+
+fi # CT_LIBELF
+
+if [ "${CT_LIBELF_TARGET}" = "y" ]; then
+
+do_libelf_target() {
+    CT_DoStep INFO "Installing libelf for the target"
+    mkdir -p "${CT_BUILD_DIR}/build-libelf"
+    CT_Pushd "${CT_BUILD_DIR}/build-libelf"
+
+    CT_DoLog EXTRA "Configuring libelf"
+    CC="${CT_TARGET}-gcc"                                   \
+    CT_DoExecLog ALL                                        \
+    "${CT_SRC_DIR}/libelf-${CT_LIBELF_VERSION}/configure"   \
+        --build=${CT_BUILD}                                 \
+        --host=${CT_TARGET}                                 \
+        --target=${CT_TARGET}                               \
+        --prefix=/usr                                       \
+        --enable-compat                                     \
+        --enable-elf64                                      \
+        --enable-shared                                     \
+        --enable-extended-format                            \
+        --enable-static
+
+    CT_DoLog EXTRA "Building libelf"
+    CT_DoExecLog ALL make
+
+    CT_DoLog EXTRA "Installing libelf"
+    CT_DoExecLog ALL make instroot="${CT_SYSROOT_DIR}" install
+
+    CT_Popd
+    CT_EndStep
+}
+
+fi # CT_LIBELF_TARGET
+
+fi # CT_LIBELF || CT_LIBELF_TARGET

scripts/build/tools/100-libelf.sh

@@ -1,43 +0,0 @@
-# Build script for libelf
-
-do_tools_libelf_get() {
-    # The server hosting libelf will return an "HTTP 300 : Multiple Choices"
-    # error code if we try to download a file that does not exists there.
-    # So we have to request the file with an explicit extension.
-    CT_GetFile "libelf-${CT_LIBELF_VERSION}" .tar.gz http://www.mr511.de/software/
-}
-
-do_tools_libelf_extract() {
-    CT_Extract "libelf-${CT_LIBELF_VERSION}"
-    CT_Patch "libelf-${CT_LIBELF_VERSION}"
-}
-
-do_tools_libelf_build() {
-    CT_DoStep INFO "Installing libelf"
-    mkdir -p "${CT_BUILD_DIR}/build-libelf"
-    CT_Pushd "${CT_BUILD_DIR}/build-libelf"
-
-    CT_DoLog EXTRA "Configuring libelf"
-    CC="${CT_TARGET}-gcc"                                   \
-    CT_DoExecLog ALL                                        \
-    "${CT_SRC_DIR}/libelf-${CT_LIBELF_VERSION}/configure"   \
-        --build=${CT_BUILD}                                 \
-        --host=${CT_TARGET}                                 \
-        --target=${CT_TARGET}                               \
-        --prefix=/usr                                       \
-        --enable-compat                                     \
-        --enable-elf64                                      \
-        --enable-shared                                     \
-        --enable-extended-format                            \
-        --enable-static
-
-    CT_DoLog EXTRA "Building libelf"
-    CT_DoExecLog ALL make
-
-    CT_DoLog EXTRA "Installing libelf"
-    CT_DoExecLog ALL make instroot="${CT_SYSROOT_DIR}" install
-
-    CT_Popd
-    CT_EndStep
-}
-

scripts/crosstool-NG.sh.in

@@ -118,6 +118,7 @@ CT_DoLog INFO "Building environment variables"
 . "${CT_LIB_DIR}/scripts/build/companion_libs/ppl.sh"
 . "${CT_LIB_DIR}/scripts/build/companion_libs/cloog.sh"
 . "${CT_LIB_DIR}/scripts/build/companion_libs/mpc.sh"
+. "${CT_LIB_DIR}/scripts/build/companion_libs/libelf.sh"
 . "${CT_LIB_DIR}/scripts/build/binutils/binutils.sh"
 . "${CT_LIB_DIR}/scripts/build/binutils/elf2flt.sh"
 . "${CT_LIB_DIR}/scripts/build/libc/${CT_LIBC}.sh"
@@ -500,6 +501,7 @@ if [ -z "${CT_RESTART}" ]; then
         do_ppl_get
         do_cloog_get
         do_mpc_get
+        do_libelf_get
         do_binutils_get
         do_elf2flt_get
         do_cc_get
@@ -529,6 +531,7 @@ if [ -z "${CT_RESTART}" ]; then
         do_ppl_extract
         do_cloog_extract
         do_mpc_extract
+        do_libelf_extract
         do_binutils_extract
         do_elf2flt_extract
         do_cc_extract

steps.mk

@@ -23,6 +23,7 @@ CT_STEPS := libc_check_config   \
             ppl                 \
             cloog               \
             mpc                 \
+            libelf              \
             binutils            \
             elf2flt             \
             cc_core_pass_1      \
@@ -34,6 +35,7 @@ CT_STEPS := libc_check_config   \
             libc_finish         \
             gmp_target          \
             mpfr_target         \
+            libelf_target       \
             binutils_target     \
             tools               \
             debug               \