Build native gdb automatically

We always used to build gdbserver for ARC, but automatic building of full
GDB hasn't been implemented. This patch replaced old-schoold gdbserver build
with a new shiny process, that will build both GDB and gdbserver. GDB
requires ncurses - that is build automatically. Native GDB build can be disabled
via option --no-native-gdb. In the latter case GDBserver still will be built
- it doesn't need any external dependencies, so there should be no harm in
building it.

Note that we used to build gdbserver with static linkage, but now it is
linked dynamically, regardless of whether native GDB is built or not. Such
gdbserver will not work if there is an error in dynamic linker - gdbserver
will not start in this case. However such cases are very rare, therefore I
don't think it makes sense to sacrifice 99.9% of cases for this one rare
case.  If somebody needs static gdbserver - they can build it manually, it's
not a rocket science.

Signed-off-by: Anton Kolesov <[email protected]>

Author: anthony-kolesov

arc-init.sh

@@ -434,17 +434,49 @@ configure_uclibc_stage2() {
     fi
 }
 
+
+# Configure application to run on ARC, that is --host=arc-snps-linux-uclibc (or
+# whatever is correct for particular case).
+# Arguments:
+# $1 - source directory
+# $2 - target triplet
+# rest are passed to configure as is
+configure_for_arc() {
+    echo "  configuring..."
+
+    local srcdir=$1
+    local triplet=$2
+    shift 2
+
+    # --prefix must correspond to prefix on *target* system, not where it will
+    # be installed on build host - prefix value might be stored somewhere in
+    # final product, therefore stored value should be one which is valid for
+    # target system. To install files on build host DESTDIR should be set when
+    # calling "make install". Note - prefix is set to /usr, DESTDIR should
+    # point to sysroot.
+    if ! $srcdir/configure --prefix=/usr --host=$triplet \
+	    --with-pkgversion="${version_str}"\
+	    --with-bugurl="$ARC_COMMON_BUGURL" \
+	    CFLAGS="$CFLAGS_FOR_TARGET" $* \
+	    >> "$logfile" 2>&1
+    then
+	echo "ERROR: failed while configuring."
+	echo "See \`$logfile' for details."
+	exit 1
+    fi
+}
+
 # Arguments:
 # $1 - step name. It should be a gerund for proper text representation, as
 # "building", not "build".
-# remaining - make targets
+# remaining - make targets. Although really can be make vars as well, like "A=aa".
 make_target() {
     local step="$1"
     shift
     echo "  $step..."
     if ! make $PARALLEL $* >> "$logfile" 2>&1
     then
-	echo "ERROR: failed while $1."
+	echo "ERROR: failed while $step."
 	echo "See \`$logfile' for details."
 	exit 1
     fi
@@ -461,7 +493,7 @@ make_target_ordered() {
     echo "  $step..."
     if ! make $* >> "$logfile" 2>&1
     then
-	echo "ERROR: failed while $1."
+	echo "ERROR: failed while $step."
 	echo "See \`$logfile' for details."
 	exit 1
     fi

build-all.sh

@@ -50,6 +50,7 @@
 #                  [--nptl | --no-nptl]
 #                  [--checkout-config <config>]
 #                  [--host <triplet>]
+#                  [--native-gdb | --no-native-gdb]
 
 # This script is a convenience wrapper to build the ARC GNU 4.4 tool
 # chains. It utilizes Joern Rennecke's build-elf32.sh script and Bendan
@@ -272,6 +273,22 @@
 #     compile software for ARC processors. Note that this makes sense only for
 #     baremetal (elf32) toolchain.
 
+# --native-gdb | --no-native-gdb
+
+#     Whether to build or not to build native GDB - GDB that will run directly
+#     on ARC Linux. Default is yes. Makes sense only for Linux toolchain
+#     (--uclibc). Note that GDB requires ncurses, which will be built
+#     automatically. That has several possible points of failure:
+#     - ncurses is not part of GNU Toolchain. Its source is autodownloaded.
+#       Build process will fail if it cannot be downloaded. If you have
+#       problems, either use --no-native-gdb or put ncurses-5.9.tar.gz into
+#       toolchain/_download_tmp directory.
+#     - static ncurses libs will be installed to sysroot. You might experience
+#       issues if you will build ncurses on your own (or via Buildroot). If that
+#       is the case - build toolchain without native GDB, and then build GDB
+#       manually with your ncurses. Buildroot handles this nicely.
+#     - Due to a bug ncurses has to be built without C++ bindings.
+
 # Where directories are specified as arguments, they are relative to the
 # current directory, unless specified as absolute names.
 
@@ -336,6 +353,7 @@ ISA_CPU="arc700"
 UCLIBC_DEFCFG=""
 CONFIG_EXTRA=""
 DO_PDF="--pdf"
+DO_NATIVE_GDB=yes
 rel_rpaths="--no-rel-rpaths"
 DISABLEWERROR="--disable-werror"
 CFLAGS_FOR_TARGET=""
@@ -552,6 +570,14 @@ case ${opt} in
 	TOOLCHAIN_HOST="$1"
 	;;
 
+    --native-gdb)
+	DO_NATIVE_GDB=yes
+	;;
+
+    --no-native-gdb)
+	DO_NATIVE_GDB=no
+	;;
+
     ?*)
 	echo "Unknown argument $1"
 	echo
@@ -585,6 +611,7 @@ case ${opt} in
 	echo "                      [--nptl | --no-nptl]"
 	echo "                      [--checkout-config <config>]"
 	echo "                      [--host <triplet>]"
+	echo "                      [--native-gdb | --no-native-gdb]"
 	exit 1
 	;;
 
@@ -741,6 +768,7 @@ export ISA_CPU
 export DO_SIM
 export CONFIG_EXTRA
 export DO_PDF
+export DO_NATIVE_GDB
 export PARALLEL
 export UCLIBC_DEFCFG
 export DISABLEWERROR

build-uclibc.sh

@@ -541,48 +541,74 @@ done
 echo "  finished creating symlinks"
 
 # -----------------------------------------------------------------------------
-# gdbserver has to be built on its own.
-
-echo "Building gdbserver to run on an ARC ..." | tee -a "${logfile}"
-echo "=======================================" >> "${logfile}"
-
-build_dir_init gdbserver
-
-# ARC_COMMON_BUGURL is defined in arc-init.sh, which has been source.
-config_path=$(calcConfigPath "${ARC_GNU}")/gdb/gdb/gdbserver
-if "${config_path}"/configure \
-        --with-pkgversion="${version_str}"\
-        --with-bugurl="$ARC_COMMON_BUGURL" \
-        --host=${triplet} >> "${logfile}" 2>> "${logfile}"
-then
-    echo "  finished configuring gdbserver"
-else
-    echo "ERROR: gdbserver configure failed. Please see"
-    echo "       \"${logfile}\" for details."
-    exit 1
-fi
-
-CC=${triplet}-gcc
-export CC
-if make ${PARALLEL} \
-    CFLAGS="-static -fcommon -mno-sdata -O3 ${CFLAGS_FOR_TARGET}" \
-    >> "${logfile}" 2>&1
-then
-    echo "  finished building gdbserver to run on an arc"
-else
-    echo "ERROR: gdbserver build was not successful. Please see"
-    echo "       \"${logfile}\" for details."
-    exit 1
-fi
+# Native GDB
+
+if [ $DO_NATIVE_GDB = yes ]; then
+
+    # GDB needs ncurses (termcap to be exact).
+    # Since ncurses is a separate product it is an outlier with regards of build process.
+    echo "Building native ncurses to run on an ARC ..." | tee -a "${logfile}"
+
+    ncurses_version=5.9
+    ncurses_url_base=http://ftp.gnu.org/pub/gnu/ncurses
+    ncurses_tar=ncurses-${ncurses_version}.tar.gz
+    ncurses_url=$ncurses_url_base/$ncurses_tar
+    cd "$ARC_GNU/toolchain"
+    mkdir -p _download_tmp
+    if [ ! -s _download_tmp/$ncurses_tar ]; then
+	wget -nv -O _download_tmp/$ncurses_tar $ncurses_url
+    fi
 
-mkdir -p ${INSTALLDIR}/target-bin
-if cp gdbserver ${INSTALLDIR}/target-bin
-then
-    echo "  finished installing gdbserver to run on an ARC"
+    build_dir_init ncurses
+    tar xaf $ARC_GNU/toolchain/_download_tmp/$ncurses_tar --strip-components=1
+    # Ada is not supported on ARC, so it has to be disabled, otherwise dumb
+    # configure script might find Ada compiler for host system and will try to
+    # use it as a compiler for ARC.
+    # C++ has to be disabled because of STAR9000908736 - there is an error when
+    # linking its demo application. Otherwise there is no reason to disable C++
+    # support.
+    configure_for_arc . $triplet --without-cxx-binding --without-ada
+    make_target building
+    make_target_ordered installing install DESTDIR=$SYSROOTDIR
+
+    echo "Building native GDB to run on an ARC ..." | tee -a "${logfile}"
+
+    build_dir_init native_gdb
+
+    config_path=$(calcConfigPath "${ARC_GNU}")/gdb
+    configure_for_arc "$config_path" $triplet \
+	--disable-gas --disable-ld --disable-binutils
+    make_target building
+    # For reasons I do not know arc-linux-strip is ignored by install-sh, even
+    # though gdb/Makefile sets STRIPPROG. But it installs it in some
+    # funny/complex way, which perhaps is source of an issue. To avoid any
+    # troubles just set STRIPPROG to arc-linux-strip. Note: STRIP is Makefile
+    # variable; STRIPPROG is variable used by install-sh; STRIP is already set
+    # correctly, but STRIPPROG is not.
+    # Unforunately strip will strip complete symbol table, instead of just
+    # debug symbols.
+    make_target_ordered installing install-strip-gdb DESTDIR=$SYSROOTDIR \
+	STRIPPROG=${triplet}-strip
 else
-    echo "ERROR: gdbserver install was not successful. Please see"
-    echo "       \"${logfile}\" for details."
-    exit 1
+    # If native GDB has been disabled, then simple gdbserver still will be
+    # built. It doesn't need ncurses.
+    echo "Building gdbserver to run on an ARC ..." | tee -a "$logfile"
+
+    build_dir_init gdbserver
+    # Static options are same as when gdbserver is configured by the top-level
+    # configure script.
+    config_path=$(calcConfigPath "${ARC_GNU}")/gdb/gdb/gdbserver
+    LDFLAGS="-static-libstdc++ -static-libgcc" \
+	configure_for_arc "$config_path" $triplet
+    make_target building
+
+    # gdbserver makefile lacks install-strip target. It is possible to trick
+    # gdbserver Makefile to install stripped binary by setting INSTAL_PROGRAM
+    # Makefile variable to 'install -c -s', however this way gdbserver would be
+    # stripped from all symbols, not just debug symbols.
+    # Note that $SYSROOTDIR/usr/bin might not exist yet.
+    mkdir -p $SYSROOTDIR/usr/bin
+    ${triplet}-objcopy -g gdbserver $SYSROOTDIR/usr/bin/gdbserver
 fi
 
 echo "DONE  UCLIBC: $(date)" | tee -a "${logfile}"