build: added libexpat build support

This allows commands such as "info os files"
previously we had expat support on x86_64 only.

Author: guyush1

.gitmodules

@@ -6,3 +6,6 @@
 	path = src/submodule_packages/binutils-gdb
 	url = [email protected]:guyush1/binutils-gdb.git
 	branch = gdb-static
+[submodule "src/submodule_packages/libexpat"]
+	path = src/submodule_packages/libexpat
+	url = [email protected]:guyush1/libexpat.git

Dockerfile

@@ -19,6 +19,7 @@ RUN apt update && apt install -y \
     gcc-powerpc-linux-gnu \
     git \
     libncurses-dev \
+    libtool \
     m4  \
     make \
     patch \

src/compilation/build.sh

@@ -68,6 +68,17 @@ function set_ncurses_link_variables() {
     export LDFLAGS="-L$ncursesw_build_dir/lib $LDFLAGS"
 }
 
+function set_libexpat_link_variables() {
+    # Set up libexpat library link variables
+    #
+    # Parameters:
+    # $1: libexpat build dir
+    local libexpat_build_dir="$1"
+
+    # Allow tui mode by adding our custom built static libexpat library to the linker search path.
+    export LDFLAGS="-L$libexpat_build_dir/lib/.libs $LDFLAGS"
+}
+
 function build_iconv() {
     # Build libiconv.
     #
@@ -214,6 +225,56 @@ function build_ncurses() {
     popd > /dev/null
 }
 
+function build_libexpat() {
+    # Build libexpat.
+    #
+    # Parameters:
+    # $1: libexpat package directory
+    # $2: target architecture
+    #
+    # Echoes:
+    # The libexpat build directory
+    #
+    # Returns:
+    # 0: success
+    # 1: failure
+    local libexpat_dir="$1"
+    local target_arch="$2"
+    local libexpat_build_dir="$(realpath "$libexpat_dir/build-$target_arch")"
+
+    echo "$libexpat_build_dir"
+    mkdir -p "$libexpat_build_dir"
+
+    if [[ -f "$libexpat_build_dir/lib/.libs/libexpat.a" ]]; then
+        >&2 echo "Skipping build: libexpat already built for $target_arch"
+        return 0
+    fi
+
+    pushd "$libexpat_build_dir" > /dev/null
+
+    >&2 fancy_title "Building libexpat for $target_arch"
+
+    # Generate configure if it doesnt exist.
+    if [[ ! -f "$libexpat_build_dir/../expat/configure" ]]; then
+        ../expat/buildconf.sh ../expat/
+    fi
+
+    ../expat/configure --enable-static "CC=$CC" "CXX=$CXX" "--host=$HOST" \
+        "CFLAGS=$CFLAGS" "CXXFLAGS=$CXXFLAGS" 1>&2
+    if [[ $? -ne 0 ]]; then
+        return 1
+    fi
+
+    make -j$(nproc) 1>&2
+    if [[ $? -ne 0 ]]; then
+        return 1
+    fi
+
+    >&2 fancy_title "Finished building libexpat for $target_arch"
+
+    popd > /dev/null
+}
+
 function build_python() {
     # Build python.
     #
@@ -373,6 +434,7 @@ function build_gdb() {
 
     ../configure -C --enable-static --with-static-standard-libraries --disable-inprocess-agent \
                  --enable-tui "$python_flag" \
+                 --with-expat --with-libexpat-type="static" \
                  "--with-libiconv-prefix=$libiconv_prefix" --with-libiconv-type=static \
                  "--with-gmp=$libgmp_prefix" \
                  "--with-mpfr=$libmpfr_prefix" \
@@ -517,6 +579,9 @@ function build_gdb_with_dependencies() {
     fi
     set_ncurses_link_variables "$ncursesw_build_dir"
 
+    libexpat_build_dir="$(build_libexpat "$packages_dir/libexpat" "$target_arch")"
+    set_libexpat_link_variables "$libexpat_build_dir"
+
     if [[ "$with_python" == "yes" ]]; then
         build_python "$packages_dir/cpython-static" "$target_arch"
         if [[ $? -ne 0 ]]; then