cross-gdb: Add LZMA support configuration

This commit adds a new configuration for enabling the LZMA compression
support through the liblzma, which is required by the GDB's "mini
debuginfo" feature.

Note that this configuration is not enabled by default because it is a
niche feature and requires the liblzma, which is currently not built by
the crosstool-ng for the host (gdb also keeps this feature disabled by
default unless liblzma is available for the host).

Signed-off-by: Stephanos Ioannidis <[email protected]>

Author: stephanosio

config/debug/gdb.in.cross

@@ -85,6 +85,17 @@ config GDB_CROSS_PYTHON_BINARY
       help message in gdb's configure script for the --with-python option
       for further guidance.
 
+config GDB_CROSS_LZMA
+    bool
+    prompt "Build GDB with LZMA"
+    help
+      Build GDB with liblzma, a compression library supporting the LZMA
+      algorithm. LZMA is used by the GDB's "mini debuginfo" feature, which is
+      only useful on the platforms using the ELF object file format.
+
+      Note that crosstool-ng does not build liblzma for the host and you are
+      responsible for providing this library on the build system.
+
 config GDB_CROSS_EXTRA_CONFIG_ARRAY
     string
     prompt "Cross-gdb extra config"

scripts/build/debug/300-gdb.sh

@@ -59,6 +59,12 @@ do_debug_gdb_build_cross()
         cross_extra_config+=("--disable-sim")
     fi
 
+    if [ "${CT_GDB_CROSS_LZMA}" = "y" ]; then
+        cross_extra_config+=("--with-lzma")
+    else
+        cross_extra_config+=("--without-lzma")
+    fi
+
     if ${CT_HOST}-gcc --version 2>&1 | grep clang; then
         # clang detects the line from gettext's _ macro as format string
         # not being a string literal and produces a lot of warnings - which