Move GDB out of HostTools.

Test: ./checkbuild.py gdb
Test: ./checkbuild.py --system windows gdb
Test: ./checkbuild.py --system windows64 gdb
Test: cd samples/NdkGdbSample && \
          ./gradlew installDebug && \
          $NDK/ndk-gdb --launch
Bug: http://b/62547070

Change-Id: I4e2472de84f1ca475f9235dc983fb61e261701a9

4 files changed, 213 insertions, 111 deletions

diff --git a/build/tools/build-gdb-stub.sh b/build/tools/build-gdb-stub.sh
deleted file mode 100755
index 2dfd6434d..000000000
--- a/build/tools/build-gdb-stub.sh
+++ /dev/null
@@ -1,81 +0,0 @@
-#!/bin/bash
-
-NDK_BUILDTOOLS_PATH="$(dirname $0)"
-. "$NDK_BUILDTOOLS_PATH/prebuilt-common.sh"
-. "$NDK_BUILDTOOLS_PATH/common-build-host-funcs.sh"
-
-PROGRAM_PARAMETERS=""
-PROGRAM_DESCRIPTION="\
-This program is used to build the gdb stub for Windows and replace a
-gdb executable with it. Because of the replacing nature of this, I
-check to see if there's a gdb-orig.exe there already and if so, 'undo'
-the process first by putting it back. Sample usage:
-
-$0 --gdb-executable-path=\$NDK/toolchains/arm-linux-androideabi-4.8/prebuilt/bin/arm-linux-androideabi-gdb.exe \\
-   --python-prefix-dir=\$NDK/prebuilt/windows \\
-   --mingw-w64-gcc-path=\$HOME/i686-w64-mingw32/bin/i686-w64-mingw32-gcc
-"
-
-NDK_DIR=$ANDROID_NDK_ROOT
-
-PYTHON_PREFIX_DIR=
-register_var_option "--python-prefix-dir=<path>" PYTHON_PREFIX_DIR "Python prefix directory."
-
-GDB_EXECUTABLE_PATH=
-register_var_option "--gdb-executable-path=<path>" GDB_EXECUTABLE_PATH "GDB executable file to stubify."
-
-MINGW_W64_GCC=
-register_var_option "--mingw-w64-gcc=<program>" MINGW_W64_GCC "MinGW-w64 gcc program to use."
-
-DEBUG_STUB=
-register_var_option "--debug" DEBUG_STUB "Build stub in debug mode."
-
-extract_parameters "$@"
-
-if [ -n "$DEBUG_STUB" ]; then
-    STUB_CFLAGS="-O0 -g -D_DEBUG"
-else
-    STUB_CFLAGS="-O2 -s -DNDEBUG"
-fi
-
-if [ ! -f "$GDB_EXECUTABLE_PATH" ]; then
-    panic "GDB executable $GDB_EXECUTABLE_PATH doesn't exist!"
-fi
-
-if [ ! -d "$PYTHON_PREFIX_DIR" ]; then
-    panic "Python prefix dir $PYTHON_PREFIX_DIR doesn't exist!"
-fi
-
-if [ -z "$MINGW_W64_GCC" ]; then
-    panic "Please specify an existing MinGW-w64 cross compiler with --mingw-w64-gcc=<program>"
-fi
-
-GDB_BIN_DIR=$(cd $(dirname "$GDB_EXECUTABLE_PATH"); pwd)
-PYTHON_PREFIX_DIR=$(cd "$PYTHON_PREFIX_DIR"; pwd)
-PYTHON_BIN_DIR=${PYTHON_PREFIX_DIR}/bin
-
-# Sed is used to get doubled up Windows style dir separators.
-GDB_TO_PYTHON_REL_DIR=$(relpath "$GDB_BIN_DIR" "$PYTHON_BIN_DIR" | sed -e s./.\\\\\\\\.g)
-PYTHONHOME_REL_DIR=$(relpath "$GDB_BIN_DIR" "$PYTHON_PREFIX_DIR" | sed -e s./.\\\\\\\\.g)
-dump "GDB_TO_PYTHON_REL_DIR=$GDB_TO_PYTHON_REL_DIR"
-dump "PYTHONHOME_REL_DIR=$PYTHONHOME_REL_DIR"
-
-GDB_EXECUTABLE_ORIG=$(dirname "$GDB_EXECUTABLE_PATH")/$(basename "$GDB_EXECUTABLE_PATH" ".exe")-orig.exe
-if [ -f "$GDB_EXECUTABLE_ORIG" ] ; then
-    echo "Warning : Found an existing gdb-stub called $GDB_EXECUTABLE_ORIG so will un-do a previous run of this script."
-    cp "$GDB_EXECUTABLE_ORIG" "$GDB_EXECUTABLE_PATH"
-fi
-cp "$GDB_EXECUTABLE_PATH" "$GDB_EXECUTABLE_ORIG"
-
-GDB_EXECUTABLE_ORIG_FILENAME=$(basename "$GDB_EXECUTABLE_ORIG")
-
-# Build the stub in-place of the real gdb.
-run $MINGW_W64_GCC $STUB_CFLAGS "$NDK_DIR/sources/host-tools/gdb-stub/gdb-stub.c" \
-                    -o "$GDB_EXECUTABLE_PATH" \
-                    -DGDB_TO_PYTHON_REL_DIR=\"$GDB_TO_PYTHON_REL_DIR\" \
-                    -DPYTHONHOME_REL_DIR=\"$PYTHONHOME_REL_DIR\" \
-                    -DGDB_EXECUTABLE_ORIG_FILENAME=\"$GDB_EXECUTABLE_ORIG_FILENAME\"
-
-fail_panic "Can't build gdb stub!"
-
-dump "GDB Stub done!"
diff --git a/ndk/autoconf.py b/ndk/autoconf.py
index edd447540..0c9e98895 100644
--- a/ndk/autoconf.py
+++ b/ndk/autoconf.py
@@ -144,21 +144,14 @@ class AutoconfBuilder:
                 automatically.
         """
         with self.cd():
-            build_host_args: List[str]
-            if self.no_build_or_host:
-                build_host_args = []
-            else:
-                build_triple = HOST_TRIPLE_MAP[get_default_host()]
-                host_triple = HOST_TRIPLE_MAP[self.host]
-                build_host_args = [
-                    f'--build={build_triple}',
-                    f'--host={host_triple}',
-                ]
-
+            build_triple = HOST_TRIPLE_MAP[get_default_host()]
+            host_triple = HOST_TRIPLE_MAP[self.host]
             configure_args = [
                 str(self.configure_script),
                 f'--prefix={self.install_directory}',
-            ] + build_host_args + args
+                f'--build={build_triple}',
+                f'--host={host_triple}',
+            ] + args
 
             flags_str = ' '.join(self.toolchain.flags + self.flags)
             cc = f'{self.toolchain.cc} {flags_str}'
diff --git a/ndk/checkbuild.py b/ndk/checkbuild.py
index f6dd4011f..b2ef56e89 100755
--- a/ndk/checkbuild.py
+++ b/ndk/checkbuild.py
@@ -67,6 +67,7 @@ from build.lib import build_support
 import ndk.abis
 from ndk.autoconf import AutoconfBuilder
 import ndk.ansi
+import ndk.autoconf
 import ndk.builds
 import ndk.config
 import ndk.deps
@@ -603,7 +604,6 @@ class HostTools(ndk.builds.Module):
     @property
     def notices(self) -> List[str]:
         return [
-            ndk.paths.android_path('toolchain/gdb/gdb-7.11/COPYING'),
             ndk.paths.android_path('toolchain/python/Python-2.7.5/LICENSE'),
             str(self.make_src / 'COPYING'),
             ndk.paths.ndk_path('sources/host-tools/toolbox/NOTICE'),
@@ -646,9 +646,6 @@ class HostTools(ndk.builds.Module):
         ndk.builds.invoke_external_build(
             'toolchain/python/build.py', build_args)
 
-        print('Building GDB...')
-        ndk.builds.invoke_external_build('toolchain/gdb/build.py', build_args)
-
         print('Building YASM...')
         ndk.builds.invoke_external_build('toolchain/yasm/build.py', build_args)
 
@@ -657,7 +654,6 @@ class HostTools(ndk.builds.Module):
         ndk.ext.shutil.create_directory(install_dir)
 
         packages = [
-            'gdb-multiarch-7.11',
             'ndk-python',
             'ndk-yasm',
         ]
@@ -1114,6 +1110,208 @@ class Platforms(ndk.builds.Module):
                         'This file forces git to keep the directory.')
 
 
+class Gdb(ndk.builds.Module):
+    """Module for multi-arch host GDB.
+
+    Note that the device side, gdbserver, is a separate module because it needs
+    to be cross compiled for all four Android ABIs.
+    """
+
+    name = 'gdb'
+    path = 'prebuilt/{host}'
+
+    deps = {
+        'host-tools',
+    }
+
+    GDB_VERSION = '7.11'
+
+    expat_src = ndk.paths.ANDROID_DIR / 'toolchain/expat/expat-2.0.1'
+    lzma_src = ndk.paths.ANDROID_DIR / 'toolchain/xz'
+    gdb_src = ndk.paths.ANDROID_DIR / f'toolchain/gdb/gdb-{GDB_VERSION}'
+
+    notice_group = ndk.builds.NoticeGroup.TOOLCHAIN
+
+    _expat_builder: Optional[ndk.autoconf.AutoconfBuilder] = None
+    _lzma_builder: Optional[ndk.autoconf.AutoconfBuilder] = None
+    _gdb_builder: Optional[ndk.autoconf.AutoconfBuilder] = None
+
+    @property
+    def notices(self) -> List[str]:
+        return [
+            str(self.expat_src / 'COPYING'),
+            str(self.gdb_src / 'COPYING'),
+            str(self.lzma_src / 'COPYING'),
+        ]
+
+    @property
+    def intermediate_out_dir(self) -> Path:
+        """Path for intermediate outputs of this module."""
+        return Path(self.out_dir) / self.host.value / 'gdb'
+
+    @property
+    def expat_builder(self) -> ndk.autoconf.AutoconfBuilder:
+        """Returns the lazily initialized expat builder for this module."""
+        if self._expat_builder is None:
+            self._expat_builder = ndk.autoconf.AutoconfBuilder(
+                self.expat_src / 'configure',
+                self.intermediate_out_dir / 'expat', self.host)
+        return self._expat_builder
+
+    @property
+    def lzma_builder(self) -> ndk.autoconf.AutoconfBuilder:
+        """Returns the lazily initialized lzma builder for this module."""
+        if self._lzma_builder is None:
+            self._lzma_builder = ndk.autoconf.AutoconfBuilder(
+                self.lzma_src / 'configure',
+                self.intermediate_out_dir / 'lzma',
+                self.host,
+                add_toolchain_to_path=True)
+        return self._lzma_builder
+
+    @property
+    def gdb_builder(self) -> ndk.autoconf.AutoconfBuilder:
+        """Returns the lazily initialized gdb builder for this module."""
+        if self._gdb_builder is None:
+            self._gdb_builder = ndk.autoconf.AutoconfBuilder(
+                self.gdb_src / 'configure',
+                self.intermediate_out_dir / 'gdb', self.host)
+        return self._gdb_builder
+
+    @property
+    def gdb_stub_install_path(self) -> Path:
+        """The gdb stub install path."""
+        return self.gdb_builder.install_directory / 'bin/gdb-stub'
+
+    def build_expat(self) -> None:
+        """Builds the expat dependency."""
+        self.expat_builder.build([
+            '--disable-shared',
+            '--enable-static',
+        ])
+
+    def build_lzma(self) -> None:
+        """Builds the liblzma dependency."""
+        self.lzma_builder.build([
+            '--disable-shared',
+            '--enable-static',
+            '--disable-xz',
+            '--disable-xzdec',
+            '--disable-lzmadev',
+            '--disable-scripts',
+            '--disable-doc',
+        ])
+
+    def build_gdb(self) -> None:
+        """Builds GDB itself."""
+        targets = ' '.join(ndk.abis.ALL_TRIPLES)
+        # TODO: Cleanup Python module so we don't need this explicit path.
+        python_config = (Path(
+            self.out_dir) / self.host.value / 'python' / ndk.hosts.host_to_tag(
+                self.host) / 'install/host-tools/bin/python-config.sh')
+        configure_args = [
+            '--with-expat',
+            f'--with-libexpat-prefix={self.expat_builder.install_directory}',
+            f'--with-python={python_config}',
+            f'--enable-targets={targets}',
+            '--disable-shared',
+            '--disable-werror',
+            '--disable-nls',
+            '--disable-docs',
+            '--without-mpc',
+            '--without-mpfr',
+            '--without-gmp',
+            '--without-isl',
+            '--disable-sim',
+            '--enable-gdbserver=no',
+        ]
+
+        configure_args.extend([
+            '--with-lzma',
+            f'--with-liblzma-prefix={self.lzma_builder.install_directory}',
+        ])
+
+        self.gdb_builder.build(configure_args)
+
+    def build_gdb_stub(self) -> None:
+        """Builds a gdb wrapper to setup PYTHONHOME.
+
+        We need to use gdb with the Python it was built against, so we need to
+        setup PYTHONHOME to point to the NDK's Python, not the host's.
+        """
+        if self.host.is_windows:
+            # TODO: Does it really need to be an executable?
+            # It's probably an executable because the original author wanted a
+            # .exe rather than a .cmd. Not sure how disruptive this change
+            # would be now. Presumably hardly at all because everyone needs to
+            # use ndk-gdb for reasonable behavior anyway?
+            self.build_exe_gdb_stub()
+        else:
+            self.build_sh_gdb_stub()
+
+    def build_exe_gdb_stub(self) -> None:
+        # Don't need to worry about extension here because it'll be renamed on
+        # install anyway.
+        gdb_stub_path = self.gdb_builder.install_directory / 'bin/gdb-stub'
+        stub_src = ndk.paths.NDK_DIR / 'sources/host-tools/gdb-stub/gdb-stub.c'
+        mingw_path = (ndk.paths.ANDROID_DIR /
+                      'prebuilts/gcc/linux-x86/host/x86_64-w64-mingw32-4.8/bin'
+                      / 'x86_64-w64-mingw32-gcc')
+
+        cmd = [
+            str(mingw_path),
+            '-O2',
+            '-s',
+            '-DNDEBUG',
+            str(stub_src),
+            '-o',
+            str(gdb_stub_path),
+        ]
+        pp_cmd = ' '.join([pipes.quote(arg) for arg in cmd])
+        print('Running: {}'.format(pp_cmd))
+        subprocess.run(cmd, check=True)
+
+    def build_sh_gdb_stub(self) -> None:
+        self.gdb_stub_install_path.write_text(
+            textwrap.dedent("""\
+            #!/bin/bash
+            GDBDIR=$(cd $(dirname $0) && pwd)
+            PYTHONHOME="$GDBDIR/.." "$GDBDIR/gdb-orig" "$@"
+            """))
+        self.gdb_stub_install_path.chmod(0o755)
+
+    def build(self) -> None:
+        """Builds GDB."""
+        if self.intermediate_out_dir.exists():
+            shutil.rmtree(self.intermediate_out_dir)
+
+        self.build_expat()
+        self.build_lzma()
+        self.build_gdb()
+        self.build_gdb_stub()
+
+    def install(self) -> None:
+        """Installs GDB."""
+        install_dir = Path(self.get_install_path())
+        copy_tree(
+            str(self.gdb_builder.install_directory / 'bin'),
+            str(install_dir / 'bin'))
+        gdb_share_dir = self.gdb_builder.install_directory / 'share/gdb'
+        gdb_share_install_dir = install_dir / 'share/gdb'
+        if gdb_share_install_dir.exists():
+            shutil.rmtree(gdb_share_install_dir)
+        shutil.copytree(gdb_share_dir, gdb_share_install_dir)
+
+        # gdb is currently gdb(.exe)? and the gdb stub is currently gdb-stub.
+        # Make them gdb-orig(.exe)? and gdb(.exe)? respectively.
+        exe_suffix = '.exe' if self.host.is_windows else ''
+        gdb_exe = install_dir / ('bin/gdb' + exe_suffix)
+        gdb_exe.rename(install_dir / ('bin/gdb-orig' + exe_suffix))
+
+        gdb_stub = install_dir / 'bin/gdb-stub'
+        gdb_stub.rename(install_dir / ('bin/gdb' + exe_suffix))
+
+
 class LibShaderc(ndk.builds.Module):
     name = 'libshaderc'
     path = 'sources/third_party/shaderc'
@@ -2299,6 +2497,7 @@ ALL_MODULES = [
     Changelog(),
     Clang(),
     CpuFeatures(),
+    Gdb(),
     GdbServer(),
     Gtest(),
     HostTools(),
diff --git a/sources/host-tools/gdb-stub/gdb-stub.c b/sources/host-tools/gdb-stub/gdb-stub.c
index edb76cb33..49c6fc321 100644
--- a/sources/host-tools/gdb-stub/gdb-stub.c
+++ b/sources/host-tools/gdb-stub/gdb-stub.c
@@ -43,21 +43,12 @@
  #define dbg_printf(...) do {} while(0)
 #endif
 
-// When built for the Android NDK, values are
-// passed in on the GCC commandline, and when
-// built for mingw-builds, these defaults are
-// used.
-#ifndef GDB_TO_PYTHON_REL_DIR
- #define GDB_TO_PYTHON_REL_DIR "..\\opt\\bin"
-#endif
+#define GDB_TO_PYTHON_REL_DIR "."
 
-#ifndef GDB_EXECUTABLE_ORIG_FILENAME
- #define GDB_EXECUTABLE_ORIG_FILENAME "gdborig.exe"
-#endif
+#define GDB_EXECUTABLE_ORIG_FILENAME "gdb-orig.exe"
 
-#ifndef PYTHONHOME_REL_DIR
- #define PYTHONHOME_REL_DIR "..\\opt"
-#endif
+// The stub is installed to $PREBUILTS/bin, PYTHONHOME is $PREBUILTS.
+#define PYTHONHOME_REL_DIR ".."
 
 #define DIE_IF_FALSE(var) \
 	do { \