linux: improve support for cross-compiling

This CL adds support for a 'sysroot' GYP define, that should point to the target root filesystem for cross-compilation.
It passes that argument to the compiler and linker which uses it to prefix its hard-coded path (e.g. /usr/include)
It also points pkg-config to look for package configs there, and rewrite the paths to be prefixed by 'sysroot' (since pkg-config doesn't do it itself)

Review URL: http://codereview.chromium.org/199016


git-svn-id: svn://svn.chromium.org/chrome/trunk/src@25418 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 114 insertions, 27 deletions

diff --git a/build/linux/pkg-config-wrapper b/build/linux/pkg-config-wrapper
new file mode 100755
index 0000000..abd34ef
--- /dev/null
+++ b/build/linux/pkg-config-wrapper
@@ -0,0 +1,14 @@
+#!/bin/sh
+
+root="$1"
+if [ -z "$root" ]
+then
+  echo "usage: $0 /path/to/sysroot [pkg-config-arguments]" >&2
+  exit 1
+fi
+
+rewrite=`dirname $0`/rewrite_dirs.py
+
+shift
+config_path=$root/usr/lib/pkgconfig:$root/usr/share/pkgconfig
+PKG_CONFIG_PATH=$config_path pkg-config "$@" | $rewrite $root
diff --git a/build/linux/rewrite_dirs.py b/build/linux/rewrite_dirs.py
new file mode 100755
index 0000000..9a00f96
--- /dev/null
+++ b/build/linux/rewrite_dirs.py
@@ -0,0 +1,61 @@
+#!/usr/bin/python
+
+"""Rewrites paths in -I, -L and other option to be relative to a sysroot."""
+
+import sys
+import os
+
+REWRITE_PREFIX = ['-I',
+                  '-idirafter',
+                  '-imacros',
+                  '-imultilib',
+                  '-include',
+                  '-iprefix',
+                  '-iquote',
+                  '-isystem',
+                  '-L']
+
+def RewritePath(path, sysroot):
+  """Rewrites a path by prefixing it with the sysroot if it is absolute."""
+  if os.path.isabs(path):
+    path = path.lstrip('/')
+    return os.path.join(sysroot, path)
+  else:
+    return path
+
+def RewriteLine(line, sysroot):
+  """Rewrites all the paths in recognized options."""
+  args = line.split()
+  count = len(args)
+  i = 0
+  while i < count:
+    for prefix in REWRITE_PREFIX:
+      # The option can be either in the form "-I /path/to/dir" or
+      # "-I/path/to/dir" so handle both.
+      if args[i] == prefix:
+        i += 1
+        try:
+          args[i] = RewritePath(args[i], sysroot)
+        except IndexError:
+          sys.stderr.write('Missing argument following %s\n' % prefix)
+          break
+      elif args[i].startswith(prefix):
+        args[i] = prefix + RewritePath(args[i][len(prefix):], sysroot)
+    i += 1
+
+  return ' '.join(args)
+
+def main(argv):
+  try:
+    sysroot = argv[1]
+  except IndexError:
+    sys.stderr.write('usage: %s /path/to/sysroot\n' % argv[0])
+    return 1
+
+  for line in sys.stdin.readlines():
+    line = RewriteLine(line.strip(), sysroot)
+    print line
+  return 0
+
+if __name__ == '__main__':
+  sys.exit(main(sys.argv))
diff --git a/build/linux/system.gyp b/build/linux/system.gyp
index e10c905..7b6d82c 100644
--- a/build/linux/system.gyp
+++ b/build/linux/system.gyp
@@ -3,21 +3,33 @@
 # found in the LICENSE file.
 
 {
+  'variables' : {
+    'includes': [
+      '../common.gypi',
+    ],
+    'conditions': [
+      ['sysroot!=""', {
+        'pkg-config': './pkg-config-wrapper "<(sysroot)"',
+      }, {
+        'pkg-config': 'pkg-config'
+      }],
+    ],
+  },
   'targets': [
     {
       'target_name': 'gtk',
       'type': 'settings',
       'direct_dependent_settings': {
         'cflags': [
-          '<!@(pkg-config --cflags gtk+-2.0 gthread-2.0)',
+          '<!@(<(pkg-config) --cflags gtk+-2.0 gthread-2.0)',
         ],
       },
       'link_settings': {
         'ldflags': [
-          '<!@(pkg-config --libs-only-L --libs-only-other gtk+-2.0 gthread-2.0)',
+          '<!@(<(pkg-config) --libs-only-L --libs-only-other gtk+-2.0 gthread-2.0)',
         ],
         'libraries': [
-          '<!@(pkg-config --libs-only-l gtk+-2.0 gthread-2.0)',
+          '<!@(<(pkg-config) --libs-only-l gtk+-2.0 gthread-2.0)',
         ],
       },
     },
@@ -26,15 +38,15 @@
       'type': 'settings',
       'direct_dependent_settings': {
         'cflags': [
-          '<!@(pkg-config --cflags nss)',
+          '<!@(<(pkg-config) --cflags nss)',
         ],
       },
       'link_settings': {
         'ldflags': [
-          '<!@(pkg-config --libs-only-L --libs-only-other nss)',
+          '<!@(<(pkg-config) --libs-only-L --libs-only-other nss)',
         ],
         'libraries': [
-          '<!@(pkg-config --libs-only-l nss)',
+          '<!@(<(pkg-config) --libs-only-l nss)',
         ],
       },
     },
@@ -43,15 +55,15 @@
       'type': 'settings',
       'direct_dependent_settings': {
         'cflags': [
-          '<!@(pkg-config --cflags freetype2)',
+          '<!@(<(pkg-config) --cflags freetype2)',
         ],
       },
       'link_settings': {
         'ldflags': [
-          '<!@(pkg-config --libs-only-L --libs-only-other freetype2)',
+          '<!@(<(pkg-config) --libs-only-L --libs-only-other freetype2)',
         ],
         'libraries': [
-          '<!@(pkg-config --libs-only-l freetype2)',
+          '<!@(<(pkg-config) --libs-only-l freetype2)',
         ],
       },
     },
@@ -60,15 +72,15 @@
       'type': 'settings',
       'direct_dependent_settings': {
         'cflags': [
-          '<!@(pkg-config --cflags fontconfig)',
+          '<!@(<(pkg-config) --cflags fontconfig)',
         ],
       },
       'link_settings': {
         'ldflags': [
-          '<!@(pkg-config --libs-only-L --libs-only-other fontconfig)',
+          '<!@(<(pkg-config) --libs-only-L --libs-only-other fontconfig)',
         ],
         'libraries': [
-          '<!@(pkg-config --libs-only-l fontconfig)',
+          '<!@(<(pkg-config) --libs-only-l fontconfig)',
         ],
       },
     },
@@ -77,15 +89,15 @@
       'type': 'settings',
       'direct_dependent_settings': {
         'cflags': [
-          '<!@(pkg-config --cflags gdk-2.0)',
+          '<!@(<(pkg-config) --cflags gdk-2.0)',
         ],
       },
       'link_settings': {
         'ldflags': [
-          '<!@(pkg-config --libs-only-L --libs-only-other gdk-2.0)',
+          '<!@(<(pkg-config) --libs-only-L --libs-only-other gdk-2.0)',
         ],
         'libraries': [
-          '<!@(pkg-config --libs-only-l gdk-2.0)',
+          '<!@(<(pkg-config) --libs-only-l gdk-2.0)',
         ],
       },
     },
@@ -94,15 +106,15 @@
       'type': 'settings',
       'direct_dependent_settings': {
         'cflags': [
-          '<!@(pkg-config --cflags gconf-2.0)',
+          '<!@(<(pkg-config) --cflags gconf-2.0)',
         ],
       },
       'link_settings': {
         'ldflags': [
-          '<!@(pkg-config --libs-only-L --libs-only-other gconf-2.0)',
+          '<!@(<(pkg-config) --libs-only-L --libs-only-other gconf-2.0)',
         ],
         'libraries': [
-          '<!@(pkg-config --libs-only-l gconf-2.0)',
+          '<!@(<(pkg-config) --libs-only-l gconf-2.0)',
         ],
       },
     },
@@ -111,15 +123,15 @@
       'type': 'settings',
       'direct_dependent_settings': {
         'cflags': [
-          '<!@(pkg-config --cflags x11)',
+          '<!@(<(pkg-config) --cflags x11)',
         ],
       },
       'link_settings': {
         'ldflags': [
-          '<!@(pkg-config --libs-only-L --libs-only-other x11)',
+          '<!@(<(pkg-config) --libs-only-L --libs-only-other x11)',
         ],
         'libraries': [
-          '<!@(pkg-config --libs-only-l x11)',
+          '<!@(<(pkg-config) --libs-only-l x11)',
         ],
       },
     },
@@ -131,15 +143,15 @@
 #       'type': 'settings',
 #       'direct_dependent_settings': {
 #         'cflags': [
-#           '<!@(pkg-config --cflags gnome-keyring-1)',
+#           '<!@(<(pkg-config) --cflags gnome-keyring-1)',
 #         ],
 #       },
 #       'link_settings': {
 #         'ldflags': [
-#           '<!@(pkg-config --libs-only-L --libs-only-other gnome-keyring-1)',
+#           '<!@(<(pkg-config) --libs-only-L --libs-only-other gnome-keyring-1)',
 #         ],
 #         'libraries': [
-#           '<!@(pkg-config --libs-only-l gnome-keyring-1)',
+#           '<!@(<(pkg-config) --libs-only-l gnome-keyring-1)',
 #         ],
 #       },
 #     },
@@ -148,15 +160,15 @@
 #       'type': 'settings',
 #       'direct_dependent_settings': {
 #         'cflags': [
-#           '<!@(pkg-config --cflags dbus-glib-1)',
+#           '<!@(<(pkg-config) --cflags dbus-glib-1)',
 #         ],
 #       },
 #       'link_settings': {
 #         'ldflags': [
-#           '<!@(pkg-config --libs-only-L --libs-only-other dbus-glib-1)',
+#           '<!@(<(pkg-config) --libs-only-L --libs-only-other dbus-glib-1)',
 #         ],
 #         'libraries': [
-#           '<!@(pkg-config --libs-only-l dbus-glib-1)',
+#           '<!@(<(pkg-config) --libs-only-l dbus-glib-1)',
 #         ],
 #       },
 #     },