Allow configure script to bootstrap out of source.

diff --git a/configure.py b/configure.py
index 2eacbfe..69f6075 100755 (executable)
--- a/configure.py
+++ b/configure.py
@@ -28,7 +28,8 @@ import string
 import subprocess
 import sys
 
-sys.path.insert(0, 'misc')
+sourcedir = os.path.dirname(os.path.realpath(__file__))
+sys.path.insert(0, os.path.join(sourcedir, 'misc'))
 import ninja_syntax
 
 
@@ -251,11 +252,11 @@ if platform.is_msvc():
     objext = '.obj'
 
 def src(filename):
-    return os.path.join('src', filename)
+    return os.path.join('$sourcedir', 'src', filename)
 def built(filename):
     return os.path.join('$builddir', filename)
 def doc(filename):
-    return os.path.join('doc', filename)
+    return os.path.join('$sourcedir', 'doc', filename)
 def cc(name, **kwargs):
     return n.build(built(name + objext), 'cxx', src(name + '.c'), **kwargs)
 def cxx(name, **kwargs):
@@ -267,6 +268,7 @@ def binary(name):
         return exe
     return name
 
+n.variable('sourcedir', sourcedir)
 n.variable('builddir', 'build')
 n.variable('cxx', CXX)
 if platform.is_msvc():
@@ -415,10 +417,10 @@ objs = []
 if platform.supports_ninja_browse():
     n.comment('browse_py.h is used to inline browse.py.')
     n.rule('inline',
-           command='src/inline.sh $varname < $in > $out',
+           command=src('inline.sh') + ' $varname < $in > $out',
            description='INLINE $out')
     n.build(built('browse_py.h'), 'inline', src('browse.py'),
-            implicit='src/inline.sh',
+            implicit=src('inline.sh'),
             variables=[('varname', 'kBrowsePy')])
     n.newline()
 
@@ -591,11 +593,12 @@ n.newline()
 if not host.is_mingw():
     n.comment('Regenerate build files if build script changes.')
     n.rule('configure',
-           command='${configure_env}%s configure.py $configure_args' %
+           command='${configure_env}%s $sourcedir/configure.py $configure_args' %
                options.with_python,
            generator=True)
     n.build('build.ninja', 'configure',
-            implicit=['configure.py', os.path.normpath('misc/ninja_syntax.py')])
+            implicit=['$sourcedir/configure.py',
+                      os.path.normpath('$sourcedir/misc/ninja_syntax.py')])
     n.newline()
 
 n.default(ninja)