Update VS files only if something changed.

If you change only some project in meson.build,
only that .vcxproj file will be updated and reloaded.

If you change something not related to VS solution and projects
or simply touch the meson.build file, nothing will be reloaded.

1 files changed, 14 insertions, 6 deletions

diff --git a/mesonbuild/backend/vs2010backend.py b/mesonbuild/backend/vs2010backend.py
index f9f7b93..8ac88ce 100644
--- a/mesonbuild/backend/vs2010backend.py
+++ b/mesonbuild/backend/vs2010backend.py
@@ -25,7 +25,7 @@ from .. import dependencies
 from .. import mlog
 from .. import compilers
 from ..compilers import CompilerArgs
-from ..mesonlib import MesonException, File, python_command
+from ..mesonlib import MesonException, File, python_command, replace_if_different
 from ..environment import Environment, build_filename
 
 def autodetect_vs_version(build):
@@ -69,6 +69,9 @@ def split_o_flags_args(args):
             o_flags += ['/O' + f for f in flags]
     return o_flags
 
+def generate_guid_from_path(path, path_type):
+    return str(uuid.uuid5(uuid.NAMESPACE_URL, 'meson-vs-' + path_type + ':' + str(path))).upper()
+
 class RegenInfo:
     def __init__(self, source_dir, build_dir, depfiles):
         self.source_dir = source_dir
@@ -265,7 +268,7 @@ class Vs2010Backend(backends.Backend):
         for path in iterpaths:
             if path not in self.subdirs:
                 basename = path.name
-                identifier = str(uuid.uuid4()).upper()
+                identifier = generate_guid_from_path(path, 'subdir')
                 # top-level directories have None as their parent_dir
                 parent_dir = path.parent
                 parent_identifier = self.subdirs[parent_dir][0] \
@@ -279,7 +282,8 @@ class Vs2010Backend(backends.Backend):
 
     def generate_solution(self, sln_filename, projlist):
         default_projlist = self.get_build_by_default_targets()
-        with open(sln_filename, 'w', encoding='utf-8') as ofile:
+        sln_filename_tmp = sln_filename + '~'
+        with open(sln_filename_tmp, 'w', encoding='utf-8') as ofile:
             ofile.write('Microsoft Visual Studio Solution File, Format '
                         'Version 11.00\n')
             ofile.write('# Visual Studio ' + self.vs_version + '\n')
@@ -380,6 +384,7 @@ class Vs2010Backend(backends.Backend):
                         ofile.write("\t\t{%s} = {%s}\n" % (subdir[0], subdir[1]))
                 ofile.write('\tEndGlobalSection\n')
             ofile.write('EndGlobal\n')
+        replace_if_different(sln_filename, sln_filename_tmp)
 
     def generate_projects(self):
         startup_project = self.environment.coredata.backend_options['backend_startup_project'].value
@@ -674,11 +679,14 @@ class Vs2010Backend(backends.Backend):
         raise MesonException('Could not find a C or C++ compiler. MSVC can only build C/C++ projects.')
 
     def _prettyprint_vcxproj_xml(self, tree, ofname):
-        tree.write(ofname, encoding='utf-8', xml_declaration=True)
+        ofname_tmp = ofname + '~'
+        tree.write(ofname_tmp, encoding='utf-8', xml_declaration=True)
+
         # ElementTree can not do prettyprinting so do it manually
-        doc = xml.dom.minidom.parse(ofname)
-        with open(ofname, 'w', encoding='utf-8') as of:
+        doc = xml.dom.minidom.parse(ofname_tmp)
+        with open(ofname_tmp, 'w', encoding='utf-8') as of:
             of.write(doc.toprettyxml())
+        replace_if_different(ofname, ofname_tmp)
 
     def gen_vcxproj(self, target, ofname, guid):
         mlog.debug('Generating vcxproj %s.' % target.name)