Q&D experiment to scan and build C++ modules with VS.vsmodtest

3 files changed, 83 insertions, 2 deletions

diff --git a/mesonbuild/backend/ninjabackend.py b/mesonbuild/backend/ninjabackend.py
index 417f6d9..6323830 100644
--- a/mesonbuild/backend/ninjabackend.py
+++ b/mesonbuild/backend/ninjabackend.py
@@ -328,11 +328,14 @@ int dummy;
             self.write_rules(outfile)
             self.write_builds(outfile)
 
-            default = 'default all\n\n'
+
+            default = 'default fakeall\n\n'
             outfile.write(default)
         # Only overwrite the old build file after the new one has been
         # fully created.
         os.replace(tempfilename, outfilename)
+        import shutil
+        shutil.copy(outfilename, outfilename + '.hackbak')
         self.generate_compdb()
 
     # http://clang.llvm.org/docs/JSONCompilationDatabase.html
@@ -2685,6 +2688,13 @@ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485'''))
         self.add_build(elem)
         # Alias that runs the target defined above
         self.create_target_alias('meson-uninstall')
+        cmd = self.environment.get_build_command() + ['--internal', 'scanhack']
+        elem = NinjaBuildElement(self.all_outputs, 'meson-fakeall', 'CUSTOM_COMMAND', 'PHONY')
+        elem.add_item('COMMAND', cmd)
+        elem.add_item('pool', 'console')
+        self.add_build(elem)
+        # Alias that runs the target defined above
+        self.create_target_alias('meson-fakeall')
 
     def generate_ending(self):
         targetlist = []
diff --git a/mesonbuild/compilers/compilers.py b/mesonbuild/compilers/compilers.py
index bb698fc..63aea8d 100644
--- a/mesonbuild/compilers/compilers.py
+++ b/mesonbuild/compilers/compilers.py
@@ -44,7 +44,7 @@ lib_suffixes = ('a', 'lib', 'dll', 'dylib', 'so')
 # This means we can't include .h headers here since they could be C, C++, ObjC, etc.
 lang_suffixes = {
     'c': ('c',),
-    'cpp': ('cpp', 'cc', 'cxx', 'c++', 'hh', 'hpp', 'ipp', 'hxx'),
+    'cpp': ('cpp', 'cc', 'cxx', 'c++', 'hh', 'hpp', 'ipp', 'hxx', 'ixx'),
     'cuda': ('cu',),
     # f90, f95, f03, f08 are for free-form fortran ('f90' recommended)
     # f, for, ftn, fpp are for fixed-form fortran ('f' or 'for' recommended)
diff --git a/mesonbuild/scripts/fakeall.py b/mesonbuild/scripts/fakeall.py
new file mode 100644
index 0000000..1630c10
--- /dev/null
+++ b/mesonbuild/scripts/fakeall.py
@@ -0,0 +1,71 @@
+# Copyright 2019 The Meson development team
+
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+
+#     http://www.apache.org/licenses/LICENSE-2.0
+
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import json, os, sys, subprocess
+
+def scan_file(src):
+    moddeps = []
+    for line in open(src):
+        if line.startswith('import '):
+            line = line.strip()
+            modnum = line.split('M')[-1][:-1]
+            d = 'src{}.ixx'.format(modnum)
+            if d not in moddeps:
+                moddeps.append(d)
+    return moddeps
+
+def scan_deps():
+    compdb = json.load(open('compile_commands.json'))
+    src2obj = {}
+    name2path = {}
+    mmap = {}
+    obj_deps = {} # AWFUL HACK! Should put the dep on the generated ifc file instead but can't because of Ninja limitation of one output per rule if you need dep files as well.
+    for o in compdb:
+        full_srcname = o['file']
+        srcname = os.path.split(full_srcname)[1]
+        objname = o['output']
+        assert(srcname.endswith('.ixx') or srcname.endswith('.cpp'))
+        src2obj[srcname] = objname
+        name2path[srcname] = full_srcname
+    for o in compdb:
+        full_srcname = o['file']
+        objname = o['output']
+        srcname = os.path.split(full_srcname)[1]
+        mod_deps = scan_file(full_srcname)
+        obj_deps[objname] = [src2obj[x] for x in mod_deps]
+    #for k, v in obj_deps.items():
+    #    print(k, '=>', v)
+    return obj_deps
+
+def rewrite_ninja(obj_deps):
+    ifilename = 'build.ninja.hackbak'
+    ofilename = 'build.ninja'
+    ofile = open(ofilename, 'w')
+    for line in open(ifilename):
+        if line.startswith('build '):
+            line = line.strip()
+            out, deps = line.split(':', 1)
+            out_obj = out.split(' ', 1)[1]
+            dep_objs = obj_deps.get(out_obj, [])
+            if len(dep_objs) > 0:
+                deps += ' | ' + ' '.join(dep_objs)
+            line = out + ':' + deps + '\n'
+        ofile.write(line)
+
+def run(args):
+    print('Scanning and rewriting Ninja file.')
+    obj_deps = scan_deps()
+    rewrite_ninja(obj_deps)
+    sys.exit(subprocess.run(['ninja', 'all']).returncode)
+