Fix crash when installing a vala library and python sources

Installing python sources causes the python module to call
create_install_data() before Ninja backends adds extra outputs to Vala
targets.

Target objects are supposed to be immutable, adding outputs that late is
totally wrong. Add extra vala outputs immediately, but be careful
because the main output is only added later in post_init(). Luckily
the base class already puts a placeholder item in self.outputs for the
main filename so we can just replace self.outputs[0] instead of
replacing the whole list which would contain vala outputs at that stage.
This is surprisingly what SharedLibrary was already doing.

data/test.schema.json

@@ -27,6 +27,7 @@
               "shared_lib",
               "python_lib",
               "python_limited_lib",
+              "python_bytecode",
               "pdb",
               "implib",
               "py_implib",

mesonbuild/backend/ninjabackend.py

@@ -1694,8 +1694,6 @@ class NinjaBackend(backends.Backend):
             # Without this, it will write it inside c_out_dir
             args += ['--vapi', os.path.join('..', target.vala_vapi)]
             valac_outputs.append(vapiname)
-            target.outputs += [target.vala_header, target.vala_vapi]
-            target.install_tag += ['devel', 'devel']
             # Install header and vapi to default locations if user requests this
             if len(target.install_dir) > 1 and target.install_dir[1] is True:
                 target.install_dir[1] = self.environment.get_includedir()
@@ -1706,8 +1704,6 @@ class NinjaBackend(backends.Backend):
                 girname = os.path.join(self.get_target_dir(target), target.vala_gir)
                 args += ['--gir', os.path.join('..', target.vala_gir)]
                 valac_outputs.append(girname)
-                target.outputs.append(target.vala_gir)
-                target.install_tag.append('devel')
                 # Install GIR to default location if requested by user
                 if len(target.install_dir) > 3 and target.install_dir[3] is True:
                     target.install_dir[3] = os.path.join(self.environment.get_datadir(), 'gir-1.0')

mesonbuild/build.py

@@ -789,6 +789,12 @@ class BuildTarget(Target):
             # relocation-model=pic is rustc's default and Meson does not
             # currently have a way to disable PIC.
             self.pic = True
+        if 'vala' in self.compilers and self.is_linkable_target():
+            self.outputs += [self.vala_header, self.vala_vapi]
+            self.install_tag += ['devel', 'devel']
+            if self.vala_gir:
+                self.outputs.append(self.vala_gir)
+                self.install_tag.append('devel')
 
     def __repr__(self):
         repr_str = "<{0} {1}: {2}>"
@@ -1945,7 +1951,7 @@ class Executable(BuildTarget):
         self.filename = self.name
         if self.suffix:
             self.filename += '.' + self.suffix
-        self.outputs = [self.filename]
+        self.outputs[0] = self.filename
 
         # The import library this target will generate
         self.import_filename = None
@@ -2086,7 +2092,7 @@ class StaticLibrary(BuildTarget):
             else:
                 self.suffix = 'a'
         self.filename = self.prefix + self.name + '.' + self.suffix
-        self.outputs = [self.filename]
+        self.outputs[0] = self.filename
 
     def get_link_deps_mapping(self, prefix: str) -> T.Mapping[str, str]:
         return {}

run_project_tests.py

@@ -40,6 +40,7 @@ import time
 import typing as T
 import xml.etree.ElementTree as ET
 import collections
+import importlib.util
 
 from mesonbuild import build
 from mesonbuild import environment
@@ -169,7 +170,7 @@ class InstalledFile:
             return None
 
         # Handle the different types
-        if self.typ in {'py_implib', 'py_limited_implib', 'python_lib', 'python_limited_lib', 'python_file'}:
+        if self.typ in {'py_implib', 'py_limited_implib', 'python_lib', 'python_limited_lib', 'python_file', 'python_bytecode'}:
             val = p.as_posix()
             val = val.replace('@PYTHON_PLATLIB@', python.platlib)
             val = val.replace('@PYTHON_PURELIB@', python.purelib)
@@ -196,6 +197,8 @@ class InstalledFile:
                     return p.with_suffix('.dll.a')
                 else:
                     return None
+            if self.typ == 'python_bytecode':
+                return p.parent / importlib.util.cache_from_source(p.name)
         elif self.typ in {'file', 'dir'}:
             return p
         elif self.typ == 'shared_lib':

test cases/vala/7 shared library/lib/meson.build

@@ -33,3 +33,8 @@ shared_library('installed_vala_onlyvapi', 'mylib.vala',
   dependencies : valadeps,
   install : true,
   install_dir : [false, false, join_paths(get_option('datadir'), 'vala', 'vapi')])
+
+# Regression test: Vala libraries were broken when also installing python modules.
+# https://gitlab.gnome.org/GNOME/gitg/-/issues/412
+python = import('python').find_installation()
+python.install_sources('source.py')

test cases/vala/7 shared library/test.json

@@ -9,6 +9,8 @@
     {"type": "file", "file": "usr/include/installed_vala_onlyh.h"},
     {"type": "file", "file": "usr/share/vala/vapi/installed_vala_all.vapi"},
     {"type": "file", "file": "usr/share/vala-1.0/vapi/installed_vala_all_nolib.vapi"},
-    {"type": "file", "file": "usr/share/vala/vapi/installed_vala_onlyvapi.vapi"}
+    {"type": "file", "file": "usr/share/vala/vapi/installed_vala_onlyvapi.vapi"},
+    {"type": "python_file", "file": "usr/@PYTHON_PURELIB@/source.py"},
+    {"type": "python_bytecode", "file": "usr/@PYTHON_PURELIB@/source.py"}
   ]
 }