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.

2 files changed, 8 insertions, 6 deletions

diff --git a/mesonbuild/backend/ninjabackend.py b/mesonbuild/backend/ninjabackend.py
index 6c739ed0a..491f2a63d 100644
--- a/mesonbuild/backend/ninjabackend.py
+++ b/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')
diff --git a/mesonbuild/build.py b/mesonbuild/build.py
index edec75d90..09437037a 100644
--- a/mesonbuild/build.py
+++ b/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 {}