devenv: Set GI_TYPELIB_PATH and LD_LIBRARY_PATH (#8548)

4 files changed, 46 insertions, 9 deletions

diff --git a/docs/markdown/Commands.md b/docs/markdown/Commands.md
index 0751aed..fc8cdd2 100644
--- a/docs/markdown/Commands.md
+++ b/docs/markdown/Commands.md
@@ -295,5 +295,12 @@ These variables are set in environment in addition to those set using `meson.add
 - `PATH` includes every directory where there is an executable that would be
   installed into `bindir`. On windows it also includes every directory where there
   is a DLL needed to run those executables.
+- `LD_LIBRARY_PATH` includes every directory where there is a shared library that
+  would be installed into `libdir`. This allows to run system application using
+  custom build of some libraries. For example running system GEdit when building
+  GTK from git. On OSX the environment variable is `DYLD_LIBRARY_PATH` and
+  `PATH` on Windows.
+- `GI_TYPELIB_PATH` includes every directory where a GObject Introspection
+  typelib is built. This is automatically set when using `gnome.generate_gir()`.
 
 {{ devenv_arguments.inc }}
diff --git a/docs/markdown/snippets/devenv.md b/docs/markdown/snippets/devenv.md
index c3bac10..1160945 100644
--- a/docs/markdown/snippets/devenv.md
+++ b/docs/markdown/snippets/devenv.md
@@ -26,4 +26,10 @@ These variables are set in environment in addition to those set using `meson.add
 - `PATH` includes every directory where there is an executable that would be
   installed into `bindir`. On windows it also includes every directory where there
   is a DLL needed to run those executables.
-
+- `LD_LIBRARY_PATH` includes every directory where there is a shared library that
+  would be installed into `libdir`. This allows to run system application using
+  custom build of some libraries. For example running system GEdit when building
+  GTK from git. On OSX the environment variable is `DYLD_LIBRARY_PATH` and
+  `PATH` on Windows.
+- `GI_TYPELIB_PATH` includes every directory where a GObject Introspection
+  typelib is built. This is automatically set when using `gnome.generate_gir()`.
diff --git a/mesonbuild/backend/backends.py b/mesonbuild/backend/backends.py
index 9624ed6..5ce27c3 100644
--- a/mesonbuild/backend/backends.py
+++ b/mesonbuild/backend/backends.py
@@ -1496,18 +1496,33 @@ class Backend:
     def get_devenv(self) -> build.EnvironmentVariables:
         env = build.EnvironmentVariables()
         extra_paths = set()
+        library_paths = set()
         for t in self.build.get_targets().values():
             cross_built = not self.environment.machines.matches_build_machine(t.for_machine)
             can_run = not cross_built or not self.environment.need_exe_wrapper()
-            in_bindir = t.should_install() and not t.get_install_dir(self.environment)[1]
-            if isinstance(t, build.Executable) and can_run and in_bindir:
+            in_default_dir = t.should_install() and not t.get_install_dir(self.environment)[1]
+            if not can_run or not in_default_dir:
+                continue
+            tdir = os.path.join(self.environment.get_build_dir(), self.get_target_dir(t))
+            if isinstance(t, build.Executable):
                 # Add binaries that are going to be installed in bindir into PATH
                 # so they get used by default instead of searching on system when
                 # in developer environment.
-                extra_paths.add(os.path.join(self.environment.get_build_dir(), self.get_target_dir(t)))
+                extra_paths.add(tdir)
                 if mesonlib.is_windows() or mesonlib.is_cygwin():
                     # On windows we cannot rely on rpath to run executables from build
                     # directory. We have to add in PATH the location of every DLL needed.
                     extra_paths.update(self.determine_windows_extra_paths(t, []))
+            elif isinstance(t, build.SharedLibrary):
+                # Add libraries that are going to be installed in libdir into
+                # LD_LIBRARY_PATH. This allows running system applications using
+                # that library.
+                library_paths.add(tdir)
+        if mesonlib.is_windows() or mesonlib.is_cygwin():
+            extra_paths.update(library_paths)
+        elif mesonlib.is_osx():
+            env.prepend('DYLD_LIBRARY_PATH', list(library_paths))
+        else:
+            env.prepend('LD_LIBRARY_PATH', list(library_paths))
         env.prepend('PATH', list(extra_paths))
         return env
diff --git a/mesonbuild/modules/gnome.py b/mesonbuild/modules/gnome.py
index 8a48ca8..dc2979e 100644
--- a/mesonbuild/modules/gnome.py
+++ b/mesonbuild/modules/gnome.py
@@ -50,11 +50,13 @@ gresource_dep_needed_version = '>= 2.51.1'
 native_glib_version = None
 
 class GnomeModule(ExtensionModule):
-    gir_dep = None
-
-    install_glib_compile_schemas = False
-    install_gio_querymodules = []
-    install_gtk_update_icon_cache = False
+    def __init__(self, interpreter: 'Interpreter') -> None:
+        super().__init__(interpreter)
+        self.gir_dep = None
+        self.install_glib_compile_schemas = False
+        self.install_gio_querymodules = []
+        self.install_gtk_update_icon_cache = False
+        self.devenv = None
 
     @staticmethod
     def _get_native_glib_version(state):
@@ -480,6 +482,12 @@ class GnomeModule(ExtensionModule):
 
         return girtarget
 
+    def _devenv_append(self, varname: str, value: str) -> None:
+        if self.devenv is None:
+            self.devenv = build.EnvironmentVariables()
+            self.interpreter.build.devenv.append(self.devenv)
+        self.devenv.append(varname, [value])
+
     def _get_gir_dep(self, state):
         if not self.gir_dep:
             self.gir_dep = self._get_native_dep(state, 'gobject-introspection-1.0')
@@ -884,6 +892,7 @@ class GnomeModule(ExtensionModule):
             typelib_cmd += ["--includedir=" + incdir]
 
         typelib_target = self._make_typelib_target(state, typelib_output, typelib_cmd, kwargs)
+        self._devenv_append('GI_TYPELIB_PATH', os.path.join(state.environment.get_build_dir(), state.subdir))
 
         rv = [scan_target, typelib_target]