Allow capturing command output of a custom target.

For commands that always output to stdout and don't have a "-o" or
"--output" or some other similar option, this 'capture' setting allows
the build to capture the result and place it in the output file.

2 files changed, 12 insertions, 6 deletions

diff --git a/mesonbuild/backend/backends.py b/mesonbuild/backend/backends.py
index bdba44f..fbc5079 100644
--- a/mesonbuild/backend/backends.py
+++ b/mesonbuild/backend/backends.py
@@ -37,7 +37,7 @@ class InstallData():
 
 class ExecutableSerialisation():
     def __init__(self, name, fname, cmd_args, env, is_cross, exe_wrapper,
-                 workdir, extra_paths):
+                 workdir, extra_paths, capture):
         self.name = name
         self.fname = fname
         self.cmd_args = cmd_args
@@ -46,6 +46,7 @@ class ExecutableSerialisation():
         self.exe_runner = exe_wrapper
         self.workdir = workdir
         self.extra_paths = extra_paths
+        self.capture = capture
 
 class TestSerialisation:
     def __init__(self, name, suite, fname, is_cross, exe_wrapper, is_parallel, cmd_args, env,
@@ -176,7 +177,8 @@ class Backend():
                 raise MesonException('Unknown data type in object list.')
         return obj_list
 
-    def serialise_executable(self, exe, cmd_args, workdir, env={}):
+    def serialise_executable(self, exe, cmd_args, workdir, env={},
+                             capture=None):
         import uuid
         # Can't just use exe.name here; it will likely be run more than once
         if isinstance(exe, (dependencies.ExternalProgram,
@@ -207,7 +209,7 @@ class Backend():
                 extra_paths = []
             es = ExecutableSerialisation(basename, exe_fullpath, cmd_args, env,
                                          is_cross, exe_wrapper, workdir,
-                                         extra_paths)
+                                         extra_paths, capture)
             pickle.dump(es, f)
         return exe_data
 
diff --git a/mesonbuild/backend/ninjabackend.py b/mesonbuild/backend/ninjabackend.py
index 15f298b..7855729 100644
--- a/mesonbuild/backend/ninjabackend.py
+++ b/mesonbuild/backend/ninjabackend.py
@@ -379,15 +379,19 @@ int dummy;
                 tmp = [tmp]
             for fname in tmp:
                 elem.add_dep(os.path.join(self.get_target_dir(d), fname))
+        # If the target requires capturing stdout, then use the serialized
+        # executable wrapper to capture that output and save it to a file.
+        #
         # Windows doesn't have -rpath, so for EXEs that need DLLs built within
         # the project, we need to set PATH so the DLLs are found. We use
         # a serialized executable wrapper for that and check if the
         # CustomTarget command needs extra paths first.
-        if mesonlib.is_windows() and \
-           self.determine_windows_extra_paths(target.command[0]):
+        if target.capture or (mesonlib.is_windows() and
+                self.determine_windows_extra_paths(target.command[0])):
             exe_data = self.serialise_executable(target.command[0], cmd[1:],
                 # All targets are built from the build dir
-                self.environment.get_build_dir())
+                self.environment.get_build_dir(),
+                capture=ofilenames[0] if target.capture else None)
             cmd = [sys.executable, self.environment.get_build_command(),
                    '--internal', 'exe', exe_data]
             cmd_type = 'meson_exe.py custom'