Merge pull request #712 from QuLogic/capturing-custom-target

Allow capturing command output of a custom target. 

9 files changed, 70 insertions, 11 deletions

diff --git a/authors.txt b/authors.txt
index e9fceb0..ddccebc 100644
--- a/authors.txt
+++ b/authors.txt
@@ -41,3 +41,4 @@ Vincent Szolnoky
 Zhe Wang
 Wim Taymans
 Matthias Klumpp
+Elliott Sales de Andrade
diff --git a/mesonbuild/backend/backends.py b/mesonbuild/backend/backends.py
index 806a6f3..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,
@@ -176,18 +177,25 @@ 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
-        scratch_file = 'meson_exe_{0}_{1}.dat'.format(exe.name,
+        if isinstance(exe, (dependencies.ExternalProgram,
+                            build.BuildTarget, build.CustomTarget)):
+            basename = exe.name
+        else:
+            basename = os.path.basename(exe)
+        scratch_file = 'meson_exe_{0}_{1}.dat'.format(basename,
                                                       str(uuid.uuid4())[:8])
         exe_data = os.path.join(self.environment.get_scratch_dir(), scratch_file)
         with open(exe_data, 'wb') as f:
             if isinstance(exe, dependencies.ExternalProgram):
                 exe_fullpath = exe.fullpath
+            elif isinstance(exe, (build.BuildTarget, build.CustomTarget)):
+                exe_fullpath = [self.get_target_filename_abs(exe)]
             else:
-                exe_fullpath = [os.path.join(self.environment.get_build_dir(),
-                                             self.get_target_filename(exe))]
+                exe_fullpath = [exe]
             is_cross = self.environment.is_cross_build() and \
                 self.environment.cross_info.need_cross_compiler() and \
                 self.environment.cross_info.need_exe_wrapper()
@@ -199,9 +207,9 @@ class Backend():
                 extra_paths = self.determine_windows_extra_paths(exe)
             else:
                 extra_paths = []
-            es = ExecutableSerialisation(exe.name, exe_fullpath, cmd_args, env,
+            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'
diff --git a/mesonbuild/build.py b/mesonbuild/build.py
index dd03d81..ace4853 100644
--- a/mesonbuild/build.py
+++ b/mesonbuild/build.py
@@ -927,6 +927,7 @@ class CustomTarget:
     known_kwargs = {'input' : True,
                     'output' : True,
                     'command' : True,
+                    'capture' : False,
                     'install' : True,
                     'install_dir' : True,
                     'build_always' : True,
@@ -982,6 +983,10 @@ class CustomTarget:
                 raise InvalidArguments('Output argument not a string.')
             if '/' in i:
                 raise InvalidArguments('Output must not contain a path segment.')
+        self.capture = kwargs.get('capture', False)
+        if self.capture and len(self.output) != 1:
+            raise InvalidArguments(
+                'Capturing can only output to a single file.')
         if 'command' not in kwargs:
             raise InvalidArguments('Missing keyword argument "command".')
         cmd = kwargs['command']
@@ -1010,6 +1015,9 @@ class CustomTarget:
             else:
                 raise InvalidArguments('Argument %s in "command" is invalid.' % i)
         self.command = final_cmd
+        if self.capture and '@OUTPUT@' in self.command:
+            raise InvalidArguments(
+                '@OUTPUT@ is not allowed when capturing output.')
         if 'install' in kwargs:
             self.install = kwargs['install']
             if not isinstance(self.install, bool):
diff --git a/mesonbuild/scripts/meson_exe.py b/mesonbuild/scripts/meson_exe.py
index f075fa0..1a0fcda 100644
--- a/mesonbuild/scripts/meson_exe.py
+++ b/mesonbuild/scripts/meson_exe.py
@@ -59,6 +59,13 @@ def run_exe(exe):
                          stderr=subprocess.PIPE,
                          env=child_env,
                          cwd=exe.workdir)
+    stdout, stderr = p.communicate()
+    if exe.capture and p.returncode == 0:
+        with open(exe.capture, 'wb') as output:
+            output.write(stdout)
+    if stderr:
+        sys.stderr.buffer.write(stderr)
+    return p.returncode
 
 def run(args):
     global options
@@ -68,7 +75,7 @@ def run(args):
         print(sys.argv[0] + ' [data file]')
     exe_data_file = options.args[0]
     exe = pickle.load(open(exe_data_file, 'rb'))
-    run_exe(exe)
+    return run_exe(exe)
 
 if __name__ == '__main__':
     sys.exit(run(sys.argv[1:]))
diff --git a/test cases/common/117 custom target capture/data_source.txt b/test cases/common/117 custom target capture/data_source.txt
new file mode 100644
index 0000000..0c23cc0
--- /dev/null
+++ b/test cases/common/117 custom target capture/data_source.txt
@@ -0,0 +1 @@
+This is a text only input file.
diff --git a/test cases/common/117 custom target capture/installed_files.txt b/test cases/common/117 custom target capture/installed_files.txt
new file mode 100644
index 0000000..d90a6b0
--- /dev/null
+++ b/test cases/common/117 custom target capture/installed_files.txt
@@ -0,0 +1 @@
+usr/subdir/data.dat
diff --git a/test cases/common/117 custom target capture/meson.build b/test cases/common/117 custom target capture/meson.build
new file mode 100644
index 0000000..6c19752
--- /dev/null
+++ b/test cases/common/117 custom target capture/meson.build
@@ -0,0 +1,16 @@
+project('custom target', 'c')
+
+python = find_program('python3')
+
+# Note that this will not add a dependency to the compiler executable.
+# Code will not be rebuilt if it changes.
+comp = '@0@/@1@'.format(meson.current_source_dir(), 'my_compiler.py')
+
+mytarget = custom_target('bindat',
+output : 'data.dat',
+input : 'data_source.txt',
+capture : true,
+command : [python, comp, '@INPUT@'],
+install : true,
+install_dir : 'subdir'
+)
diff --git a/test cases/common/117 custom target capture/my_compiler.py b/test cases/common/117 custom target capture/my_compiler.py
new file mode 100755
index 0000000..3e9ec23
--- /dev/null
+++ b/test cases/common/117 custom target capture/my_compiler.py
@@ -0,0 +1,13 @@
+#!/usr/bin/env python3
+
+import sys
+
+if __name__ == '__main__':
+    if len(sys.argv) != 2:
+        print(sys.argv[0], 'input_file')
+        sys.exit(1)
+    ifile = open(sys.argv[1]).read()
+    if ifile != 'This is a text only input file.\n':
+        print('Malformed input')
+        sys.exit(1)
+    print('This is a binary output file.')