Don't let build_always take precedence over build_by_default (#3816)

* Don't let build_always take precedence over build_by_default

* Test for proper interaction of build_by_default with build_always

Fixes #3815

4 files changed, 53 insertions, 15 deletions

diff --git a/mesonbuild/build.py b/mesonbuild/build.py
index ec0d8cc..6ee13d2 100644
--- a/mesonbuild/build.py
+++ b/mesonbuild/build.py
@@ -1797,7 +1797,8 @@ class CustomTarget(Target):
             raise InvalidArguments('build_always and build_always_stale are mutually exclusive. Combine build_by_default and build_always_stale.')
         elif 'build_always' in kwargs:
             mlog.warning('build_always is deprecated. Combine build_by_default and build_always_stale instead.')
-            self.build_by_default = kwargs['build_always']
+            if 'build_by_default' not in kwargs:
+                self.build_by_default = kwargs['build_always']
             self.build_always_stale = kwargs['build_always']
         elif 'build_always_stale' in kwargs:
             self.build_always_stale = kwargs['build_always_stale']
diff --git a/run_unittests.py b/run_unittests.py
index 8b664a3..0444199 100755
--- a/run_unittests.py
+++ b/run_unittests.py
@@ -1122,12 +1122,18 @@ class AllPlatformTests(BasePlatformTests):
         testdir = os.path.join(self.common_test_dir, '137 build by default')
         self.init(testdir)
         self.build()
-        genfile = os.path.join(self.builddir, 'generated.dat')
-        exe = os.path.join(self.builddir, 'fooprog' + exe_suffix)
-        self.assertPathExists(genfile)
-        self.assertPathDoesNotExist(exe)
+        genfile1 = os.path.join(self.builddir, 'generated1.dat')
+        genfile2 = os.path.join(self.builddir, 'generated2.dat')
+        exe1 = os.path.join(self.builddir, 'fooprog' + exe_suffix)
+        exe2 = os.path.join(self.builddir, 'barprog' + exe_suffix)
+        self.assertPathExists(genfile1)
+        self.assertPathExists(genfile2)
+        self.assertPathDoesNotExist(exe1)
+        self.assertPathDoesNotExist(exe2)
         self.build(target=('fooprog' + exe_suffix))
-        self.assertPathExists(exe)
+        self.assertPathExists(exe1)
+        self.build(target=('barprog' + exe_suffix))
+        self.assertPathExists(exe2)
 
     def test_internal_include_order(self):
         testdir = os.path.join(self.common_test_dir, '138 include order')
diff --git a/test cases/common/137 build by default/checkexists.py b/test cases/common/137 build by default/checkexists.py
new file mode 100644
index 0000000..6664f72
--- /dev/null
+++ b/test cases/common/137 build by default/checkexists.py
@@ -0,0 +1,10 @@
+#!/usr/bin/env python3
+
+import os.path, sys
+
+invert = False
+for path in sys.argv[1:]:
+    if path == '--not':
+        invert = True
+    elif not os.path.exists(path) ^ invert:
+        sys.exit(1)
diff --git a/test cases/common/137 build by default/meson.build b/test cases/common/137 build by default/meson.build
index 6569548..b28b634 100644
--- a/test cases/common/137 build by default/meson.build
+++ b/test cases/common/137 build by default/meson.build
@@ -3,22 +3,43 @@ project('build on all', 'c')
 py3_mod = import('python3')
 py3 = py3_mod.find_python()
 
-executable('fooprog', 'foo.c', build_by_default : false)
+executable('fooprog', 'foo.c',
+    build_by_default : false,
+)
+
+executable('barprog', 'foo.c',
+    build_by_default : false,
+    build_always : true,
+)
+
 comp = files('mygen.py')
-mytarget = custom_target('gendat',
-  output : 'generated.dat',
+checkexists = files('checkexists.py')
+
+mytarget = custom_target('gendat1',
+  output : 'generated1.dat',
+  input : 'source.txt',
+  command : [py3] + comp + ['@INPUT@', '@OUTPUT@'],
+  build_by_default : true,
+)
+
+mytarget = custom_target('gendat2',
+  output : 'generated2.dat',
   input : 'source.txt',
   command : [py3] + comp + ['@INPUT@', '@OUTPUT@'],
   build_by_default : true,
+  build_always : false,
 )
 
-ct_output = join_paths(meson.build_root(), 'generated.dat')
-exe_output = join_paths(meson.build_root(), 'fooprog')
+ct1_output = join_paths(meson.build_root(), 'generated1.dat')
+ct2_output = join_paths(meson.build_root(), 'generated2.dat')
+exe1_output = join_paths(meson.build_root(), 'fooprog')
+exe2_output = join_paths(meson.build_root(), 'barprog')
+
 if host_machine.system() == 'windows'
-  exe_output += '.exe'
+  exe1_output += '.exe'
+  exe2_output += '.exe'
 endif
 
-ct_exists_exe_nexists = 'import os.path, sys; sys.exit(not os.path.exists(sys.argv[1]) and os.path.exists(sys.argv[2]))'
-
 test('check-build-by-default', py3,
-     args : ['-c', ct_exists_exe_nexists, ct_output, exe_output])
+     args : [checkexists,
+        ct1_output, ct2_output, '--not', exe1_output, exe2_output])