Add MVP implementation of overriding options.

mesonbuild/backend/ninjabackend.py

@@ -283,6 +283,12 @@ int dummy;
                 return False
         return True
 
+    def get_option_for_target(self, option_name, target):
+        if option_name in target.option_overrides:
+            override = target.option_overrides[option_name]
+            return self.environment.coredata.validate_option_value(option_name, override)
+        return self.environment.coredata.get_builtin_option('unity')
+
     def generate_target(self, target, outfile):
         if isinstance(target, build.CustomTarget):
             self.generate_custom_target(target, outfile)
@@ -336,7 +342,7 @@ int dummy;
         outname = self.get_target_filename(target)
         obj_list = []
         use_pch = self.environment.coredata.base_options.get('b_pch', False)
-        is_unity = self.environment.coredata.get_builtin_option('unity')
+        is_unity = self.get_option_for_target('unity', target)
         if use_pch and target.has_pch():
             pch_objects = self.generate_pch(target, outfile)
         else:

mesonbuild/build.py

@@ -47,6 +47,7 @@ known_basic_kwargs = {'install': True,
                       'objects': True,
                       'native': True,
                       'build_by_default': True,
+                      'override_options': True,
                       }
 
 # These contain kwargs supported by both static and shared libraries. These are
@@ -305,6 +306,7 @@ class BuildTarget(Target):
         self.extra_args = {}
         self.generated = []
         self.extra_files = []
+        self.option_overrides = {}
         # Sources can be:
         # 1. Pre-existing source files in the source tree
         # 2. Pre-existing sources generated by configure_file in the build tree
@@ -670,6 +672,14 @@ class BuildTarget(Target):
                 self.pic = kwargs.get('pic', False)
                 if not isinstance(self.pic, bool):
                     raise InvalidArguments('Argument pic to static library {!r} must be boolean'.format(self.name))
+        overrides = stringlistify(kwargs.get('override_options', []))
+        for o in overrides:
+            if '=' not in o:
+                raise InvalidArguments('Overrides must be of form "key=value"')
+            k, v = o.split('=', 1)
+            k = k.strip()
+            v = v.strip()
+            self.option_overrides[k] = v
 
     def get_filename(self):
         return self.filename

mesonbuild/coredata.py

@@ -30,6 +30,12 @@ class UserOption:
     def parse_string(self, valuestring):
         return valuestring
 
+    # Check that the input is a valid value and return the
+    # "cleaned" or "native" version. For example the Boolean
+    # option could take the string "true" and return True.
+    def validate_value(self, value):
+        raise RuntimeError('Derived option class did not override validate_value.')
+
 class UserStringOption(UserOption):
     def __init__(self, name, description, value, choices=None):
         super().__init__(name, description, choices)
@@ -43,6 +49,10 @@ class UserStringOption(UserOption):
         self.validate(newvalue)
         self.value = newvalue
 
+    def validate_value(self, value):
+        self.validate(value)
+        return value
+
 class UserBooleanOption(UserOption):
     def __init__(self, name, description, value):
         super().__init__(name, description, [True, False])
@@ -70,6 +80,9 @@ class UserBooleanOption(UserOption):
     def __bool__(self):
         return self.value
 
+    def validate_value(self, value):
+        return self.tobool(value)
+
 class UserComboOption(UserOption):
     def __init__(self, name, description, choices, value):
         super().__init__(name, description, choices)
@@ -86,22 +99,35 @@ class UserComboOption(UserOption):
             raise MesonException('Value "%s" for combo option "%s" is not one of the choices. Possible choices are: %s.' % (newvalue, self.name, optionsstring))
         self.value = newvalue
 
+    def validate_value(self, value):
+        if value not in self.choices:
+            raise MesonException('Value %s not one of accepted values.' % value)
+
 class UserStringArrayOption(UserOption):
     def __init__(self, name, description, value, **kwargs):
         super().__init__(name, description, kwargs.get('choices', []))
         self.set_value(value)
 
-    def set_value(self, newvalue):
-        if isinstance(newvalue, str):
-            if not newvalue.startswith('['):
-                raise MesonException('Valuestring does not define an array: ' + newvalue)
-            newvalue = eval(newvalue, {}, {}) # Yes, it is unsafe.
+    def validate(self, value):
+        if isinstance(value, str):
+            if not value.startswith('['):
+                raise MesonException('Valuestring does not define an array: ' + value)
+            newvalue = eval(value, {}, {}) # Yes, it is unsafe.
+        else:
+            newvalue = value
         if not isinstance(newvalue, list):
             raise MesonException('"{0}" should be a string array, but it is not'.format(str(newvalue)))
         for i in newvalue:
             if not isinstance(i, str):
                 raise MesonException('String array element "{0}" is not a string.'.format(str(newvalue)))
-        self.value = newvalue
+        return newvalue
+
+    def set_value(self, newvalue):
+        self.value = self.validate(newvalue)
+
+    def validate_value(self, value):
+        self.validate(value)
+        return value
 
 # This class contains all data that must persist over multiple
 # invocations of Meson. It is roughly the same thing as
@@ -203,6 +229,13 @@ class CoreData:
             raise RuntimeError('Tried to set unknown builtin option %s.' % optname)
         self.builtins[optname].set_value(value)
 
+    def validate_option_value(self, option_name, override_value):
+        for opts in (self.builtins, self.base_options, self.compiler_options, self.user_options):
+            if option_name in opts:
+                opt = opts[option_name]
+                return opt.validate_value(override_value)
+        raise MesonException('Tried to validate unknown option %s.' % option_name)
+
 def load(filename):
     load_fail_msg = 'Coredata file {!r} is corrupted. Try with a fresh build tree.'.format(filename)
     try:

test cases/common/139 override options/four.c

@@ -0,0 +1,9 @@
+int func();
+
+static int duplicate_func() {
+    return -4;
+}
+
+int main(int argc, char **argv) {
+    return duplicate_func() + func();
+}

test cases/common/139 override options/meson.build

@@ -0,0 +1,6 @@
+project('option override', 'c',
+  default_options : 'unity=true')
+
+executable('mustunity', 'one.c', 'two.c')
+executable('notunity', 'three.c', 'four.c',
+  override_options : ['unity=false'])

test cases/common/139 override options/one.c

@@ -0,0 +1,3 @@
+static int hidden_func() {
+    return 0;
+}

test cases/common/139 override options/three.c

@@ -0,0 +1,7 @@
+static int duplicate_func() {
+    return 4;
+}
+
+int func() {
+    return duplicate_func();
+}

test cases/common/139 override options/two.c

@@ -0,0 +1,6 @@
+/*
+ * Requires a Unity build. Otherwise hidden_func is not specified.
+ */
+int main(int argc, char **argv) {
+    return hidden_func();
+}