compilers: convert `b_sanitize` to a free-form array option

In the preceding commit we have started to perform compiler checks for
the value of `b_sanitize`, which allows us to detect sanitizers that
aren't supported by the compiler toolchain. But we haven't yet loosened
the option itself to accept arbitrary values, so until now it's still
only possible to pass sanitizer combinations known by Meson, which is
quite restrictive.

Lift that restriction by adapting the `b_sanitize` option to become a
free-form array. Like this, users can pass whatever combination of
comma-separated sanitizers to Meson, which will then figure out whether
that combination is supported via the compiler checks. This lifts a
couple of restrictions and makes the supporting infrastructure way more
future proof.

A couple of notes regarding backwards compatibility:

  - All previous values of `b_sanitize` will remain valid as the syntax
    for free-form array values and valid combo choices is the same. We
    also treat 'none' specially so that we know to convert it into an
    empty array.

  - Even though the option has been converted into a free-form array,
    callers of `get_option('b_sanitize')` continue to get a string as
    value. We may eventually want to introduce a kwarg to alter this
    behaviour, but for now it is expected to be good enough for most use
    cases.

Fixes #8283
Fixes #7761
Fixes #5154
Fixes #1582

Co-authored-by: Dylan Baker <dylan@pnwbakers.com>
Signed-off-by: Patrick Steinhardt <ps@pks.im>

1 files changed, 13 insertions, 4 deletions

diff --git a/mesonbuild/interpreter/interpreter.py b/mesonbuild/interpreter/interpreter.py
index ff93ac6..42e6243 100644
--- a/mesonbuild/interpreter/interpreter.py
+++ b/mesonbuild/interpreter/interpreter.py
@@ -1068,14 +1068,14 @@ class Interpreter(InterpreterBase, HoldableObject):
 
     @typed_pos_args('get_option', str)
     @noKwargs
-    def func_get_option(self, nodes: mparser.BaseNode, args: T.Tuple[str],
-                        kwargs: 'TYPE_kwargs') -> T.Union[options.UserOption, 'TYPE_var']:
+    def func_get_option(self, node: mparser.BaseNode, args: T.Tuple[str],
+                        kwargs: kwtypes.FuncGetOption) -> T.Union[options.UserOption, 'TYPE_var']:
         optname = args[0]
+
         if ':' in optname:
             raise InterpreterException('Having a colon in option name is forbidden, '
                                        'projects are not allowed to directly access '
                                        'options of other subprojects.')
-
         if optname_regex.search(optname.split('.', maxsplit=1)[-1]) is not None:
             raise InterpreterException(f'Invalid option name {optname!r}')
 
@@ -1096,6 +1096,15 @@ class Interpreter(InterpreterBase, HoldableObject):
             ocopy.name = optname
             ocopy.value = value
             return ocopy
+        elif optname == 'b_sanitize':
+            assert isinstance(value_object, options.UserStringArrayOption)
+            # To ensure backwards compatibility this always returns a string.
+            # We may eventually want to introduce a new "format" kwarg that
+            # allows the user to modify this behaviour, but for now this is
+            # likely good enough for most usecases.
+            if not value:
+                return 'none'
+            return ','.join(sorted(value))
         elif isinstance(value_object, options.UserOption):
             if isinstance(value_object.value, str):
                 return P_OBJ.OptionString(value, f'{{{optname}}}')
@@ -3090,7 +3099,7 @@ class Interpreter(InterpreterBase, HoldableObject):
         if OptionKey('b_sanitize') not in self.coredata.optstore:
             return
         if (self.coredata.optstore.get_value('b_lundef') and
-                self.coredata.optstore.get_value('b_sanitize') != 'none'):
+                self.coredata.optstore.get_value('b_sanitize')):
             value = self.coredata.optstore.get_value('b_sanitize')
             mlog.warning(textwrap.dedent(f'''\
                     Trying to use {value} sanitizer on Clang with b_lundef.