options: use dataclasses for UserOption

This reduces code, makes this clearer, and will be a nice step toward
the goal of getting everything typesafe.

For `UserIntegerOption` this makes a fairly nice, but substantial change
in that the old method used a tuple of `(min, value, max)` to pass to the
initializer, while all other types just passed `value`. The new
`UserIntegerOption` does the same, with keyword arguments for the min
and max values.

7 files changed, 28 insertions, 26 deletions

diff --git a/mesonbuild/compilers/compilers.py b/mesonbuild/compilers/compilers.py
index 12bcd1e4c..1432afb85 100644
--- a/mesonbuild/compilers/compilers.py
+++ b/mesonbuild/compilers/compilers.py
@@ -224,16 +224,16 @@ class BaseOption(T.Generic[_T]):
     choices: T.Any = None
 
     def init_option(self, name: OptionKey) -> options.UserOption[_T]:
-        keywords = {'value': self.default}
+        keywords = {}
         if self.choices:
             keywords['choices'] = self.choices
-        return self.opt_type(name.name, self.description, **keywords)
+        return self.opt_type(name.name, self.description, self.default, **keywords)
 
 
 BASE_OPTIONS: T.Mapping[OptionKey, BaseOption] = {
     OptionKey('b_pch'): BaseOption(options.UserBooleanOption, 'Use precompiled headers', True),
     OptionKey('b_lto'): BaseOption(options.UserBooleanOption, 'Use link time optimization', False),
-    OptionKey('b_lto_threads'): BaseOption(options.UserIntegerOption, 'Use multiple threads for Link Time Optimization', (None, None, 0)),
+    OptionKey('b_lto_threads'): BaseOption(options.UserIntegerOption, 'Use multiple threads for Link Time Optimization', 0),
     OptionKey('b_lto_mode'): BaseOption(options.UserComboOption, 'Select between different LTO modes.', 'default',
                                         choices=['default', 'thin']),
     OptionKey('b_thinlto_cache'): BaseOption(options.UserBooleanOption, 'Use LLVM ThinLTO caching for faster incremental builds', False),
diff --git a/mesonbuild/compilers/cpp.py b/mesonbuild/compilers/cpp.py
index b17e18b3e..7fa9aa833 100644
--- a/mesonbuild/compilers/cpp.py
+++ b/mesonbuild/compilers/cpp.py
@@ -242,8 +242,8 @@ class ClangCPPCompiler(_StdCPPLibMixin, ClangCPPStds, ClangCompiler, CPPCompiler
         opts[key] = options.UserComboOption(
             self.make_option_name(key),
             'C++ exception handling type.',
-            ['none', 'default', 'a', 's', 'sc'],
-            'default')
+            'default',
+            ['none', 'default', 'a', 's', 'sc'])
 
         key = self.form_compileropt_key('rtti')
         opts[key] = options.UserBooleanOption(
@@ -398,8 +398,8 @@ class ArmclangCPPCompiler(ArmclangCompiler, CPPCompiler):
         opts[key] = options.UserComboOption(
             self.make_option_name(key),
             'C++ exception handling type.',
-            ['none', 'default', 'a', 's', 'sc'],
-            'default')
+            'default',
+            ['none', 'default', 'a', 's', 'sc'])
 
         key = self.form_compileropt_key('std')
         std_opt = opts[key]
@@ -448,8 +448,8 @@ class GnuCPPCompiler(_StdCPPLibMixin, GnuCPPStds, GnuCompiler, CPPCompiler):
         opts[key] = options.UserComboOption(
             self.make_option_name(key),
             'C++ exception handling type.',
-            ['none', 'default', 'a', 's', 'sc'],
-            'default')
+            'default',
+            ['none', 'default', 'a', 's', 'sc'])
 
         key = self.form_compileropt_key('rtti')
         opts[key] = options.UserBooleanOption(
@@ -577,8 +577,8 @@ class ElbrusCPPCompiler(ElbrusCompiler, CPPCompiler):
         opts[key] = options.UserComboOption(
             self.make_option_name(key),
             'C++ exception handling type.',
-            ['none', 'default', 'a', 's', 'sc'],
-            'default')
+            'default',
+            ['none', 'default', 'a', 's', 'sc'])
 
         key = self.form_compileropt_key('debugstl')
         opts[key] = options.UserBooleanOption(
@@ -660,8 +660,8 @@ class IntelCPPCompiler(IntelGnuLikeCompiler, CPPCompiler):
         opts[key] = options.UserComboOption(
             self.make_option_name(key),
             'C++ exception handling type.',
-            ['none', 'default', 'a', 's', 'sc'],
-            'default')
+            'default',
+            ['none', 'default', 'a', 's', 'sc'])
 
         key = self.form_compileropt_key('rtti')
         opts[key] = options.UserBooleanOption(
@@ -753,8 +753,8 @@ class VisualStudioLikeCPPCompilerMixin(CompilerMixinBase):
         opts[key] = options.UserComboOption(
             self.make_option_name(key),
             'C++ exception handling type.',
-            ['none', 'default', 'a', 's', 'sc'],
-            'default')
+            'default',
+            ['none', 'default', 'a', 's', 'sc'])
 
         key = self.form_compileropt_key('rtti')
         opts[key] = options.UserBooleanOption(
diff --git a/mesonbuild/compilers/cuda.py b/mesonbuild/compilers/cuda.py
index 07fda95dd..aefcc512b 100644
--- a/mesonbuild/compilers/cuda.py
+++ b/mesonbuild/compilers/cuda.py
@@ -648,12 +648,13 @@ class CudaCompiler(Compiler):
 
         opts = super().get_options()
 
+        # XXX: cpp_std is correct, the annotations are wrong
         key = self.form_compileropt_key('std')
         opts[key] = options.UserComboOption(
             self.make_option_name(key),
             'C++ language standard to use with CUDA',
-            cpp_stds,
-            'none')
+            'none',
+            cpp_stds)
 
         key = self.form_compileropt_key('ccbindir')
         opts[key] = options.UserStringOption(
diff --git a/mesonbuild/compilers/cython.py b/mesonbuild/compilers/cython.py
index 2d0f21d00..ba04aea0b 100644
--- a/mesonbuild/compilers/cython.py
+++ b/mesonbuild/compilers/cython.py
@@ -73,15 +73,15 @@ class CythonCompiler(Compiler):
         opts[key] = options.UserComboOption(
             self.make_option_name(key),
             'Python version to target',
-            ['2', '3'],
-            '3')
+            '3',
+            ['2', '3'])
 
         key = self.form_compileropt_key('language')
         opts[key] = options.UserComboOption(
             self.make_option_name(key),
             'Output C or C++ files',
-            ['c', 'cpp'],
-            'c')
+            'c',
+            ['c', 'cpp'])
 
         return opts
 
diff --git a/mesonbuild/compilers/fortran.py b/mesonbuild/compilers/fortran.py
index f771e4c40..b004727b4 100644
--- a/mesonbuild/compilers/fortran.py
+++ b/mesonbuild/compilers/fortran.py
@@ -120,8 +120,8 @@ class FortranCompiler(CLikeCompiler, Compiler):
         opts[key] = options.UserComboOption(
             self.make_option_name(key),
             'Fortran language standard to use',
-            ['none'],
-            'none')
+            'none',
+            ['none'])
 
         return opts
 
diff --git a/mesonbuild/compilers/mixins/emscripten.py b/mesonbuild/compilers/mixins/emscripten.py
index fa8620569..24ffceda6 100644
--- a/mesonbuild/compilers/mixins/emscripten.py
+++ b/mesonbuild/compilers/mixins/emscripten.py
@@ -63,7 +63,8 @@ class EmscriptenMixin(Compiler):
         opts[key] = options.UserIntegerOption(
             self.make_option_name(key),
             'Number of threads to use in web assembly, set to 0 to disable',
-            (0, None, 4))  # Default was picked at random
+            4,  # Default was picked at random
+            min_value=0)
 
         return opts
 
diff --git a/mesonbuild/compilers/rust.py b/mesonbuild/compilers/rust.py
index 40c85ee68..7fe16c6f8 100644
--- a/mesonbuild/compilers/rust.py
+++ b/mesonbuild/compilers/rust.py
@@ -240,8 +240,8 @@ class RustCompiler(Compiler):
         opts[key] = options.UserComboOption(
             self.make_option_name(key),
             'Rust edition to use',
-            ['none', '2015', '2018', '2021', '2024'],
-            'none')
+            'none',
+            ['none', '2015', '2018', '2021', '2024'])
 
         return opts