cmake: add project language to cmakelists.txt

cmake: get language from Meson project if not specified as depedency(..., langugage: ...)

deps: add threads method:cmake

dependency('threads', method: 'cmake') is useful for cmake unit tests
or those who just want to find threads using cmake.

cmake: project(... Fortran) generally also requires C language

1 files changed, 29 insertions, 9 deletions

diff --git a/mesonbuild/dependencies/misc.py b/mesonbuild/dependencies/misc.py
index bfd450c..d773eb7 100644
--- a/mesonbuild/dependencies/misc.py
+++ b/mesonbuild/dependencies/misc.py
@@ -22,6 +22,7 @@ import sysconfig
 from .. import mlog
 from .. import mesonlib
 from ..environment import detect_cpu_family
+from ..mesonlib import listify
 
 from .base import (
     DependencyException, DependencyMethods, ExternalDependency,
@@ -109,15 +110,34 @@ class ThreadDependency(ExternalDependency):
     def __init__(self, environment, kwargs):
         super().__init__('threads', environment, None, kwargs)
         self.name = 'threads'
-        self.is_found = True
-        # Happens if you are using a language with threads
-        # concept without C, such as plain Cuda.
-        if self.clib_compiler is None:
-            self.compile_args = []
-            self.link_args = []
-        else:
-            self.compile_args = self.clib_compiler.thread_flags(environment)
-            self.link_args = self.clib_compiler.thread_link_flags(environment)
+        self.is_found = False
+        methods = listify(self.methods)
+        if DependencyMethods.AUTO in methods:
+            self.is_found = True
+            # Happens if you are using a language with threads
+            # concept without C, such as plain Cuda.
+            if self.clib_compiler is None:
+                self.compile_args = []
+                self.link_args = []
+            else:
+                self.compile_args = self.clib_compiler.thread_flags(environment)
+                self.link_args = self.clib_compiler.thread_link_flags(environment)
+            return
+
+        if DependencyMethods.CMAKE in methods:
+            # for unit tests and for those who simply want
+            # dependency('threads', method: 'cmake')
+            cmakedep = CMakeDependency('Threads', environment, kwargs)
+            if cmakedep.found():
+                self.compile_args = cmakedep.get_compile_args()
+                self.link_args = cmakedep.get_link_args()
+                self.version = cmakedep.get_version()
+                self.is_found = True
+                return
+
+    @staticmethod
+    def get_methods():
+        return [DependencyMethods.AUTO, DependencyMethods.CMAKE]
 
 
 class BlocksDependency(ExternalDependency):