Add blocks dependency

This allows easily enabling the blocks clang extension.

2 files changed, 35 insertions, 1 deletions

diff --git a/mesonbuild/dependencies/__init__.py b/mesonbuild/dependencies/__init__.py
index 846f3de..631451c 100644
--- a/mesonbuild/dependencies/__init__.py
+++ b/mesonbuild/dependencies/__init__.py
@@ -18,7 +18,7 @@ from .base import (  # noqa: F401
     ExternalDependency, NotFoundDependency, ExternalLibrary, ExtraFrameworkDependency, InternalDependency,
     PkgConfigDependency, CMakeDependency, find_external_dependency, get_dep_identifier, packages, _packages_accept_language)
 from .dev import GMockDependency, GTestDependency, LLVMDependency, ValgrindDependency
-from .misc import (CoarrayDependency, HDF5Dependency, MPIDependency, NetCDFDependency, OpenMPDependency, Python3Dependency, ThreadDependency, PcapDependency, CupsDependency, LibWmfDependency, LibGCryptDependency, GpgmeDependency, ShadercDependency)
+from .misc import (BlocksDependency, CoarrayDependency, HDF5Dependency, MPIDependency, NetCDFDependency, OpenMPDependency, Python3Dependency, ThreadDependency, PcapDependency, CupsDependency, LibWmfDependency, LibGCryptDependency, GpgmeDependency, ShadercDependency)
 from .platform import AppleFrameworks
 from .ui import GLDependency, GnuStepDependency, Qt4Dependency, Qt5Dependency, SDL2Dependency, WxDependency, VulkanDependency
 
@@ -31,6 +31,7 @@ packages.update({
     'valgrind': ValgrindDependency,
 
     # From misc:
+    'blocks': BlocksDependency,
     'boost': BoostDependency,
     'coarray': CoarrayDependency,
     'mpi': MPIDependency,
diff --git a/mesonbuild/dependencies/misc.py b/mesonbuild/dependencies/misc.py
index 23a283f..c62f49f 100644
--- a/mesonbuild/dependencies/misc.py
+++ b/mesonbuild/dependencies/misc.py
@@ -412,6 +412,39 @@ class ThreadDependency(ExternalDependency):
             self.link_args = self.clib_compiler.thread_link_flags(environment)
 
 
+class BlocksDependency(ExternalDependency):
+    def __init__(self, environment, kwargs):
+        super().__init__('blocks', environment, None, kwargs)
+        self.name = 'blocks'
+        self.is_found = False
+
+        if self.env.machines[self.for_machine].is_darwin():
+            self.compile_args = []
+            self.link_args = []
+        else:
+            self.compile_args = ['-fblocks']
+            self.link_args = ['-lBlocksRuntime']
+
+            if not self.clib_compiler.has_header('Block.h', '', environment, disable_cache=True) or \
+               not self.clib_compiler.find_library('BlocksRuntime', environment, []):
+                mlog.log(mlog.red('ERROR:'), 'BlocksRuntime not found.')
+                return
+
+        source = '''
+            int main(int argc, char **argv)
+            {
+                int (^callback)(void) = ^ int (void) { return 0; };
+                return callback();
+            }'''
+
+        with self.clib_compiler.compile(source, extra_args=self.compile_args + self.link_args) as p:
+            if p.returncode != 0:
+                mlog.log(mlog.red('ERROR:'), 'Compiler does not support blocks extension.')
+                return
+
+            self.is_found = True
+
+
 class Python3Dependency(ExternalDependency):
     def __init__(self, environment, kwargs):
         super().__init__('python3', environment, None, kwargs)