haiku: do not add pthread arguments

Haiku has pthreads, but they are part of the standard C library, and do
not need either special compiler or linker flags.

mesonbuild/backend/backends.py

@@ -509,7 +509,7 @@ class Backend:
             # For 'automagic' deps: Boost and GTest. Also dependency('threads').
             # pkg-config puts the thread flags itself via `Cflags:`
             if dep.need_threads():
-                commands += compiler.thread_flags()
+                commands += compiler.thread_flags(self.environment)
         # Fortran requires extra include directives.
         if compiler.language == 'fortran':
             for lt in target.link_targets:

mesonbuild/backend/ninjabackend.py

@@ -2430,7 +2430,7 @@ rule FORTRAN_DEP_HACK
         # pkg-config puts the thread flags itself via `Cflags:`
         for d in target.external_deps:
             if d.need_threads():
-                commands += linker.thread_link_flags()
+                commands += linker.thread_link_flags(self.environment)
         # Only non-static built targets need link args and link dependencies
         if not isinstance(target, build.StaticLibrary):
             commands += target.link_args

mesonbuild/compilers/c.py

@@ -16,9 +16,11 @@ import subprocess, os.path, tempfile
 
 from .. import mlog
 from .. import coredata
-from ..mesonlib import EnvironmentException, version_compare, Popen_safe, listify
-from ..mesonlib import for_windows, for_darwin, for_cygwin
 from . import compilers
+from ..mesonlib import (
+    EnvironmentException, version_compare, Popen_safe, listify,
+    for_windows, for_darwin, for_cygwin, for_haiku,
+)
 
 from .compilers import (
     GCC_MINGW,
@@ -281,12 +283,12 @@ class CCompiler(Compiler):
             # Add compile flags needed by dependencies
             args += d.get_compile_args()
             if d.need_threads():
-                args += self.thread_flags()
+                args += self.thread_flags(env)
             if mode == 'link':
                 # Add link flags needed to find dependencies
                 args += d.get_link_args()
                 if d.need_threads():
-                    args += self.thread_link_flags()
+                    args += self.thread_link_flags(env)
         # Select a CRT if needed since we're linking
         if mode == 'link':
             args += self.get_linker_debug_crt_args()
@@ -781,10 +783,14 @@ class CCompiler(Compiler):
                         return [trial]
         return None
 
-    def thread_flags(self):
+    def thread_flags(self, env):
+        if for_haiku(self.is_cross, env):
+            return []
         return ['-pthread']
 
-    def thread_link_flags(self):
+    def thread_link_flags(self, env):
+        if for_haiku(self.is_cross, env):
+            return []
         return ['-pthread']
 
     def has_multi_arguments(self, args, env):
@@ -1005,10 +1011,10 @@ class VisualStudioCCompiler(CCompiler):
         return []
 
     # FIXME, no idea what these should be.
-    def thread_flags(self):
+    def thread_flags(self, env):
         return []
 
-    def thread_link_flags(self):
+    def thread_link_flags(self, env):
         return []
 
     def get_options(self):

mesonbuild/linkers.py

@@ -48,7 +48,7 @@ class VisualStudioLinker(StaticLinker):
     def build_rpath_args(self, build_dir, from_dir, rpath_paths, build_rpath, install_rpath):
         return []
 
-    def thread_link_flags(self):
+    def thread_link_flags(self, env):
         return []
 
     def get_option_link_args(self, options):
@@ -100,7 +100,7 @@ class ArLinker(StaticLinker):
     def get_always_args(self):
         return []
 
-    def thread_link_flags(self):
+    def thread_link_flags(self, env):
         return []
 
     def get_option_link_args(self, options):

mesonbuild/mesonlib.py

@@ -292,6 +292,18 @@ def for_darwin(is_cross, env):
         return env.cross_info.config['host_machine']['system'] == 'darwin'
     return False
 
+def for_haiku(is_cross, env):
+    """
+    Host machine is Haiku?
+
+    Note: 'host' is the machine on which compiled binaries will run
+    """
+    if not is_cross:
+        return is_haiku()
+    elif env.cross_info.has_host():
+        return env.cross_info.config['host_machine']['system'] == 'haiku'
+    return False
+
 def exe_exists(arglist):
     try:
         p = subprocess.Popen(arglist, stdout=subprocess.PIPE, stderr=subprocess.PIPE)