Don't rely on -fPIC being ignored where it's meaningless

clang considers it an error to try to use -fPIC for a windows target

v2:
'' isn't consistently elided, use []

run_unittests.py

@@ -2165,7 +2165,9 @@ int main(int argc, char **argv) {
                 '/NOLOGO', '/DLL', '/DEBUG', '/IMPLIB:' + impfile,
                 '/OUT:' + outfile, objectfile]
         else:
-            extra_args += ['-fPIC']
+            if not (compiler.compiler_type.is_windows_compiler or
+                    compiler.compiler_type.is_osx_compiler):
+                extra_args += ['-fPIC']
             link_cmd = compiler.get_exelist() + ['-shared', '-o', outfile, objectfile]
             if not mesonbuild.mesonlib.is_osx():
                 link_cmd += ['-Wl,-soname=' + os.path.basename(outfile)]
@@ -3495,7 +3497,7 @@ class LinuxlikeTests(BasePlatformTests):
         is true and not when it is false. This can't be an ordinary test case
         because we need to inspect the compiler database.
         '''
-        if is_cygwin() or is_osx():
+        if is_windows() or is_cygwin() or is_osx():
             raise unittest.SkipTest('PIC not relevant')
 
         testdir = os.path.join(self.common_test_dir, '3 static')

test cases/common/143 C and CPP link/meson.build

@@ -36,7 +36,11 @@ if cxx.get_argument_syntax() == 'msvc'
   compile_cmd = ['/c', '@INPUT@', '/Fo@OUTPUT@']
   stlib_cmd = [static_linker, '/OUT:@OUTPUT@', '@INPUT@']
 else
-  compile_cmd = ['-c', '-fPIC', '@INPUT@', '-o', '@OUTPUT@']
+ picflag = []
+ if not ['darwin', 'windows'].contains(host_machine.system())
+    picflag = ['-fPIC']
+  endif
+  compile_cmd = ['-c', picflag, '@INPUT@', '-o', '@OUTPUT@']
   stlib_cmd = ['ar', 'csr', '@OUTPUT@', '@INPUT@']
 endif
 

test cases/common/59 exe static shared/meson.build

@@ -1,8 +1,12 @@
 project('statchain', 'c')
 
 subdir('subdir')
-# Test that -fPIC in c_args is also accepted
+# Test that -fPIC in c_args is also accepted (on platforms where it's permitted)
-statlib2 = static_library('stat2', 'stat2.c', c_args : '-fPIC', pic : false)
+picflag = []
+if not ['darwin', 'windows'].contains(host_machine.system())
+  picflag = ['-fPIC']
+endif
+statlib2 = static_library('stat2', 'stat2.c', c_args : picflag, pic : false)
 # Test that pic is needed for both direct and indirect static library
 # dependencies of shared libraries (on Linux and BSD)
 statlib = static_library('stat', 'stat.c', link_with : [shlib, statlib2], pic : true)