environment: get environment variables for both host and build machines

Fixes #8605

mesonbuild/compilers/compilers.py

@@ -1236,19 +1236,26 @@ def get_global_options(lang: str,
     largkey = argkey.evolve('link_args')
     envkey = argkey.evolve('env_args')
 
+    comp_key = argkey if argkey in env.options else envkey
+
+    comp_options = env.options.get(comp_key, [])
+    link_options = env.options.get(largkey, [])
+
     cargs = coredata.UserArrayOption(
         description + ' compiler',
-        env.options.get(argkey, []), split_args=True, user_input=True, allow_dups=True)
-    # the compiler args always gets the environemtn variable arguments
-    cargs.extend_value(env.options.get(envkey, []))
+        comp_options, split_args=True, user_input=True, allow_dups=True)
 
     largs = coredata.UserArrayOption(
         description + ' linker',
-        env.options.get(largkey, []), split_args=True, user_input=True, allow_dups=True)
-    # The linker gets the compiler environment variable only if the comiler
-    # acts as the linker
-    if comp.INVOKES_LINKER:
-        largs.extend_value(env.options.get(envkey, []))
+        link_options, split_args=True, user_input=True, allow_dups=True)
+
+    if comp.INVOKES_LINKER and comp_key == envkey:
+        # If the compiler acts as a linker driver, and we're using the
+        # environment variable flags for both the compiler and linker
+        # arguments, then put the compiler flags in the linker flags as well.
+        # This is how autotools works, and the env vars freature is for
+        # autotools compatibility.
+        largs.extend_value(comp_options)
 
     opts: 'KeyedOptionDictType' = {argkey: cargs, largkey: largs}
 

mesonbuild/environment.py

@@ -798,11 +798,7 @@ class Environment:
 
         env_opts: T.DefaultDict[OptionKey, T.List[str]] = collections.defaultdict(list)
 
-        if self.is_cross_build():
-            for_machine = MachineChoice.BUILD
-        else:
-            for_machine = MachineChoice.HOST
-        for evar, keyname in opts:
+        for (evar, keyname), for_machine in itertools.product(opts, MachineChoice):
             p_env = _get_env_var(for_machine, self.is_cross_build(), evar)
             if p_env is not None:
                 # these may contain duplicates, which must be removed, else
@@ -832,7 +828,7 @@ class Environment:
                             key = key.evolve(lang=lang)
                             env_opts[key].extend(p_list)
                     elif keyname == 'cppflags':
-                        key = OptionKey('args', machine=for_machine, lang='c')
+                        key = OptionKey('env_args', machine=for_machine, lang='c')
                         for lang in compilers.compilers.LANGUAGES_USING_CPPFLAGS:
                             key = key.evolve(lang=lang)
                             env_opts[key].extend(p_list)