Store build flags into coredata as it is persistent and needs to survive over Meson reconfigurations.

backends.py

@@ -320,7 +320,7 @@ class Backend():
         commands = []
         commands += compiler.get_always_flags()
         commands += self.build.get_global_flags(compiler)
-        commands += self.build.get_external_args(compiler)
+        commands += self.environment.coredata.external_args[compiler.get_language()]
         commands += target.get_extra_args(compiler.get_language())
         if self.environment.coredata.buildtype != 'plain':
             commands += compiler.get_debug_flags()

build.py

@@ -33,8 +33,6 @@ class Build:
         self.compilers = []
         self.cross_compilers = []
         self.global_args = {}
-        self.external_args = {} # These are set from "the outside" with e.g. mesonconf
-        self.external_link_args = {}
         self.tests = []
         self.headers = []
         self.man = []
@@ -60,25 +58,6 @@ class Build:
         if self.has_language(compiler.get_language()):
             return
         self.compilers.append(compiler)
-        self.get_flags_from_envvars(compiler)
-
-    def get_flags_from_envvars(self, compiler):
-        lang = compiler.get_language()
-        if lang == 'c':
-            compile_flags = os.environ.get('CFLAGS', '').split()
-            compile_flags += os.environ.get('CPPFLAGS', '').split()
-            link_flags = compile_flags + os.environ.get('LDFLAGS', '').split()
-        elif lang == 'cpp':
-            compile_flags = os.environ.get('CXXFLAGS', '').split()
-            compile_flags += os.environ.get('CPPFLAGS', '').split()
-            link_flags = compile_flags + os.environ.get('LDFLAGS', '').split()
-        else:
-            compile_flags = []
-            link_flags = []
-        if len(compile_flags) > 0:
-            self.external_args[lang] = compile_flags
-        if len(link_flags) > 0:
-            self.external_link_args[lang] = link_flags
 
     def add_cross_compiler(self, compiler):
         if len(self.cross_compilers) == 0:

coredata.py

@@ -41,6 +41,8 @@ class CoreData():
         self.unity = options.unity
         self.coverage = options.coverage
         self.user_options = {}
+        self.external_args = {} # These are set from "the outside" with e.g. mesonconf
+        self.external_link_args = {}
         if options.cross_file is not None:
             self.cross_file = os.path.join(os.getcwd(), options.cross_file)
         else:

environment.py

@@ -1449,6 +1449,20 @@ def get_library_dirs():
         unixdirs.append('/usr/local/lib')
         return unixdirs
 
+def get_flags_from_envvars(lang):
+    if lang == 'c':
+        compile_flags = os.environ.get('CFLAGS', '').split()
+        compile_flags += os.environ.get('CPPFLAGS', '').split()
+        link_flags = compile_flags + os.environ.get('LDFLAGS', '').split()
+    elif lang == 'cpp':
+        compile_flags = os.environ.get('CXXFLAGS', '').split()
+        compile_flags += os.environ.get('CPPFLAGS', '').split()
+        link_flags = compile_flags + os.environ.get('LDFLAGS', '').split()
+    else:
+        compile_flags = []
+        link_flags = []
+    return (compile_flags, link_flags)
+
 class CrossBuildInfo():
     def __init__(self, filename):
         self.items = {}

interpreter.py

@@ -955,6 +955,11 @@ class Interpreter():
                 if cross_comp is not None:
                     self.coredata.cross_compilers[lang] = cross_comp
             mlog.log('Using native %s compiler "' % lang, mlog.bold(' '.join(comp.get_exelist())), '". (%s %s)' % (comp.id, comp.version), sep='')
+            if not comp.get_language() in self.coredata.external_args:
+                print('getting from envvars')
+                (ext_compile_flags, ext_link_flags) = environment.get_flags_from_envvars(comp.get_language())
+                self.coredata.external_args[comp.get_language()] = ext_compile_flags
+                self.coredata.external_link_args[comp.get_language()] = ext_link_flags
             self.build.add_compiler(comp)
             if is_cross:
                 mlog.log('Using cross %s compiler "' % lang, mlog.bold(' '.join(cross_comp.get_exelist())), '". (%s %s)' % (cross_comp.id, cross_comp.version), sep='')

mesonconf.py

@@ -47,6 +47,9 @@ class Conf:
     def save(self):
         # Only called if something has changed so overwrite unconditionally.
         pickle.dump(self.coredata, open(self.coredata_file, 'wb'))
+        # We don't write the build file because any changes to it
+        # are erased when Meson is executed the nex time, i.e. the next
+        # time Ninja is run.
 
     def print_aligned(self, arr):
         if len(arr) == 0:
@@ -115,9 +118,7 @@ class Conf:
                 if os.path.isabs(v):
                     raise ConfException('Locale dir %s must not be an absolute path.' % v)
                 self.coredata.localedir = v
-            else:
-                if k not in self.coredata.user_options:
-                    raise ConfException('Unknown option %s.' % k)
+            elif k in self.coredata.user_options:
                 tgt = self.coredata.user_options[k]
                 if isinstance(tgt, optinterpreter.UserBooleanOption):
                     tgt.set_value(self.tobool(v))
@@ -131,6 +132,24 @@ class Conf:
                     tgt.set_value(v)
                 else:
                     raise ConfException('Internal error, unknown option type.')
+            elif k.endswith('linkflags'):
+                lang = k[:-9]
+                if not lang in self.coredata.external_link_args:
+                    raise ConfException('Unknown language %s in linkflags.' % lang)
+                # TODO, currently split on spaces, make it so that user
+                # can pass in an array string.
+                newvalue = v.split()
+                self.coredata.external_link_args[lang] = newvalue
+            elif k.endswith('flags'):
+                lang = k[:-5]
+                if not lang in self.coredata.external_args:
+                    raise ConfException('Unknown language %s in compile flags' % lang)
+                # TODO same fix as above
+                newvalue = v.split()
+                self.coredata.external_args[lang] = newvalue
+            else:
+                raise ConfException('Unknown option %s.' % k)
+
 
     def print_conf(self):
         print('Core properties\n')
@@ -146,6 +165,14 @@ class Conf:
         carr.append(['unity', 'Unity build', self.coredata.unity])
         self.print_aligned(carr)
         print('')
+        print('Compiler flags\n')
+        for (lang, flags) in self.coredata.external_args.items():
+            print(lang + 'flags', str(flags))
+        print('')
+        print('Linker flags\n')
+        for (lang, flags) in self.coredata.external_link_args.items():
+            print(lang + 'linkflags', str(flags))
+        print('')
         print('Directories\n')
         parr = []
         parr.append(['installprefix', 'Install prefix', self.coredata.prefix])
@@ -157,15 +184,18 @@ class Conf:
         parr.append(['localedir', 'Locale file directory', self.coredata.localedir])
         self.print_aligned(parr)
         print('')
-        print('Project options\n')
-        options = self.coredata.user_options
-        keys = list(options.keys())
-        keys.sort()
-        optarr = []
-        for key in keys:
-            opt = options[key]
-            optarr.append([key, opt.description, opt.value])
-        self.print_aligned(optarr)
+        if len(self.coredata.user_options) == 0:
+            print('This project does not have any options')
+        else:
+            print('Project options\n')
+            options = self.coredata.user_options
+            keys = list(options.keys())
+            keys.sort()
+            optarr = []
+            for key in keys:
+                opt = options[key]
+                optarr.append([key, opt.description, opt.value])
+            self.print_aligned(optarr)
 
 if __name__ == '__main__':
     (options, args) = parser.parse_args(sys.argv)

ninjabackend.py

@@ -817,7 +817,7 @@ class NinjaBackend(backends.Backend):
         commands += linker.get_linker_always_flags()
         commands += linker.get_buildtype_linker_flags(self.environment.coredata.buildtype)
         if not(isinstance(target, build.StaticLibrary)):
-            commands += self.build.get_external_link_args(linker)
+            commands += self.environment.coredata.external_link_args[linker.get_language()]
         if isinstance(target, build.Executable):
             commands += linker.get_std_exe_link_flags()
         elif isinstance(target, build.SharedLibrary):