save build flags in .config.bb

src/main.cc

@@ -96,22 +96,42 @@ int main(int argc, char **argv) {
 		sys::chdir(workDir);
 	}
 
+	// Read in variables from conf if it exists
+	BBVariables variables;
+	if (sys::fileExists(outDir + "/.config.bb")) {
+		std::ifstream f = sys::ifstream(outDir + "/.config.bb");
+		BBParser parser(f, BBParser::FLAG_NONE);
+		parser.parse(variables);
+	}
+
 	// Read non-option arguments (variable definitions and args)
+	bool varsChanged = false;
 	std::vector<std::string> args;
-	BBVariables vars;
 	while (optind < argc) {
 		char *arg = argv[optind++];
 		char *eq = strchr(arg, '=');
 		if (eq == nullptr) {
 			args.push_back(arg);
 		} else {
-			std::stringstream ss(eq + 1);
-			BBParser parser(ss, BBParser::FLAG_NONE);
-			parser.parseList(vars, vars[std::string(arg, eq - arg)]);
+			varsChanged = true;
+			std::stringstream val(eq + 1);
+			BBParser parser(val, BBParser::FLAG_NONE);
+			std::string key(arg, eq - arg);
+			std::vector<std::string> &list = variables[key];
+			list.clear();
+			parser.parseList(variables, list);
 		}
 	}
 
-	std::unique_ptr<DepNode> root = buildDepTree(outDir, vars);
+	// If our variables changed, write out the new ones
+	if (varsChanged) {
+		std::ofstream f = sys::ofstream(outDir + "/.config.bb");
+		BBWriter w(f);
+		w.write(variables);
+	}
+
+	// Build dependency graph
+	std::unique_ptr<DepNode> root = buildDepTree(outDir, variables);
 	if (root == nullptr) {
 		logger::log("No source files.");
 		return 0;
@@ -119,6 +139,7 @@ int main(int argc, char **argv) {
 
 	sys::mkdirp(outDir);
 
+	// Build compile commands
 	{
 		std::ofstream f = sys::ofstream(outDir + "/compile_commands.json");
 		compdb::Writer writer(f);
@@ -126,6 +147,7 @@ int main(int argc, char **argv) {
 		sys::symlink(outDir + "/compile_commands.json", "compile_commands.json");
 	}
 
+	// Build the project
 	if (root->hasChanged(outDir)) {
 		root->build(outDir);
 	} else {