Handle commanddb filename defaults and --command-database-out option.

Jamroot.jam

@@ -22,7 +22,7 @@ import virtual-target ;
 
 path-constant SELF : . ;
 
-project b2
+project /bfgroup/b2
     : build-dir .build
     : requirements
         <cxxstd>11

src/build/project.jam

@@ -42,6 +42,7 @@ import print ;
 import property-set ;
 import regex ;
 import sequence ;
+import command-db ;
 
 
 .debug-loading = [ MATCH ^(--debug-loading)$ : [ modules.peek : ARGV ] ] ;
@@ -712,11 +713,12 @@ rule initialize (
 
     # load-parent can end up loading this module again. Make sure this is not
     # duplicated.
+    local attributes ;
     if ! $($(module-name).attributes)
     {
         $(module-name).attributes = [ new project-attributes $(location)
             $(module-name) ] ;
-        local attributes = $($(module-name).attributes) ;
+        attributes = $($(module-name).attributes) ;
 
         if $(location)
         {
@@ -791,6 +793,12 @@ rule initialize (
     }
 
     .current-project = [ target $(module-name) ] ;
+
+    if $(jamroot) && [ $(attributes).get build-dir ]
+    {
+        command-db.set-output-dir
+            [ path.native [ $(attributes).get build-dir ] ] ;
+    }
 }
 
 
@@ -1312,6 +1320,7 @@ module project-rules
     {
         import path ;
         import project ;
+        import command-db ;
 
         local caller = [ CALLER_MODULE ] ;
         local attributes = [ project.attributes $(caller) ] ;
@@ -1382,6 +1391,12 @@ module project-rules
                 }
             }
         }
+
+        if $(explicit-build-dir)
+        {
+            command-db.set-output-dir
+                [ path.native [ $(attributes).get build-dir ] ] ;
+        }
     }
 
     # Declare and set a project global constant. Project global constants are

src/engine/bindjam.cpp

@@ -21,6 +21,7 @@ Distributed under the Boost Software License, Version 1.0.
 #include "value.h"
 #include "variable.h"
 
+#include "mod_command_db.h"
 #include "mod_db.h"
 #include "mod_jam_builtin.h"
 #include "mod_jam_class.h"
@@ -823,7 +824,8 @@ void bind_jam(FRAME * f)
 		.bind(string_module())
 		.bind(sysinfo_module())
 		.bind(version_module())
-		.bind(db_module());
+		.bind(db_module())
+		.bind(command_db_module());
 }
 
 }} // namespace b2::jam

src/engine/jam.cpp

@@ -138,7 +138,7 @@
 #include "variable.h"
 #include "execcmd.h"
 #include "mod_sysinfo.h"
-#include "command_db.h"
+#include "mod_command_db.h"
 
 #include <errno.h>
 #include <string.h>

src/engine/command_db.cpp → src/engine/mod_command_db.cpp

@@ -4,14 +4,15 @@ Distributed under the Boost Software License, Version 1.0.
 (See accompanying file LICENSE.txt or https://www.bfgroup.xyz/b2/LICENSE.txt)
 */
 
-#include "command_db.h"
+#include "mod_command_db.h"
 
 #include "command.h"
 #include "cwd.h"
 #include "events.h"
 #include "lists.h"
 #include "mod_db.h"
 #include "output.h"
+#include "pathsys.h"
 #include "regexp.h"
 
 #include "ext_bfgroup_lyra.h"
@@ -25,6 +26,7 @@ struct database
 	bool output_flag = false;
 	std::string output_format = "json";
 	std::string output_filename = "compile_commands.json";
+	std::string output_directory;
 	std::string db_directory;
 	std::unordered_map<std::string, std::unique_ptr<regex::program>>
 		regex_cache;
@@ -36,6 +38,7 @@ struct database
 		// B2 doesn't change directories. And runs everything relative to CWD.
 		// So we can cache the value to fill into the database.
 		db_directory = b2::cwd_str();
+		output_directory = db_directory;
 	}
 
 	static database & get()
@@ -65,7 +68,7 @@ struct database
 				[](int s) { database::get().exit_main(s); }));
 	}
 
-	void set_output_filename(const std::string & f) {}
+	void set_output_filename(const std::string & f) { output_filename = f; }
 
 	void pre_exec_cmd(TARGET * t)
 	{
@@ -121,7 +124,19 @@ struct database
 	void exit_main(int status)
 	{
 		if (status == EXIT_FAIL) return;
-		prop_db->write_file(output_filename, output_format);
+		std::string filename = output_filename;
+		if (!b2::paths::is_rooted(output_filename))
+		{
+			if (!b2::paths::is_rooted(output_directory))
+				filename = b2::cwd_str() + "/";
+			filename += output_directory + "/" + output_filename;
+			filename = b2::paths::normalize(filename);
+		}
+		if (prop_db->write_file(filename, output_format))
+			out_printf("...wrote command database '%s'...\n", filename.c_str());
+		else
+			err_printf("...writing to command database '%s' FAILED...\n",
+				filename.c_str());
 	}
 };
 
@@ -136,7 +151,15 @@ void declare_args(lyra::cli & cli)
 		[](const std::string & f) { database::get().set_output_filename(f); },
 		"filename")
 			   .name("--command-database-out")
-			   .help("Filename to output the command database to.");
+			   .help(
+				   "Filename to output the command database to. "
+				   "A relative path for the filename is rooted to the project "
+				   "build-dir.");
+}
+
+void set_output_dir(value_ref dirname)
+{
+	database::get().output_directory = dirname;
 }
 
 }} // namespace b2::command_db

src/engine/mod_command_db.h

@@ -0,0 +1,44 @@
+/*
+Copyright 2024 René Ferdinand Rivera Morell
+Distributed under the Boost Software License, Version 1.0.
+(See accompanying file LICENSE.txt or https://www.bfgroup.xyz/b2/LICENSE.txt)
+*/
+
+#ifndef B2_COMMAND_DB_H
+#define B2_COMMAND_DB_H
+
+#include "config.h"
+
+#include "bind.h"
+#include "value.h"
+
+namespace lyra {
+class cli;
+} // namespace lyra
+
+namespace b2 {
+
+namespace command_db {
+
+void declare_args(lyra::cli &);
+
+void set_output_dir(value_ref dirname);
+
+} // namespace command_db
+
+struct command_db_module : b2::bind::module_<command_db_module>
+{
+	const char * module_name = "command-db";
+
+	template <class Binder>
+	void def(Binder & binder)
+	{
+		binder.def(
+			&command_db::set_output_dir, "set-output-dir", ("dirname" * _1));
+		binder.loaded();
+	}
+};
+
+} // namespace b2
+
+#endif

src/engine/mod_db.cpp

@@ -42,13 +42,14 @@ void b2::property_db::emplace(list_cref k, value_ref v)
 	db[nk] = v;
 }
 
-void b2::property_db::write_file(value_ref filename, value_ref format)
+bool b2::property_db::write_file(value_ref filename, value_ref format)
 {
 	if (!format->has_value())
 	{
 		format = b2::value::make("json");
 	}
-	if (format == "json") write_file_json(filename);
+	if (format == "json") return write_file_json(filename);
+	return false;
 }
 
 std::string b2::property_db::dump(value_ref format)
@@ -101,19 +102,23 @@ void build_json_from_db(const T & db, nlohmann::json & out)
 }
 } // namespace
 
-void b2::property_db::write_file_json(value_ref filename)
+bool b2::property_db::write_file_json(value_ref filename)
 {
 	nlohmann::json out;
 	build_json_from_db(db, out);
 	FILE * file = std::fopen(filename->str(), "w");
-	try
+	if (file)
 	{
-		auto data = out.dump(0);
-		std::fwrite(data.c_str(), data.size(), 1, file);
+		try
+		{
+			auto data = out.dump(0);
+			return std::fwrite(data.c_str(), data.size(), 1, file) == 1;
+		}
+		catch (const std::exception &)
+		{}
+		std::fclose(file);
 	}
-	catch (const std::exception &)
-	{}
-	std::fclose(file);
+	return false;
 }
 
 std::string b2::property_db::dump_json()

src/engine/mod_db.h

@@ -36,7 +36,7 @@ end::reference[] */
 struct property_db : public object
 {
 	void emplace(list_cref k, value_ref v);
-	void write_file(value_ref filename, value_ref format);
+	bool write_file(value_ref filename, value_ref format);
 	std::string dump(value_ref format);
 
 	private:
@@ -58,7 +58,7 @@ struct property_db : public object
 	};
 	using db_type = std::map<list_ref, value_ref, key_less>;
 	db_type db;
-	void write_file_json(value_ref filename);
+	bool write_file_json(value_ref filename);
 	std::string dump_json();
 };