Rewrite and redesign codegen and feature system

Also switch to somewhat proper C23 flags while we're at it.

This is a huge change. It took me forever, in between being really busy.
Sorry about that. But the good news is I'm now free to start integrating
the various patches that have accumulated since last release. Well, at
least in between still being really busy. Gotta manage expectations.

The main benefit of introducing GAMESPECIFIC() is that features
that don't apply to a particular game no longer show up *at all*, and
less time is wasted on init. It also enables a cool optimisation wherein
unnecessary REQUIRE_GAMEDATA() checks can elided at compile time
whenever the gamedata is known up-front to always exist in supported
games.

The DEF_FEAT_CVAR macro family meanwhile makes it easier to manage the
lifecycle of cvars/ccmds, with less manual registering, unhiding and
such.

Originally I was going to try and just hack these features into the
existing codegen abomination, but it just got too terrible. This rewrite
should make it easier to continue tweaking codegen behaviour in future.
It also has slightly better error messages.

1 files changed, 12 insertions, 19 deletions

diff --git a/src/l4dwarp.c b/src/l4dwarp.c
index b9e019d..eb638e4 100644
--- a/src/l4dwarp.c
+++ b/src/l4dwarp.c
@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Michael Smith <mikesmiffy128@gmail.com>
+ * Copyright © 2025 Michael Smith <mikesmiffy128@gmail.com>
  * Copyright © 2023 Willian Henrique <wsimanbrazil@yahoo.com.br>
  *
  * Permission to use, copy, modify, and/or distribute this software for any
@@ -36,12 +36,15 @@
 #include "x86util.h"
 
 FEATURE("Left 4 Dead warp testing")
+GAMESPECIFIC(L4D)
 REQUIRE(clientcon)
 REQUIRE(ent)
 REQUIRE(trace)
 REQUIRE_GAMEDATA(off_entpos)
 REQUIRE_GAMEDATA(off_eyeang)
 REQUIRE_GAMEDATA(off_teamnum)
+REQUIRE_GAMEDATA(vtidx_AddBoxOverlay2)
+REQUIRE_GAMEDATA(vtidx_AddLineOverlay)
 REQUIRE_GAMEDATA(vtidx_Teleport)
 
 DECL_VFUNC_DYN(void, Teleport, const struct vec3f */*pos*/,
@@ -99,7 +102,7 @@ static struct vec3f warptarget(void *ent) {
 	};
 }
 
-DEF_CCMD_HERE_UNREG(sst_l4d_testwarp, "Simulate a bot warping to you "
+DEF_FEAT_CCMD_HERE(sst_l4d_testwarp, "Simulate a bot warping to you "
 		"(specify \"staystuck\" to skip take-control simulation)",
 		CON_SERVERSIDE | CON_CHEAT) {
 	bool staystuck = false;
@@ -167,9 +170,9 @@ static bool draw_testpos(struct vec3f start, struct vec3f testpos,
 	return false;
 }
 
+// note: UNREG because testwarp can still work without this
 DEF_CCMD_HERE_UNREG(sst_l4d_previewwarp, "Visualise bot warp unstuck logic "
-		"(use clear_debug_overlays to remove)",
-		CON_SERVERSIDE | CON_CHEAT) {
+		"(use clear_debug_overlays to remove)", CON_SERVERSIDE | CON_CHEAT) {
 	struct edict *ed = ent_getedict(con_cmdclient + 1);
 	if_cold (!ed || !ed->ent_unknown) {
 		errmsg_errorx("couldn't access player entity");
@@ -306,26 +309,16 @@ static bool init_filter(void) {
 	return false;
 }
 
-PREINIT {
-	return GAMETYPE_MATCHES(L4D);
-}
-
 INIT {
 	struct con_cmd *z_add = con_findcmd("z_add");
 	if (!z_add || !find_EntityPlacementTest(z_add->cb)) {
 		errmsg_errorx("couldn't find EntityPlacementTest function");
-		return false;
+		return FEAT_INCOMPAT;
 	}
 	if (!init_filter()) {
-		errmsg_errorx("couldn't init trace filter for EntityPlacementTest");
-		return false;
+		errmsg_errorx("couldn't find trace filter ctor for EntityPlacementTest");
+		return FEAT_INCOMPAT;
 	}
-	con_reg(sst_l4d_testwarp);
-	// NOTE: assuming has_vtidx_AddLineOverlay && has_vtidx_AddBoxOverlay2
-	// since those are specified for L4D.
-	// TODO(opt): add some zero-cost/compile-time way to make sure gamedata
-	// exists in a game-specific scenario? (probably requires declarative
-	// game-specific features in codegen, which hasn't been high-priority)
 	if_cold (!has_off_collision) {
 		errmsg_warnx("missing m_Collision gamedata - warp preview unavailable");
 	}
@@ -334,9 +327,9 @@ INIT {
 				"warp preview unavailable");
 	}
 	else {
-		con_reg(sst_l4d_previewwarp);
+		con_regcmd(sst_l4d_previewwarp);
 	}
-	return true;
+	return FEAT_OK;
 }
 
 // vi: sw=4 ts=4 noet tw=80 cc=80