From dc85a4df4be3ea696d34064104beab0cffe0f92d Mon Sep 17 00:00:00 2001
From: Bill Currie <bill@taniwha.org>
Date: Thu, 14 Nov 2024 20:58:21 +0900
Subject: [PATCH] [qfcc] Specify entry-point interface variables

Yet another step closer to having a working glsl compiler.
---
 tools/qfcc/include/spirv.h       |  5 +++++
 tools/qfcc/source/target_spirv.c | 10 +++++++++-
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/tools/qfcc/include/spirv.h b/tools/qfcc/include/spirv.h
index 064879b16..d94dd7a50 100644
--- a/tools/qfcc/include/spirv.h
+++ b/tools/qfcc/include/spirv.h
@@ -30,9 +30,13 @@
 
 #include <spirv/unified1/spirv.h>
 
+#include "QF/darray.h"
+
 #include "tools/qfcc/include/defspace.h"
 #include "tools/qfcc/include/expr.h"
 
+typedef struct symbol_s symbol_t;
+
 typedef struct entrypoint_s {
 	struct entrypoint_s *next;
 	SpvExecutionModel model;
@@ -47,6 +51,7 @@ typedef struct module_s {
 	ex_list_t   extinst_imports;
 	const expr_t *addressing_model;
 	const expr_t *memory_model;
+	struct DARRAY_TYPE (symbol_t *) interface_syms;
 	//entrypoint_t *entry_points;
 	defspace_t *entry_points;
 	defspace_t *exec_modes;
diff --git a/tools/qfcc/source/target_spirv.c b/tools/qfcc/source/target_spirv.c
index 7a0de08e0..0af757ee2 100644
--- a/tools/qfcc/source/target_spirv.c
+++ b/tools/qfcc/source/target_spirv.c
@@ -470,6 +470,8 @@ spirv_variable (symbol_t *sym, spirvctx_t *ctx)
 	auto storage = spirv_storage_class (sym->var.storage);
 	if (storage == SpvStorageClassFunction) {
 		space = ctx->decl_space;
+	} else {
+		DARRAY_APPEND (&ctx->module->interface_syms, sym);
 	}
 	auto type = sym->type;
 	unsigned tid = type_id (type, ctx);
@@ -584,11 +586,16 @@ spirv_EntryPoint (unsigned func_id, const char *func_name,
 				  SpvExecutionModel model, spirvctx_t *ctx)
 {
 	int len = strlen (func_name) + 1;
+	int iface_start = 3 + RUP(len, 4) / 4;
 	auto linkage = ctx->module->entry_points;
-	auto insn = spirv_new_insn (SpvOpEntryPoint, 3 + RUP(len, 4) / 4, linkage);
+	int count = ctx->module->interface_syms.size;
+	auto insn = spirv_new_insn (SpvOpEntryPoint, iface_start + count, linkage);
 	INSN (insn, 1) = model;
 	INSN (insn, 2) = func_id;
 	memcpy (&INSN (insn, 3), func_name, len);
+	for (int i = 0; i < count; i++) {
+		INSN (insn, iface_start + i) = ctx->module->interface_syms.a[i]->id;
+	}
 }
 
 typedef struct {
@@ -1169,6 +1176,7 @@ spirv_write (struct pr_info_s *pr, const char *filename)
 	pr->module->globals = defspace_new (ds_backed);
 	pr->module->func_declarations = defspace_new (ds_backed);
 	pr->module->func_definitions = defspace_new (ds_backed);
+	DARRAY_INIT (&pr->module->interface_syms, 16);
 
 	spirvctx_t ctx = {
 		.module = pr->module,