From 04560f61a6a2a54920b3c28db55766b7d9a0dec7 Mon Sep 17 00:00:00 2001
From: Bill Currie <bill@taniwha.org>
Date: Sun, 3 Nov 2024 18:03:31 +0900
Subject: [PATCH] [qfcc] Separate out backend variable declaration

This time, rua/v6p/v6 share the code properly, since it's only spirv
that needs something specific at this stage.
---
 tools/qfcc/include/def.h         |  2 ++
 tools/qfcc/include/target.h      |  4 +++
 tools/qfcc/source/def.c          | 20 ++++++++---
 tools/qfcc/source/symtab.c       | 60 +++++++++++++++++++-------------
 tools/qfcc/source/target_rua.c   |  1 +
 tools/qfcc/source/target_spirv.c |  6 ++++
 tools/qfcc/source/target_v6.c    |  2 ++
 7 files changed, 66 insertions(+), 29 deletions(-)

diff --git a/tools/qfcc/include/def.h b/tools/qfcc/include/def.h
index 28e023c88..8cadf0756 100644
--- a/tools/qfcc/include/def.h
+++ b/tools/qfcc/include/def.h
@@ -270,6 +270,8 @@ void initialize_def (struct symbol_s *sym,
 					 const struct expr_s *init, struct defspace_s *space,
 					 storage_class_t storage, struct symtab_s *symtab);
 
+void declare_def (specifier_t spec, const expr_t *init, symtab_t *symtab);
+
 /** Convenience function for obtaining a def's actual offset.
 
 	Takes care of an alias def's relative offset.
diff --git a/tools/qfcc/include/target.h b/tools/qfcc/include/target.h
index 3bd0a8c9a..bb666db7f 100644
--- a/tools/qfcc/include/target.h
+++ b/tools/qfcc/include/target.h
@@ -29,14 +29,18 @@
 #define __target_h
 
 typedef struct symbol_s symbol_t;
+typedef struct symtab_s symtab_t;
 typedef struct type_s type_t;
 typedef struct function_s function_t;
 typedef struct expr_s expr_t;
+typedef struct specifier_s specifier_t;
 
 typedef struct {
 	bool      (*value_too_large) (const type_t *val_type);
 	void      (*build_scope) (symbol_t *fsym);
 	void      (*build_code) (function_t *func, const expr_t *statements);
+	void      (*declare_sym) (specifier_t spec, const expr_t *init,
+							  symtab_t *symtab);
 } target_t;
 
 extern target_t current_target;
diff --git a/tools/qfcc/source/def.c b/tools/qfcc/source/def.c
index e966d356c..08bb4f9cf 100644
--- a/tools/qfcc/source/def.c
+++ b/tools/qfcc/source/def.c
@@ -550,10 +550,6 @@ initialize_def (symbol_t *sym, const expr_t *init, defspace_t *space,
 	symbol_t   *check = symtab_lookup (symtab, sym->name);
 	reloc_t    *relocs = 0;
 
-	if (check && check->table == symtab->parent
-		&& symtab->parent->type == stab_param) {
-		error (0, "%s shadows a parameter", sym->name);
-	}
 	if (check && check->table == symtab) {
 		if (check->sy_type != sy_def || !type_same (check->type, sym->type)) {
 			error (0, "%s redefined", sym->name);
@@ -686,6 +682,22 @@ initialize_def (symbol_t *sym, const expr_t *init, defspace_t *space,
 	sym->def->initializer = init;
 }
 
+void
+declare_def (specifier_t spec, const expr_t *init, symtab_t *symtab)
+{
+	symbol_t   *sym = spec.sym;
+	defspace_t *space = symtab->space;
+
+	if (spec.storage == sc_static) {
+		space = pr.near_data;
+	}
+
+	initialize_def (sym, init, space, spec.storage, symtab);
+	if (sym->def) {
+		sym->def->nosave |= spec.nosave;
+	}
+}
+
 static int
 def_overlap (def_t *d, int offset, int size)
 {
diff --git a/tools/qfcc/source/symtab.c b/tools/qfcc/source/symtab.c
index fbe452614..bb7164ede 100644
--- a/tools/qfcc/source/symtab.c
+++ b/tools/qfcc/source/symtab.c
@@ -47,6 +47,7 @@
 #include "tools/qfcc/include/shared.h"
 #include "tools/qfcc/include/strpool.h"
 #include "tools/qfcc/include/symtab.h"
+#include "tools/qfcc/include/target.h"
 #include "tools/qfcc/include/type.h"
 
 ALLOC_STATE (symtab_t, symtabs);
@@ -254,57 +255,66 @@ make_symbol (const char *name, const type_t *type, defspace_t *space,
 	return sym;
 }
 
+static bool
+shadows_param (symbol_t *sym, symtab_t *symtab)
+{
+	symbol_t   *check = symtab_lookup (symtab, sym->name);
+
+	if (check && check->table == symtab->parent
+		&& symtab->parent->type == stab_param) {
+		error (0, "%s shadows a parameter", sym->name);
+		return true;
+	}
+	return false;
+}
+
 symbol_t *
 declare_symbol (specifier_t spec, const expr_t *init, symtab_t *symtab)
 {
-	symbol_t   *s = spec.sym;
-	defspace_t *space = symtab->space;
+	symbol_t   *sym = spec.sym;
 
-	if (s->table) {
+	if (sym->table) {
 		// due to the way declarations work, we need a new symbol at all times.
 		// redelcarations will be checked later
-		s = new_symbol (s->name);
-		*s = *spec.sym;
-		s->table = nullptr;
+		sym = new_symbol (sym->name);
+		*sym = *spec.sym;
+		sym->table = nullptr;
 	}
 
 	if (!spec.type_expr && !spec.is_function) {
-		spec = default_type (spec, s);
+		spec = default_type (spec, sym);
 	}
 	if (!spec.storage) {
 		spec.storage = current_storage;
 	}
-	if (spec.storage == sc_static) {
-		space = pr.near_data;
-	}
 
-	if (spec.type && (spec.is_typedef || !s->type || !is_func (s->type))) {
-		s->type = append_type (spec.sym->type, spec.type);
+	if (spec.type && (spec.is_typedef || !sym->type || !is_func (sym->type))) {
+		sym->type = append_type (spec.sym->type, spec.type);
 	}
 
 	if (spec.is_typedef) {
 		if (init) {
-			error (0, "typedef %s is initialized", s->name);
+			error (0, "typedef %s is initialized", sym->name);
 		}
-		s->sy_type = sy_type;
-		s->type = find_type (s->type);
-		s->type = find_type (alias_type (s->type, s->type, s->name));
-		symtab_addsymbol (symtab, s);
+		sym->sy_type = sy_type;
+		sym->type = find_type (sym->type);
+		sym->type = find_type (alias_type (sym->type, sym->type, sym->name));
+		symtab_addsymbol (symtab, sym);
 	} else {
-		if (spec.is_function && is_func (s->type)) {
+		if (spec.is_function && is_func (sym->type)) {
 			if (init) {
-				error (0, "function %s is initialized", s->name);
+				error (0, "function %s is initialized", sym->name);
 			}
-			s = function_symbol (spec);
+			sym = function_symbol (spec);
 		} else {
-			s->type = find_type (s->type);
-			initialize_def (s, init, space, spec.storage, symtab);
-			if (s->def) {
-				s->def->nosave |= spec.nosave;
+			if (!shadows_param (sym, symtab)) {
+				sym->type = find_type (sym->type);
+				spec.sym = sym;
+				current_target.declare_sym (spec, init, symtab);
 			}
 		}
 	}
-	return s;
+	return sym;
 }
 
 symbol_t *
diff --git a/tools/qfcc/source/target_rua.c b/tools/qfcc/source/target_rua.c
index 295ac8747..740bd98c1 100644
--- a/tools/qfcc/source/target_rua.c
+++ b/tools/qfcc/source/target_rua.c
@@ -209,4 +209,5 @@ target_t ruamoko_target = {
 	.value_too_large = ruamoko_value_too_large,
 	.build_scope = ruamoko_build_scope,
 	.build_code = ruamoko_build_code,
+	.declare_sym = declare_def,
 };
diff --git a/tools/qfcc/source/target_spirv.c b/tools/qfcc/source/target_spirv.c
index 26ff2baac..ba4ad561c 100644
--- a/tools/qfcc/source/target_spirv.c
+++ b/tools/qfcc/source/target_spirv.c
@@ -918,8 +918,14 @@ spirv_build_code (function_t *func, const expr_t *statements)
 {
 }
 
+static void
+spirv_declare_sym (specifier_t spec, const expr_t *init, symtab_t *symtab)
+{
+}
+
 target_t spirv_target = {
 	.value_too_large = spirv_value_too_large,
 	.build_scope = spirv_build_scope,
 	.build_code = spirv_build_code,
+	.declare_sym = spirv_declare_sym,
 };
diff --git a/tools/qfcc/source/target_v6.c b/tools/qfcc/source/target_v6.c
index bf003c064..2d53612bf 100644
--- a/tools/qfcc/source/target_v6.c
+++ b/tools/qfcc/source/target_v6.c
@@ -132,10 +132,12 @@ target_t v6_target = {
 	.value_too_large = v6_value_too_large,
 	.build_scope = v6p_build_scope,
 	.build_code = v6p_build_code,
+	.declare_sym = declare_def,
 };
 
 target_t v6p_target = {
 	.value_too_large = v6_value_too_large,
 	.build_scope = v6p_build_scope,
 	.build_code = v6p_build_code,
+	.declare_sym = declare_def,
 };