From 82ce36c981267650078c9ca2d53787aeac2e2dd9 Mon Sep 17 00:00:00 2001
From: Bill Currie <bill@taniwha.org>
Date: Wed, 1 Nov 2023 16:07:12 +0900
Subject: [PATCH] [qfcc] Add macro support for __FILE__ and __LINE__

There are some expansion problems, but this moves their handling to
where it needs to be.
---
 tools/qfcc/include/rua-lang.h |  7 +++++
 tools/qfcc/source/cpp.c       | 21 ++++++++++++++
 tools/qfcc/source/qc-lex.l    | 53 +++++++++++++++++++++++++++++++++++
 3 files changed, 81 insertions(+)

diff --git a/tools/qfcc/include/rua-lang.h b/tools/qfcc/include/rua-lang.h
index 3b9b7f56a..3cf24ece8 100644
--- a/tools/qfcc/include/rua-lang.h
+++ b/tools/qfcc/include/rua-lang.h
@@ -47,6 +47,9 @@ typedef struct rua_expr_s {
 	const char *text;
 } rua_expr_t;
 
+typedef struct rua_macro_s rua_macro_t;
+typedef void (*rua_macro_f) (rua_macro_t *macro, void *scanner);
+
 typedef struct rua_macro_s {
 	const char *name;
 	symtab_t   *params;
@@ -54,6 +57,7 @@ typedef struct rua_macro_s {
 	rua_expr_t **tail;
 	int         num_tokens;
 	int         num_params;
+	rua_macro_f update;
 } rua_macro_t;
 
 typedef struct rua_tok_s {
@@ -97,6 +101,9 @@ void rua_include_file (const char *name, void *scanner);
 void rua_embed_file (const char *name, void *scanner);
 int rua_parse_define (const char *def);
 
+void rua_macro_file (rua_macro_t *macro, void *scanner);
+void rua_macro_line (rua_macro_t *macro, void *scanner);
+
 #include "tools/qfcc/source/pre-parse.h"
 
 #endif//__rua_lang_h
diff --git a/tools/qfcc/source/cpp.c b/tools/qfcc/source/cpp.c
index 8865a4b5e..a65dbaab4 100644
--- a/tools/qfcc/source/cpp.c
+++ b/tools/qfcc/source/cpp.c
@@ -384,10 +384,31 @@ cpp_include (const char *opt, const char *arg)
 }
 #undef CPP_INCLUDE
 
+static void
+make_magic_macro (symtab_t *tab, const char *name, rua_macro_f update)
+{
+	rua_macro_t *macro = malloc (sizeof (*macro));
+	*macro = (rua_macro_t) {
+		.name = save_string (name),
+		.tail = &macro->tokens,
+		.update = update,
+	};
+	auto sym = symtab_lookup (tab, macro->name);
+	if (sym) {
+		internal_error (0, "\"%s\" redefined", macro->name);
+	}
+	sym = new_symbol (macro->name);
+	sym->sy_type = sy_macro;
+	sym->s.macro = macro;
+	symtab_addsymbol (tab, sym);
+}
+
 void cpp_define (const char *arg)
 {
 	if (!cpp_macros) {
 		cpp_macros = new_symtab (0, stab_global);
+		make_magic_macro (cpp_macros, "__FILE__", rua_macro_file);
+		make_magic_macro (cpp_macros, "__LINE__", rua_macro_line);
 	}
 	size_t len = strlen (arg);
 	if (len > 0x10000) {
diff --git a/tools/qfcc/source/qc-lex.l b/tools/qfcc/source/qc-lex.l
index bf7fc1629..76a2e89f1 100644
--- a/tools/qfcc/source/qc-lex.l
+++ b/tools/qfcc/source/qc-lex.l
@@ -1426,6 +1426,9 @@ qc_process (rua_extra_t *extra, int token, rua_tok_t *tok, yyscan_t scanner)
 		}
 	}
 	if (macro) {
+		if (macro->update) {
+			macro->update (macro, scanner);
+		}
 		expand_macro (extra, macro);
 		if (0) dump_expr_stack (extra);
 		return YYPUSH_MORE;
@@ -2008,3 +2011,53 @@ rua_parse_define (const char *def)
 	dstring_delete (extra.dstr);
 	return status;
 }
+
+void
+rua_macro_file (rua_macro_t *macro, void *scanner)
+{
+	int         file = pr.source_file;
+	if (macro->tokens && macro->tokens->location.file == file) {
+		return;
+	}
+	macro->tokens = 0;
+	macro->tail = &macro->tokens;
+	macro->num_tokens = 0;
+
+	rua_expr_t *expr = malloc (sizeof (*expr));
+	macro->num_tokens++;
+	const char *file_str = save_string (va (0, "\"%s\"",
+											quote_string (GETSTR (file))));
+	*expr = (rua_expr_t) {
+		.location = { .file = file },
+		.textlen = strlen (file_str),
+		.token = -rua_string,
+		.text = file_str,
+	};
+	*macro->tail = expr;
+	macro->tail = &expr->next;
+}
+
+void
+rua_macro_line (rua_macro_t *macro, void *scanner)
+{
+	int         line = pr.source_line;
+
+	if (macro->tokens && macro->tokens->location.first_line == line) {
+		return;
+	}
+	macro->tokens = 0;
+	macro->tail = &macro->tokens;
+	macro->num_tokens = 0;
+
+	rua_expr_t *expr = malloc (sizeof (*expr));
+	macro->num_tokens++;
+	const char *line_str = save_string (va (0, "%d", line));
+	*expr = (rua_expr_t) {
+		.location = { .first_line = line },
+		.textlen = strlen (line_str),
+		.token = -rua_number,
+		.text = line_str,
+	};
+	*macro->tail = expr;
+	macro->tail = &expr->next;
+}