From 6417c31a69ce06f35e00771fd2ecc87dbe48cd7a Mon Sep 17 00:00:00 2001
From: lemon <lsof@mailbox.org>
Date: Tue, 24 Feb 2026 14:08:35 +0100
Subject: C23 true and false keywords

---
 c/c.c           | 8 +++++---
 doc/cstd.md     | 1 -
 embedfilesdir.c | 4 ++++
 3 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/c/c.c b/c/c.c
index d4e0aa6..019fb15 100644
--- a/c/c.c
+++ b/c/c.c
@@ -161,7 +161,7 @@ isexprtok(struct comp *cm)
       static const bool tks[] = {
 #define tk(x) [x] = 1
          tk('+'), tk('-'), tk('*'), tk('&'), tk('~'), tk('!'), tk(TKINC), tk(TKDEC),
-         tk(TKWsizeof), tk(TKW_Alignof), tk(TKWalignof),
+         tk(TKWsizeof), tk(TKW_Alignof), tk(TKWalignof), tk(TKWtrue), tk(TKWfalse),
          tk('('), tk(TKNUMLIT), tk(TKCHRLIT), tk(TKSTRLIT), tk(TKW_Generic)
 #undef tk
       };
@@ -1080,6 +1080,9 @@ Unary:
          error(&tk.span, "bad %s literal %'tk", tk.t == TKNUMLIT ? "number" : "character", &tk);
       ex.ty.t = ty.t ? ty.t : TYINT;
       break;
+   case TKWtrue: case TKWfalse:
+      ex = mkexpr(ENUMLIT, tk.span, mktype(TYBOOL), .u = tk.t == TKWtrue);
+      break;
    case TKSTRLIT:
       ty = mktype(((const char []){TYCHAR, TYSHORT, TYINT})[tk.wide]);
       ex = mkexpr(ESTRLIT, tk.span, mkarrtype(ty, 0, tk.len+1), { .s.p = (void *)tk.s, .s.n = tk.len });
@@ -2312,8 +2315,7 @@ declspec(struct declstate *st, struct comp *cm, struct span *pspan)
       case TKWunsigned:
          arith |= KUNSIGNED;
          break;
-      case TKW_Bool:
-      case TKWbool:
+      case TKW_Bool: case TKWbool:
          if (arith & KBOOL) goto DupArith;
          arith |= KBOOL;
          break;
diff --git a/doc/cstd.md b/doc/cstd.md
index 63e39cd..9c235b4 100644
--- a/doc/cstd.md
+++ b/doc/cstd.md
@@ -25,7 +25,6 @@ A list of missing standard C features:
   - Digit separator '
   - Attributes (`[[...]]` syntax)
   - Labels followed by declarations and }
-  - `true` and `false` keywords
   - `auto` for type inference, `typeof_unqual`, `constexpr`
   - `unreachable` macro in `<stddef.h>`
   - checked int arithmetic (`<stdckdint.h>`)
diff --git a/embedfilesdir.c b/embedfilesdir.c
index 7d97f98..d1c8dd4 100644
--- a/embedfilesdir.c
+++ b/embedfilesdir.c
@@ -14,7 +14,9 @@ struct embedfile embedfilesdir[] = {
 typedef __typeof__((char*)0 - (char*)0) ptrdiff_t;\n\
 typedef __typeof__(sizeof 0) size_t;\n\
 typedef __typeof__(L'a') wchar_t;\n\
+#undef NULL\n\
 #define NULL ((void *)0)\n\
+#undef offsetof\n\
 #define offsetof(type, memb) ((size_t)((char *)&((type *)0)->memb - (char *)0))\n\
 ")},
 
@@ -33,9 +35,11 @@ typedef __builtin_va_list __gnuc_va_list;\n\
 
 {"stdbool.h", S("\
 #pragma once\n\
+#if __STDC_VERSION__ < 202311L /* in C23 they are keywords */\n\
 #define bool _Bool \n\
 #define true 1\n\
 #define false 0\n\
+#endif\n\
 #define __bool_true_false_are_defined 1\n\
 ")},
 
-- 
cgit v1.2.3