From 3048a0b59baae16727d0c259353ff4be1ae559b4 Mon Sep 17 00:00:00 2001
From: lemon <lsof@mailbox.org>
Date: Sun, 12 Oct 2025 10:06:06 +0200
Subject: typeof

---
 c.c          | 22 ++++++++++++++++++++++
 keywords.def |  1 +
 2 files changed, 23 insertions(+)

diff --git a/c.c b/c.c
index 30ea13a..29028b2 100644
--- a/c.c
+++ b/c.c
@@ -102,6 +102,7 @@ isdecltok(struct comp *cm)
    case TKWextern: case TKWstatic: case TKWinline: case TKW_Noreturn:
    case TKWconst: case TKWvolatile: case TKWvoid: case TKWfloat:
    case TKWdouble: case TKWregister: case TKW_Static_assert:
+   case TKW__typeof__: case TKWtypeof: case TKWtypeof_unqual:
       return 1;
    case TKIDENT:
       return (decl = finddecl(cm, tk.s)) && decl->scls == SCTYPEDEF;
@@ -1837,6 +1838,21 @@ tagtype(struct comp *cm, enum toktag kind)
    return t;
 }
 
+static union type
+ptypeof(struct comp *cm)
+{
+   union type ty;
+   expect(cm, '(', NULL);
+   if (isdecltok(cm)) { /* typeof (type) */
+      struct declstate st = { DCASTEXPR };
+      ty = pdecl(&st, cm).ty;
+   } else { /* typeof (expr) */
+      ty = commaexpr(cm).ty;
+   }
+   expect(cm, ')', NULL);
+   return ty;
+}
+
 static void
 declspec(struct declstate *st, struct comp *cm)
 {
@@ -1924,6 +1940,12 @@ declspec(struct declstate *st, struct comp *cm)
          if (!span.ex.len) span.ex = tk.span.ex;
          joinspan(&span.ex, tk.span.ex);
          goto End;
+      case TKW__typeof__: case TKWtypeof:
+         lex(cm, &tk);
+         st->base = ptypeof(cm);
+         if (!span.ex.len) span.ex = tk.span.ex;
+         joinspan(&span.ex, tk.span.ex);
+         goto End;
       case TKIDENT:
          if (!st->base.t && !arith && (decl = finddecl(cm, tk.s))
              && decl->scls == SCTYPEDEF) {
diff --git a/keywords.def b/keywords.def
index e0bb92f..258a396 100644
--- a/keywords.def
+++ b/keywords.def
@@ -13,6 +13,7 @@ _(_Imaginary,      STDC99)
 _(_Noreturn,       STDC11)
 _(_Static_assert,  STDC11)
 _(_Thread_local,   STDC11)
+_(__typeof__,      0)
 _(alignas,         STDC23)
 _(alignof,         STDC23)
 _(auto,            0)
-- 
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