https://gitlab.gnome.org/GNOME/gobject-introspection/-/issues/519
https://gitlab.gnome.org/GNOME/gobject-introspection/-/commit/2812471365c75ab51347a9101771128f8ab283ab

From 2812471365c75ab51347a9101771128f8ab283ab Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bernhard=20Rosenkr=C3=A4nzer?= <bero@lindev.ch>
Date: Sat, 8 Feb 2025 14:04:12 +0100
Subject: [PATCH] Handle C99 _Complex declarations

Fixes https://gitlab.gnome.org/GNOME/gobject-introspection/-/issues/519
--- a/giscanner/scannerlexer.l
+++ b/giscanner/scannerlexer.l
@@ -211,6 +211,7 @@ stringtext				([^\\\"])|(\\.)
 "break"					{ return BREAK; }
 "case"					{ return CASE; }
 "char"					{ return BASIC_TYPE; }
+"_Complex"				{ return COMPLEX; }
 "const"					{ return CONST; }
 "continue"				{ return CONTINUE; }
 "default"				{ return DEFAULT; }
--- a/giscanner/scannerparser.y
+++ b/giscanner/scannerparser.y
@@ -275,7 +275,7 @@ set_or_merge_base_type (GISourceType *type,
 %token ELLIPSIS ADDEQ SUBEQ MULEQ DIVEQ MODEQ XOREQ ANDEQ OREQ SL SR
 %token SLEQ SREQ EQ NOTEQ LTEQ GTEQ ANDAND OROR PLUSPLUS MINUSMINUS ARROW
 
-%token AUTO BREAK CASE CONST CONTINUE DEFAULT DO ELSE ENUM
+%token AUTO BREAK CASE COMPLEX CONST CONTINUE DEFAULT DO ELSE ENUM
 %token EXTENSION EXTERN FOR GOTO IF INLINE REGISTER RESTRICT
 %token RETURN SHORT SIGNED SIZEOF STATIC STRUCT SWITCH THREAD_LOCAL TYPEDEF
 %token UNION UNSIGNED VOID VOLATILE WHILE
@@ -907,6 +907,10 @@ type_specifier
 	  {
 		$$ = gi_source_type_new (CTYPE_VOID);
 	  }
+	| COMPLEX
+	  {
+		$$ = gi_source_basic_type_new ("_Complex");
+	  }
 	| SIGNED
 	  {
 		$$ = gi_source_basic_type_new ("signed");
-- 
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