From 26d5cc694a4746b886a9f1949603440b6f2c0ad8 Mon Sep 17 00:00:00 2001
From: Christoffer Lerno <christoffer@aegik.com>
Date: Tue, 8 Jul 2025 11:43:49 +0200
Subject: [PATCH] Formatting option "%h" now supports pointers.

---
 lib/std/io/formatter.c3                 |  5 +++++
 releasenotes.md                         |  1 +
 src/compiler/compiler_internal.h        |  3 ++-
 src/compiler/sema_expr.c                |  4 ++--
 test/test_suite/attributes/format_h.c3t | 13 +++++++++++++
 5 files changed, 23 insertions(+), 3 deletions(-)
 create mode 100644 test/test_suite/attributes/format_h.c3t

diff --git a/lib/std/io/formatter.c3 b/lib/std/io/formatter.c3
index 491a9ba60..db21b9bca 100644
--- a/lib/std/io/formatter.c3
+++ b/lib/std/io/formatter.c3
@@ -495,6 +495,11 @@ fn usz? Formatter.vprintf(&self, String format, any[] anys)
 							out = ((char*)current.ptr)[:current.type.sizeof];
 							break;
 						}
+						if (current.type.kindof == POINTER)
+						{
+							out = ((*(char**)current.ptr))[:current.type.inner.sizeof];
+							break;
+						}
 						total_len += self.out_substr("<INVALID>")!;
 						continue;
 				}
diff --git a/releasenotes.md b/releasenotes.md
index 047b08e7b..7a1a39748 100644
--- a/releasenotes.md
+++ b/releasenotes.md
@@ -12,6 +12,7 @@
 - Catch accidental `foo == BAR;` where `foo = BAR;` was most likely intended. #2274
 - Improve error message when doing a rethrow in a function that doesn't return an optional.
 - Add `--list-asm` to view all supported `asm` instructions.
+- Formatting option "%h" now supports pointers.
 
 ### Fixes
 - mkdir/rmdir would not work properly with substring paths on non-windows platforms.
diff --git a/src/compiler/compiler_internal.h b/src/compiler/compiler_internal.h
index f50683870..1c7f5acb9 100644
--- a/src/compiler/compiler_internal.h
+++ b/src/compiler/compiler_internal.h
@@ -3241,9 +3241,10 @@ static inline Type *type_flatten_no_export(Type *type)
 	}
 }
 
-static inline bool type_flat_is_char_array_slice(Type *type)
+static inline bool type_flat_is_valid_for_arg_h(Type *type)
 {
 	type = type_flatten(type);
+	if (type->type_kind == TYPE_POINTER) return true;
 	if (type->type_kind != TYPE_ARRAY && type->type_kind != TYPE_SLICE) return false;
 	switch (type->array.base->type_kind)
 	{
diff --git a/src/compiler/sema_expr.c b/src/compiler/sema_expr.c
index e8ed0b7ad..e1cc4431e 100644
--- a/src/compiler/sema_expr.c
+++ b/src/compiler/sema_expr.c
@@ -2168,9 +2168,9 @@ NEXT_FLAG:
 				goto NEXT;
 			case 'H':
 			case 'h':
-				if (!type_flat_is_char_array_slice(type))
+				if (!type_flat_is_valid_for_arg_h(type))
 				{
-					RETURN_SEMA_ERROR(vaargs[idx], "Expected a char array or slice here.");
+					RETURN_SEMA_ERROR(vaargs[idx], "Expected a pointer, char array or slice here.");
 				}
 				goto NEXT;
 			default:
diff --git a/test/test_suite/attributes/format_h.c3t b/test/test_suite/attributes/format_h.c3t
new file mode 100644
index 000000000..940f53e01
--- /dev/null
+++ b/test/test_suite/attributes/format_h.c3t
@@ -0,0 +1,13 @@
+module test;
+import std;
+
+struct Foo
+{
+	int x, y;
+}
+fn int main()
+{
+	Foo f = { 33, 12323 };
+	io::printfn("%h", &f);
+	return 0;
+}