From 8b6735a6aa7474c0b253aecc94fbd15d74c85998 Mon Sep 17 00:00:00 2001
From: Christoffer Lerno <christoffer@aegik.com>
Date: Tue, 16 Apr 2024 19:42:32 +0200
Subject: [PATCH] Allow recursive function definitions as long as they are
 pointers #1182. Add 'zstr' variants for `string::new_format` /
 `string::tformat`.

---
 lib/std/core/string.c3                           | 16 ++++++++++++++++
 releasenotes.md                                  |  3 ++-
 src/compiler/parse_global.c                      |  1 +
 src/compiler/sema_decls.c                        |  6 +++---
 src/compiler/sema_expr.c                         |  2 +-
 .../functions/recursive_through_generic.c3       |  2 +-
 6 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/lib/std/core/string.c3 b/lib/std/core/string.c3
index 54e553e6f..69664fb73 100644
--- a/lib/std/core/string.c3
+++ b/lib/std/core/string.c3
@@ -38,6 +38,13 @@ macro String tformat(String fmt, ...)
 	return str.str_view();
 }
 
+macro ZString tformat_zstr(String fmt, ...)
+{
+	DString str = dstring::temp_with_capacity(fmt.len + $vacount * 8);
+	str.appendf(fmt, $vasplat());
+	return str.zstr_view();
+}
+
 macro String new_format(String fmt, ..., Allocator* allocator = allocator::heap())
 {
 	@pool(allocator)
@@ -48,6 +55,15 @@ macro String new_format(String fmt, ..., Allocator* allocator = allocator::heap(
 	};
 }
 
+macro ZString new_format_zstr(String fmt, ..., Allocator* allocator = allocator::heap())
+{
+	@pool(allocator)
+	{
+		DString str = dstring::temp_with_capacity(fmt.len + $vacount * 8);
+		str.appendf(fmt, $vasplat());
+		return str.copy_zstr(allocator);
+	};
+}
 
 macro bool char_in_set(char c, String set)
 {
diff --git a/releasenotes.md b/releasenotes.md
index 54b06fbd2..10e51bf0f 100644
--- a/releasenotes.md
+++ b/releasenotes.md
@@ -5,12 +5,13 @@
 ### Changes / improvements
 - Support `defer (catch err)`
 - Added `print-input` command argument to print all files used for compilation
+- Allow recursive function definitions as long as they are pointers. #1182
 
 ### Fixes
 - Incorrect length passed to scratch buffer printf.
 
 ### Stdlib changes
-None
+- Add 'zstr' variants for `string::new_format` / `string::tformat`.
 
 ## 0.5.5 Change list
 
diff --git a/src/compiler/parse_global.c b/src/compiler/parse_global.c
index 62b282a63..000cf1bb4 100644
--- a/src/compiler/parse_global.c
+++ b/src/compiler/parse_global.c
@@ -1831,6 +1831,7 @@ static inline Decl *parse_def_type(ParseContext *c)
 			return poisoned_decl;
 		}
 		if (!parse_attributes_for_global(c, decl)) return poisoned_decl;
+		RANGE_EXTEND_PREV(decl_type);
 		RANGE_EXTEND_PREV(decl);
 		CONSUME_EOS_OR_RET(poisoned_decl);
 		return decl;
diff --git a/src/compiler/sema_decls.c b/src/compiler/sema_decls.c
index d7e3d920b..6eb78f556 100644
--- a/src/compiler/sema_decls.c
+++ b/src/compiler/sema_decls.c
@@ -914,7 +914,7 @@ static inline bool sema_analyse_signature(SemaContext *context, Signature *sig,
 				return false;
 			}
 		}
-		if (!sema_resolve_type_structure(context, rtype_info->type, rtype_info->span)) return false;
+		if (type_is_func_ptr(rtype_info->type) && !sema_resolve_type_structure(context, rtype_info->type, rtype_info->span)) return false;
 	}
 
 	// We don't support more than MAX_PARAMS number of params. This makes everything sane.
@@ -1092,8 +1092,8 @@ static inline bool sema_analyse_signature(SemaContext *context, Signature *sig,
 
 		if (type_info)
 		{
-			if (!sema_resolve_type_structure(context, type_info->type, type_info->span)) return false;
-
+			Type *type = type_info->type;
+			if (type_is_func_ptr(type) && !sema_resolve_type_structure(context, type, type_info->span)) return false;
 			param->type = type_info->type;
 			if (!sema_set_abi_alignment(context, param->type, &param->alignment)) return false;
 		}
diff --git a/src/compiler/sema_expr.c b/src/compiler/sema_expr.c
index 951052618..96abbf10c 100644
--- a/src/compiler/sema_expr.c
+++ b/src/compiler/sema_expr.c
@@ -7574,7 +7574,7 @@ static inline bool sema_expr_analyse_lambda(SemaContext *context, Type *target_t
 	{
 		if (!type_is_func_ptr(flat))
 		{
-			SEMA_ERROR(expr, "Can't convert a lambda to %s.", type_quoted_error_string(target_type));
+			RETURN_SEMA_ERROR(expr, "Can't convert a lambda to %s.", type_quoted_error_string(target_type));
 		}
 		if (!sema_resolve_type_decl(context, flat->pointer)) return false;
 	}
diff --git a/test/test_suite/functions/recursive_through_generic.c3 b/test/test_suite/functions/recursive_through_generic.c3
index 1b250e547..919fac100 100644
--- a/test/test_suite/functions/recursive_through_generic.c3
+++ b/test/test_suite/functions/recursive_through_generic.c3
@@ -5,7 +5,7 @@ fn void! main()
 {
 }
 
-def FooFunc = fn void! (Bar*); // #error: Recursive definition
+def FooFunc = fn void! (Bar); // #error: Recursive definition
 def Foo = HashMap(<String, FooFunc>);
 
 struct Bar