Fix #6348

src/check_type.cpp

@@ -2859,6 +2859,26 @@ gb_internal void add_map_key_type_dependencies(CheckerContext *ctx, Type *key) {
 	}
 }
 
+gb_internal void validate_map_key(CheckerContext *ctx, Ast *node, Type *key) {
+	if (!is_type_valid_for_keys(key)) {
+		if (is_type_boolean(key)) {
+			error(node, "A boolean cannot be used as a key for a map, use an array instead for this case");
+		} else {
+			gbString str = type_to_string(key);
+			error(node, "Invalid type of a key for a map, got '%s'", str);
+			gb_string_free(str);
+		}
+		return;
+	}
+	if (type_size_of(key) == 0) {
+		gbString str = type_to_string(key);
+		error(node, "Invalid type of a key for a map of size 0, got '%s'", str);
+		gb_string_free(str);
+		return;
+	}
+	add_map_key_type_dependencies(ctx, key);
+}
+
 gb_internal void check_map_type(CheckerContext *ctx, Type *type, Ast *node) {
 	GB_ASSERT(type->kind == Type_Map);
 	ast_node(mt, MapType, node);
@@ -2878,30 +2898,29 @@ gb_internal void check_map_type(CheckerContext *ctx, Type *type, Ast *node) {
 	Type *key   = check_type(ctx, mt->key);
 	Type *value = check_type(ctx, mt->value);
 
-	if (!is_type_valid_for_keys(key)) {
-		if (is_type_boolean(key)) {
-			error(node, "A boolean cannot be used as a key for a map, use an array instead for this case");
-		} else {
-			gbString str = type_to_string(key);
-			error(node, "Invalid type of a key for a map, got '%s'", str);
-			gb_string_free(str);
-		}
-	}
-	if (type_size_of(key) == 0) {
-		gbString str = type_to_string(key);
-		error(node, "Invalid type of a key for a map of size 0, got '%s'", str);
-		gb_string_free(str);
-	}
-
 	type->Map.key   = key;
 	type->Map.value = value;
 
-	add_map_key_type_dependencies(ctx, key);
+	// If the key type is still being resolved its struct fields may be empty causing false invalid key errors.
+	// Defer to check_deferred_map_key_types which runs after all global entities are resolved.
+	if (key->kind == Type_Named && key->Named.type_name && key->Named.type_name->state.load() == EntityState_InProgress) {
+		array_add(&ctx->checker->deferred_map_key_checks, node);
+	} else {
+		validate_map_key(ctx, node, key);
+	}
 
 	init_core_map_type(ctx->checker);
 	init_map_internal_types(type);
 }
 
+gb_internal void check_deferred_map_key_types(Checker *c) {
+	CheckerContext ctx = c->builtin_ctx;
+	ctx.decl = make_decl_info(nullptr, nullptr);
+	for (Ast *node : c->deferred_map_key_checks) {
+		validate_map_key(&ctx, node, node->tav.type->Map.key);
+	}
+}
+
 gb_internal void check_matrix_type(CheckerContext *ctx, Type **type, Ast *node) {
 	ast_node(mt, MatrixType, node);
 

src/checker.cpp

@@ -1603,6 +1603,7 @@ gb_internal void init_checker(Checker *c) {
 	// NOTE(bill): 1 Mi elements should be enough on average
 	array_init(&c->procs_to_check, heap_allocator(), 0, 1<<20);
 	array_init(&c->nested_proc_lits, heap_allocator(), 0, 1<<20);
+	array_init(&c->deferred_map_key_checks, heap_allocator());
 
 	mpsc_init(&c->global_untyped_queue, a); // , 1<<20);
 	mpsc_init(&c->soa_types_to_complete, a); // , 1<<20);
@@ -1617,6 +1618,7 @@ gb_internal void destroy_checker(Checker *c) {
 
 	array_free(&c->nested_proc_lits);
 	array_free(&c->procs_to_check);
+	array_free(&c->deferred_map_key_checks);
 	mpsc_destroy(&c->global_untyped_queue);
 	mpsc_destroy(&c->soa_types_to_complete);
 }
@@ -5051,6 +5053,8 @@ gb_internal void check_all_global_entities(Checker *c) {
 		}
 	}
 
+	check_deferred_map_key_types(c);
+
 	in_single_threaded_checker_stage.store(false, std::memory_order_relaxed);
 }
 

src/checker.hpp

@@ -598,6 +598,7 @@ struct Checker {
 	BlockingMutex nested_proc_lits_mutex;
 	Array<DeclInfo *> nested_proc_lits;
 
+	Array<Ast *> deferred_map_key_checks;
 
 	MPSCQueue<UntypedExprInfo> global_untyped_queue;
 	MPSCQueue<Type *> soa_types_to_complete;

tests/issues/run.bat

@@ -29,6 +29,7 @@ set COMMON=-define:ODIN_TEST_FANCY=false -file -vet -strict-style -ignore-unused
 ..\..\..\odin test ..\test_issue_6068.odin %COMMON%  || exit /b
 ..\..\..\odin test ..\test_issue_6101.odin %COMMON%  || exit /b
 ..\..\..\odin test ..\test_issue_6165.odin %COMMON%  || exit /b
+..\..\..\odin test ..\test_issue_6348.odin %COMMON%  || exit /b
 
 @echo off
 

tests/issues/run.sh

@@ -36,6 +36,7 @@ $ODIN test ../test_issue_5699.odin $COMMON
 $ODIN test ../test_issue_6068.odin $COMMON
 $ODIN test ../test_issue_6101.odin $COMMON
 $ODIN test ../test_issue_6165.odin $COMMON
+$ODIN test ../test_issue_6348.odin $COMMON
 set +x
 
 popd

tests/issues/test_issue_6348.odin

@@ -0,0 +1,26 @@
+// Tests issue #6348 https://github.com/odin-lang/Odin/issues/6348
+package test_issues
+
+import "core:testing"
+
+// Key type declared before map type
+Foo1 :: struct { f: proc(^Bar1) }
+Bar1 :: struct { m: map[Foo1]int }
+
+// Map type declared before key type
+Bar2 :: struct { m: map[Foo2]int }
+Foo2 :: struct { f: proc(^Bar2) }
+
+// Named proc type alias
+MyProc :: proc(^Bar3)
+Foo3    :: struct { f: MyProc }
+Bar3    :: struct { m: map[Foo3]int }
+
+// Chain
+Foo4 :: struct { f: proc(^Baz4) }
+Baz4 :: struct { g: proc(^Bar4) }
+Bar4 :: struct { m: map[Foo4]int }
+
+
+@(test)
+test_issue_6348 :: proc(t: ^testing.T) {}