diff --git a/src/analyze.cpp b/src/analyze.cpp index de71673c49..35e94cd8e4 100644 --- a/src/analyze.cpp +++ b/src/analyze.cpp @@ -273,12 +273,19 @@ static void preview_function_labels(CodeGen *g, AstNode *node, FnTableEntry *fn_ static void resolve_struct_type(CodeGen *g, ImportTableEntry *import, TypeTableEntry *struct_type) { assert(struct_type->id == TypeTableEntryIdStruct); + AstNode *decl_node = struct_type->data.structure.decl_node; + + if (struct_type->data.structure.embedded_in_current) { + add_node_error(g, decl_node, + buf_sprintf("struct has infinite size")); + return; + } + if (struct_type->data.structure.fields) { // we already resolved this type. skip return; } - AstNode *decl_node = struct_type->data.structure.decl_node; assert(struct_type->di_type); @@ -293,6 +300,9 @@ static void resolve_struct_type(CodeGen *g, ImportTableEntry *import, TypeTableE uint64_t first_field_align_in_bits = 0; uint64_t offset_in_bits = 0; + // this field should be set to true only during the recursive calls to resolve_struct_type + struct_type->data.structure.embedded_in_current = true; + for (int i = 0; i < field_count; i += 1) { AstNode *field_node = decl_node->data.struct_decl.fields.at(i); TypeStructField *type_struct_field = &struct_type->data.structure.fields[i]; @@ -321,6 +331,7 @@ static void resolve_struct_type(CodeGen *g, ImportTableEntry *import, TypeTableE offset_in_bits += type_struct_field->type_entry->size_in_bits; } + struct_type->data.structure.embedded_in_current = false; LLVMStructSetBody(struct_type->type_ref, element_types, field_count, false); diff --git a/src/analyze.hpp b/src/analyze.hpp index e48a4d28c7..4d932fe2f4 100644 --- a/src/analyze.hpp +++ b/src/analyze.hpp @@ -43,6 +43,9 @@ struct TypeTableEntryStruct { bool is_packed; int field_count; TypeStructField *fields; + + // set this flag temporarily to detect infinite loops + bool embedded_in_current; }; struct TypeTableEntryNumLit { diff --git a/test/run_tests.cpp b/test/run_tests.cpp index 2566df9ada..53efe09ae2 100644 --- a/test/run_tests.cpp +++ b/test/run_tests.cpp @@ -828,6 +828,16 @@ fn f() { } )SOURCE", 2, ".tmp_source.zig:3:21: error: expected type 'i32', got 'void'", ".tmp_source.zig:4:15: error: incompatible types: 'i32' and 'void'"); + + add_compile_fail_case("direct struct loop", R"SOURCE( +struct A { a : A, } + )SOURCE", 1, ".tmp_source.zig:2:1: error: struct has infinite size"); + + add_compile_fail_case("indirect struct loop", R"SOURCE( +struct A { b : B, } +struct B { c : C, } +struct C { a : A, } + )SOURCE", 1, ".tmp_source.zig:2:1: error: struct has infinite size"); } static void print_compiler_invocation(TestCase *test_case) {