From e64eb74eef40c4c79b493006feadce4499a8a9dd Mon Sep 17 00:00:00 2001
From: gingerBill <bill@gingerbill.org>
Date: Wed, 27 Jan 2021 15:27:38 +0000
Subject: [PATCH] Fix #831

---
 src/check_expr.cpp | 51 ++++++++++++++++++++++++++++++++++++++++++++++
 src/checker.cpp    |  7 +++++--
 2 files changed, 56 insertions(+), 2 deletions(-)

diff --git a/src/check_expr.cpp b/src/check_expr.cpp
index 63b275c99..b001ed7a8 100644
--- a/src/check_expr.cpp
+++ b/src/check_expr.cpp
@@ -1801,6 +1801,50 @@ void check_unary_expr(CheckerContext *c, Operand *o, Token op, Ast *node) {
 	o->mode = Addressing_Value;
 }
 
+void add_comparison_procedures_for_fields(CheckerContext *c, Type *t) {
+	if (t == nullptr) {
+		return;
+	}
+	t = base_type(t);
+	if (!is_type_comparable(t)) {
+		return;
+	}
+	switch (t->kind) {
+	case Type_Basic:
+		switch (t->Basic.kind) {
+		case Basic_complex64:
+			add_package_dependency(c, "runtime", "complex64_eq");
+			add_package_dependency(c, "runtime", "complex64_ne");
+			break;
+		case Basic_complex128:
+			add_package_dependency(c, "runtime", "complex128_eq");
+			add_package_dependency(c, "runtime", "complex128_ne");
+			break;
+		case Basic_quaternion128:
+			add_package_dependency(c, "runtime", "quaternion128_eq");
+			add_package_dependency(c, "runtime", "quaternion128_ne");
+			break;
+		case Basic_quaternion256:
+			add_package_dependency(c, "runtime", "quaternion256_eq");
+			add_package_dependency(c, "runtime", "quaternion256_ne");
+			break;
+		case Basic_cstring:
+			add_package_dependency(c, "runtime", "cstring_to_string");
+			/*fallthrough*/
+		case Basic_string:
+			add_package_dependency(c, "runtime", "string_eq");
+			add_package_dependency(c, "runtime", "string_ne");
+			break;
+		}
+		break;
+	case Type_Struct:
+		for_array(i, t->Struct.fields) {
+			add_comparison_procedures_for_fields(c, t->Struct.fields[i]->type);
+		}
+		break;
+	}
+}
+
 
 void check_comparison(CheckerContext *c, Operand *x, Operand *y, TokenKind op) {
 	if (x->mode == Addressing_Type && y->mode == Addressing_Type) {
@@ -1867,6 +1911,13 @@ void check_comparison(CheckerContext *c, Operand *x, Operand *y, TokenKind op) {
 			defer (gb_string_free(type_string));
 			err_str = gb_string_make(temporary_allocator(),
 				gb_bprintf("operator '%.*s' not defined for type '%s'", LIT(token_strings[op]), type_string));
+		} else {
+			Type *comparison_type = x->type;
+			if (x->type == err_type && is_operand_nil(*x)) {
+				comparison_type = y->type;
+			}
+
+			add_comparison_procedures_for_fields(c, comparison_type);
 		}
 	} else {
 		gbString xt, yt;
diff --git a/src/checker.cpp b/src/checker.cpp
index 1e1eac984..c7dbc7b2f 100644
--- a/src/checker.cpp
+++ b/src/checker.cpp
@@ -3,7 +3,7 @@
 
 void check_expr(CheckerContext *c, Operand *operand, Ast *expression);
 void check_expr_or_type(CheckerContext *c, Operand *operand, Ast *expression, Type *type_hint=nullptr);
-
+void add_comparison_procedures_for_fields(CheckerContext *c, Type *t);
 
 bool is_operand_value(Operand o) {
 	switch (o.mode) {
@@ -648,8 +648,8 @@ void add_package_dependency(CheckerContext *c, char const *package_name, char co
 	AstPackage *p = get_core_package(&c->checker->info, make_string_c(package_name));
 	Entity *e = scope_lookup(p->scope, n);
 	GB_ASSERT_MSG(e != nullptr, "%s", name);
+	GB_ASSERT(c->decl != nullptr);
 	ptr_set_add(&c->decl->deps, e);
-	// add_type_info_type(c, e->type);
 }
 
 void add_declaration_dependency(CheckerContext *c, Entity *e) {
@@ -1425,6 +1425,7 @@ void add_type_info_type(CheckerContext *c, Type *t) {
 			Entity *f = bt->Struct.fields[i];
 			add_type_info_type(c, f->type);
 		}
+		add_comparison_procedures_for_fields(c, bt);
 		break;
 
 	case Type_BitFieldValue:
@@ -4453,6 +4454,7 @@ void check_parsed_files(Checker *c) {
 
 	CheckerContext prev_context = c->init_ctx;
 	defer (c->init_ctx = prev_context);
+	c->init_ctx.decl = make_decl_info(nullptr, nullptr);
 
 	TIME_SECTION("check procedure bodies");
 	// NOTE(bill): Nested procedures bodies will be added to this "queue"
@@ -4514,6 +4516,7 @@ void check_parsed_files(Checker *c) {
 			if (align > 0 && ptr_set_exists(&c->info.minimum_dependency_set, e)) {
 				add_type_info_type(&c->init_ctx, e->type);
 			}
+
 		} else if (e->kind == Entity_Procedure) {
 			DeclInfo *decl = e->decl_info;
 			ast_node(pl, ProcLit, decl->proc_lit);