From a73c20916d4845e97b5973cc30af1e2223e05a45 Mon Sep 17 00:00:00 2001
From: Ruofan XU <47302112+SleepyRoy@users.noreply.github.com>
Date: Wed, 3 Feb 2021 17:57:06 +0800
Subject: [PATCH] checker: refactor and clean up c.check_basic() (#8508)

---
 vlib/v/checker/check_types.v | 102 ++++++++---------------------------
 1 file changed, 22 insertions(+), 80 deletions(-)

diff --git a/vlib/v/checker/check_types.v b/vlib/v/checker/check_types.v
index 1e90230b34..ef9536c8b7 100644
--- a/vlib/v/checker/check_types.v
+++ b/vlib/v/checker/check_types.v
@@ -22,110 +22,52 @@ pub fn (mut c Checker) check_expected_call_arg(got table.Type, expected_ table.T
 }
 
 pub fn (mut c Checker) check_basic(got table.Type, expected table.Type) bool {
-	if got == expected {
-		return true
-	}
-	t := c.table
-	got_idx := t.unalias_num_type(got).idx()
-	exp_idx := t.unalias_num_type(expected).idx()
-	// exp_is_optional := expected.has_flag(.optional)
-	// got_is_optional := got.has_flag(.optional)
-	// if (exp_is_optional && !got_is_optional) || (!exp_is_optional && got_is_optional) {
-	// return false
-	//}
-	// println('check: $got_type_sym.name, $exp_type_sym.name')
-	// # NOTE: use idxs here, and symbols below for perf
-	// got_is_ptr := got.is_ptr()
-	if got_idx == exp_idx {
+	got_, exp_ := c.table.unalias_num_type(got), c.table.unalias_num_type(expected)
+	if got_.idx() == exp_.idx() {
 		// this is returning true even if one type is a ptr
 		// and the other is not, is this correct behaviour?
 		return true
 	}
-	if got_idx == table.none_type_idx && expected.has_flag(.optional) {
-		return false
+	if (exp_.is_pointer() || exp_.is_number()) && (got_.is_pointer() || got_.is_number()) {
+		return true
 	}
-	exp_is_ptr := expected.is_ptr()
 	// allow pointers to be initialized with 0. TODO: use none instead
-	if exp_is_ptr && got_idx == table.int_type_idx {
+	if expected.is_ptr() && got_.idx() == table.int_type_idx {
 		return true
 	}
-	if exp_idx == table.voidptr_type_idx || got_idx == table.voidptr_type_idx {
+	// TODO: use sym so it can be absorbed into below [.voidptr, .any] logic
+	if expected.idx() == table.array_type_idx || got.idx() == table.array_type_idx {
 		return true
 	}
-	if exp_idx == table.any_type_idx || got_idx == table.any_type_idx {
-		return true
-	}
-	// TODO i64 as int etc
-	if (exp_idx in table.pointer_type_idxs || exp_idx in table.number_type_idxs)
-		&& (got_idx in table.pointer_type_idxs || got_idx in table.number_type_idxs) {
-		return true
-	}
-	// if exp_idx in pointer_type_idxs && got_idx in pointer_type_idxs {
-	// return true
-	// }
-	// see hack in checker IndexExpr line #691
-	if (got_idx == table.byte_type_idx && exp_idx == table.byteptr_type_idx)
-		|| (exp_idx == table.byte_type_idx && got_idx == table.byteptr_type_idx) {
-		return true
-	}
-	if (got_idx == table.char_type_idx && exp_idx == table.charptr_type_idx)
-		|| (exp_idx == table.char_type_idx && got_idx == table.charptr_type_idx) {
-		return true
-	}
-	// TODO: this should no longer be needed
-	// if expected == table.t_type && got == table.t_type {
-	// return true
-	// }
-	// # NOTE: use symbols from this point on for perf
-	got_type_sym := t.get_type_symbol(got)
-	exp_type_sym := t.get_type_symbol(expected)
-	//
-	if exp_type_sym.kind == .function && got_type_sym.kind == .int {
-		// TODO temporary
-		// fn == 0
-		return true
-	}
-	// array/map fn
-	if got_type_sym.kind in [.array, .map] && exp_type_sym.kind == got_type_sym.kind {
+	got_sym, exp_sym := c.table.get_type_symbol(got), c.table.get_type_symbol(expected)
+	// array/map as argument
+	if got_sym.kind in [.array, .map, .array_fixed] && exp_sym.kind == got_sym.kind {
 		if c.table.type_to_str(got) == c.table.type_to_str(expected).trim('&') {
 			return true
 		}
 	}
-	// fixed array fn
-	if got_type_sym.kind == .array_fixed && exp_type_sym.kind == .array_fixed {
-		if c.table.type_to_str(got) == c.table.type_to_str(expected).trim('&') {
+	// e.g. [4096]byte vs byteptr
+	if got_sym.kind == .array_fixed {
+		info := got_sym.info as table.ArrayFixed
+		if c.table.type_to_str(info.elem_type) == c.table.type_to_str(expected).trim('ptr') {
 			return true
 		}
 	}
-	if got_type_sym.kind == .array_fixed && exp_type_sym.kind == .byteptr {
-		info := got_type_sym.info as table.ArrayFixed
-		if info.elem_type.idx() == table.byte_type_idx {
-			return true
-		}
-	}
-	// TODO
-	// if exp_type_sym.name == 'array' || got_type_sym.name == 'array' {
-	if got_idx == table.array_type_idx || exp_idx == table.array_type_idx {
-		return true
-	}
-	// TODO
-	// accept [] when an expected type is an array
-	if got_type_sym.kind == .array && exp_type_sym.kind == .array
-		&& got_type_sym.name == 'array_void' {
-		return true
-	}
-	// type alias
-	if (got_type_sym.kind == .alias && got_type_sym.parent_idx == exp_idx)
-		|| (exp_type_sym.kind == .alias && exp_type_sym.parent_idx == got_idx) {
+	if exp_sym.kind in [.voidptr, .any] || got_sym.kind in [.voidptr, .any] {
 		return true
 	}
 	// sum type
 	if c.table.sumtype_has_variant(expected, c.table.mktyp(got)) {
 		return true
 	}
+	// type alias
+	if (got_sym.kind == .alias && got_sym.parent_idx == expected.idx())
+		|| (exp_sym.kind == .alias && exp_sym.parent_idx == got.idx()) {
+		return true
+	}
 	// fn type
-	if got_type_sym.kind == .function && exp_type_sym.kind == .function {
-		return c.check_matching_function_symbols(got_type_sym, exp_type_sym)
+	if got_sym.kind == .function && exp_sym.kind == .function {
+		return c.check_matching_function_symbols(got_sym, exp_sym)
 	}
 	return false
 }