From f8e03d3647811f7d4244cbb68369f9e3401e53b9 Mon Sep 17 00:00:00 2001
From: xhd2015 <xhd2015@gmail.com>
Date: Fri, 31 May 2024 13:13:50 +0800
Subject: [PATCH] bypass type resolution with const operations

---
 cmd/xgo/runtime_gen/core/version.go           |  4 +--
 cmd/xgo/version.go                            |  4 +--
 patch/syntax/vars.go                          | 31 ++++++++++++++++---
 runtime/core/version.go                       |  4 +--
 runtime/test/debug/debug_test.go              | 17 ++++++++--
 .../test/patch_const/patch_const_op_test.go   | 20 ++++++++++++
 6 files changed, 68 insertions(+), 12 deletions(-)
 create mode 100644 runtime/test/patch_const/patch_const_op_test.go

diff --git a/cmd/xgo/runtime_gen/core/version.go b/cmd/xgo/runtime_gen/core/version.go
index 46d3739a..e2c0cdfc 100755
--- a/cmd/xgo/runtime_gen/core/version.go
+++ b/cmd/xgo/runtime_gen/core/version.go
@@ -7,8 +7,8 @@ import (
 )
 
 const VERSION = "1.0.38"
-const REVISION = "d939407b345d1697a3a32cf48c5b659d017c4cff+1"
-const NUMBER = 248
+const REVISION = "808e011ba0498b1aaff762095543c880301dc26b+1"
+const NUMBER = 249
 
 // these fields will be filled by compiler
 const XGO_VERSION = ""
diff --git a/cmd/xgo/version.go b/cmd/xgo/version.go
index eef8b97d..ab61b634 100644
--- a/cmd/xgo/version.go
+++ b/cmd/xgo/version.go
@@ -3,8 +3,8 @@ package main
 import "fmt"
 
 const VERSION = "1.0.38"
-const REVISION = "d939407b345d1697a3a32cf48c5b659d017c4cff+1"
-const NUMBER = 248
+const REVISION = "808e011ba0498b1aaff762095543c880301dc26b+1"
+const NUMBER = 249
 
 func getRevision() string {
 	revSuffix := ""
diff --git a/patch/syntax/vars.go b/patch/syntax/vars.go
index 66ac2b05..b4fe83f3 100644
--- a/patch/syntax/vars.go
+++ b/patch/syntax/vars.go
@@ -837,12 +837,35 @@ func getConstDeclValueType(expr syntax.Expr) string {
 		if isBoolOp(expr.Op) {
 			return "bool"
 		}
-		if expr.X != nil {
-			return getConstDeclValueType(expr.X)
+		xIsNil := expr.X == nil
+		yIsNil := expr.Y == nil
+		if xIsNil && yIsNil {
+			return ""
+		}
+		// see https://github.com/xhd2015/xgo/issues/172
+		// var x = 5*y, y's type is not known
+		var xType string
+		if !xIsNil {
+			xType = getConstDeclValueType(expr.X)
+		}
+		var yType string
+		if !yIsNil {
+			yType = getConstDeclValueType(expr.Y)
+		}
+		// either is nil
+		if xIsNil != yIsNil {
+			if xType != "" {
+				return xType
+			}
+			return yType
 		}
-		if expr.Y != nil {
-			return getConstDeclValueType(expr.Y)
+		// 5*5 -> int
+		// 5*X -> unknown
+		if xType == yType {
+			return xType
 		}
+		return ""
+		// TODO: handle SelectorExpr and iota
 	case *syntax.ParenExpr:
 		return getConstDeclValueType(expr.X)
 	}
diff --git a/runtime/core/version.go b/runtime/core/version.go
index 46d3739a..e2c0cdfc 100644
--- a/runtime/core/version.go
+++ b/runtime/core/version.go
@@ -7,8 +7,8 @@ import (
 )
 
 const VERSION = "1.0.38"
-const REVISION = "d939407b345d1697a3a32cf48c5b659d017c4cff+1"
-const NUMBER = 248
+const REVISION = "808e011ba0498b1aaff762095543c880301dc26b+1"
+const NUMBER = 249
 
 // these fields will be filled by compiler
 const XGO_VERSION = ""
diff --git a/runtime/test/debug/debug_test.go b/runtime/test/debug/debug_test.go
index 56541598..f1812114 100644
--- a/runtime/test/debug/debug_test.go
+++ b/runtime/test/debug/debug_test.go
@@ -5,8 +5,21 @@
 
 package debug
 
-import "testing"
+import (
+	"testing"
+	"time"
+
+	"github.com/xhd2015/xgo/runtime/mock"
+)
+
+const A = 20 * time.Second
 
 func TestHello(t *testing.T) {
-	t.Logf("hello world!")
+	mock.PatchByName("github.com/xhd2015/xgo/runtime/test/debug", "A", func() time.Duration {
+		return 10 * time.Second
+	})
+	a := A
+	if a != 20*time.Second {
+		t.Fatalf("expect patch A failed because current xgo does not resolve operation type, actual: a=%v, want: %v", a, 20*time.Second)
+	}
 }
diff --git a/runtime/test/patch_const/patch_const_op_test.go b/runtime/test/patch_const/patch_const_op_test.go
new file mode 100644
index 00000000..511850cf
--- /dev/null
+++ b/runtime/test/patch_const/patch_const_op_test.go
@@ -0,0 +1,20 @@
+package patch_const
+
+import (
+	"testing"
+	"time"
+
+	"github.com/xhd2015/xgo/runtime/mock"
+)
+
+const A = 20 * time.Second
+
+func TestPatchConstOp(t *testing.T) {
+	mock.PatchByName("github.com/xhd2015/xgo/runtime/test/patch_const", "A", func() time.Duration {
+		return 10 * time.Second
+	})
+	a := A
+	if a != 20*time.Second {
+		t.Fatalf("expect patch A failed because current xgo does not resolve operation type, actual: a=%v, want: %v", a, 20*time.Second)
+	}
+}