Initial commit: Go 1.23 release state

test/convlit.go

@@ -0,0 +1,74 @@
+// errorcheck
+
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Verify that illegal assignments with both explicit and implicit conversions of literals are detected.
+// Does not compile.
+
+package main
+
+import "unsafe"
+
+// explicit conversion of constants
+var x1 = string(1)
+var x2 string = string(1)
+var x3 = int(1.5)     // ERROR "convert|truncate"
+var x4 int = int(1.5) // ERROR "convert|truncate"
+var x5 = "a" + string(1)
+var x6 = int(1e100)      // ERROR "overflow|cannot convert"
+var x7 = float32(1e1000) // ERROR "overflow|cannot convert"
+
+// unsafe.Pointer can only convert to/from uintptr
+var _ = string(unsafe.Pointer(uintptr(65)))  // ERROR "convert|conversion"
+var _ = float64(unsafe.Pointer(uintptr(65))) // ERROR "convert|conversion"
+var _ = int(unsafe.Pointer(uintptr(65)))     // ERROR "convert|conversion"
+
+// implicit conversions merit scrutiny
+var s string
+var bad1 string = 1  // ERROR "conver|incompatible|invalid|cannot"
+var bad2 = s + 1     // ERROR "conver|incompatible|invalid|cannot"
+var bad3 = s + 'a'   // ERROR "conver|incompatible|invalid|cannot"
+var bad4 = "a" + 1   // ERROR "literals|incompatible|convert|invalid"
+var bad5 = "a" + 'a' // ERROR "literals|incompatible|convert|invalid"
+
+var bad6 int = 1.5       // ERROR "convert|truncate"
+var bad7 int = 1e100     // ERROR "overflow|truncated to int|truncated"
+var bad8 float32 = 1e200 // ERROR "overflow"
+
+// but these implicit conversions are okay
+var good1 string = "a"
+var good2 int = 1.0
+var good3 int = 1e9
+var good4 float64 = 1e20
+
+// explicit conversion of string is okay
+var _ = []rune("abc")
+var _ = []byte("abc")
+
+// implicit is not
+var _ []int = "abc"  // ERROR "cannot use|incompatible|invalid|cannot convert"
+var _ []byte = "abc" // ERROR "cannot use|incompatible|invalid|cannot convert"
+
+// named string is okay
+type Tstring string
+
+var ss Tstring = "abc"
+var _ = []rune(ss)
+var _ = []byte(ss)
+
+// implicit is still not
+var _ []rune = ss // ERROR "cannot use|incompatible|invalid"
+var _ []byte = ss // ERROR "cannot use|incompatible|invalid"
+
+// named slice is now ok
+type Trune []rune
+type Tbyte []byte
+
+var _ = Trune("abc") // ok
+var _ = Tbyte("abc") // ok
+
+// implicit is still not
+var _ Trune = "abc" // ERROR "cannot use|incompatible|invalid|cannot convert"
+var _ Tbyte = "abc" // ERROR "cannot use|incompatible|invalid|cannot convert"