pkg/ast: introduce hex-encoded string literals

The stringnozescapes does not make sense with filename,
also we may need similar escaping for string flags.
Handle escaped strings on ast level instead.
This avoids introducing new type and works seamleassly with flags.

As alternative I've also tried using strconv.Quote/Unquote
but it leads to ugly half-escaped strings:
"\xb0\x80s\xe8\xd4N\x91\xe3ڒ,\"C\x82D\xbb\x88\\i\xe2i\xc8\xe9\xd85\xb1\x14):M\xdcn"

Make hex-encoded strings a separate string format instead.

3 files changed, 9 insertions, 16 deletions

diff --git a/pkg/compiler/testdata/all.txt b/pkg/compiler/testdata/all.txt
index 9d94a81a1..789071964 100644
--- a/pkg/compiler/testdata/all.txt
+++ b/pkg/compiler/testdata/all.txt
@@ -40,10 +40,13 @@ strings {
 	f11	stringnoz[string_flags1]
 	f12	string[string_flags2]
 	f13	stringnoz[string_flags2]
+	f14	string[`abcdef`, 4]
+	f15	string[string_flags3, 4]
 } [packed]
 
 string_flags1 = "foo", "barbaz"
 string_flags2 = ""
+string_flags3 = "ab", `010203`, `de`
 int_flags = 0, 1, 0xabc, 'x', -11
 _ = 1, 2
 _ = C1, C2
diff --git a/pkg/compiler/testdata/errors2.txt b/pkg/compiler/testdata/errors2.txt
index 47d76ab89..b5ab19ebf 100644
--- a/pkg/compiler/testdata/errors2.txt
+++ b/pkg/compiler/testdata/errors2.txt
@@ -267,6 +267,7 @@ foo$525(a int8[-256:256])		### int range [18446744073709551360:256] is too large
 foo$526(a int8[-255:255])		### int range [18446744073709551361:255] is too large for base type of size 8
 foo$527(a int16[-40000:40000])		### int range [18446744073709511616:40000] is too large for base type of size 16
 foo$528(a ptr[in, s405])
+foo$529(a ptr[in, string[`abcdde`, 3]])	### string value "\xab\xcd\xde\x00" exceeds buffer length 3
 
 type type500 proc[C1, 8, int8]	### values starting from 1 with step 8 overflow base type for 32 procs
 type type501 int8		### unused type type501
diff --git a/pkg/compiler/types.go b/pkg/compiler/types.go
index 251e0fcaa..43efee202 100644
--- a/pkg/compiler/types.go
+++ b/pkg/compiler/types.go
@@ -514,12 +514,11 @@ func genTextType(t *ast.Type) prog.TextKind {
 }
 
 const (
-	stringnoz        = "stringnoz"
-	stringnozescapes = "stringnozescapes"
+	stringnoz = "stringnoz"
 )
 
 var typeString = &typeDesc{
-	Names:        []string{"string", stringnoz, stringnozescapes},
+	Names:        []string{"string", stringnoz},
 	CanBeTypedef: true,
 	OptArgs:      2,
 	Args: []namedArg{
@@ -527,7 +526,7 @@ var typeString = &typeDesc{
 		{Name: "size", Type: typeArgInt},
 	},
 	Check: func(comp *compiler, t *ast.Type, args []*ast.Type, base prog.IntTypeCommon) {
-		if (t.Ident == stringnoz || t.Ident == stringnozescapes) && len(args) > 1 {
+		if t.Ident == stringnoz && len(args) > 1 {
 			comp.error(args[0].Pos, "fixed-size string can't be non-zero-terminated")
 		}
 	},
@@ -559,7 +558,7 @@ var typeString = &typeDesc{
 			return &prog.BufferType{
 				TypeCommon: base.TypeCommon,
 				Kind:       prog.BufferFilename,
-				NoZ:        t.Ident == stringnoz || t.Ident == stringnozescapes,
+				NoZ:        t.Ident == stringnoz,
 			}
 		}
 		subkind := ""
@@ -576,7 +575,7 @@ var typeString = &typeDesc{
 			Kind:       prog.BufferString,
 			SubKind:    subkind,
 			Values:     vals,
-			NoZ:        t.Ident == stringnoz || t.Ident == stringnozescapes,
+			NoZ:        t.Ident == stringnoz,
 		}
 	},
 }
@@ -592,16 +591,6 @@ func (comp *compiler) genStrings(t *ast.Type, args []*ast.Type) []string {
 	}
 	if t.Ident == stringnoz {
 		return vals
-	} else if t.Ident == stringnozescapes {
-		for i := range vals {
-			unquote, err := strconv.Unquote(`"` + vals[i] + `"`)
-			if err != nil {
-				comp.error(args[0].Pos, fmt.Sprintf("unable to unquote stringnozescapes %q: %v", vals[i], err))
-			} else {
-				vals[i] = unquote
-			}
-		}
-		return vals
 	}
 	var size uint64
 	if len(args) > 1 {