hare

commit 577fafa83ce9f075efcf5c7ee53a162b9ca30d85
parent 147f3d5c907a04d6091d0a216ebf27d6d0e0299b
Author: Alexey Yerin <yyp@disroot.org>
Date:   Thu, 14 Oct 2021 23:19:32 +0300

types: strflag: special case 0 value to not match on anything

This would cause things like this to work incorrectly:

    type permissions = enum u8 {
    	NONE  = 0,
    	READ  = 1 << 0,
    	WRITE = 1 << 1,
    };

    const perm = permissions::READ;
    strflag(type(permissions), &perm) // => NONE|READ

Signed-off-by: Alexey Yerin <yyp@disroot.org>

Diffstat:
M
types/util.ha
 | 
27
++++++++++++++++++++-------

1 file changed, 20 insertions(+), 7 deletions(-)
diff --git a/types/util.ha b/types/util.ha
@@ -44,8 +44,7 @@ export fn strenum(ty: type, val: *void) str = {
 // TODO: should we have a static version of that?
 
 // Returns the names of enabled flags of a bitfield enum at "val" formatted as
-// '|' operation, or "0" when the value doesn't match any flags. The string
-// must be freed by the caller.
+// '|' operation. The string must be freed by the caller.
 export fn strflag(ty: type, val: *void) str = {
 	const ty = unwrap(ty);
 	const en = ty.repr as enumerated;
@@ -78,19 +77,33 @@ export fn strflag(ty: type, val: *void) str = {
 	};
 
 	let buf: []u8 = alloc([]);
+	let zeroname = "";
+
+	let pipe = false;
 
 	for (let i = 0z; i < len(en.values); i += 1) {
-		if (en.values[i].1.u & value != 0) {
-			if (i > 0) {
+		const val = en.values[i];
+		if (val.1.u == 0) {
+			zeroname = val.0;
+			continue;
+		};
+		if (val.1.u & value != 0) {
+			if (pipe) {
 				append(buf, '|': u8);
 			};
-			const name = en.values[i].0;
-			append(buf, *(&name: *[]u8)...);
+			append(buf, *(&val.0: *[]u8)...);
+			pipe = true;
+		} else {
+			pipe = false;
 		};
 	};
 
+	if (value == 0) {
+		append(buf, *(&zeroname: *[]u8)...);
+	};
+
 	if (len(buf) == 0) {
-		append(buf, '0': u8);
+		abort("Enum has invalid value");
 	};
 
 	return *(&buf: *str);