Add JS_AtomToCStringLen (#1071)

Cherry-pick of bellard/quickjs@8381245.

Co-authored-by: Fabrice Bellard <[email protected]>
Co-authored-by: Haruma <[email protected]>

Author: harumazzz

quickjs.c

@@ -3459,15 +3459,18 @@ static __maybe_unused void print_atom(JSContext *ctx, JSAtom atom)
 }
 
 /* free with JS_FreeCString() */
-const char *JS_AtomToCString(JSContext *ctx, JSAtom atom)
+const char *JS_AtomToCStringLen(JSContext *ctx, size_t *plen, JSAtom atom)
 {
     JSValue str;
     const char *cstr;
 
     str = JS_AtomToString(ctx, atom);
-    if (JS_IsException(str))
+    if (JS_IsException(str)) {
+        if (plen)
+            *plen = 0;
         return NULL;
-    cstr = JS_ToCString(ctx, str);
+    }
+    cstr = JS_ToCStringLen(ctx, plen, str);
     JS_FreeValue(ctx, str);
     return cstr;
 }

quickjs.h

@@ -544,7 +544,11 @@ JS_EXTERN void JS_FreeAtom(JSContext *ctx, JSAtom v);
 JS_EXTERN void JS_FreeAtomRT(JSRuntime *rt, JSAtom v);
 JS_EXTERN JSValue JS_AtomToValue(JSContext *ctx, JSAtom atom);
 JS_EXTERN JSValue JS_AtomToString(JSContext *ctx, JSAtom atom);
-JS_EXTERN const char *JS_AtomToCString(JSContext *ctx, JSAtom atom);
+JS_EXTERN const char *JS_AtomToCStringLen(JSContext *ctx, size_t *plen, JSAtom atom);
+static inline const char *JS_AtomToCString(JSContext *ctx, JSAtom atom) 
+{
+    return JS_AtomToCStringLen(ctx, NULL, atom);
+}
 JS_EXTERN JSAtom JS_ValueToAtom(JSContext *ctx, JSValueConst val);
 
 /* object class support */