js: Use strings and stringstreams instead of GString

std::ostringstream is the C++ standard library version of GString. If we
are not doing any formatting but only appending other strings, then we can
even just use std::string and the + operator.

This allows using RAII so we can get rid of a goto, and just generally be
more memory-safe.

We continue using GString in gjs_hyphen_from_camel() for performance
reasons, because we would like a modifiable C buffer that we can pass to
canonicalize_key(), and the only way to get a modifiable buffer out of
std::string would be to copy it.

Note: stream.str() _creates_ a std::string object, and copies the string
data. string.c_str() returns a const char* _without_ copying.

1 files changed, 13 insertions, 16 deletions

diff --git a/modules/print.cpp b/modules/print.cpp
index e73a35af..cb0f1e3b 100644
--- a/modules/print.cpp
+++ b/modules/print.cpp
@@ -5,6 +5,8 @@
 
 #include <config.h>
 
+#include <string>
+
 #include <glib.h>
 
 #include <js/CallArgs.h>
@@ -85,8 +87,9 @@ static bool gjs_log_error(JSContext* cx, unsigned argc, JS::Value* vp) {
 
 GJS_JSAPI_RETURN_CONVENTION
 static bool gjs_print_parse_args(JSContext* cx, const JS::CallArgs& argv,
-                                 GjsAutoChar* buffer) {
-    GString* str = g_string_new("");
+                                 std::string* buffer) {
+    g_assert(buffer && "forgot out parameter");
+    buffer->clear();
     for (unsigned n = 0; n < argv.length(); ++n) {
         /* JS::ToString might throw, in which case we will only log that the
          * value could not be converted to string */
@@ -96,23 +99,17 @@ static bool gjs_print_parse_args(JSContext* cx, const JS::CallArgs& argv,
 
         if (jstr) {
             JS::UniqueChars s(JS_EncodeStringToUTF8(cx, jstr));
-            if (!s) {
-                g_string_free(str, true);
+            if (!s)
                 return false;
-            }
 
-            g_string_append(str, s.get());
+            *buffer += s.get();
             if (n < (argv.length() - 1))
-                g_string_append_c(str, ' ');
+                *buffer += ' ';
         } else {
-            *buffer = g_string_free(str, true);
-            if (!*buffer)
-                *buffer = g_strdup("<invalid string>");
+            *buffer = "<invalid string>";
             return true;
         }
     }
-    *buffer = g_string_free(str, false);
-
     return true;
 }
 
@@ -120,11 +117,11 @@ GJS_JSAPI_RETURN_CONVENTION
 static bool gjs_print(JSContext* context, unsigned argc, JS::Value* vp) {
     JS::CallArgs argv = JS::CallArgsFromVp(argc, vp);
 
-    GjsAutoChar buffer;
+    std::string buffer;
     if (!gjs_print_parse_args(context, argv, &buffer))
         return false;
 
-    g_print("%s\n", buffer.get());
+    g_print("%s\n", buffer.c_str());
 
     argv.rval().setUndefined();
     return true;
@@ -134,11 +131,11 @@ GJS_JSAPI_RETURN_CONVENTION
 static bool gjs_printerr(JSContext* context, unsigned argc, JS::Value* vp) {
     JS::CallArgs argv = JS::CallArgsFromVp(argc, vp);
 
-    GjsAutoChar buffer;
+    std::string buffer;
     if (!gjs_print_parse_args(context, argv, &buffer))
         return false;
 
-    g_printerr("%s\n", buffer.get());
+    g_printerr("%s\n", buffer.c_str());
 
     argv.rval().setUndefined();
     return true;