llscan.cc: Add findjsinstances --verbose option (#125)

Add --verbose (-v) option to findjsinstances so that the output
of v8 inspect is displayed for each instance of a type instead
of v8 print output. This makes it quicker to view the contents
of objects especially where there are few instances of the same
kind.

PR-URL: #125
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

Author: hhellyer

README.md

@@ -224,7 +224,8 @@ The following subcommands are supported:
                          dumped.
 
                          Syntax: v8 bt [number]
-      findjsinstances -- List all objects which share the specified map.
+      findjsinstances -- List every object with the specified type name.
+                         Use -v or --verbose to display detailed `v8 inspect` output for each object.
                          Accepts the same options as `v8 inspect`
       findjsobjects   -- List all object types and instance counts grouped by typename and sorted by instance count.
                          Requires `LLNODE_RANGESFILE` environment variable to be set to a file containing memory ranges for the

src/llnode.cc

@@ -38,6 +38,7 @@ char** CommandBase::ParseInspectOptions(char** cmd,
       {"length", required_argument, nullptr, 'l'},
       {"print-map", no_argument, nullptr, 'm'},
       {"print-source", no_argument, nullptr, 's'},
+      {"verbose", no_argument, nullptr, 'v'},
       {nullptr, 0, nullptr, 0}};
 
   int argc = 1;
@@ -55,7 +56,7 @@ char** CommandBase::ParseInspectOptions(char** cmd,
   optind = 0;
   opterr = 1;
   do {
-    int arg = getopt_long(argc, args, "Fmsl:", opts, nullptr);
+    int arg = getopt_long(argc, args, "Fmsvl:", opts, nullptr);
     if (arg == -1) break;
 
     switch (arg) {
@@ -71,6 +72,9 @@ char** CommandBase::ParseInspectOptions(char** cmd,
       case 's':
         options->print_source = true;
         break;
+      case 'v':
+        options->detailed = true;
+        break;
       default:
         continue;
     }
@@ -356,7 +360,9 @@ bool PluginInitialize(SBDebugger d) {
                          "Alias for `v8 findjsobjects`");
 
   v8.AddCommand("findjsinstances", new llnode::FindInstancesCmd(),
-                "List all objects which share the specified map.\n"
+                "List every object with the specified type name.\n"
+                "Use -v or --verbose to display detailed `v8 inspect` output "
+                "for each object.\n"
                 "Accepts the same options as `v8 inspect`");
 
   interpreter.AddCommand("findjsinstances", new llnode::FindInstancesCmd(),

src/llscan.cc

@@ -81,7 +81,7 @@ bool FindObjectsCmd::DoExecute(SBDebugger d, char** cmd,
 bool FindInstancesCmd::DoExecute(SBDebugger d, char** cmd,
                                  SBCommandReturnObject& result) {
   if (cmd == nullptr || *cmd == nullptr) {
-    result.SetError("USAGE: v8 findjsinstances [-Fm] instance_name\n");
+    result.SetError("USAGE: v8 findjsinstances [flags] instance_name\n");
     return false;
   }
 

test/usage-test.js

@@ -28,7 +28,7 @@ tape('usage messages', (t) => {
   });
 
   sess.stderr.linesUntil(/USAGE/, (lines) => {
-    const re = /^error: USAGE: v8 findjsinstances \[-Fm\] instance_name$/;
+    const re = /^error: USAGE: v8 findjsinstances \[flags\] instance_name$/;
 
     t.ok(re.test(removeBlankLines(lines)[0]),
          'findjsinstances usage message');