inspector: implement --heap-prof

In addition implements --heap-prof-name, --heap-prof-dir and
--heap-prof-interval.
These flags are similar to --cpu-prof flags but they are meant
for the V8 sampling heap profiler instead of the CPU profiler.

PR-URL: https://github.com/nodejs/node/pull/27596
Fixes: https://github.com/nodejs/node/issues/27421
Reviewed-By: Jan Krems <jan.krems@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>

1 files changed, 31 insertions, 0 deletions

diff --git a/src/node_options.cc b/src/node_options.cc
index 37aefca1e4..da7a49231f 100644
--- a/src/node_options.cc
+++ b/src/node_options.cc
@@ -168,6 +168,19 @@ void EnvironmentOptions::CheckOptions(std::vector<std::string>* errors) {
     }
   }
 
+  if (!heap_prof) {
+    if (!heap_prof_name.empty()) {
+      errors->push_back("--heap-prof-name must be used with --heap-prof");
+    }
+    if (!heap_prof_dir.empty()) {
+      errors->push_back("--heap-prof-dir must be used with --heap-prof");
+    }
+    // We can't catch the case where the value passed is the default value,
+    // then the option just becomes a noop which is fine.
+    if (heap_prof_interval != kDefaultHeapProfInterval) {
+      errors->push_back("--heap-prof-interval must be used with --heap-prof");
+    }
+  }
   debug_options_.CheckOptions(errors);
 #endif  // HAVE_INSPECTOR
 }
@@ -369,6 +382,24 @@ EnvironmentOptionsParser::EnvironmentOptionsParser() {
             "Directory where the V8 profiles generated by --cpu-prof will be "
             "placed. Does not affect --prof.",
             &EnvironmentOptions::cpu_prof_dir);
+  AddOption(
+      "--heap-prof",
+      "Start the V8 heap profiler on start up, and write the heap profile "
+      "to disk before exit. If --heap-prof-dir is not specified, write "
+      "the profile to the current working directory.",
+      &EnvironmentOptions::heap_prof);
+  AddOption("--heap-prof-name",
+            "specified file name of the V8 CPU profile generated with "
+            "--heap-prof",
+            &EnvironmentOptions::heap_prof_name);
+  AddOption("--heap-prof-dir",
+            "Directory where the V8 heap profiles generated by --heap-prof "
+            "will be placed.",
+            &EnvironmentOptions::heap_prof_dir);
+  AddOption("--heap-prof-interval",
+            "specified sampling interval in bytes for the V8 heap "
+            "profile generated with --heap-prof. (default: 512 * 1024)",
+            &EnvironmentOptions::heap_prof_interval);
 #endif  // HAVE_INSPECTOR
   AddOption("--redirect-warnings",
             "write warnings to file instead of stderr",