Move the watcher helper function out of the ddprof CLI's responsibility

include/perf_watcher.hpp

@@ -161,4 +161,6 @@ int sample_type_id_to_count_sample_type_id(int idx);
 
 // Helper functions, mostly for tests
 uint64_t perf_event_default_sample_type();
-void log_watcher(const PerfWatcher *w, int idx);
+void log_watcher(const PerfWatcher *w, int idx);
+
+std::string_view watcher_help_text();

src/ddprof_cli.cc

@@ -24,48 +24,7 @@ std::string api_key_to_dbg_string(const std::string_view value) {
 } // namespace
 
 //clang-format off
-void DDProfCLI::help_events() {
-  std::cout << "\nEvent Configuration Documentation\n";
-  std::cout << "===================================\n";
-  std::cout << "Events define " MYNAME "'s instrumentation settings.\n\n";
-  std::cout << "General Syntax for Event Configuration:\n";
-  std::cout << "---------------------------------------\n";
-  std::cout << "Events are defined by their type and various parameters. The configuration follows this basic syntax:\n\n";
-  std::cout << "<type Of event> <key1>:<value1>\n";
-  std::cout << "or alternatively you can use a comma as a separator:\n";
-  std::cout << "<type Of event>,<key1>:<value1>\n\n";
-
-  std::cout << "Common Examples:\n";
-  std::cout << "----------------\n";
-  std::cout << "1. CPU profiling with a custom sampling frequency: `-e \"sCPU,p=50\"`\n";
-  std::cout << "2. Allocation tracking to monitor what's active in the application: `-e sALLOC,mode=l`\n\n";
-
-  std::cout << "Event Types:\n";
-  std::cout << "------------\n";
-  std::cout << "Please consult the `perf_watcher.hpp` file for a comprehensive list of available events. \n";
-  std::cout << "Note: Some events may require hardware support and elevated permissions.\n\n";
-
-  std::cout << "Configuration Keys:\n";
-  std::cout << "-------------------\n";
-  std::cout << "- `s|value_scale|scale`: Scaling factor for the event.\n";
-  std::cout << "- `f|frequency|freq`: Frequency at which the event occurs.\n";
-  std::cout << "- `e|event|eventname|ev`: Name of the event.\n";
-  std::cout << "- `g|group|groupname|gr`: Name of the group to which the event belongs.\n";
-  std::cout << "- `i|id`: Identifier for the event.\n";
-  std::cout << "- `l|label`: Label for the event.\n";
-  std::cout << "- `m|mode`: Mode of the event.\n";
-  std::cout << "- `n|arg_num|argno`: Argument number of the event.\n";
-  std::cout << "- `o|raw_offset|rawoff`: Raw offset of the event.\n";
-  std::cout << "- `p|period|per`: Period of the event.\n";
-  std::cout << "- `r|register|regno`: Register number of the event.\n";
-  std::cout << "- `z|raw_size|rawsz`: Raw size of the event.\n\n";
-
-  std::cout << "Disclaimer:\n";
-  std::cout << "-----------\n";
-  std::cout << "Please note that this documentation is currently under construction. We recommend the use of presets.\n";
-  std::cout << "Not all options may be fully supported within the Datadog UI at present, and the described grammar is subject to change.\n";
-  std::cout << "Exercise caution and double-check your configurations before implementation.\n";
-}
+void DDProfCLI::help_events() { std::cout << watcher_help_text(); }
 //clang-format on
 
 int DDProfCLI::parse(int argc, const char *argv[]) {

src/perf_watcher.cc

@@ -140,3 +140,51 @@ void log_watcher(const PerfWatcher *w, int idx) {
   if (Any(EventConfMode::kLiveCallgraph & w->output_mode))
     PRINT_NFO("    Outputting to live callgraph");
 }
+
+std::string_view watcher_help_text() {
+  static const std::string help_text =
+      // clang-format off
+      "\nEvent Configuration Documentation\n"
+"===================================\n"
+"Events define " + std::string(MYNAME) + "'s instrumentation settings.\n\n"
+"General Syntax for Event Configuration:\n"
+"---------------------------------------\n"
+"Events are defined by their type and associated key value settings:\n\n"
+"<type Of event> <key1>:<value1>\n"
+"Or using comma as a separator: \n"
+"<type Of event>,<key1>:<value1>\n"
+"Events are repeatable\n\n"
+"Common Examples:\n"
+"----------------\n"
+"1. CPU profiling with a custom sampling frequency: -e \"sCPU p=50\"\n"
+"2. Live Allocation Tracking (leak detection):\n"
+"  -e sALLOC,mode=l\n\n"
+"Event Types:\n"
+"------------\n"
+"The most common types are:\n"
+"- sCPU for CPU Time \n"
+"- sALLOC for allocations (only available in wrapper mode) \n"
+"Please consult the `https://github.com/DataDog/ddprof/blob/main/include/perf_watcher.hpp#L117-L138` for an up to date list of available events. \n"
+"Note: Some events may require hardware support and elevated permissions.\n\n"
+"Configuration Keys:\n"
+"-------------------\n"
+"- `s|value_scale|scale`: Scaling factor for the event.\n"
+"- `f|frequency|freq`: Frequency at which the event occurs.\n"
+"- `e|event|eventname|ev`: Name of the event.\n"
+"- `g|group|groupname|gr`: Name of the group to which the event belongs.\n"
+"- `i|id`: Identifier for the event.\n"
+"- `l|label`: Label for the event.\n"
+"- `m|mode`: Mode of the event.\n"
+"- `n|arg_num|argno`: Argument number to retrieve a value associated with this event.\n"
+"- `p|period|per`: Period of the event.\n"
+"- `r|register|regno`: Register to retrieve the value associated with this event.\n"
+"- `o|raw_offset|rawoff`: Raw offset to retrieve the value associated with this event.\n"
+"- `z|raw_size|rawsz`: Raw size associated to raw offset.\n\n"
+"Disclaimer:\n"
+"-----------\n"
+"Please note that this documentation is currently under construction. We recommend the use of presets.\n"
+"Not all options may be fully supported within the Datadog UI at present, and the described grammar is subject to change.\n"
+"Exercise caution and double-check your configurations before implementation.\n";
+  // clang-format on
+  return help_text;
+}