instrumentation: Add preBuild and postBuild hooks for ninja

Allows instrumentation indexing and callbacks to occur at the start or end of
every `ninja` invocation.

Help/manual/cmake-instrumentation.7.rst

@@ -117,8 +117,10 @@ optional.
   should be one of the following:
 
   * ``postGenerate``
-  * ``preCMakeBuild``
+  * ``preBuild`` (:ref:`Ninja Generators`. only, when ``ninja`` is invoked)
-  * ``postCMakeBuild``
+  * ``postBuild`` (:ref:`Ninja Generators`. only, when ``ninja`` completes)
+  * ``preCMakeBuild`` (when ``cmake --build`` is invoked)
+  * ``postCMakeBuild`` (when ``cmake --build`` completes)
   * ``postInstall``
   * ``postTest``
 

Source/cmGlobalNinjaGenerator.cxx

@@ -32,6 +32,7 @@
 #include "cmGeneratedFileStream.h"
 #include "cmGeneratorTarget.h"
 #include "cmGlobalGenerator.h"
+#include "cmInstrumentation.h"
 #include "cmLinkLineComputer.h"
 #include "cmList.h"
 #include "cmListFileCache.h"
@@ -1761,6 +1762,13 @@ void cmGlobalNinjaGenerator::WriteBuiltinTargets(std::ostream& os)
   this->WriteTargetRebuildManifest(os);
   this->WriteTargetClean(os);
   this->WriteTargetHelp(os);
+#if !defined(CMAKE_BOOTSTRAP)
+  if (this->GetCMakeInstance()
+        ->GetInstrumentation()
+        ->HasPreOrPostBuildHook()) {
+    this->WriteTargetInstrument(os);
+  }
+#endif
 
   for (std::string const& config : this->GetConfigNames()) {
     this->WriteTargetDefault(*this->GetConfigFileStream(config));
@@ -1835,6 +1843,14 @@ void cmGlobalNinjaGenerator::WriteTargetRebuildManifest(std::ostream& os)
   }
   reBuild.ImplicitDeps.push_back(this->CMakeCacheFile);
 
+#if !defined(CMAKE_BOOTSTRAP)
+  if (this->GetCMakeInstance()
+        ->GetInstrumentation()
+        ->HasPreOrPostBuildHook()) {
+    reBuild.ExplicitDeps.push_back(this->NinjaOutputPath("start_instrument"));
+  }
+#endif
+
   // Use 'console' pool to get non buffered output of the CMake re-run call
   // Available since Ninja 1.5
   if (this->SupportsDirectConsole()) {
@@ -2180,6 +2196,42 @@ void cmGlobalNinjaGenerator::WriteTargetHelp(std::ostream& os)
   }
 }
 
+void cmGlobalNinjaGenerator::WriteTargetInstrument(std::ostream& os)
+{
+  // Write rule
+  {
+    cmNinjaRule rule("START_INSTRUMENT");
+    rule.Command = cmStrCat(
+      "\"", cmSystemTools::GetCTestCommand(), "\" --start-instrumentation \"",
+      this->GetCMakeInstance()->GetHomeOutputDirectory(), "\"");
+#ifndef _WIN32
+    /*
+     * On Unix systems, Ninja will prefix the command with `/bin/sh -c`.
+     * Use exec so that Ninja is the parent process of the command.
+     */
+    rule.Command = cmStrCat("exec ", rule.Command);
+#endif
+    rule.Description = "Collecting build metrics";
+    rule.Comment = "Rule to initialize instrumentation daemon.";
+    rule.Restat = "1";
+    WriteRule(*this->RulesFileStream, rule);
+  }
+
+  // Write build
+  {
+    cmNinjaBuild phony("phony");
+    phony.Comment = "Phony target to keep START_INSTRUMENTATION out of date.";
+    phony.Outputs.push_back(this->NinjaOutputPath("CMakeFiles/instrument"));
+    cmNinjaBuild instrument("START_INSTRUMENT");
+    instrument.Comment = "Start instrumentation daemon.";
+    instrument.Outputs.push_back(this->NinjaOutputPath("start_instrument"));
+    instrument.ExplicitDeps.push_back(
+      this->NinjaOutputPath("CMakeFiles/instrument"));
+    WriteBuild(os, phony);
+    WriteBuild(os, instrument);
+  }
+}
+
 void cmGlobalNinjaGenerator::InitOutputPathPrefix()
 {
   this->OutputPathPrefix =

Source/cmGlobalNinjaGenerator.h

@@ -536,6 +536,7 @@ private:
   void WriteTargetRebuildManifest(std::ostream& os);
   bool WriteTargetCleanAdditional(std::ostream& os);
   void WriteTargetClean(std::ostream& os);
+  void WriteTargetInstrument(std::ostream& os);
   void WriteTargetHelp(std::ostream& os);
 
   void ComputeTargetDependsClosure(

Source/cmInstrumentation.cxx

@@ -11,6 +11,7 @@
 #include <cm/optional>
 
 #include <cm3p/json/writer.h>
+#include <cm3p/uv.h>
 
 #include "cmsys/Directory.hxx"
 #include "cmsys/FStream.hxx"
@@ -22,6 +23,7 @@
 #include "cmStringAlgorithms.h"
 #include "cmSystemTools.h"
 #include "cmTimestamp.h"
+#include "cmUVProcessChain.h"
 
 cmInstrumentation::cmInstrumentation(std::string const& binary_dir)
 {
@@ -485,3 +487,46 @@ std::string cmInstrumentation::ComputeSuffixTime()
      << std::setfill('0') << std::setw(4) << tms;
   return ss.str();
 }
+
+/*
+ * Called by ctest --start-instrumentation as part of the START_INSTRUMENTATION
+ * rule when using the Ninja generator.
+ * This creates a detached process which waits for the Ninja process to die
+ * before running the postBuild hook. In this way, the postBuild hook triggers
+ * after every ninja invocation, regardless of whether the build passed or
+ * failed.
+ */
+int cmInstrumentation::SpawnBuildDaemon()
+{
+  // preBuild Hook
+  this->CollectTimingData(cmInstrumentationQuery::Hook::PreBuild);
+
+  // postBuild Hook
+  if (this->HasHook(cmInstrumentationQuery::Hook::PostBuild)) {
+    auto ninja_pid = uv_os_getppid();
+    if (ninja_pid) {
+      std::vector<std::string> args;
+      args.push_back(cmSystemTools::GetCTestCommand());
+      args.push_back("--wait-and-collect-instrumentation");
+      args.push_back(this->binaryDir);
+      args.push_back(std::to_string(ninja_pid));
+      auto builder = cmUVProcessChainBuilder().SetDetached().AddCommand(args);
+      auto chain = builder.Start();
+      uv_run(&chain.GetLoop(), UV_RUN_DEFAULT);
+    }
+  }
+  return 0;
+}
+
+/*
+ * Always called by ctest --wait-and-collect-instrumentation in a detached
+ * process. Waits for the given PID to end before running the postBuild hook.
+ *
+ * See SpawnBuildDaemon()
+ */
+int cmInstrumentation::CollectTimingAfterBuild(int ppid)
+{
+  while (0 == uv_kill(ppid, 0)) {
+  };
+  return this->CollectTimingData(cmInstrumentationQuery::Hook::PostBuild);
+}

Source/cmInstrumentation.h

@@ -46,6 +46,8 @@ public:
                       std::string& callback);
   void ClearGeneratedQueries();
   int CollectTimingData(cmInstrumentationQuery::Hook hook);
+  int SpawnBuildDaemon();
+  int CollectTimingAfterBuild(int ppid);
   std::string errorMsg;
 
 private:

Source/ctest.cxx

@@ -189,6 +189,18 @@ int main(int argc, char const* const* argv)
     return cmCTestLaunch::Main(argc, argv, cmCTestLaunch::Op::Instrument);
   }
 
+  // Dispatch post-build instrumentation daemon for ninja
+  if (argc == 3 && strcmp(argv[1], "--start-instrumentation") == 0) {
+    return cmInstrumentation(argv[2]).SpawnBuildDaemon();
+  }
+
+  // Dispatch 'ctest --collect-instrumentation' once given PID finishes
+  if (argc == 4 &&
+      strcmp(argv[1], "--wait-and-collect-instrumentation") == 0) {
+    return cmInstrumentation(argv[2]).CollectTimingAfterBuild(
+      std::stoi(argv[3]));
+  }
+
   // Dispatch 'ctest --collect-instrumentation' mode directly.
   if (argc == 3 && strcmp(argv[1], "--collect-instrumentation") == 0) {
     return cmInstrumentation(argv[2]).CollectTimingData(

Tests/RunCMake/Instrumentation/RunCMakeTest.cmake

@@ -6,7 +6,7 @@ function(instrument test)
   set(config "${CMAKE_CURRENT_LIST_DIR}/config")
   set(ENV{CMAKE_CONFIG_DIR} ${config})
   cmake_parse_arguments(ARGS
-    "BUILD;INSTALL;TEST;COPY_QUERIES;NO_WARN;STATIC_QUERY;DYNAMIC_QUERY;INSTALL_PARALLEL;MANUAL_HOOK"
+    "BUILD;BUILD_MAKE_PROGRAM;INSTALL;TEST;COPY_QUERIES;NO_WARN;STATIC_QUERY;DYNAMIC_QUERY;INSTALL_PARALLEL;MANUAL_HOOK"
     "CHECK_SCRIPT;CONFIGURE_ARG" "" ${ARGN})
   set(RunCMake_TEST_BINARY_DIR ${RunCMake_BINARY_DIR}/${test})
   set(uuid "a37d1069-1972-4901-b9c9-f194aaf2b6e0")
@@ -58,6 +58,9 @@ function(instrument test)
   if (ARGS_BUILD)
     run_cmake_command(${test}-build ${CMAKE_COMMAND} --build . --config Debug)
   endif()
+  if (ARGS_BUILD_MAKE_PROGRAM)
+    run_cmake_command(${test}-make-program ${RunCMake_MAKE_PROGRAM})
+  endif()
   if (ARGS_INSTALL)
     run_cmake_command(${test}-install ${CMAKE_COMMAND} --install . --prefix install --config Debug)
   endif()
@@ -112,3 +115,8 @@ instrument(cmake-command-bad-arg NO_WARN)
 instrument(cmake-command-parallel-install
   BUILD INSTALL TEST NO_WARN INSTALL_PARALLEL DYNAMIC_QUERY
   CHECK_SCRIPT check-data-dir.cmake)
+if (UNIX AND ${RunCMake_GENERATOR} MATCHES "^Ninja")
+  instrument(cmake-command-ninja NO_WARN
+    BUILD_MAKE_PROGRAM
+    CHECK_SCRIPT check-ninja-hooks.cmake)
+endif()

Tests/RunCMake/Instrumentation/check-ninja-hooks.cmake

@@ -0,0 +1,35 @@
+set(NUM_TRIES 30)
+set(DELAY 1)
+
+if (NOT EXISTS ${v1}/preBuild.hook)
+  set(RunCMake_TEST_FAILED "preBuild hook did not run\n")
+endif()
+
+macro(hasPostBuildArtifacts)
+  if (NOT postBuildRan AND EXISTS ${v1}/postBuild.hook)
+    set(postBuildRan 1)
+  endif()
+  if (NOT dataDirClean)
+    file(GLOB snippets "${v1}/data/*")
+    if ("${snippets}" STREQUAL "")
+      set(dataDirClean 1)
+    endif()
+  endif()
+endmacro()
+
+set(postBuildRan 0)
+set(dataDirClean 0)
+foreach(_ RANGE ${NUM_TRIES})
+  hasPostBuildArtifacts()
+  if (postBuildRan AND dataDirClean)
+    break()
+  endif()
+  execute_process(COMMAND ${CMAKE_COMMAND} -E sleep ${DELAY})
+endforeach()
+
+if (NOT postBuildRan)
+  string(APPEND RunCMake_TEST_FAILED "postBuild hook did not run\n")
+endif()
+if (NOT dataDirClean)
+  string(APPEND RunCMake_TEST_FAILED "Snippet files not fully removed post build\n")
+endif()

Tests/RunCMake/Instrumentation/hook.cmake

@@ -68,3 +68,7 @@ has_key(vendorString ${staticSystemInformation} ${hasStaticInfo})
 if (NOT ERROR_MESSAGE MATCHES "^$")
   message(FATAL_ERROR ${ERROR_MESSAGE})
 endif()
+
+get_filename_component(dataDir ${index} DIRECTORY)
+get_filename_component(v1 ${dataDir} DIRECTORY)
+file(TOUCH ${v1}/${hook}.hook)

Tests/RunCMake/Instrumentation/query/cmake-command-ninja.cmake

@@ -0,0 +1,6 @@
+cmake_instrumentation(
+  API_VERSION 1
+  DATA_VERSION 1
+  HOOKS preBuild postBuild
+  CALLBACK "\"${CMAKE_COMMAND}\" -P \"${CMAKE_SOURCE_DIR}/../hook.cmake\" 0"
+)