From 5c092c2b40199ba05bc4a5bd4daed503a65d6c49 Mon Sep 17 00:00:00 2001
From: Joerg Bornemann <joerg.bornemann@qt.io>
Date: Mon, 24 Aug 2020 21:05:05 +0200
Subject: [PATCH] CMake: Implement configure -trace

Task-number: QTBUG-85373
Change-Id: Ib9ac35ec98dd5b6c272f58f8a61a124d1d262ec0
Reviewed-by: Cristian Adam <cristian.adam@qt.io>
---
 cmake/QtTargetHelpers.cmake      | 36 +++++++++++++++++++++++++++-----
 cmake/configure-cmake-mapping.md |  3 ++-
 2 files changed, 33 insertions(+), 6 deletions(-)

diff --git a/cmake/QtTargetHelpers.cmake b/cmake/QtTargetHelpers.cmake
index c79ce47363..d7a8e3c86b 100644
--- a/cmake/QtTargetHelpers.cmake
+++ b/cmake/QtTargetHelpers.cmake
@@ -326,10 +326,36 @@ function(qt_internal_export_modern_cmake_config_targets_file)
     qt_install(EXPORT ${export_name} NAMESPACE Qt:: DESTINATION "${__arg_CONFIG_INSTALL_DIR}")
 endfunction()
 
-function(qt_create_tracepoints name tracePointsFile)
-    #### TODO
-    string(TOLOWER "${name}" name)
+function(qt_create_tracepoints name tracepoints_file)
+    string(TOLOWER "${name}" provider_name)
+    string(PREPEND provider_name "qt")
+    set(header_filename "${provider_name}_tracepoints_p.h")
+    set(header_path "${CMAKE_CURRENT_BINARY_DIR}/${header_filename}")
 
-    file(GENERATE OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/qt${name}_tracepoints_p.h" CONTENT
-        "#include <private/qtrace_p.h>")
+    if(QT_FEATURE_lttng OR QT_FEATURE_etw)
+        set(source_path "${CMAKE_CURRENT_BINARY_DIR}/${provider_name}_tracepoints.cpp")
+        qt_configure_file(OUTPUT "${source_path}"
+            CONTENT "#define TRACEPOINT_CREATE_PROBES
+#define TRACEPOINT_DEFINE
+#define include \"${header_filename}\"")
+        target_sources(${name} PRIVATE "${source_path}")
+        target_compile_definitions(${name} PRIVATE Q_TRACEPOINT)
+
+        if(QT_FEATURE_lttng)
+            set(tracegen_arg "lttng")
+            target_link_libraries(${name} PRIVATE LTTng::UST)
+        elseif(QT_FEATURE_etw)
+            set(tracegen_arg "etw")
+        endif()
+
+        qt_get_tool_target_name(tracegen_target tracegen)
+        get_filename_component(tracepoints_filepath "${tracepoints_file}" ABSOLUTE)
+        add_custom_command(OUTPUT "${header_path}"
+            COMMAND ${tracegen_target} ${tracegen_arg} "${tracepoints_filepath}" "${header_path}"
+            VERBATIM)
+        add_custom_target(${name}_tracepoints_header DEPENDS "${header_path}")
+        add_dependencies(${name} ${name}_tracepoints_header)
+    else()
+        qt_configure_file(OUTPUT "${header_path}" CONTENT "#include <private/qtrace_p.h>\n")
+    endif()
 endfunction()
diff --git a/cmake/configure-cmake-mapping.md b/cmake/configure-cmake-mapping.md
index 62e4e1acd7..2f6814e283 100644
--- a/cmake/configure-cmake-mapping.md
+++ b/cmake/configure-cmake-mapping.md
@@ -50,7 +50,8 @@ The effort of this is tracked in QTBUG-85373 and QTBUG-85349.
 | -qtlibinfix <infix>                   |                                                   |                                                                 |
 | -testcocoon                           |                                                   |                                                                 |
 | -gcov                                 |                                                   |                                                                 |
-| -trace [backend]                      |                                                   |                                                                 |
+| -trace [backend]                      | -DINPUT_trace=yes or -DINPUT_trace=<backend>      |                                                                 |
+|                                       | or -DFEATURE_<backend>                            |                                                                 |
 | -sanitize <arg>                       | -DFEATURE_sanitize_<arg>                          |                                                                 |
 | -coverage <arg>                       |                                                   |                                                                 |
 | -c++std c++2a                         | -DFEATURE_cxx2a=ON                                |                                                                 |