Merge topic 'automoc-rerun-missing-dependency'

9ac3503d30 AutoMoc: Re-run moc if a dependency is missing

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !5180

Source/cmQtAutoMocUic.cxx

@@ -192,7 +192,7 @@ public:
   {
   public:
     // -- Parse Cache
-    bool ParseCacheChanged = false;
+    std::atomic<bool> ParseCacheChanged = ATOMIC_VAR_INIT(false);
     cmFileTime ParseCacheTime;
     ParseCacheT ParseCache;
 
@@ -1777,16 +1777,24 @@ bool cmQtAutoMocUicT::JobProbeDepsMocT::Probe(MappingT const& mapping,
   {
     // Check dependency timestamps
     std::string const sourceDir = SubDirPrefix(sourceFile);
-    for (std::string const& dep : mapping.SourceFile->ParseData->Moc.Depends) {
+    auto& dependencies = mapping.SourceFile->ParseData->Moc.Depends;
+    for (auto it = dependencies.begin(); it != dependencies.end(); ++it) {
+      auto& dep = *it;
+
       // Find dependency file
       auto const depMatch = FindDependency(sourceDir, dep);
       if (depMatch.first.empty()) {
-        Log().Warning(GenT::MOC,
-                      cmStrCat(MessagePath(sourceFile), " depends on ",
-                               MessagePath(dep),
-                               " but the file does not exist."));
-        continue;
+        if (reason != nullptr) {
+          *reason =
+            cmStrCat("Generating ", MessagePath(outputFile), " from ",
+                     MessagePath(sourceFile), ", because its dependency ",
+                     MessagePath(dep), " vanished.");
+        }
+        dependencies.erase(it);
+        BaseEval().ParseCacheChanged = true;
+        return true;
       }
+
       // Test if dependency file is older
       if (outputFileTime.Older(depMatch.second)) {
         if (reason != nullptr) {

Tests/QtAutogen/RerunMocOnMissingDependency/CMakeLists.txt

@@ -0,0 +1,80 @@
+# This test checks whether a missing dependency of the moc output triggers an AUTOMOC re-run.
+
+cmake_minimum_required(VERSION 3.10)
+project(RerunMocOnMissingDependency)
+include("../AutogenCoreTest.cmake")
+
+# Create an executable to generate a clean target
+set(main_source "${CMAKE_CURRENT_BINARY_DIR}/generated_main.cpp")
+file(WRITE "${main_source}" "int main() {}")
+add_executable(exe "${main_source}")
+
+# Utility variables
+set(testProjectTemplateDir "${CMAKE_CURRENT_SOURCE_DIR}/MocOnMissingDependency")
+set(testProjectSrc "${CMAKE_CURRENT_BINARY_DIR}/MocOnMissingDependency")
+set(testProjectBinDir "${CMAKE_CURRENT_BINARY_DIR}/MocOnMissingDependency-build")
+if(DEFINED Qt5Core_VERSION AND Qt5Core_VERSION VERSION_GREATER_EQUAL "5.15.0")
+    set(moc_depfiles_supported TRUE)
+else()
+    set(moc_depfiles_supported FALSE)
+endif()
+
+# Utility macros
+macro(sleep)
+  message(STATUS "Sleeping for a few seconds.")
+  execute_process(COMMAND "${CMAKE_COMMAND}" -E sleep 1)
+endmacro()
+
+macro(rebuild buildName)
+  message(STATUS "Starting build ${buildName}.")
+  execute_process(COMMAND "${CMAKE_COMMAND}" --build . WORKING_DIRECTORY "${testProjectBinDir}"
+      RESULT_VARIABLE result OUTPUT_VARIABLE output)
+  if (result)
+    message(FATAL_ERROR "Build ${buildName} failed.")
+  else()
+    message(STATUS "Build ${buildName} finished.")
+  endif()
+endmacro()
+
+# Create the test project from the template
+file(COPY "${testProjectTemplateDir}" DESTINATION "${CMAKE_CURRENT_BINARY_DIR}")
+configure_file("${testProjectTemplateDir}/CMakeLists.txt.in" "${testProjectSrc}/CMakeLists.txt" @ONLY)
+
+# Initial build
+file(REMOVE_RECURSE "${testProjectBinDir}")
+try_compile(MOC_RERUN
+  "${testProjectBinDir}"
+  "${testProjectSrc}"
+  MocOnMissingDependency
+  CMAKE_FLAGS "-DQT_TEST_VERSION=${QT_TEST_VERSION}"
+              "-DCMAKE_AUTOGEN_VERBOSE=ON"
+              "-DQT_QMAKE_EXECUTABLE:FILEPATH=${QT_QMAKE_EXECUTABLE}"
+  OUTPUT_VARIABLE output
+)
+if (NOT MOC_RERUN)
+  message(FATAL_ERROR "Initial build of mocOnMissingDependency failed. Output: ${output}")
+endif()
+
+# Sleep to ensure new timestamps
+sleep()
+
+if(moc_depfiles_supported)
+    # Remove the dependency inc1/foo.h and build again.
+    # We expect that the moc_XXX.cpp file gets re-generated. But only if we have depfile support.
+    file(REMOVE_RECURSE "${testProjectSrc}/inc1")
+    rebuild(2)
+    if(NOT output MATCHES "AutoMoc: Generating \"[^\"]*moc_myobject.cpp\"")
+        message(FATAL_ERROR "moc_myobject.cpp was not re-generated "
+            "after removing one of its dependencies")
+    endif()
+endif()
+
+# Sleep to ensure new timestamps
+sleep()
+
+# The next build should *not* re-renerate any moc outputs
+rebuild(3)
+if(output MATCHES "AutoMoc: Generating")
+    message(FATAL_ERROR "moc_myobject.cpp was not re-generated "
+        "after removing one of its dependencies")
+endif()

Tests/QtAutogen/RerunMocOnMissingDependency/MocOnMissingDependency/CMakeLists.txt.in

@@ -0,0 +1,7 @@
+cmake_minimum_required(VERSION 3.18)
+project(MocOnMissingDependency)
+include("@CMAKE_CURRENT_LIST_DIR@/../AutogenCoreTest.cmake")
+set(CMAKE_AUTOMOC ON)
+add_executable(MocOnMissingDependency main.cpp myobject.cpp)
+target_include_directories(MocOnMissingDependency PRIVATE inc1 inc2)
+target_link_libraries(MocOnMissingDependency PRIVATE ${QT_QTCORE_TARGET})

Tests/QtAutogen/RerunMocOnMissingDependency/MocOnMissingDependency/inc1/foo.h

@@ -0,0 +1,2 @@
+
+#include <qobject.h>

Tests/QtAutogen/RerunMocOnMissingDependency/MocOnMissingDependency/inc2/foo.h

@@ -0,0 +1,2 @@
+
+#include <qobject.h>

Tests/QtAutogen/RerunMocOnMissingDependency/MocOnMissingDependency/main.cpp

@@ -0,0 +1,9 @@
+#include <iostream>
+
+#include "myobject.h"
+
+int main(int argc, char* argv[])
+{
+  MyObject obj;
+  return 0;
+}

Tests/QtAutogen/RerunMocOnMissingDependency/MocOnMissingDependency/myobject.cpp

@@ -0,0 +1,6 @@
+#include "myobject.h"
+
+MyObject::MyObject(QObject* parent)
+  : QObject(parent)
+{
+}

Tests/QtAutogen/RerunMocOnMissingDependency/MocOnMissingDependency/myobject.h

@@ -0,0 +1,10 @@
+#pragma once
+
+#include <foo.h>
+
+class MyObject : public QObject
+{
+  Q_OBJECT
+public:
+  MyObject(QObject* parent = 0);
+};

Tests/QtAutogen/Tests.cmake

@@ -21,6 +21,7 @@ ADD_AUTOGEN_TEST(RccOnly rccOnly)
 ADD_AUTOGEN_TEST(RccSkipSource)
 ADD_AUTOGEN_TEST(RerunMocBasic)
 ADD_AUTOGEN_TEST(RerunMocOnAddFile)
+ADD_AUTOGEN_TEST(RerunMocOnMissingDependency)
 ADD_AUTOGEN_TEST(RerunRccConfigChange)
 ADD_AUTOGEN_TEST(RerunRccDepends)
 ADD_AUTOGEN_TEST(SameName sameName)