AUTOUIC: Fix generating of dependency rules for UI header files

We could not rely on .ui files when generating the ninja rules
for the generated UI header files. .ui files might be added to the
target sources but never processed by AUTOUIC afterward, since UI
header files are never included in a source code. Instead of adding
dependency rules based on the .ui files, this approach scans
non-generated source files for includes of the UI header files,
as AUTOUIC does. This gives the consistent set of UI header files
at configure time, that could be used to generate byproducts rules
for the AUTOUIC. Also, the path to the generated UI header file depends
not on the .ui file location but on the include line is used in source
files.

Fixes: #16776

15 files changed, 144 insertions, 83 deletions

diff --git a/Source/CMakeLists.txt b/Source/CMakeLists.txt
index 9a18184fd3..0142c07ecb 100644
--- a/Source/CMakeLists.txt
+++ b/Source/CMakeLists.txt
@@ -432,6 +432,8 @@ set(SRCS
   cmQtAutoMocUic.h
   cmQtAutoRcc.cxx
   cmQtAutoRcc.h
+  cmQtAutoUicHelpers.cxx
+  cmQtAutoUicHelpers.h
   cmRST.cxx
   cmRST.h
   cmRuntimeDependencyArchive.cxx
diff --git a/Source/cmQtAutoGen.cxx b/Source/cmQtAutoGen.cxx
index 57fcd2da76..898d862221 100644
--- a/Source/cmQtAutoGen.cxx
+++ b/Source/cmQtAutoGen.cxx
@@ -384,3 +384,39 @@ bool cmQtAutoGen::RccLister::list(std::string const& qrcFile,
   }
   return true;
 }
+
+bool cmQtAutoGen::FileRead(std::string& content, std::string const& filename,
+                           std::string* error)
+{
+  content.clear();
+  if (!cmSystemTools::FileExists(filename, true)) {
+    if (error != nullptr) {
+      *error = "Not a file.";
+    }
+    return false;
+  }
+
+  unsigned long const length = cmSystemTools::FileLength(filename);
+  cmsys::ifstream ifs(filename.c_str(), (std::ios::in | std::ios::binary));
+
+  // Use lambda to save destructor calls of ifs
+  return [&ifs, length, &content, error]() -> bool {
+    if (!ifs) {
+      if (error != nullptr) {
+        *error = "Opening the file for reading failed.";
+      }
+      return false;
+    }
+    content.reserve(length);
+    using IsIt = std::istreambuf_iterator<char>;
+    content.assign(IsIt{ ifs }, IsIt{});
+    if (!ifs) {
+      content.clear();
+      if (error != nullptr) {
+        *error = "Reading from the file failed.";
+      }
+      return false;
+    }
+    return true;
+  }();
+}
diff --git a/Source/cmQtAutoGen.h b/Source/cmQtAutoGen.h
index 466a954a98..b9ae360291 100644
--- a/Source/cmQtAutoGen.h
+++ b/Source/cmQtAutoGen.h
@@ -100,6 +100,9 @@ public:
                               std::vector<std::string> const& newOpts,
                               bool isQt5);
 
+  static bool FileRead(std::string& content, std::string const& filename,
+                       std::string* error = nullptr);
+
   /** @class RccLister
    * @brief Lists files in qrc resource files
    */
diff --git a/Source/cmQtAutoGenInitializer.cxx b/Source/cmQtAutoGenInitializer.cxx
index 2894201c9b..9d8086397c 100644
--- a/Source/cmQtAutoGenInitializer.cxx
+++ b/Source/cmQtAutoGenInitializer.cxx
@@ -902,6 +902,13 @@ bool cmQtAutoGenInitializer::InitScanFiles()
   // The reason is that their file names might be discovered from source files
   // at generation time.
   if (this->MocOrUicEnabled()) {
+    std::set<std::string> uicIncludes;
+    auto collectUicIncludes = [&](std::unique_ptr<cmSourceFile> const& sf) {
+      std::string content;
+      FileRead(content, sf->GetFullPath());
+      this->AutoUicHelpers.CollectUicIncludes(uicIncludes, content);
+    };
+
     for (const auto& sf : this->Makefile->GetSourceFiles()) {
       // sf->GetExtension() is only valid after sf->ResolveFullPath() ...
       // Since we're iterating over source files that might be not in the
@@ -914,6 +921,10 @@ bool cmQtAutoGenInitializer::InitScanFiles()
       std::string const& extLower =
         cmSystemTools::LowerCase(sf->GetExtension());
 
+      bool const skipAutogen = sf->GetPropertyAsBool(kw.SKIP_AUTOGEN);
+      bool const skipUic =
+        (skipAutogen || sf->GetPropertyAsBool(kw.SKIP_AUTOUIC) ||
+         !this->Uic.Enabled);
       if (cm->IsAHeaderExtension(extLower)) {
         if (!cm::contains(this->AutogenTarget.Headers, sf.get())) {
           auto muf = makeMUFile(sf.get(), fullPath, {}, false);
@@ -921,6 +932,9 @@ bool cmQtAutoGenInitializer::InitScanFiles()
             addMUHeader(std::move(muf), extLower);
           }
         }
+        if (!skipUic && !sf->GetIsGenerated()) {
+          collectUicIncludes(sf);
+        }
       } else if (cm->IsACLikeSourceExtension(extLower)) {
         if (!cm::contains(this->AutogenTarget.Sources, sf.get())) {
           auto muf = makeMUFile(sf.get(), fullPath, {}, false);
@@ -928,11 +942,11 @@ bool cmQtAutoGenInitializer::InitScanFiles()
             addMUSource(std::move(muf));
           }
         }
+        if (!skipUic && !sf->GetIsGenerated()) {
+          collectUicIncludes(sf);
+        }
       } else if (this->Uic.Enabled && (extLower == kw.ui)) {
         // .ui file
-        bool const skipAutogen = sf->GetPropertyAsBool(kw.SKIP_AUTOGEN);
-        bool const skipUic =
-          (skipAutogen || sf->GetPropertyAsBool(kw.SKIP_AUTOUIC));
         if (!skipUic) {
           // Check if the .ui file has uic options
           std::string const uicOpts = sf->GetSafeProperty(kw.AUTOUIC_OPTIONS);
@@ -942,35 +956,22 @@ bool cmQtAutoGenInitializer::InitScanFiles()
             this->Uic.UiFilesWithOptions.emplace_back(fullPath,
                                                       cmExpandedList(uicOpts));
           }
-
-          auto uiHeaderRelativePath = cmSystemTools::RelativePath(
-            this->LocalGen->GetCurrentSourceDirectory(),
-            cmSystemTools::GetFilenamePath(fullPath));
-
-          // Avoid creating a path containing adjacent slashes
-          if (!uiHeaderRelativePath.empty() &&
-              uiHeaderRelativePath.back() != '/') {
-            uiHeaderRelativePath += '/';
-          }
-
-          auto uiHeaderFilePath = cmStrCat(
-            '/', uiHeaderRelativePath, "ui_"_s,
-            cmSystemTools::GetFilenameWithoutLastExtension(fullPath), ".h"_s);
-
-          ConfigString uiHeader;
-          std::string uiHeaderGenex;
-          this->ConfigFileNamesAndGenex(
-            uiHeader, uiHeaderGenex, cmStrCat(this->Dir.Build, "/include"_s),
-            uiHeaderFilePath);
-
-          this->Uic.UiHeaders.emplace_back(
-            std::make_pair(uiHeader, uiHeaderGenex));
         } else {
           // Register skipped .ui file
           this->Uic.SkipUi.insert(fullPath);
         }
       }
     }
+
+    for (const auto& include : uicIncludes) {
+      ConfigString uiHeader;
+      std::string uiHeaderGenex;
+      this->ConfigFileNamesAndGenex(uiHeader, uiHeaderGenex,
+                                    cmStrCat(this->Dir.Build, "/include"_s),
+                                    cmStrCat("/"_s, include));
+      this->Uic.UiHeaders.emplace_back(
+        std::make_pair(uiHeader, uiHeaderGenex));
+    }
   }
 
   // Process GENERATED sources and headers
diff --git a/Source/cmQtAutoGenInitializer.h b/Source/cmQtAutoGenInitializer.h
index e76817b9c4..3ec87d212d 100644
--- a/Source/cmQtAutoGenInitializer.h
+++ b/Source/cmQtAutoGenInitializer.h
@@ -17,6 +17,7 @@
 
 #include "cmFilePathChecksum.h"
 #include "cmQtAutoGen.h"
+#include "cmQtAutoUicHelpers.h"
 
 class cmGeneratorTarget;
 class cmGlobalGenerator;
@@ -170,6 +171,7 @@ private:
   std::string ConfigDefault;
   std::vector<std::string> ConfigsList;
   std::string TargetsFolder;
+  cmQtAutoUicHelpers AutoUicHelpers;
 
   /** Common directories.  */
   struct
diff --git a/Source/cmQtAutoGenerator.cxx b/Source/cmQtAutoGenerator.cxx
index 568926e3c5..0c6b5e6dc5 100644
--- a/Source/cmQtAutoGenerator.cxx
+++ b/Source/cmQtAutoGenerator.cxx
@@ -121,43 +121,6 @@ bool cmQtAutoGenerator::MakeParentDirectory(std::string const& filename)
   return success;
 }
 
-bool cmQtAutoGenerator::FileRead(std::string& content,
-                                 std::string const& filename,
-                                 std::string* error)
-{
-  content.clear();
-  if (!cmSystemTools::FileExists(filename, true)) {
-    if (error != nullptr) {
-      *error = "Not a file.";
-    }
-    return false;
-  }
-
-  unsigned long const length = cmSystemTools::FileLength(filename);
-  cmsys::ifstream ifs(filename.c_str(), (std::ios::in | std::ios::binary));
-
-  // Use lambda to save destructor calls of ifs
-  return [&ifs, length, &content, error]() -> bool {
-    if (!ifs) {
-      if (error != nullptr) {
-        *error = "Opening the file for reading failed.";
-      }
-      return false;
-    }
-    content.reserve(length);
-    using IsIt = std::istreambuf_iterator<char>;
-    content.assign(IsIt{ ifs }, IsIt{});
-    if (!ifs) {
-      content.clear();
-      if (error != nullptr) {
-        *error = "Reading from the file failed.";
-      }
-      return false;
-    }
-    return true;
-  }();
-}
-
 bool cmQtAutoGenerator::FileWrite(std::string const& filename,
                                   std::string const& content,
                                   std::string* error)
diff --git a/Source/cmQtAutoGenerator.h b/Source/cmQtAutoGenerator.h
index 5c3a8adccb..66399d7e8a 100644
--- a/Source/cmQtAutoGenerator.h
+++ b/Source/cmQtAutoGenerator.h
@@ -70,8 +70,6 @@ public:
 
   // -- File system methods
   static bool MakeParentDirectory(std::string const& filename);
-  static bool FileRead(std::string& content, std::string const& filename,
-                       std::string* error = nullptr);
   static bool FileWrite(std::string const& filename,
                         std::string const& content,
                         std::string* error = nullptr);
diff --git a/Source/cmQtAutoMocUic.cxx b/Source/cmQtAutoMocUic.cxx
index 2753fd57c0..86d54f9e1a 100644
--- a/Source/cmQtAutoMocUic.cxx
+++ b/Source/cmQtAutoMocUic.cxx
@@ -30,6 +30,7 @@
 #include "cmGeneratedFileStream.h"
 #include "cmQtAutoGen.h"
 #include "cmQtAutoGenerator.h"
+#include "cmQtAutoUicHelpers.h"
 #include "cmStringAlgorithms.h"
 #include "cmSystemTools.h"
 #include "cmWorkerPool.h"
@@ -281,7 +282,7 @@ public:
     std::vector<std::string> Options;
     std::unordered_map<std::string, UiFile> UiFiles;
     std::vector<std::string> SearchPaths;
-    cmsys::RegularExpression RegExpInclude;
+    cmQtAutoUicHelpers AutoUicHelpers;
   };
 
   /** Uic shared variables.  */
@@ -761,11 +762,7 @@ std::string cmQtAutoMocUicT::MocSettingsT::MacrosString() const
   return res;
 }
 
-cmQtAutoMocUicT::UicSettingsT::UicSettingsT()
-{
-  this->RegExpInclude.compile("(^|\n)[ \t]*#[ \t]*include[ \t]+"
-                              "[\"<](([^ \">]+/)?ui_[^ \">/]+\\.h)[\">]");
-}
+cmQtAutoMocUicT::UicSettingsT::UicSettingsT() = default;
 
 cmQtAutoMocUicT::UicSettingsT::~UicSettingsT() = default;
 
@@ -1056,16 +1053,7 @@ void cmQtAutoMocUicT::JobParseT::UicIncludes()
   }
 
   std::set<std::string> includes;
-  {
-    const char* contentChars = this->Content.c_str();
-    cmsys::RegularExpression const& regExp = this->UicConst().RegExpInclude;
-    cmsys::RegularExpressionMatch match;
-    while (regExp.find(contentChars, match)) {
-      includes.emplace(match.match(2));
-      // Forward content pointer
-      contentChars += match.end();
-    }
-  }
+  this->UicConst().AutoUicHelpers.CollectUicIncludes(includes, this->Content);
   this->CreateKeys(this->FileHandle->ParseData->Uic.Include, includes,
                    UiUnderscoreLength);
 }
diff --git a/Source/cmQtAutoUicHelpers.cxx b/Source/cmQtAutoUicHelpers.cxx
new file mode 100644
index 0000000000..751ae08575
--- /dev/null
+++ b/Source/cmQtAutoUicHelpers.cxx
@@ -0,0 +1,25 @@
+/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+   file Copyright.txt or https://cmake.org/licensing for details.  */
+#include "cmQtAutoUicHelpers.h"
+
+cmQtAutoUicHelpers::cmQtAutoUicHelpers()
+{
+  RegExpInclude.compile("(^|\n)[ \t]*#[ \t]*include[ \t]+"
+                        "[\"<](([^ \">]+/)?ui_[^ \">/]+\\.h)[\">]");
+}
+
+void cmQtAutoUicHelpers::CollectUicIncludes(std::set<std::string>& includes,
+                                            const std::string& content) const
+{
+  if (content.find("ui_") == std::string::npos) {
+    return;
+  }
+
+  const char* contentChars = content.c_str();
+  cmsys::RegularExpressionMatch match;
+  while (this->RegExpInclude.find(contentChars, match)) {
+    includes.emplace(match.match(2));
+    // Forward content pointer
+    contentChars += match.end();
+  }
+}
diff --git a/Source/cmQtAutoUicHelpers.h b/Source/cmQtAutoUicHelpers.h
new file mode 100644
index 0000000000..6b09a31daa
--- /dev/null
+++ b/Source/cmQtAutoUicHelpers.h
@@ -0,0 +1,20 @@
+/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+   file Copyright.txt or https://cmake.org/licensing for details.  */
+#pragma once
+
+#include <set>
+#include <string>
+
+#include "cmsys/RegularExpression.hxx"
+
+class cmQtAutoUicHelpers
+{
+public:
+  cmQtAutoUicHelpers();
+  virtual ~cmQtAutoUicHelpers() = default;
+  void CollectUicIncludes(std::set<std::string>& includes,
+                          const std::string& content) const;
+
+private:
+  cmsys::RegularExpression RegExpInclude;
+};
diff --git a/Tests/QtAutogen/RerunUicOnFileChange/CMakeLists.txt b/Tests/QtAutogen/RerunUicOnFileChange/CMakeLists.txt
index 1f636af451..a9ccece5d5 100644
--- a/Tests/QtAutogen/RerunUicOnFileChange/CMakeLists.txt
+++ b/Tests/QtAutogen/RerunUicOnFileChange/CMakeLists.txt
@@ -27,10 +27,12 @@ endmacro()
 
 configure_file("${testProjectTemplateDir}/mocwidget.h" "${testProjectSrc}/mocwidget.h" COPYONLY)
 configure_file("${testProjectTemplateDir}/main.cpp" "${testProjectSrc}/main.cpp" COPYONLY)
+configure_file("${testProjectTemplateDir}/subdir/subdircheck.cpp" "${testProjectSrc}/subdir/subdircheck.cpp" COPYONLY)
 configure_file("${testProjectTemplateDir}/CMakeLists.txt.in" "${testProjectSrc}/CMakeLists.txt" @ONLY)
 
 set(Num 1)
 configure_file("${testProjectTemplateDir}/mainwindow.ui.in" "${testProjectSrc}/mainwindow.ui" @ONLY)
+configure_file("${testProjectTemplateDir}/subdir/mainwindowsubdir.ui.in" "${testProjectSrc}/subdir/mainwindowsubdir.ui" @ONLY)
 
 if(CMAKE_GENERATOR_INSTANCE)
     set(_D_CMAKE_GENERATOR_INSTANCE "-DCMAKE_GENERATOR_INSTANCE=${CMAKE_GENERATOR_INSTANCE}")
@@ -94,6 +96,7 @@ sleep()
 
 set(Num 2)
 configure_file("${testProjectTemplateDir}/mainwindow.ui.in" "${testProjectSrc}/mainwindow.ui" @ONLY)
+configure_file("${testProjectTemplateDir}/subdir/mainwindowsubdir.ui.in" "${testProjectSrc}/subdir/mainwindowsubdir.ui" @ONLY)
 rebuild(2)
 
 execute_process(COMMAND "${testProjectBinDir}/${extra_bin_path}UicOnFileChange" RESULT_VARIABLE result)
diff --git a/Tests/QtAutogen/RerunUicOnFileChange/UicOnFileChange/CMakeLists.txt.in b/Tests/QtAutogen/RerunUicOnFileChange/UicOnFileChange/CMakeLists.txt.in
index fa9dd6bee3..2a1998d10f 100644
--- a/Tests/QtAutogen/RerunUicOnFileChange/UicOnFileChange/CMakeLists.txt.in
+++ b/Tests/QtAutogen/RerunUicOnFileChange/UicOnFileChange/CMakeLists.txt.in
@@ -6,6 +6,8 @@ include("@CMAKE_CURRENT_LIST_DIR@/../AutogenGuiTest.cmake")
 # Enable CMAKE_AUTOUIC for all targets
 set(CMAKE_AUTOUIC ON)
 
-add_executable(UicOnFileChange main.cpp mainwindow.ui)
+add_executable(UicOnFileChange main.cpp mainwindow.ui
+    subdir/subdircheck.cpp subdir/mainwindowsubdir.ui
+)
 target_include_directories(UicOnFileChange PRIVATE ${CMAKE_CURRENT_SOURCE_DIR})
 target_link_libraries(UicOnFileChange ${QT_QTCORE_TARGET} ${QT_LIBRARIES})
diff --git a/Tests/QtAutogen/RerunUicOnFileChange/UicOnFileChange/main.cpp b/Tests/QtAutogen/RerunUicOnFileChange/UicOnFileChange/main.cpp
index fd810fa247..3981268846 100644
--- a/Tests/QtAutogen/RerunUicOnFileChange/UicOnFileChange/main.cpp
+++ b/Tests/QtAutogen/RerunUicOnFileChange/UicOnFileChange/main.cpp
@@ -1,9 +1,11 @@
 #include "ui_mainwindow.h"
 
+extern bool subdircheck();
+
 int main(int argc, char* argv[])
 {
   MocWidget mw;
   Ui::Widget mwUi;
   mwUi.setupUi(&mw);
-  return mw.objectName() == "Widget2" ? 0 : 1;
+  return mw.objectName() == "Widget2" && subdircheck() ? 0 : 1;
 }
diff --git a/Tests/QtAutogen/RerunUicOnFileChange/UicOnFileChange/subdir/mainwindowsubdir.ui.in b/Tests/QtAutogen/RerunUicOnFileChange/UicOnFileChange/subdir/mainwindowsubdir.ui.in
new file mode 100644
index 0000000000..a6a31f6d42
--- /dev/null
+++ b/Tests/QtAutogen/RerunUicOnFileChange/UicOnFileChange/subdir/mainwindowsubdir.ui.in
@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>WidgetSubdir</class>
+ <widget class="MocWidget" name="WidgetSubdir@Num@"/>
+ <resources/>
+ <connections/>
+</ui>
diff --git a/Tests/QtAutogen/RerunUicOnFileChange/UicOnFileChange/subdir/subdircheck.cpp b/Tests/QtAutogen/RerunUicOnFileChange/UicOnFileChange/subdir/subdircheck.cpp
new file mode 100644
index 0000000000..3b36a10df8
--- /dev/null
+++ b/Tests/QtAutogen/RerunUicOnFileChange/UicOnFileChange/subdir/subdircheck.cpp
@@ -0,0 +1,9 @@
+#include "ui_mainwindowsubdir.h"
+
+bool subdircheck()
+{
+  MocWidget mw;
+  Ui::WidgetSubdir mwUi;
+  mwUi.setupUi(&mw);
+  return mw.objectName() == "WidgetSubdir2";
+}