AUTOUIC: Revert "Fix generating of dependency rules for UI header files"

Revert commit e5ec0e52f4 (AUTOUIC: Fix generating of dependency rules
for UI header files, 2021-07-22, v3.21.1~8^2) because it caused
regressions.  For example, changing one C++ source can now cause many
others to rebuild.  Revert the change pending further investigation.

Fixes: #22531
Issue: #16776

10 files changed, 81 insertions, 119 deletions

diff --git a/Source/CMakeLists.txt b/Source/CMakeLists.txt
index 0142c07..9a18184 100644
--- a/Source/CMakeLists.txt
+++ b/Source/CMakeLists.txt
@@ -432,8 +432,6 @@ 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 898d862..57fcd2d 100644
--- a/Source/cmQtAutoGen.cxx
+++ b/Source/cmQtAutoGen.cxx
@@ -384,39 +384,3 @@ 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 b9ae360..466a954 100644
--- a/Source/cmQtAutoGen.h
+++ b/Source/cmQtAutoGen.h
@@ -100,9 +100,6 @@ 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 6cc8328..4dd78e5 100644
--- a/Source/cmQtAutoGenInitializer.cxx
+++ b/Source/cmQtAutoGenInitializer.cxx
@@ -902,13 +902,6 @@ 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
@@ -921,10 +914,6 @@ 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);
@@ -932,9 +921,6 @@ 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);
@@ -942,11 +928,11 @@ 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);
@@ -956,22 +942,35 @@ 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 3ec87d2..e76817b 100644
--- a/Source/cmQtAutoGenInitializer.h
+++ b/Source/cmQtAutoGenInitializer.h
@@ -17,7 +17,6 @@
 
 #include "cmFilePathChecksum.h"
 #include "cmQtAutoGen.h"
-#include "cmQtAutoUicHelpers.h"
 
 class cmGeneratorTarget;
 class cmGlobalGenerator;
@@ -171,7 +170,6 @@ 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 0c6b5e6..568926e 100644
--- a/Source/cmQtAutoGenerator.cxx
+++ b/Source/cmQtAutoGenerator.cxx
@@ -121,6 +121,43 @@ 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 66399d7..5c3a8ad 100644
--- a/Source/cmQtAutoGenerator.h
+++ b/Source/cmQtAutoGenerator.h
@@ -70,6 +70,8 @@ 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 86d54f9..2753fd5 100644
--- a/Source/cmQtAutoMocUic.cxx
+++ b/Source/cmQtAutoMocUic.cxx
@@ -30,7 +30,6 @@
 #include "cmGeneratedFileStream.h"
 #include "cmQtAutoGen.h"
 #include "cmQtAutoGenerator.h"
-#include "cmQtAutoUicHelpers.h"
 #include "cmStringAlgorithms.h"
 #include "cmSystemTools.h"
 #include "cmWorkerPool.h"
@@ -282,7 +281,7 @@ public:
     std::vector<std::string> Options;
     std::unordered_map<std::string, UiFile> UiFiles;
     std::vector<std::string> SearchPaths;
-    cmQtAutoUicHelpers AutoUicHelpers;
+    cmsys::RegularExpression RegExpInclude;
   };
 
   /** Uic shared variables.  */
@@ -762,7 +761,11 @@ std::string cmQtAutoMocUicT::MocSettingsT::MacrosString() const
   return res;
 }
 
-cmQtAutoMocUicT::UicSettingsT::UicSettingsT() = default;
+cmQtAutoMocUicT::UicSettingsT::UicSettingsT()
+{
+  this->RegExpInclude.compile("(^|\n)[ \t]*#[ \t]*include[ \t]+"
+                              "[\"<](([^ \">]+/)?ui_[^ \">/]+\\.h)[\">]");
+}
 
 cmQtAutoMocUicT::UicSettingsT::~UicSettingsT() = default;
 
@@ -1053,7 +1056,16 @@ void cmQtAutoMocUicT::JobParseT::UicIncludes()
   }
 
   std::set<std::string> includes;
-  this->UicConst().AutoUicHelpers.CollectUicIncludes(includes, this->Content);
+  {
+    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->CreateKeys(this->FileHandle->ParseData->Uic.Include, includes,
                    UiUnderscoreLength);
 }
diff --git a/Source/cmQtAutoUicHelpers.cxx b/Source/cmQtAutoUicHelpers.cxx
deleted file mode 100644
index 751ae08..0000000
--- a/Source/cmQtAutoUicHelpers.cxx
+++ /dev/null
@@ -1,25 +0,0 @@
-/* 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
deleted file mode 100644
index 6b09a31..0000000
--- a/Source/cmQtAutoUicHelpers.h
+++ /dev/null
@@ -1,20 +0,0 @@
-/* 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;
-};