Merge topic 'clang-tidy-module-cmsys-fstream-check'

ffa970559c clang-tidy module: add tests for cmsys::fstream check
d520853682 clang-tidy module: add check for cmsys::fstream
c67b91a7a6 Source: silence false positives for cmsys::fstream check
01d8308406 Tests: remove stderr from clang-tidy module tests

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !7869

Source/cmGeneratedFileStream.cxx

@@ -27,7 +27,7 @@ cmGeneratedFileStream::cmGeneratedFileStream(Encoding encoding)
 cmGeneratedFileStream::cmGeneratedFileStream(std::string const& name,
                                              bool quiet, Encoding encoding)
   : cmGeneratedFileStreamBase(name)
-  , Stream(this->TempName.c_str())
+  , Stream(this->TempName.c_str()) // NOLINT(cmake-use-cmsys-fstream)
 {
   // Check if the file opened.
   if (!*this && !quiet) {
@@ -67,10 +67,11 @@ cmGeneratedFileStream& cmGeneratedFileStream::Open(std::string const& name,
 
   // Open the temporary output file.
   if (binaryFlag) {
-    this->Stream::open(this->TempName.c_str(),
-                       std::ios::out | std::ios::binary);
+    this->Stream::open( // NOLINT(cmake-use-cmsys-fstream)
+      this->TempName.c_str(), std::ios::out | std::ios::binary);
   } else {
-    this->Stream::open(this->TempName.c_str());
+    this->Stream::open( // NOLINT(cmake-use-cmsys-fstream)
+      this->TempName.c_str());
   }
 
   // Check if the file opened.
@@ -87,7 +88,7 @@ bool cmGeneratedFileStream::Close()
   this->Okay = !this->fail();
 
   // Close the temporary output file.
-  this->Stream::close();
+  this->Stream::close(); // NOLINT(cmake-use-cmsys-fstream)
 
   // Remove the temporary file (possibly by renaming to the real file).
   return this->cmGeneratedFileStreamBase::Close();

Utilities/ClangTidyModule/CMakeLists.txt

@@ -16,6 +16,8 @@ add_library(cmake-clang-tidy-module MODULE
 
   UseCmstrlenCheck.cxx
   UseCmstrlenCheck.h
+  UseCmsysFstreamCheck.cxx
+  UseCmsysFstreamCheck.h
   )
 target_include_directories(cmake-clang-tidy-module PRIVATE ${CLANG_INCLUDE_DIRS})
 target_link_libraries(cmake-clang-tidy-module PRIVATE clang-tidy)

Utilities/ClangTidyModule/Module.cxx

@@ -4,6 +4,7 @@
 #include <clang-tidy/ClangTidyModuleRegistry.h>
 
 #include "UseCmstrlenCheck.h"
+#include "UseCmsysFstreamCheck.h"
 
 namespace clang {
 namespace tidy {
@@ -14,6 +15,8 @@ public:
   void addCheckFactories(ClangTidyCheckFactories& CheckFactories) override
   {
     CheckFactories.registerCheck<UseCmstrlenCheck>("cmake-use-cmstrlen");
+    CheckFactories.registerCheck<UseCmsysFstreamCheck>(
+      "cmake-use-cmsys-fstream");
   }
 };
 

Utilities/ClangTidyModule/Tests/CMakeLists.txt

@@ -11,3 +11,4 @@ function(add_run_clang_tidy_test check_name)
 endfunction()
 
 add_run_clang_tidy_test(cmake-use-cmstrlen)
+add_run_clang_tidy_test(cmake-use-cmsys-fstream)

Utilities/ClangTidyModule/Tests/RunClangTidy.cmake

@@ -3,14 +3,12 @@ if(EXISTS "${CMAKE_CURRENT_LIST_DIR}/${CHECK_NAME}.clang-tidy")
   set(config_arg "--config-file=${CMAKE_CURRENT_LIST_DIR}/${CHECK_NAME}.clang-tidy")
 endif()
 
-foreach(o out err)
-  if(EXISTS "${CMAKE_CURRENT_LIST_DIR}/${CHECK_NAME}-std${o}.txt")
-    file(READ "${CMAKE_CURRENT_LIST_DIR}/${CHECK_NAME}-std${o}.txt" expect_std${o})
-    string(REGEX REPLACE "\n+$" "" expect_std${o} "${expect_std${o}}")
-  else()
-    set(expect_std${o} "")
-  endif()
-endforeach()
+if(EXISTS "${CMAKE_CURRENT_LIST_DIR}/${CHECK_NAME}-stdout.txt")
+  file(READ "${CMAKE_CURRENT_LIST_DIR}/${CHECK_NAME}-stdout.txt" expect_stdout)
+  string(REGEX REPLACE "\n+$" "" expect_stdout "${expect_stdout}")
+else()
+  set(expect_stdout "")
+endif()
 
 set(source_file "${RunClangTidy_BINARY_DIR}/${CHECK_NAME}.cxx")
 configure_file("${CMAKE_CURRENT_LIST_DIR}/${CHECK_NAME}.cxx" "${source_file}" COPYONLY)
@@ -39,14 +37,12 @@ if(NOT result EQUAL 0)
   string(APPEND RunClangTidy_TEST_FAILED "Expected result: 0, actual result: ${result}\n")
 endif()
 
-foreach(o out err)
-  string(REGEX REPLACE "\n+$" "" actual_std${o} "${actual_std${o}}")
-  if(NOT actual_std${o} STREQUAL expect_std${o})
-    string(REPLACE "\n" "\n  " expect_std${o}_formatted "  ${expect_std${o}}")
-    string(REPLACE "\n" "\n  " actual_std${o}_formatted "  ${actual_std${o}}")
-    string(APPEND RunClangTidy_TEST_FAILED "Expected std${o}:\n${expect_std${o}_formatted}\nActual std${o}:\n${actual_std${o}_formatted}\n")
-  endif()
-endforeach()
+string(REGEX REPLACE "\n+$" "" actual_stdout "${actual_stdout}")
+if(NOT actual_stdout STREQUAL expect_stdout)
+  string(REPLACE "\n" "\n  " expect_stdout_formatted "  ${expect_stdout}")
+  string(REPLACE "\n" "\n  " actual_stdout_formatted "  ${actual_stdout}")
+  string(APPEND RunClangTidy_TEST_FAILED "Expected stdout:\n${expect_stdout_formatted}\nActual stdout:\n${actual_stdout_formatted}\n")
+endif()
 
 if(EXISTS "${CMAKE_CURRENT_LIST_DIR}/${CHECK_NAME}-fixit.cxx")
   set(expect_fixit_file "${CMAKE_CURRENT_LIST_DIR}/${CHECK_NAME}-fixit.cxx")

Utilities/ClangTidyModule/Tests/cmake-use-cmstrlen-stderr.txt

@@ -1,2 +0,0 @@
-4 warnings generated.
-clang-tidy applied 4 of 4 suggested fixes.

Utilities/ClangTidyModule/Tests/cmake-use-cmsys-fstream-fixit.cxx

@@ -0,0 +1,81 @@
+#include <fstream>
+#include <vector>
+
+namespace cmsys {
+using std::ifstream;
+using std::ofstream;
+using std::fstream;
+}
+
+namespace ns {
+using std::ifstream;
+using std::ofstream;
+using std::fstream;
+
+namespace ns {
+using std::ifstream;
+using std::ofstream;
+using std::fstream;
+}
+
+class cl
+{
+public:
+  using ifstream = cmsys::ifstream;
+  using ofstream = cmsys::ofstream;
+  using fstream = cmsys::fstream;
+};
+
+using ifs = cmsys::ifstream;
+using ofs = cmsys::ofstream;
+using fs = cmsys::fstream;
+}
+
+int main()
+{
+  using std::ifstream;
+  using std::ofstream;
+  using std::fstream;
+
+  // Correction needed
+  cmsys::ifstream ifsUnqual;
+  cmsys::ifstream ifsQual;
+  cmsys::ifstream ifsNS;
+  cmsys::ifstream ifsNested;
+  cmsys::ifstream ifsClass;
+  cmsys::ifstream ifsRenamed;
+
+  cmsys::ofstream ofsUnqual;
+  cmsys::ofstream ofsQual;
+  cmsys::ofstream ofsNS;
+  cmsys::ofstream ofsNested;
+  cmsys::ofstream ofsClass;
+  cmsys::ofstream ofsRenamed;
+
+  cmsys::fstream fsUnqual;
+  cmsys::fstream fsQual;
+  cmsys::fstream fsNS;
+  cmsys::fstream fsNested;
+  cmsys::fstream fsClass;
+  cmsys::fstream fsRenamed;
+
+  cmsys::ifstream::off_type offsetQual = 0;
+  cmsys::ifstream::off_type offsetUnqual = 0;
+  cmsys::ifstream::off_type offsetNS = 0;
+  cmsys::ifstream::off_type offsetNested = 0;
+  cmsys::ifstream::traits_type::off_type offsetTraitsNested = 0;
+  cmsys::ifstream::traits_type::off_type offsetTraitsClass = 0;
+
+  std::vector<cmsys::ifstream> ifsVectorUnqual;
+
+  // No correction needed
+  cmsys::ifstream ifsCmsys;
+  cmsys::ofstream ofsCmsys;
+  cmsys::fstream fsCmsys;
+  cmsys::ifstream::off_type offsetCmsys = 0;
+  cmsys::ifstream::traits_type::off_type offsetTraitsCmsys = 0;
+  std::vector<cmsys::ifstream> ifsVectorCmsys;
+  std::basic_ifstream<wchar_t> ifsWchar;
+
+  return 0;
+}

Utilities/ClangTidyModule/Tests/cmake-use-cmsys-fstream-stdout.txt

@@ -0,0 +1,155 @@
+cmake-use-cmsys-fstream.cxx:24:20: warning: use cmsys::ifstream [cmake-use-cmsys-fstream]
+  using ifstream = std::ifstream;
+                   ^~~~~~~~~~~~~
+                   cmsys::ifstream
+cmake-use-cmsys-fstream.cxx:24:20: note: FIX-IT applied suggested code changes
+cmake-use-cmsys-fstream.cxx:25:20: warning: use cmsys::ofstream [cmake-use-cmsys-fstream]
+  using ofstream = std::ofstream;
+                   ^~~~~~~~~~~~~
+                   cmsys::ofstream
+cmake-use-cmsys-fstream.cxx:25:20: note: FIX-IT applied suggested code changes
+cmake-use-cmsys-fstream.cxx:26:19: warning: use cmsys::fstream [cmake-use-cmsys-fstream]
+  using fstream = std::fstream;
+                  ^~~~~~~~~~~~
+                  cmsys::fstream
+cmake-use-cmsys-fstream.cxx:26:19: note: FIX-IT applied suggested code changes
+cmake-use-cmsys-fstream.cxx:29:13: warning: use cmsys::ifstream [cmake-use-cmsys-fstream]
+using ifs = std::ifstream;
+            ^~~~~~~~~~~~~
+            cmsys::ifstream
+cmake-use-cmsys-fstream.cxx:29:13: note: FIX-IT applied suggested code changes
+cmake-use-cmsys-fstream.cxx:30:13: warning: use cmsys::ofstream [cmake-use-cmsys-fstream]
+using ofs = std::ofstream;
+            ^~~~~~~~~~~~~
+            cmsys::ofstream
+cmake-use-cmsys-fstream.cxx:30:13: note: FIX-IT applied suggested code changes
+cmake-use-cmsys-fstream.cxx:31:12: warning: use cmsys::fstream [cmake-use-cmsys-fstream]
+using fs = std::fstream;
+           ^~~~~~~~~~~~
+           cmsys::fstream
+cmake-use-cmsys-fstream.cxx:31:12: note: FIX-IT applied suggested code changes
+cmake-use-cmsys-fstream.cxx:41:3: warning: use cmsys::ifstream [cmake-use-cmsys-fstream]
+  ifstream ifsUnqual;
+  ^~~~~~~~
+  cmsys::ifstream
+cmake-use-cmsys-fstream.cxx:41:3: note: FIX-IT applied suggested code changes
+cmake-use-cmsys-fstream.cxx:42:3: warning: use cmsys::ifstream [cmake-use-cmsys-fstream]
+  std::ifstream ifsQual;
+  ^~~~~~~~~~~~~
+  cmsys::ifstream
+cmake-use-cmsys-fstream.cxx:42:3: note: FIX-IT applied suggested code changes
+cmake-use-cmsys-fstream.cxx:43:3: warning: use cmsys::ifstream [cmake-use-cmsys-fstream]
+  ns::ifstream ifsNS;
+  ^~~~~~~~~~~~
+  cmsys::ifstream
+cmake-use-cmsys-fstream.cxx:43:3: note: FIX-IT applied suggested code changes
+cmake-use-cmsys-fstream.cxx:44:3: warning: use cmsys::ifstream [cmake-use-cmsys-fstream]
+  ns::ns::ifstream ifsNested;
+  ^~~~~~~~~~~~~~~~
+  cmsys::ifstream
+cmake-use-cmsys-fstream.cxx:44:3: note: FIX-IT applied suggested code changes
+cmake-use-cmsys-fstream.cxx:45:3: warning: use cmsys::ifstream [cmake-use-cmsys-fstream]
+  ns::cl::ifstream ifsClass;
+  ^~~~~~~~~~~~~~~~
+  cmsys::ifstream
+cmake-use-cmsys-fstream.cxx:45:3: note: FIX-IT applied suggested code changes
+cmake-use-cmsys-fstream.cxx:46:3: warning: use cmsys::ifstream [cmake-use-cmsys-fstream]
+  ns::ifs ifsRenamed;
+  ^~~~~~~
+  cmsys::ifstream
+cmake-use-cmsys-fstream.cxx:46:3: note: FIX-IT applied suggested code changes
+cmake-use-cmsys-fstream.cxx:48:3: warning: use cmsys::ofstream [cmake-use-cmsys-fstream]
+  ofstream ofsUnqual;
+  ^~~~~~~~
+  cmsys::ofstream
+cmake-use-cmsys-fstream.cxx:48:3: note: FIX-IT applied suggested code changes
+cmake-use-cmsys-fstream.cxx:49:3: warning: use cmsys::ofstream [cmake-use-cmsys-fstream]
+  std::ofstream ofsQual;
+  ^~~~~~~~~~~~~
+  cmsys::ofstream
+cmake-use-cmsys-fstream.cxx:49:3: note: FIX-IT applied suggested code changes
+cmake-use-cmsys-fstream.cxx:50:3: warning: use cmsys::ofstream [cmake-use-cmsys-fstream]
+  ns::ofstream ofsNS;
+  ^~~~~~~~~~~~
+  cmsys::ofstream
+cmake-use-cmsys-fstream.cxx:50:3: note: FIX-IT applied suggested code changes
+cmake-use-cmsys-fstream.cxx:51:3: warning: use cmsys::ofstream [cmake-use-cmsys-fstream]
+  ns::ns::ofstream ofsNested;
+  ^~~~~~~~~~~~~~~~
+  cmsys::ofstream
+cmake-use-cmsys-fstream.cxx:51:3: note: FIX-IT applied suggested code changes
+cmake-use-cmsys-fstream.cxx:52:3: warning: use cmsys::ofstream [cmake-use-cmsys-fstream]
+  ns::cl::ofstream ofsClass;
+  ^~~~~~~~~~~~~~~~
+  cmsys::ofstream
+cmake-use-cmsys-fstream.cxx:52:3: note: FIX-IT applied suggested code changes
+cmake-use-cmsys-fstream.cxx:53:3: warning: use cmsys::ofstream [cmake-use-cmsys-fstream]
+  ns::ofs ofsRenamed;
+  ^~~~~~~
+  cmsys::ofstream
+cmake-use-cmsys-fstream.cxx:53:3: note: FIX-IT applied suggested code changes
+cmake-use-cmsys-fstream.cxx:55:3: warning: use cmsys::fstream [cmake-use-cmsys-fstream]
+  fstream fsUnqual;
+  ^~~~~~~
+  cmsys::fstream
+cmake-use-cmsys-fstream.cxx:55:3: note: FIX-IT applied suggested code changes
+cmake-use-cmsys-fstream.cxx:56:3: warning: use cmsys::fstream [cmake-use-cmsys-fstream]
+  std::fstream fsQual;
+  ^~~~~~~~~~~~
+  cmsys::fstream
+cmake-use-cmsys-fstream.cxx:56:3: note: FIX-IT applied suggested code changes
+cmake-use-cmsys-fstream.cxx:57:3: warning: use cmsys::fstream [cmake-use-cmsys-fstream]
+  ns::fstream fsNS;
+  ^~~~~~~~~~~
+  cmsys::fstream
+cmake-use-cmsys-fstream.cxx:57:3: note: FIX-IT applied suggested code changes
+cmake-use-cmsys-fstream.cxx:58:3: warning: use cmsys::fstream [cmake-use-cmsys-fstream]
+  ns::ns::fstream fsNested;
+  ^~~~~~~~~~~~~~~
+  cmsys::fstream
+cmake-use-cmsys-fstream.cxx:58:3: note: FIX-IT applied suggested code changes
+cmake-use-cmsys-fstream.cxx:59:3: warning: use cmsys::fstream [cmake-use-cmsys-fstream]
+  ns::ns::fstream fsClass;
+  ^~~~~~~~~~~~~~~
+  cmsys::fstream
+cmake-use-cmsys-fstream.cxx:59:3: note: FIX-IT applied suggested code changes
+cmake-use-cmsys-fstream.cxx:60:3: warning: use cmsys::fstream [cmake-use-cmsys-fstream]
+  ns::fs fsRenamed;
+  ^~~~~~
+  cmsys::fstream
+cmake-use-cmsys-fstream.cxx:60:3: note: FIX-IT applied suggested code changes
+cmake-use-cmsys-fstream.cxx:62:3: warning: use cmsys::ifstream [cmake-use-cmsys-fstream]
+  std::ifstream::off_type offsetQual = 0;
+  ^~~~~~~~~~~~~
+  cmsys::ifstream
+cmake-use-cmsys-fstream.cxx:62:3: note: FIX-IT applied suggested code changes
+cmake-use-cmsys-fstream.cxx:63:3: warning: use cmsys::ifstream [cmake-use-cmsys-fstream]
+  ifstream::off_type offsetUnqual = 0;
+  ^~~~~~~~
+  cmsys::ifstream
+cmake-use-cmsys-fstream.cxx:63:3: note: FIX-IT applied suggested code changes
+cmake-use-cmsys-fstream.cxx:64:3: warning: use cmsys::ifstream [cmake-use-cmsys-fstream]
+  ns::ifstream::off_type offsetNS = 0;
+  ^~~~~~~~~~~~
+  cmsys::ifstream
+cmake-use-cmsys-fstream.cxx:64:3: note: FIX-IT applied suggested code changes
+cmake-use-cmsys-fstream.cxx:65:3: warning: use cmsys::ifstream [cmake-use-cmsys-fstream]
+  ns::ns::ifstream::off_type offsetNested = 0;
+  ^~~~~~~~~~~~~~~~
+  cmsys::ifstream
+cmake-use-cmsys-fstream.cxx:65:3: note: FIX-IT applied suggested code changes
+cmake-use-cmsys-fstream.cxx:66:3: warning: use cmsys::ifstream [cmake-use-cmsys-fstream]
+  ns::ns::ifstream::traits_type::off_type offsetTraitsNested = 0;
+  ^~~~~~~~~~~~~~~~
+  cmsys::ifstream
+cmake-use-cmsys-fstream.cxx:66:3: note: FIX-IT applied suggested code changes
+cmake-use-cmsys-fstream.cxx:67:3: warning: use cmsys::ifstream [cmake-use-cmsys-fstream]
+  ns::cl::ifstream::traits_type::off_type offsetTraitsClass = 0;
+  ^~~~~~~~~~~~~~~~
+  cmsys::ifstream
+cmake-use-cmsys-fstream.cxx:67:3: note: FIX-IT applied suggested code changes
+cmake-use-cmsys-fstream.cxx:69:15: warning: use cmsys::ifstream [cmake-use-cmsys-fstream]
+  std::vector<ifstream> ifsVectorUnqual;
+              ^~~~~~~~
+              cmsys::ifstream
+cmake-use-cmsys-fstream.cxx:69:15: note: FIX-IT applied suggested code changes

Utilities/ClangTidyModule/Tests/cmake-use-cmsys-fstream.cxx

@@ -0,0 +1,81 @@
+#include <fstream>
+#include <vector>
+
+namespace cmsys {
+using std::ifstream;
+using std::ofstream;
+using std::fstream;
+}
+
+namespace ns {
+using std::ifstream;
+using std::ofstream;
+using std::fstream;
+
+namespace ns {
+using std::ifstream;
+using std::ofstream;
+using std::fstream;
+}
+
+class cl
+{
+public:
+  using ifstream = std::ifstream;
+  using ofstream = std::ofstream;
+  using fstream = std::fstream;
+};
+
+using ifs = std::ifstream;
+using ofs = std::ofstream;
+using fs = std::fstream;
+}
+
+int main()
+{
+  using std::ifstream;
+  using std::ofstream;
+  using std::fstream;
+
+  // Correction needed
+  ifstream ifsUnqual;
+  std::ifstream ifsQual;
+  ns::ifstream ifsNS;
+  ns::ns::ifstream ifsNested;
+  ns::cl::ifstream ifsClass;
+  ns::ifs ifsRenamed;
+
+  ofstream ofsUnqual;
+  std::ofstream ofsQual;
+  ns::ofstream ofsNS;
+  ns::ns::ofstream ofsNested;
+  ns::cl::ofstream ofsClass;
+  ns::ofs ofsRenamed;
+
+  fstream fsUnqual;
+  std::fstream fsQual;
+  ns::fstream fsNS;
+  ns::ns::fstream fsNested;
+  ns::ns::fstream fsClass;
+  ns::fs fsRenamed;
+
+  std::ifstream::off_type offsetQual = 0;
+  ifstream::off_type offsetUnqual = 0;
+  ns::ifstream::off_type offsetNS = 0;
+  ns::ns::ifstream::off_type offsetNested = 0;
+  ns::ns::ifstream::traits_type::off_type offsetTraitsNested = 0;
+  ns::cl::ifstream::traits_type::off_type offsetTraitsClass = 0;
+
+  std::vector<ifstream> ifsVectorUnqual;
+
+  // No correction needed
+  cmsys::ifstream ifsCmsys;
+  cmsys::ofstream ofsCmsys;
+  cmsys::fstream fsCmsys;
+  cmsys::ifstream::off_type offsetCmsys = 0;
+  cmsys::ifstream::traits_type::off_type offsetTraitsCmsys = 0;
+  std::vector<cmsys::ifstream> ifsVectorCmsys;
+  std::basic_ifstream<wchar_t> ifsWchar;
+
+  return 0;
+}

Utilities/ClangTidyModule/UseCmsysFstreamCheck.cxx

@@ -0,0 +1,101 @@
+/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+   file Copyright.txt or https://cmake.org/licensing for details.  */
+#include "UseCmsysFstreamCheck.h"
+
+#include <clang/ASTMatchers/ASTMatchFinder.h>
+
+namespace clang {
+namespace tidy {
+namespace cmake {
+using namespace ast_matchers;
+
+UseCmsysFstreamCheck::UseCmsysFstreamCheck(StringRef Name,
+                                           ClangTidyContext* Context)
+  : ClangTidyCheck(Name, Context)
+{
+}
+
+void UseCmsysFstreamCheck::registerMatchers(MatchFinder* Finder)
+{
+  this->createMatcher("::std::basic_ifstream", "::cmsys::ifstream", Finder,
+                      "ifstream");
+  this->createMatcher("::std::basic_ofstream", "::cmsys::ofstream", Finder,
+                      "ofstream");
+  this->createMatcher("::std::basic_fstream", "::cmsys::fstream", Finder,
+                      "fstream");
+}
+
+void UseCmsysFstreamCheck::check(const MatchFinder::MatchResult& Result)
+{
+  const TypeLoc* ParentTypeNode =
+    Result.Nodes.getNodeAs<TypeLoc>("parentType");
+  const NestedNameSpecifierLoc* ParentNameNode =
+    Result.Nodes.getNodeAs<NestedNameSpecifierLoc>("parentName");
+  const TypeLoc* RootNode = nullptr;
+  StringRef BindName;
+  StringRef Warning;
+
+  if ((RootNode = Result.Nodes.getNodeAs<TypeLoc>("ifstream")) != nullptr) {
+    BindName = "cmsys::ifstream";
+    Warning = "use cmsys::ifstream";
+  } else if ((RootNode = Result.Nodes.getNodeAs<TypeLoc>("ofstream")) !=
+             nullptr) {
+    BindName = "cmsys::ofstream";
+    Warning = "use cmsys::ofstream";
+  } else if ((RootNode = Result.Nodes.getNodeAs<TypeLoc>("fstream")) !=
+             nullptr) {
+    BindName = "cmsys::fstream";
+    Warning = "use cmsys::fstream";
+  }
+
+  if (ParentTypeNode != nullptr) {
+    if (ParentTypeNode->getBeginLoc().isValid()) {
+      this->diag(ParentTypeNode->getBeginLoc(), Warning)
+        << FixItHint::CreateReplacement(ParentTypeNode->getSourceRange(),
+                                        BindName);
+    }
+  } else if (ParentNameNode != nullptr) {
+    if (ParentNameNode->getBeginLoc().isValid()) {
+      this->diag(ParentNameNode->getBeginLoc(), Warning)
+        << FixItHint::CreateReplacement(
+             SourceRange(ParentNameNode->getBeginLoc(), RootNode->getEndLoc()),
+             BindName);
+    }
+  } else if (RootNode != nullptr) {
+    if (RootNode->getBeginLoc().isValid()) {
+      this->diag(RootNode->getBeginLoc(), Warning)
+        << FixItHint::CreateReplacement(RootNode->getSourceRange(), BindName);
+    }
+  }
+}
+
+void UseCmsysFstreamCheck::createMatcher(StringRef StdName,
+                                         StringRef CmsysName,
+                                         ast_matchers::MatchFinder* Finder,
+                                         StringRef Bind)
+{
+  TypeLocMatcher IsStd = loc(qualType(hasUnqualifiedDesugaredType(
+    recordType(hasDeclaration(classTemplateSpecializationDecl(
+      hasName(StdName),
+      hasTemplateArgument(
+        0, templateArgument(refersToType(asString("char"))))))))));
+
+  // TODO This only checks to see if the type directly refers to
+  // cmsys::fstream. There are some corner cases involving template parameters
+  // that refer to cmsys::fstream that are missed by this matcher, resulting in
+  // a false positive. Figure out how to find these indirect references to
+  // cmsys::fstream and filter them out. In the meantime, such false positives
+  // can be silenced with NOLINT(cmake-use-cmsys-fstream).
+  TypeLocMatcher IsCmsys =
+    loc(usingType(throughUsingDecl(namedDecl(hasName(CmsysName)))));
+
+  Finder->addMatcher(
+    typeLoc(IsStd, unless(IsCmsys), unless(elaboratedTypeLoc()),
+            optionally(hasParent(elaboratedTypeLoc().bind("parentType"))),
+            optionally(hasParent(nestedNameSpecifierLoc().bind("parentName"))))
+      .bind(Bind),
+    this);
+}
+}
+}
+}

Utilities/ClangTidyModule/UseCmsysFstreamCheck.h

@@ -0,0 +1,24 @@
+/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+   file Copyright.txt or https://cmake.org/licensing for details.  */
+#pragma once
+
+#include <clang-tidy/ClangTidyCheck.h>
+#include <clang/ASTMatchers/ASTMatchFinder.h>
+
+namespace clang {
+namespace tidy {
+namespace cmake {
+class UseCmsysFstreamCheck : public ClangTidyCheck
+{
+public:
+  UseCmsysFstreamCheck(StringRef Name, ClangTidyContext* Context);
+  void registerMatchers(ast_matchers::MatchFinder* Finder) override;
+  void check(const ast_matchers::MatchFinder::MatchResult& Result) override;
+
+private:
+  void createMatcher(StringRef name, StringRef CmsysName,
+                     ast_matchers::MatchFinder* Finder, StringRef bind);
+};
+}
+}
+}