Refactor: Convert parallel string/backtrace vectors to BT vectors

20 files changed, 224 insertions, 537 deletions

diff --git a/Source/cmAlgorithms.h b/Source/cmAlgorithms.h
index c192e2a..d00f420 100644
--- a/Source/cmAlgorithms.h
+++ b/Source/cmAlgorithms.h
@@ -60,6 +60,10 @@ class cmListFileBacktrace;
 using cmBacktraceRange =
   cmRange<std::vector<cmListFileBacktrace>::const_iterator>;
 
+template <typename T>
+class BT;
+using cmBTStringRange = cmRange<std::vector<BT<std::string>>::const_iterator>;
+
 template <typename Range>
 typename Range::const_iterator cmRemoveN(Range& r, size_t n)
 {
diff --git a/Source/cmCPluginAPI.cxx b/Source/cmCPluginAPI.cxx
index ace7382..e922ee5 100644
--- a/Source/cmCPluginAPI.cxx
+++ b/Source/cmCPluginAPI.cxx
@@ -173,7 +173,7 @@ void CCONV cmAddLinkDirectoryForTarget(void* arg, const char* tgt,
       std::string(tgt) + " for directory " + std::string(d));
     return;
   }
-  t->InsertLinkDirectory(d, mf->GetBacktrace());
+  t->InsertLinkDirectory(BT<std::string>(d, mf->GetBacktrace()));
 }
 
 void CCONV cmAddExecutable(void* arg, const char* exename, int numSrcs,
diff --git a/Source/cmComputeLinkDepends.cxx b/Source/cmComputeLinkDepends.cxx
index 0b27e34..15a12ba 100644
--- a/Source/cmComputeLinkDepends.cxx
+++ b/Source/cmComputeLinkDepends.cxx
@@ -607,7 +607,7 @@ cmLinkItem cmComputeLinkDepends::ResolveLinkItem(int depender_index,
       from = depender;
     }
   }
-  return from->ResolveLinkItem(name, cmListFileBacktrace());
+  return from->ResolveLinkItem(BT<std::string>(name));
 }
 
 void cmComputeLinkDepends::InferDependencies()
diff --git a/Source/cmComputeTargetDepends.cxx b/Source/cmComputeTargetDepends.cxx
index 76712f4..5d3e04f 100644
--- a/Source/cmComputeTargetDepends.cxx
+++ b/Source/cmComputeTargetDepends.cxx
@@ -323,7 +323,7 @@ void cmComputeTargetDepends::AddObjectDepends(int depender_index,
   }
   cmGeneratorTarget const* depender = this->Targets[depender_index];
   cmLinkItem const& objItem =
-    depender->ResolveLinkItem(objLib, cmListFileBacktrace());
+    depender->ResolveLinkItem(BT<std::string>(objLib));
   if (emitted.insert(objItem).second) {
     if (depender->GetType() != cmStateEnums::EXECUTABLE &&
         depender->GetType() != cmStateEnums::STATIC_LIBRARY &&
diff --git a/Source/cmGeneratorTarget.cxx b/Source/cmGeneratorTarget.cxx
index 3201ae3..648708a 100644
--- a/Source/cmGeneratorTarget.cxx
+++ b/Source/cmGeneratorTarget.cxx
@@ -145,12 +145,10 @@ private:
 class TargetPropertyEntryString : public cmGeneratorTarget::TargetPropertyEntry
 {
 public:
-  TargetPropertyEntryString(std::string propertyValue,
-                            cmListFileBacktrace backtrace,
+  TargetPropertyEntryString(BT<std::string> propertyValue,
                             cmLinkImplItem const& item = NoLinkImplItem)
     : cmGeneratorTarget::TargetPropertyEntry(item)
     , PropertyValue(std::move(propertyValue))
-    , Backtrace(std::move(backtrace))
   {
   }
 
@@ -159,46 +157,46 @@ public:
                               cmGeneratorExpressionDAGChecker*,
                               std::string const&) const override
   {
-    return this->PropertyValue;
+    return this->PropertyValue.Value;
   }
 
-  cmListFileBacktrace GetBacktrace() const override { return this->Backtrace; }
-  std::string const& GetInput() const override { return this->PropertyValue; }
+  cmListFileBacktrace GetBacktrace() const override
+  {
+    return this->PropertyValue.Backtrace;
+  }
+  std::string const& GetInput() const override
+  {
+    return this->PropertyValue.Value;
+  }
 
 private:
-  std::string PropertyValue;
-  cmListFileBacktrace Backtrace;
+  BT<std::string> PropertyValue;
 };
 
 std::unique_ptr<cmGeneratorTarget::TargetPropertyEntry>
-CreateTargetPropertyEntry(
-  const std::string& propertyValue,
-  cmListFileBacktrace backtrace = cmListFileBacktrace(),
-  bool evaluateForBuildsystem = false)
+CreateTargetPropertyEntry(const BT<std::string>& propertyValue,
+                          bool evaluateForBuildsystem = false)
 {
-  if (cmGeneratorExpression::Find(propertyValue) != std::string::npos) {
-    cmGeneratorExpression ge(std::move(backtrace));
+  if (cmGeneratorExpression::Find(propertyValue.Value) != std::string::npos) {
+    cmGeneratorExpression ge(propertyValue.Backtrace);
     std::unique_ptr<cmCompiledGeneratorExpression> cge =
-      ge.Parse(propertyValue);
+      ge.Parse(propertyValue.Value);
     cge->SetEvaluateForBuildsystem(evaluateForBuildsystem);
     return std::unique_ptr<cmGeneratorTarget::TargetPropertyEntry>(
       cm::make_unique<TargetPropertyEntryGenex>(std::move(cge)));
   }
 
   return std::unique_ptr<cmGeneratorTarget::TargetPropertyEntry>(
-    cm::make_unique<TargetPropertyEntryString>(propertyValue,
-                                               std::move(backtrace)));
+    cm::make_unique<TargetPropertyEntryString>(propertyValue));
 }
 
 void CreatePropertyGeneratorExpressions(
-  cmStringRange entries, cmBacktraceRange backtraces,
+  cmBTStringRange entries,
   std::vector<std::unique_ptr<cmGeneratorTarget::TargetPropertyEntry>>& items,
   bool evaluateForBuildsystem = false)
 {
-  auto btIt = backtraces.begin();
-  for (auto it = entries.begin(); it != entries.end(); ++it, ++btIt) {
-    items.push_back(
-      CreateTargetPropertyEntry(*it, *btIt, evaluateForBuildsystem));
+  for (auto const& entry : entries) {
+    items.push_back(CreateTargetPropertyEntry(entry, evaluateForBuildsystem));
   }
 }
 
@@ -289,35 +287,27 @@ cmGeneratorTarget::cmGeneratorTarget(cmTarget* t, cmLocalGenerator* lg)
   this->GlobalGenerator->ComputeTargetObjectDirectory(this);
 
   CreatePropertyGeneratorExpressions(t->GetIncludeDirectoriesEntries(),
-                                     t->GetIncludeDirectoriesBacktraces(),
                                      this->IncludeDirectoriesEntries);
 
   CreatePropertyGeneratorExpressions(t->GetCompileOptionsEntries(),
-                                     t->GetCompileOptionsBacktraces(),
                                      this->CompileOptionsEntries);
 
   CreatePropertyGeneratorExpressions(t->GetCompileFeaturesEntries(),
-                                     t->GetCompileFeaturesBacktraces(),
                                      this->CompileFeaturesEntries);
 
   CreatePropertyGeneratorExpressions(t->GetCompileDefinitionsEntries(),
-                                     t->GetCompileDefinitionsBacktraces(),
                                      this->CompileDefinitionsEntries);
 
   CreatePropertyGeneratorExpressions(t->GetLinkOptionsEntries(),
-                                     t->GetLinkOptionsBacktraces(),
                                      this->LinkOptionsEntries);
 
   CreatePropertyGeneratorExpressions(t->GetLinkDirectoriesEntries(),
-                                     t->GetLinkDirectoriesBacktraces(),
                                      this->LinkDirectoriesEntries);
 
   CreatePropertyGeneratorExpressions(t->GetPrecompileHeadersEntries(),
-                                     t->GetPrecompileHeadersBacktraces(),
                                      this->PrecompileHeadersEntries);
 
   CreatePropertyGeneratorExpressions(t->GetSourceEntries(),
-                                     t->GetSourceBacktraces(),
                                      this->SourceEntries, true);
 
   this->PolicyMap = t->GetPolicyMap();
@@ -698,7 +688,8 @@ void cmGeneratorTarget::AddSourceCommon(const std::string& src, bool before)
 {
   this->SourceEntries.insert(
     before ? this->SourceEntries.begin() : this->SourceEntries.end(),
-    CreateTargetPropertyEntry(src, this->Makefile->GetBacktrace(), true));
+    CreateTargetPropertyEntry(
+      BT<std::string>(src, this->Makefile->GetBacktrace()), true));
   this->ClearSourcesCache();
 }
 
@@ -719,11 +710,13 @@ void cmGeneratorTarget::AddTracedSources(std::vector<std::string> const& srcs)
 void cmGeneratorTarget::AddIncludeDirectory(const std::string& src,
                                             bool before)
 {
-  this->Target->InsertInclude(src, this->Makefile->GetBacktrace(), before);
+  this->Target->InsertInclude(
+    BT<std::string>(src, this->Makefile->GetBacktrace()), before);
   this->IncludeDirectoriesEntries.insert(
     before ? this->IncludeDirectoriesEntries.begin()
            : this->IncludeDirectoriesEntries.end(),
-    CreateTargetPropertyEntry(src, this->Makefile->GetBacktrace(), true));
+    CreateTargetPropertyEntry(
+      BT<std::string>(src, this->Makefile->GetBacktrace()), true));
 }
 
 std::vector<cmSourceFile*> const* cmGeneratorTarget::GetSourceDepends(
@@ -1675,9 +1668,9 @@ std::vector<BT<std::string>> cmGeneratorTarget::GetSourceFilePaths(
     // for TARGET_OBJECTS instead for backwards compatibility with OLD
     // behavior of CMP0024 and CMP0026 only.
 
-    cmStringRange sourceEntries = this->Target->GetSourceEntries();
-    for (std::string const& entry : sourceEntries) {
-      std::vector<std::string> items = cmExpandedList(entry);
+    cmBTStringRange sourceEntries = this->Target->GetSourceEntries();
+    for (auto const& entry : sourceEntries) {
+      std::vector<std::string> items = cmExpandedList(entry.Value);
       for (std::string const& item : items) {
         if (cmHasLiteralPrefix(item, "$<TARGET_OBJECTS:") &&
             item.back() == '>') {
@@ -6364,7 +6357,7 @@ cm::optional<cmLinkItem> cmGeneratorTarget::LookupLinkItem(
   if (name == this->GetName() || name.empty()) {
     return maybeItem;
   }
-  maybeItem = this->ResolveLinkItem(name, bt, scope->LG);
+  maybeItem = this->ResolveLinkItem(BT<std::string>(name, bt), scope->LG);
   return maybeItem;
 }
 
@@ -7377,9 +7370,9 @@ void cmGeneratorTarget::GetObjectLibrariesCMP0026(
   // there is no cmGeneratorTarget at configure-time, so search the SOURCES
   // for TARGET_OBJECTS instead for backwards compatibility with OLD
   // behavior of CMP0024 and CMP0026 only.
-  cmStringRange rng = this->Target->GetSourceEntries();
-  for (std::string const& entry : rng) {
-    std::vector<std::string> files = cmExpandedList(entry);
+  cmBTStringRange rng = this->Target->GetSourceEntries();
+  for (auto const& entry : rng) {
+    std::vector<std::string> files = cmExpandedList(entry.Value);
     for (std::string const& li : files) {
       if (cmHasLiteralPrefix(li, "$<TARGET_OBJECTS:") && li.back() == '>') {
         std::string objLibName = li.substr(17, li.size() - 18);
@@ -7607,24 +7600,21 @@ void cmGeneratorTarget::ComputeLinkImplementationLibraries(
 {
   cmLocalGenerator const* lg = this->LocalGenerator;
   cmMakefile const* mf = lg->GetMakefile();
-  cmStringRange entryRange = this->Target->GetLinkImplementationEntries();
-  cmBacktraceRange btRange = this->Target->GetLinkImplementationBacktraces();
-  cmBacktraceRange::const_iterator btIt = btRange.begin();
+  cmBTStringRange entryRange = this->Target->GetLinkImplementationEntries();
   // Collect libraries directly linked in this configuration.
-  for (cmStringRange::const_iterator le = entryRange.begin(),
-                                     end = entryRange.end();
-       le != end; ++le, ++btIt) {
+  for (auto const& entry : entryRange) {
     std::vector<std::string> llibs;
     // Keep this logic in sync with ExpandLinkItems.
     cmGeneratorExpressionDAGChecker dagChecker(this, "LINK_LIBRARIES", nullptr,
                                                nullptr);
-    cmGeneratorExpression ge(*btIt);
-    std::unique_ptr<cmCompiledGeneratorExpression> const cge = ge.Parse(*le);
+    cmGeneratorExpression ge(entry.Backtrace);
+    std::unique_ptr<cmCompiledGeneratorExpression> const cge =
+      ge.Parse(entry.Value);
     cge->SetEvaluateForBuildsystem(true);
     std::string const& evaluated =
       cge->Evaluate(this->LocalGenerator, config, head, &dagChecker, nullptr,
                     this->LinkerLanguage);
-    bool const fromGenex = evaluated != *le;
+    bool const fromGenex = evaluated != entry.Value;
     cmExpandList(evaluated, llibs);
     if (cge->GetHadHeadSensitiveCondition()) {
       impl.HadHeadSensitiveCondition = true;
@@ -7682,7 +7672,8 @@ void cmGeneratorTarget::ComputeLinkImplementationLibraries(
       }
 
       // The entry is meant for this configuration.
-      cmLinkItem item = this->ResolveLinkItem(name, *btIt, lg);
+      cmLinkItem item =
+        this->ResolveLinkItem(BT<std::string>(name, entry.Backtrace), lg);
       if (!item.Target) {
         // Report explicitly linked object files separately.
         std::string const& maybeObj = item.AsStr();
@@ -7724,7 +7715,7 @@ void cmGeneratorTarget::ComputeLinkImplementationLibraries(
       }
       // Support OLD behavior for CMP0003.
       impl.WrongConfigLibraries.push_back(
-        this->ResolveLinkItem(name, cmListFileBacktrace()));
+        this->ResolveLinkItem(BT<std::string>(name)));
     }
   }
 }
@@ -7750,16 +7741,16 @@ cmGeneratorTarget::TargetOrString cmGeneratorTarget::ResolveTargetReference(
 }
 
 cmLinkItem cmGeneratorTarget::ResolveLinkItem(
-  std::string const& name, cmListFileBacktrace const& bt) const
+  BT<std::string> const& name) const
 {
-  return this->ResolveLinkItem(name, bt, this->LocalGenerator);
+  return this->ResolveLinkItem(name, this->LocalGenerator);
 }
 
-cmLinkItem cmGeneratorTarget::ResolveLinkItem(std::string const& name,
-                                              cmListFileBacktrace const& bt,
+cmLinkItem cmGeneratorTarget::ResolveLinkItem(BT<std::string> const& name,
                                               cmLocalGenerator const* lg) const
 {
-  TargetOrString resolved = this->ResolveTargetReference(name, lg);
+  auto bt = name.Backtrace;
+  TargetOrString resolved = this->ResolveTargetReference(name.Value, lg);
 
   if (!resolved.Target) {
     return cmLinkItem(resolved.String, false, bt);
diff --git a/Source/cmGeneratorTarget.h b/Source/cmGeneratorTarget.h
index bb46211..0076085 100644
--- a/Source/cmGeneratorTarget.h
+++ b/Source/cmGeneratorTarget.h
@@ -409,10 +409,8 @@ public:
   TargetOrString ResolveTargetReference(std::string const& name,
                                         cmLocalGenerator const* lg) const;
 
-  cmLinkItem ResolveLinkItem(std::string const& name,
-                             cmListFileBacktrace const& bt) const;
-  cmLinkItem ResolveLinkItem(std::string const& name,
-                             cmListFileBacktrace const& bt,
+  cmLinkItem ResolveLinkItem(BT<std::string> const& name) const;
+  cmLinkItem ResolveLinkItem(BT<std::string> const& name,
                              cmLocalGenerator const* lg) const;
 
   // Compute the set of languages compiled by the target.  This is
diff --git a/Source/cmGlobalGenerator.cxx b/Source/cmGlobalGenerator.cxx
index 3561deb..17cd95e 100644
--- a/Source/cmGlobalGenerator.cxx
+++ b/Source/cmGlobalGenerator.cxx
@@ -1718,10 +1718,8 @@ void cmGlobalGenerator::FinalizeTargetCompileInfo()
 
   // Construct per-target generator information.
   for (const auto& mf : this->Makefiles) {
-    const cmStringRange noconfig_compile_definitions =
+    const cmBTStringRange noconfig_compile_definitions =
       mf->GetCompileDefinitionsEntries();
-    const cmBacktraceRange noconfig_compile_definitions_bts =
-      mf->GetCompileDefinitionsBacktraces();
 
     for (auto& target : mf->GetTargets()) {
       cmTarget* t = &target.second;
@@ -1735,12 +1733,8 @@ void cmGlobalGenerator::FinalizeTargetCompileInfo()
         continue;
       }
 
-      {
-        auto btIt = noconfig_compile_definitions_bts.begin();
-        auto it = noconfig_compile_definitions.begin();
-        for (; it != noconfig_compile_definitions.end(); ++it, ++btIt) {
-          t->InsertCompileDefinition(*it, *btIt);
-        }
+      for (auto const& def : noconfig_compile_definitions) {
+        t->InsertCompileDefinition(def);
       }
 
       cmPolicies::PolicyStatus polSt =
diff --git a/Source/cmMakefile.cxx b/Source/cmMakefile.cxx
index 7abbd31..9e7816f 100644
--- a/Source/cmMakefile.cxx
+++ b/Source/cmMakefile.cxx
@@ -212,59 +212,31 @@ void cmMakefile::MaybeWarnCMP0074(std::string const& pkg)
   }
 }
 
-cmStringRange cmMakefile::GetIncludeDirectoriesEntries() const
+cmBTStringRange cmMakefile::GetIncludeDirectoriesEntries() const
 {
   return this->StateSnapshot.GetDirectory().GetIncludeDirectoriesEntries();
 }
 
-cmBacktraceRange cmMakefile::GetIncludeDirectoriesBacktraces() const
-{
-  return this->StateSnapshot.GetDirectory()
-    .GetIncludeDirectoriesEntryBacktraces();
-}
-
-cmStringRange cmMakefile::GetCompileOptionsEntries() const
+cmBTStringRange cmMakefile::GetCompileOptionsEntries() const
 {
   return this->StateSnapshot.GetDirectory().GetCompileOptionsEntries();
 }
 
-cmBacktraceRange cmMakefile::GetCompileOptionsBacktraces() const
-{
-  return this->StateSnapshot.GetDirectory().GetCompileOptionsEntryBacktraces();
-}
-
-cmStringRange cmMakefile::GetCompileDefinitionsEntries() const
+cmBTStringRange cmMakefile::GetCompileDefinitionsEntries() const
 {
   return this->StateSnapshot.GetDirectory().GetCompileDefinitionsEntries();
 }
 
-cmBacktraceRange cmMakefile::GetCompileDefinitionsBacktraces() const
-{
-  return this->StateSnapshot.GetDirectory()
-    .GetCompileDefinitionsEntryBacktraces();
-}
-
-cmStringRange cmMakefile::GetLinkOptionsEntries() const
+cmBTStringRange cmMakefile::GetLinkOptionsEntries() const
 {
   return this->StateSnapshot.GetDirectory().GetLinkOptionsEntries();
 }
 
-cmBacktraceRange cmMakefile::GetLinkOptionsBacktraces() const
-{
-  return this->StateSnapshot.GetDirectory().GetLinkOptionsEntryBacktraces();
-}
-
-cmStringRange cmMakefile::GetLinkDirectoriesEntries() const
+cmBTStringRange cmMakefile::GetLinkDirectoriesEntries() const
 {
   return this->StateSnapshot.GetDirectory().GetLinkDirectoriesEntries();
 }
 
-cmBacktraceRange cmMakefile::GetLinkDirectoriesBacktraces() const
-{
-  return this->StateSnapshot.GetDirectory()
-    .GetLinkDirectoriesEntryBacktraces();
-}
-
 cmListFileBacktrace cmMakefile::GetBacktrace() const
 {
   return this->Backtrace;
@@ -1386,10 +1358,10 @@ void cmMakefile::AddLinkDirectory(std::string const& directory, bool before)
 {
   if (before) {
     this->StateSnapshot.GetDirectory().PrependLinkDirectoriesEntry(
-      directory, this->Backtrace);
+      BT<std::string>(directory, this->Backtrace));
   } else {
     this->StateSnapshot.GetDirectory().AppendLinkDirectoriesEntry(
-      directory, this->Backtrace);
+      BT<std::string>(directory, this->Backtrace));
   }
 }
 
@@ -1876,16 +1848,16 @@ void cmMakefile::AddIncludeDirectories(const std::vector<std::string>& incs,
   std::string entryString = cmJoin(incs, ";");
   if (before) {
     this->StateSnapshot.GetDirectory().PrependIncludeDirectoriesEntry(
-      entryString, this->Backtrace);
+      BT<std::string>(entryString, this->Backtrace));
   } else {
     this->StateSnapshot.GetDirectory().AppendIncludeDirectoriesEntry(
-      entryString, this->Backtrace);
+      BT<std::string>(entryString, this->Backtrace));
   }
 
   // Property on each target:
   for (auto& target : this->Targets) {
     cmTarget& t = target.second;
-    t.InsertInclude(entryString, this->Backtrace, before);
+    t.InsertInclude(BT<std::string>(entryString, this->Backtrace), before);
   }
 }
 
diff --git a/Source/cmMakefile.h b/Source/cmMakefile.h
index fd9a679..bdcab3b 100644
--- a/Source/cmMakefile.h
+++ b/Source/cmMakefile.h
@@ -33,7 +33,6 @@
 #include "cmSourceFileLocationKind.h"
 #include "cmStateSnapshot.h"
 #include "cmStateTypes.h"
-#include "cmStringAlgorithms.h"
 
 // IWYU does not see that 'std::unordered_map<std::string, cmTarget>'
 // will not compile without the complete type.
@@ -879,16 +878,11 @@ public:
   bool CheckCMP0037(std::string const& targetName,
                     cmStateEnums::TargetType targetType) const;
 
-  cmStringRange GetIncludeDirectoriesEntries() const;
-  cmBacktraceRange GetIncludeDirectoriesBacktraces() const;
-  cmStringRange GetCompileOptionsEntries() const;
-  cmBacktraceRange GetCompileOptionsBacktraces() const;
-  cmStringRange GetCompileDefinitionsEntries() const;
-  cmBacktraceRange GetCompileDefinitionsBacktraces() const;
-  cmStringRange GetLinkOptionsEntries() const;
-  cmBacktraceRange GetLinkOptionsBacktraces() const;
-  cmStringRange GetLinkDirectoriesEntries() const;
-  cmBacktraceRange GetLinkDirectoriesBacktraces() const;
+  cmBTStringRange GetIncludeDirectoriesEntries() const;
+  cmBTStringRange GetCompileOptionsEntries() const;
+  cmBTStringRange GetCompileDefinitionsEntries() const;
+  cmBTStringRange GetLinkOptionsEntries() const;
+  cmBTStringRange GetLinkDirectoriesEntries() const;
 
   std::set<std::string> const& GetSystemIncludeDirectories() const
   {
diff --git a/Source/cmState.cxx b/Source/cmState.cxx
index a045545..cfd9ad0 100644
--- a/Source/cmState.cxx
+++ b/Source/cmState.cxx
@@ -277,15 +277,10 @@ cmStateSnapshot cmState::Reset()
     cmLinkedTree<cmStateDetail::BuildsystemDirectoryStateType>::iterator it =
       this->BuildsystemDirectory.Truncate();
     it->IncludeDirectories.clear();
-    it->IncludeDirectoryBacktraces.clear();
     it->CompileDefinitions.clear();
-    it->CompileDefinitionsBacktraces.clear();
     it->CompileOptions.clear();
-    it->CompileOptionsBacktraces.clear();
     it->LinkOptions.clear();
-    it->LinkOptionsBacktraces.clear();
     it->LinkDirectories.clear();
-    it->LinkDirectoriesBacktraces.clear();
     it->DirectoryEnd = pos;
     it->NormalTargetNames.clear();
     it->ImportedTargetNames.clear();
diff --git a/Source/cmStateDirectory.cxx b/Source/cmStateDirectory.cxx
index ed5b5d8..8f83b02 100644
--- a/Source/cmStateDirectory.cxx
+++ b/Source/cmStateDirectory.cxx
@@ -19,6 +19,7 @@
 #include "cmState.h"
 #include "cmStatePrivate.h"
 #include "cmStateTypes.h"
+#include "cmStringAlgorithms.h"
 #include "cmSystemTools.h"
 
 static std::string const kBINARY_DIR = "BINARY_DIR";
@@ -63,7 +64,7 @@ cmStateDirectory::cmStateDirectory(
 }
 
 template <typename T, typename U>
-cmStringRange GetPropertyContent(T const& content, U contentEndPosition)
+cmBTStringRange GetPropertyContent(T const& content, U contentEndPosition)
 {
   auto end = content.begin() + contentEndPosition;
 
@@ -73,88 +74,59 @@ cmStringRange GetPropertyContent(T const& content, U contentEndPosition)
   return cmMakeRange(rbegin.base(), end);
 }
 
-template <typename T, typename U, typename V>
-cmBacktraceRange GetPropertyBacktraces(T const& content, U const& backtraces,
-                                       V contentEndPosition)
-{
-  auto entryEnd = content.begin() + contentEndPosition;
-
-  auto rbegin = cm::make_reverse_iterator(entryEnd);
-  rbegin = std::find(rbegin, content.rend(), cmPropertySentinal);
-
-  auto it = backtraces.begin() + std::distance(content.begin(), rbegin.base());
-
-  auto end = backtraces.end();
-  return cmMakeRange(it, end);
-}
-
-template <typename T, typename U, typename V>
-void AppendEntry(T& content, U& backtraces, V& endContentPosition,
-                 const std::string& value, const cmListFileBacktrace& lfbt)
+template <typename T, typename U>
+void AppendEntry(T& content, U& endContentPosition,
+                 const BT<std::string>& value)
 {
-  if (value.empty()) {
+  if (value.Value.empty()) {
     return;
   }
 
   assert(endContentPosition == content.size());
 
   content.push_back(value);
-  backtraces.push_back(lfbt);
 
   endContentPosition = content.size();
 }
 
-template <typename T, typename U, typename V>
-void SetContent(T& content, U& backtraces, V& endContentPosition,
-                const std::string& vec, const cmListFileBacktrace& lfbt)
+template <typename T, typename U>
+void SetContent(T& content, U& endContentPosition, const BT<std::string>& vec)
 {
   assert(endContentPosition == content.size());
 
   content.resize(content.size() + 2);
-  backtraces.resize(backtraces.size() + 2);
 
   content.back() = vec;
-  backtraces.back() = lfbt;
 
   endContentPosition = content.size();
 }
 
-template <typename T, typename U, typename V>
-void ClearContent(T& content, U& backtraces, V& endContentPosition)
+template <typename T, typename U>
+void ClearContent(T& content, U& endContentPosition)
 {
   assert(endContentPosition == content.size());
 
   content.resize(content.size() + 1);
-  backtraces.resize(backtraces.size() + 1);
 
   endContentPosition = content.size();
 }
 
-cmStringRange cmStateDirectory::GetIncludeDirectoriesEntries() const
+cmBTStringRange cmStateDirectory::GetIncludeDirectoriesEntries() const
 {
   return GetPropertyContent(
     this->DirectoryState->IncludeDirectories,
     this->Snapshot_.Position->IncludeDirectoryPosition);
 }
 
-cmBacktraceRange cmStateDirectory::GetIncludeDirectoriesEntryBacktraces() const
-{
-  return GetPropertyBacktraces(
-    this->DirectoryState->IncludeDirectories,
-    this->DirectoryState->IncludeDirectoryBacktraces,
-    this->Snapshot_.Position->IncludeDirectoryPosition);
-}
-
 void cmStateDirectory::AppendIncludeDirectoriesEntry(
-  const std::string& vec, const cmListFileBacktrace& lfbt)
+  const BT<std::string>& vec)
 {
   AppendEntry(this->DirectoryState->IncludeDirectories,
-              this->DirectoryState->IncludeDirectoryBacktraces,
-              this->Snapshot_.Position->IncludeDirectoryPosition, vec, lfbt);
+              this->Snapshot_.Position->IncludeDirectoryPosition, vec);
 }
 
 void cmStateDirectory::PrependIncludeDirectoriesEntry(
-  const std::string& vec, const cmListFileBacktrace& lfbt)
+  const BT<std::string>& vec)
 {
   auto entryEnd = this->DirectoryState->IncludeDirectories.begin() +
     this->Snapshot_.Position->IncludeDirectoryPosition;
@@ -164,167 +136,111 @@ void cmStateDirectory::PrependIncludeDirectoriesEntry(
   rbegin = std::find(rbegin, rend, cmPropertySentinal);
 
   auto entryIt = rbegin.base();
-  auto entryBegin = this->DirectoryState->IncludeDirectories.begin();
-
-  auto btIt = this->DirectoryState->IncludeDirectoryBacktraces.begin() +
-    std::distance(entryBegin, entryIt);
 
   this->DirectoryState->IncludeDirectories.insert(entryIt, vec);
-  this->DirectoryState->IncludeDirectoryBacktraces.insert(btIt, lfbt);
 
   this->Snapshot_.Position->IncludeDirectoryPosition =
     this->DirectoryState->IncludeDirectories.size();
 }
 
-void cmStateDirectory::SetIncludeDirectories(const std::string& vec,
-                                             const cmListFileBacktrace& lfbt)
+void cmStateDirectory::SetIncludeDirectories(const BT<std::string>& vec)
 {
   SetContent(this->DirectoryState->IncludeDirectories,
-             this->DirectoryState->IncludeDirectoryBacktraces,
-             this->Snapshot_.Position->IncludeDirectoryPosition, vec, lfbt);
+             this->Snapshot_.Position->IncludeDirectoryPosition, vec);
 }
 
 void cmStateDirectory::ClearIncludeDirectories()
 {
   ClearContent(this->DirectoryState->IncludeDirectories,
-               this->DirectoryState->IncludeDirectoryBacktraces,
                this->Snapshot_.Position->IncludeDirectoryPosition);
 }
 
-cmStringRange cmStateDirectory::GetCompileDefinitionsEntries() const
+cmBTStringRange cmStateDirectory::GetCompileDefinitionsEntries() const
 {
   return GetPropertyContent(
     this->DirectoryState->CompileDefinitions,
     this->Snapshot_.Position->CompileDefinitionsPosition);
 }
 
-cmBacktraceRange cmStateDirectory::GetCompileDefinitionsEntryBacktraces() const
-{
-  return GetPropertyBacktraces(
-    this->DirectoryState->CompileDefinitions,
-    this->DirectoryState->CompileDefinitionsBacktraces,
-    this->Snapshot_.Position->CompileDefinitionsPosition);
-}
-
 void cmStateDirectory::AppendCompileDefinitionsEntry(
-  const std::string& vec, const cmListFileBacktrace& lfbt)
+  const BT<std::string>& vec)
 {
   AppendEntry(this->DirectoryState->CompileDefinitions,
-              this->DirectoryState->CompileDefinitionsBacktraces,
-              this->Snapshot_.Position->CompileDefinitionsPosition, vec, lfbt);
+              this->Snapshot_.Position->CompileDefinitionsPosition, vec);
 }
 
-void cmStateDirectory::SetCompileDefinitions(const std::string& vec,
-                                             const cmListFileBacktrace& lfbt)
+void cmStateDirectory::SetCompileDefinitions(const BT<std::string>& vec)
 {
   SetContent(this->DirectoryState->CompileDefinitions,
-             this->DirectoryState->CompileDefinitionsBacktraces,
-             this->Snapshot_.Position->CompileDefinitionsPosition, vec, lfbt);
+             this->Snapshot_.Position->CompileDefinitionsPosition, vec);
 }
 
 void cmStateDirectory::ClearCompileDefinitions()
 {
   ClearContent(this->DirectoryState->CompileDefinitions,
-               this->DirectoryState->CompileDefinitionsBacktraces,
                this->Snapshot_.Position->CompileDefinitionsPosition);
 }
 
-cmStringRange cmStateDirectory::GetCompileOptionsEntries() const
+cmBTStringRange cmStateDirectory::GetCompileOptionsEntries() const
 {
   return GetPropertyContent(this->DirectoryState->CompileOptions,
                             this->Snapshot_.Position->CompileOptionsPosition);
 }
 
-cmBacktraceRange cmStateDirectory::GetCompileOptionsEntryBacktraces() const
-{
-  return GetPropertyBacktraces(
-    this->DirectoryState->CompileOptions,
-    this->DirectoryState->CompileOptionsBacktraces,
-    this->Snapshot_.Position->CompileOptionsPosition);
-}
-
-void cmStateDirectory::AppendCompileOptionsEntry(
-  const std::string& vec, const cmListFileBacktrace& lfbt)
+void cmStateDirectory::AppendCompileOptionsEntry(const BT<std::string>& vec)
 {
   AppendEntry(this->DirectoryState->CompileOptions,
-              this->DirectoryState->CompileOptionsBacktraces,
-              this->Snapshot_.Position->CompileOptionsPosition, vec, lfbt);
+              this->Snapshot_.Position->CompileOptionsPosition, vec);
 }
 
-void cmStateDirectory::SetCompileOptions(const std::string& vec,
-                                         const cmListFileBacktrace& lfbt)
+void cmStateDirectory::SetCompileOptions(const BT<std::string>& vec)
 {
   SetContent(this->DirectoryState->CompileOptions,
-             this->DirectoryState->CompileOptionsBacktraces,
-             this->Snapshot_.Position->CompileOptionsPosition, vec, lfbt);
+             this->Snapshot_.Position->CompileOptionsPosition, vec);
 }
 
 void cmStateDirectory::ClearCompileOptions()
 {
   ClearContent(this->DirectoryState->CompileOptions,
-               this->DirectoryState->CompileOptionsBacktraces,
                this->Snapshot_.Position->CompileOptionsPosition);
 }
 
-cmStringRange cmStateDirectory::GetLinkOptionsEntries() const
+cmBTStringRange cmStateDirectory::GetLinkOptionsEntries() const
 {
   return GetPropertyContent(this->DirectoryState->LinkOptions,
                             this->Snapshot_.Position->LinkOptionsPosition);
 }
 
-cmBacktraceRange cmStateDirectory::GetLinkOptionsEntryBacktraces() const
-{
-  return GetPropertyBacktraces(this->DirectoryState->LinkOptions,
-                               this->DirectoryState->LinkOptionsBacktraces,
-                               this->Snapshot_.Position->LinkOptionsPosition);
-}
-
-void cmStateDirectory::AppendLinkOptionsEntry(const std::string& vec,
-                                              const cmListFileBacktrace& lfbt)
+void cmStateDirectory::AppendLinkOptionsEntry(const BT<std::string>& vec)
 {
   AppendEntry(this->DirectoryState->LinkOptions,
-              this->DirectoryState->LinkOptionsBacktraces,
-              this->Snapshot_.Position->LinkOptionsPosition, vec, lfbt);
+              this->Snapshot_.Position->LinkOptionsPosition, vec);
 }
 
-void cmStateDirectory::SetLinkOptions(const std::string& vec,
-                                      const cmListFileBacktrace& lfbt)
+void cmStateDirectory::SetLinkOptions(const BT<std::string>& vec)
 {
   SetContent(this->DirectoryState->LinkOptions,
-             this->DirectoryState->LinkOptionsBacktraces,
-             this->Snapshot_.Position->LinkOptionsPosition, vec, lfbt);
+             this->Snapshot_.Position->LinkOptionsPosition, vec);
 }
 
 void cmStateDirectory::ClearLinkOptions()
 {
   ClearContent(this->DirectoryState->LinkOptions,
-               this->DirectoryState->LinkOptionsBacktraces,
                this->Snapshot_.Position->LinkOptionsPosition);
 }
 
-cmStringRange cmStateDirectory::GetLinkDirectoriesEntries() const
+cmBTStringRange cmStateDirectory::GetLinkDirectoriesEntries() const
 {
   return GetPropertyContent(this->DirectoryState->LinkDirectories,
                             this->Snapshot_.Position->LinkDirectoriesPosition);
 }
 
-cmBacktraceRange cmStateDirectory::GetLinkDirectoriesEntryBacktraces() const
-{
-  return GetPropertyBacktraces(
-    this->DirectoryState->LinkDirectories,
-    this->DirectoryState->LinkDirectoriesBacktraces,
-    this->Snapshot_.Position->LinkDirectoriesPosition);
-}
-
-void cmStateDirectory::AppendLinkDirectoriesEntry(
-  const std::string& vec, const cmListFileBacktrace& lfbt)
+void cmStateDirectory::AppendLinkDirectoriesEntry(const BT<std::string>& vec)
 {
   AppendEntry(this->DirectoryState->LinkDirectories,
-              this->DirectoryState->LinkDirectoriesBacktraces,
-              this->Snapshot_.Position->LinkDirectoriesPosition, vec, lfbt);
+              this->Snapshot_.Position->LinkDirectoriesPosition, vec);
 }
-void cmStateDirectory::PrependLinkDirectoriesEntry(
-  const std::string& vec, const cmListFileBacktrace& lfbt)
+void cmStateDirectory::PrependLinkDirectoriesEntry(const BT<std::string>& vec)
 {
   auto entryEnd = this->DirectoryState->LinkDirectories.begin() +
     this->Snapshot_.Position->LinkDirectoriesPosition;
@@ -334,30 +250,22 @@ void cmStateDirectory::PrependLinkDirectoriesEntry(
   rbegin = std::find(rbegin, rend, cmPropertySentinal);
 
   auto entryIt = rbegin.base();
-  auto entryBegin = this->DirectoryState->LinkDirectories.begin();
-
-  auto btIt = this->DirectoryState->LinkDirectoriesBacktraces.begin() +
-    std::distance(entryBegin, entryIt);
 
   this->DirectoryState->LinkDirectories.insert(entryIt, vec);
-  this->DirectoryState->LinkDirectoriesBacktraces.insert(btIt, lfbt);
 
   this->Snapshot_.Position->LinkDirectoriesPosition =
     this->DirectoryState->LinkDirectories.size();
 }
 
-void cmStateDirectory::SetLinkDirectories(const std::string& vec,
-                                          const cmListFileBacktrace& lfbt)
+void cmStateDirectory::SetLinkDirectories(const BT<std::string>& vec)
 {
   SetContent(this->DirectoryState->LinkDirectories,
-             this->DirectoryState->LinkDirectoriesBacktraces,
-             this->Snapshot_.Position->LinkDirectoriesPosition, vec, lfbt);
+             this->Snapshot_.Position->LinkDirectoriesPosition, vec);
 }
 
 void cmStateDirectory::ClearLinkDirectories()
 {
   ClearContent(this->DirectoryState->LinkDirectories,
-               this->DirectoryState->LinkDirectoriesBacktraces,
                this->Snapshot_.Position->LinkDirectoriesPosition);
 }
 
@@ -370,7 +278,7 @@ void cmStateDirectory::StoreProperty(const std::string& prop, ValueType value,
       this->ClearIncludeDirectories();
       return;
     }
-    this->SetIncludeDirectories(value, lfbt);
+    this->SetIncludeDirectories(BT<std::string>(value, lfbt));
     return;
   }
   if (prop == "COMPILE_OPTIONS") {
@@ -378,7 +286,7 @@ void cmStateDirectory::StoreProperty(const std::string& prop, ValueType value,
       this->ClearCompileOptions();
       return;
     }
-    this->SetCompileOptions(value, lfbt);
+    this->SetCompileOptions(BT<std::string>(value, lfbt));
     return;
   }
   if (prop == "COMPILE_DEFINITIONS") {
@@ -386,7 +294,7 @@ void cmStateDirectory::StoreProperty(const std::string& prop, ValueType value,
       this->ClearCompileDefinitions();
       return;
     }
-    this->SetCompileDefinitions(value, lfbt);
+    this->SetCompileDefinitions(BT<std::string>(value, lfbt));
     return;
   }
   if (prop == "LINK_OPTIONS") {
@@ -394,7 +302,7 @@ void cmStateDirectory::StoreProperty(const std::string& prop, ValueType value,
       this->ClearLinkOptions();
       return;
     }
-    this->SetLinkOptions(value, lfbt);
+    this->SetLinkOptions(BT<std::string>(value, lfbt));
     return;
   }
   if (prop == "LINK_DIRECTORIES") {
@@ -402,7 +310,7 @@ void cmStateDirectory::StoreProperty(const std::string& prop, ValueType value,
       this->ClearLinkDirectories();
       return;
     }
-    this->SetLinkDirectories(value, lfbt);
+    this->SetLinkDirectories(BT<std::string>(value, lfbt));
     return;
   }
 
@@ -425,23 +333,23 @@ void cmStateDirectory::AppendProperty(const std::string& prop,
                                       cmListFileBacktrace const& lfbt)
 {
   if (prop == "INCLUDE_DIRECTORIES") {
-    this->AppendIncludeDirectoriesEntry(value, lfbt);
+    this->AppendIncludeDirectoriesEntry(BT<std::string>(value, lfbt));
     return;
   }
   if (prop == "COMPILE_OPTIONS") {
-    this->AppendCompileOptionsEntry(value, lfbt);
+    this->AppendCompileOptionsEntry(BT<std::string>(value, lfbt));
     return;
   }
   if (prop == "COMPILE_DEFINITIONS") {
-    this->AppendCompileDefinitionsEntry(value, lfbt);
+    this->AppendCompileDefinitionsEntry(BT<std::string>(value, lfbt));
     return;
   }
   if (prop == "LINK_OPTIONS") {
-    this->AppendLinkOptionsEntry(value, lfbt);
+    this->AppendLinkOptionsEntry(BT<std::string>(value, lfbt));
     return;
   }
   if (prop == "LINK_DIRECTORIES") {
-    this->AppendLinkDirectoriesEntry(value, lfbt);
+    this->AppendLinkDirectoriesEntry(BT<std::string>(value, lfbt));
     return;
   }
 
diff --git a/Source/cmStateDirectory.h b/Source/cmStateDirectory.h
index 65e2f30..fac5d58c 100644
--- a/Source/cmStateDirectory.h
+++ b/Source/cmStateDirectory.h
@@ -14,7 +14,6 @@
 #include "cmProperty.h"
 #include "cmStatePrivate.h"
 #include "cmStateSnapshot.h"
-#include "cmStringAlgorithms.h"
 
 class cmStateDirectory
 {
@@ -28,47 +27,31 @@ public:
   std::string const& GetCurrentBinary() const;
   void SetCurrentBinary(std::string const& dir);
 
-  cmStringRange GetIncludeDirectoriesEntries() const;
-  cmBacktraceRange GetIncludeDirectoriesEntryBacktraces() const;
-  void AppendIncludeDirectoriesEntry(std::string const& vec,
-                                     cmListFileBacktrace const& lfbt);
-  void PrependIncludeDirectoriesEntry(std::string const& vec,
-                                      cmListFileBacktrace const& lfbt);
-  void SetIncludeDirectories(std::string const& vec,
-                             cmListFileBacktrace const& lfbt);
+  cmBTStringRange GetIncludeDirectoriesEntries() const;
+  void AppendIncludeDirectoriesEntry(BT<std::string> const& vec);
+  void PrependIncludeDirectoriesEntry(BT<std::string> const& vec);
+  void SetIncludeDirectories(BT<std::string> const& vec);
   void ClearIncludeDirectories();
 
-  cmStringRange GetCompileDefinitionsEntries() const;
-  cmBacktraceRange GetCompileDefinitionsEntryBacktraces() const;
-  void AppendCompileDefinitionsEntry(std::string const& vec,
-                                     cmListFileBacktrace const& lfbt);
-  void SetCompileDefinitions(std::string const& vec,
-                             cmListFileBacktrace const& lfbt);
+  cmBTStringRange GetCompileDefinitionsEntries() const;
+  void AppendCompileDefinitionsEntry(BT<std::string> const& vec);
+  void SetCompileDefinitions(BT<std::string> const& vec);
   void ClearCompileDefinitions();
 
-  cmStringRange GetCompileOptionsEntries() const;
-  cmBacktraceRange GetCompileOptionsEntryBacktraces() const;
-  void AppendCompileOptionsEntry(std::string const& vec,
-                                 cmListFileBacktrace const& lfbt);
-  void SetCompileOptions(std::string const& vec,
-                         cmListFileBacktrace const& lfbt);
+  cmBTStringRange GetCompileOptionsEntries() const;
+  void AppendCompileOptionsEntry(BT<std::string> const& vec);
+  void SetCompileOptions(BT<std::string> const& vec);
   void ClearCompileOptions();
 
-  cmStringRange GetLinkOptionsEntries() const;
-  cmBacktraceRange GetLinkOptionsEntryBacktraces() const;
-  void AppendLinkOptionsEntry(std::string const& vec,
-                              cmListFileBacktrace const& lfbt);
-  void PrependLinkDirectoriesEntry(std::string const& vec,
-                                   cmListFileBacktrace const& lfbt);
-  void SetLinkOptions(std::string const& vec, cmListFileBacktrace const& lfbt);
+  cmBTStringRange GetLinkOptionsEntries() const;
+  void AppendLinkOptionsEntry(BT<std::string> const& vec);
+  void PrependLinkDirectoriesEntry(BT<std::string> const& vec);
+  void SetLinkOptions(BT<std::string> const& vec);
   void ClearLinkOptions();
 
-  cmStringRange GetLinkDirectoriesEntries() const;
-  cmBacktraceRange GetLinkDirectoriesEntryBacktraces() const;
-  void AppendLinkDirectoriesEntry(std::string const& vec,
-                                  cmListFileBacktrace const& lfbt);
-  void SetLinkDirectories(std::string const& vec,
-                          cmListFileBacktrace const& lfbt);
+  cmBTStringRange GetLinkDirectoriesEntries() const;
+  void AppendLinkDirectoriesEntry(BT<std::string> const& vec);
+  void SetLinkDirectories(BT<std::string> const& vecs);
   void ClearLinkDirectories();
 
   void SetProperty(const std::string& prop, const char* value,
diff --git a/Source/cmStatePrivate.h b/Source/cmStatePrivate.h
index 6f475f2..fd46eed 100644
--- a/Source/cmStatePrivate.h
+++ b/Source/cmStatePrivate.h
@@ -67,20 +67,15 @@ struct cmStateDetail::BuildsystemDirectoryStateType
   std::string Location;
   std::string OutputLocation;
 
-  std::vector<std::string> IncludeDirectories;
-  std::vector<cmListFileBacktrace> IncludeDirectoryBacktraces;
+  std::vector<BT<std::string>> IncludeDirectories;
 
-  std::vector<std::string> CompileDefinitions;
-  std::vector<cmListFileBacktrace> CompileDefinitionsBacktraces;
+  std::vector<BT<std::string>> CompileDefinitions;
 
-  std::vector<std::string> CompileOptions;
-  std::vector<cmListFileBacktrace> CompileOptionsBacktraces;
+  std::vector<BT<std::string>> CompileOptions;
 
-  std::vector<std::string> LinkOptions;
-  std::vector<cmListFileBacktrace> LinkOptionsBacktraces;
+  std::vector<BT<std::string>> LinkOptions;
 
-  std::vector<std::string> LinkDirectories;
-  std::vector<cmListFileBacktrace> LinkDirectoriesBacktraces;
+  std::vector<BT<std::string>> LinkDirectories;
 
   std::vector<std::string> NormalTargetNames;
   std::vector<std::string> ImportedTargetNames;
diff --git a/Source/cmStateSnapshot.cxx b/Source/cmStateSnapshot.cxx
index 66cbcca..bd7db85 100644
--- a/Source/cmStateSnapshot.cxx
+++ b/Source/cmStateSnapshot.cxx
@@ -19,6 +19,10 @@
 #include "cmSystemTools.h"
 #include "cmVersion.h"
 
+#if defined(__CYGWIN__)
+#  include "cmStringAlgorithms.h"
+#endif
+
 cmStateSnapshot::cmStateSnapshot(cmState* state)
   : State(state)
 {
@@ -259,12 +263,10 @@ bool cmStateSnapshot::RaiseScope(std::string const& var, const char* varDef)
   return true;
 }
 
-template <typename T, typename U, typename V>
+template <typename T, typename U>
 void InitializeContentFromParent(T& parentContent, T& thisContent,
-                                 U& parentBacktraces, U& thisBacktraces,
-                                 V& contentEndPosition)
+                                 U& contentEndPosition)
 {
-  auto parentBegin = parentContent.begin();
   auto parentEnd = parentContent.end();
 
   auto parentRbegin = cm::make_reverse_iterator(parentEnd);
@@ -272,12 +274,7 @@ void InitializeContentFromParent(T& parentContent, T& thisContent,
   parentRbegin = std::find(parentRbegin, parentRend, cmPropertySentinal);
   auto parentIt = parentRbegin.base();
 
-  thisContent = std::vector<std::string>(parentIt, parentEnd);
-
-  auto btIt = parentBacktraces.begin() + std::distance(parentBegin, parentIt);
-  auto btEnd = parentBacktraces.end();
-
-  thisBacktraces = std::vector<cmListFileBacktrace>(btIt, btEnd);
+  thisContent = std::vector<BT<std::string>>(parentIt, parentEnd);
 
   contentEndPosition = thisContent.size();
 }
@@ -359,36 +356,26 @@ void cmStateSnapshot::InitializeFromParent()
   InitializeContentFromParent(
     parent->BuildSystemDirectory->IncludeDirectories,
     this->Position->BuildSystemDirectory->IncludeDirectories,
-    parent->BuildSystemDirectory->IncludeDirectoryBacktraces,
-    this->Position->BuildSystemDirectory->IncludeDirectoryBacktraces,
     this->Position->IncludeDirectoryPosition);
 
   InitializeContentFromParent(
     parent->BuildSystemDirectory->CompileDefinitions,
     this->Position->BuildSystemDirectory->CompileDefinitions,
-    parent->BuildSystemDirectory->CompileDefinitionsBacktraces,
-    this->Position->BuildSystemDirectory->CompileDefinitionsBacktraces,
     this->Position->CompileDefinitionsPosition);
 
   InitializeContentFromParent(
     parent->BuildSystemDirectory->CompileOptions,
     this->Position->BuildSystemDirectory->CompileOptions,
-    parent->BuildSystemDirectory->CompileOptionsBacktraces,
-    this->Position->BuildSystemDirectory->CompileOptionsBacktraces,
     this->Position->CompileOptionsPosition);
 
   InitializeContentFromParent(
     parent->BuildSystemDirectory->LinkOptions,
     this->Position->BuildSystemDirectory->LinkOptions,
-    parent->BuildSystemDirectory->LinkOptionsBacktraces,
-    this->Position->BuildSystemDirectory->LinkOptionsBacktraces,
     this->Position->LinkOptionsPosition);
 
   InitializeContentFromParent(
     parent->BuildSystemDirectory->LinkDirectories,
     this->Position->BuildSystemDirectory->LinkDirectories,
-    parent->BuildSystemDirectory->LinkDirectoriesBacktraces,
-    this->Position->BuildSystemDirectory->LinkDirectoriesBacktraces,
     this->Position->LinkDirectoriesPosition);
 
   cmProp include_regex =
diff --git a/Source/cmTarget.cxx b/Source/cmTarget.cxx
index 4f446d8..af64dce 100644
--- a/Source/cmTarget.cxx
+++ b/Source/cmTarget.cxx
@@ -83,15 +83,15 @@ cmProp cmTargetPropertyComputer::GetSources<cmTarget>(
   cmTarget const* tgt, cmMessenger* messenger,
   cmListFileBacktrace const& context)
 {
-  cmStringRange entries = tgt->GetSourceEntries();
+  cmBTStringRange entries = tgt->GetSourceEntries();
   if (entries.empty()) {
     return nullptr;
   }
 
   std::ostringstream ss;
   const char* sep = "";
-  for (std::string const& entry : entries) {
-    std::vector<std::string> files = cmExpandedList(entry);
+  for (auto const& entry : entries) {
+    std::vector<std::string> files = cmExpandedList(entry.Value);
     for (std::string const& file : files) {
       if (cmHasLiteralPrefix(file, "$<TARGET_OBJECTS:") &&
           file.back() == '>') {
@@ -187,25 +187,16 @@ public:
   std::set<std::string> SystemIncludeDirectories;
   cmTarget::LinkLibraryVectorType OriginalLinkLibraries;
   std::map<std::string, BTs<std::string>> LanguageStandardProperties;
-  std::vector<std::string> IncludeDirectoriesEntries;
-  std::vector<cmListFileBacktrace> IncludeDirectoriesBacktraces;
+  std::vector<BT<std::string>> IncludeDirectoriesEntries;
   std::vector<std::string> InstallIncludeDirectoriesEntries;
-  std::vector<std::string> CompileOptionsEntries;
-  std::vector<cmListFileBacktrace> CompileOptionsBacktraces;
-  std::vector<std::string> CompileFeaturesEntries;
-  std::vector<cmListFileBacktrace> CompileFeaturesBacktraces;
-  std::vector<std::string> CompileDefinitionsEntries;
-  std::vector<cmListFileBacktrace> CompileDefinitionsBacktraces;
-  std::vector<std::string> PrecompileHeadersEntries;
-  std::vector<cmListFileBacktrace> PrecompileHeadersBacktraces;
-  std::vector<std::string> SourceEntries;
-  std::vector<cmListFileBacktrace> SourceBacktraces;
-  std::vector<std::string> LinkOptionsEntries;
-  std::vector<cmListFileBacktrace> LinkOptionsBacktraces;
-  std::vector<std::string> LinkDirectoriesEntries;
-  std::vector<cmListFileBacktrace> LinkDirectoriesBacktraces;
-  std::vector<std::string> LinkImplementationPropertyEntries;
-  std::vector<cmListFileBacktrace> LinkImplementationPropertyBacktraces;
+  std::vector<BT<std::string>> CompileOptionsEntries;
+  std::vector<BT<std::string>> CompileFeaturesEntries;
+  std::vector<BT<std::string>> CompileDefinitionsEntries;
+  std::vector<BT<std::string>> PrecompileHeadersEntries;
+  std::vector<BT<std::string>> SourceEntries;
+  std::vector<BT<std::string>> LinkOptionsEntries;
+  std::vector<BT<std::string>> LinkDirectoriesEntries;
+  std::vector<BT<std::string>> LinkImplementationPropertyEntries;
   std::vector<std::pair<cmTarget::TLLSignature, cmListFileContext>>
     TLLCommands;
   cmListFileBacktrace Backtrace;
@@ -482,8 +473,6 @@ cmTarget::cmTarget(std::string const& name, cmStateEnums::TargetType type,
     // of the same directory property:
     cm::append(this->impl->IncludeDirectoriesEntries,
                this->impl->Makefile->GetIncludeDirectoriesEntries());
-    cm::append(this->impl->IncludeDirectoriesBacktraces,
-               this->impl->Makefile->GetIncludeDirectoriesBacktraces());
 
     {
       auto const& sysInc = this->impl->Makefile->GetSystemIncludeDirectories();
@@ -493,18 +482,12 @@ cmTarget::cmTarget(std::string const& name, cmStateEnums::TargetType type,
 
     cm::append(this->impl->CompileOptionsEntries,
                this->impl->Makefile->GetCompileOptionsEntries());
-    cm::append(this->impl->CompileOptionsBacktraces,
-               this->impl->Makefile->GetCompileOptionsBacktraces());
 
     cm::append(this->impl->LinkOptionsEntries,
                this->impl->Makefile->GetLinkOptionsEntries());
-    cm::append(this->impl->LinkOptionsBacktraces,
-               this->impl->Makefile->GetLinkOptionsBacktraces());
 
     cm::append(this->impl->LinkDirectoriesEntries,
                this->impl->Makefile->GetLinkDirectoriesEntries());
-    cm::append(this->impl->LinkDirectoriesBacktraces,
-               this->impl->Makefile->GetLinkDirectoriesBacktraces());
   }
 
   if (this->impl->TargetType == cmStateEnums::EXECUTABLE) {
@@ -613,11 +596,9 @@ void cmTarget::SetLanguageStandardProperty(std::string const& lang,
                                            const std::string& feature)
 {
   cmListFileBacktrace featureBacktrace;
-  for (size_t i = 0; i < this->impl->CompileFeaturesEntries.size(); i++) {
-    if (this->impl->CompileFeaturesEntries[i] == feature) {
-      if (i < this->impl->CompileFeaturesBacktraces.size()) {
-        featureBacktrace = this->impl->CompileFeaturesBacktraces[i];
-      }
+  for (auto const& entry : this->impl->CompileFeaturesEntries) {
+    if (entry.Value == feature) {
+      featureBacktrace = entry.Backtrace;
       break;
     }
   }
@@ -729,8 +710,7 @@ void cmTarget::AddTracedSources(std::vector<std::string> const& srcs)
 {
   if (!srcs.empty()) {
     cmListFileBacktrace lfbt = this->impl->Makefile->GetBacktrace();
-    this->impl->SourceEntries.push_back(cmJoin(srcs, ";"));
-    this->impl->SourceBacktraces.push_back(lfbt);
+    this->impl->SourceEntries.emplace_back(cmJoin(srcs, ";"), lfbt);
   }
 }
 
@@ -754,8 +734,7 @@ void cmTarget::AddSources(std::vector<std::string> const& srcs)
   }
   if (!srcFiles.empty()) {
     cmListFileBacktrace lfbt = this->impl->Makefile->GetBacktrace();
-    this->impl->SourceEntries.push_back(std::move(srcFiles));
-    this->impl->SourceBacktraces.push_back(lfbt);
+    this->impl->SourceEntries.emplace_back(std::move(srcFiles), lfbt);
   }
 }
 
@@ -843,9 +822,9 @@ public:
   {
   }
 
-  bool operator()(std::string const& entry)
+  bool operator()(BT<std::string> const& entry)
   {
-    std::vector<std::string> files = cmExpandedList(entry);
+    std::vector<std::string> files = cmExpandedList(entry.Value);
     std::vector<cmSourceFileLocation> locations;
     locations.reserve(files.size());
     std::transform(files.begin(), files.end(), std::back_inserter(locations),
@@ -866,11 +845,7 @@ cmSourceFile* cmTarget::AddSource(const std::string& src, bool before)
     cmListFileBacktrace lfbt = this->impl->Makefile->GetBacktrace();
     this->impl->SourceEntries.insert(before ? this->impl->SourceEntries.begin()
                                             : this->impl->SourceEntries.end(),
-                                     src);
-    this->impl->SourceBacktraces.insert(
-      before ? this->impl->SourceBacktraces.begin()
-             : this->impl->SourceBacktraces.end(),
-      lfbt);
+                                     BT<std::string>(src, lfbt));
   }
   if (cmGeneratorExpression::Find(src) != std::string::npos) {
     return nullptr;
@@ -1087,96 +1062,51 @@ cmStringRange cmTarget::GetInstallIncludeDirectoriesEntries() const
   return cmMakeRange(this->impl->InstallIncludeDirectoriesEntries);
 }
 
-cmStringRange cmTarget::GetIncludeDirectoriesEntries() const
+cmBTStringRange cmTarget::GetIncludeDirectoriesEntries() const
 {
   return cmMakeRange(this->impl->IncludeDirectoriesEntries);
 }
 
-cmBacktraceRange cmTarget::GetIncludeDirectoriesBacktraces() const
-{
-  return cmMakeRange(this->impl->IncludeDirectoriesBacktraces);
-}
-
-cmStringRange cmTarget::GetCompileOptionsEntries() const
+cmBTStringRange cmTarget::GetCompileOptionsEntries() const
 {
   return cmMakeRange(this->impl->CompileOptionsEntries);
 }
 
-cmBacktraceRange cmTarget::GetCompileOptionsBacktraces() const
-{
-  return cmMakeRange(this->impl->CompileOptionsBacktraces);
-}
-
-cmStringRange cmTarget::GetCompileFeaturesEntries() const
+cmBTStringRange cmTarget::GetCompileFeaturesEntries() const
 {
   return cmMakeRange(this->impl->CompileFeaturesEntries);
 }
 
-cmBacktraceRange cmTarget::GetCompileFeaturesBacktraces() const
-{
-  return cmMakeRange(this->impl->CompileFeaturesBacktraces);
-}
-
-cmStringRange cmTarget::GetCompileDefinitionsEntries() const
+cmBTStringRange cmTarget::GetCompileDefinitionsEntries() const
 {
   return cmMakeRange(this->impl->CompileDefinitionsEntries);
 }
 
-cmBacktraceRange cmTarget::GetCompileDefinitionsBacktraces() const
-{
-  return cmMakeRange(this->impl->CompileDefinitionsBacktraces);
-}
-
-cmStringRange cmTarget::GetPrecompileHeadersEntries() const
+cmBTStringRange cmTarget::GetPrecompileHeadersEntries() const
 {
   return cmMakeRange(this->impl->PrecompileHeadersEntries);
 }
 
-cmBacktraceRange cmTarget::GetPrecompileHeadersBacktraces() const
-{
-  return cmMakeRange(this->impl->PrecompileHeadersBacktraces);
-}
-
-cmStringRange cmTarget::GetSourceEntries() const
+cmBTStringRange cmTarget::GetSourceEntries() const
 {
   return cmMakeRange(this->impl->SourceEntries);
 }
 
-cmBacktraceRange cmTarget::GetSourceBacktraces() const
-{
-  return cmMakeRange(this->impl->SourceBacktraces);
-}
-
-cmStringRange cmTarget::GetLinkOptionsEntries() const
+cmBTStringRange cmTarget::GetLinkOptionsEntries() const
 {
   return cmMakeRange(this->impl->LinkOptionsEntries);
 }
 
-cmBacktraceRange cmTarget::GetLinkOptionsBacktraces() const
-{
-  return cmMakeRange(this->impl->LinkOptionsBacktraces);
-}
-
-cmStringRange cmTarget::GetLinkDirectoriesEntries() const
+cmBTStringRange cmTarget::GetLinkDirectoriesEntries() const
 {
   return cmMakeRange(this->impl->LinkDirectoriesEntries);
 }
 
-cmBacktraceRange cmTarget::GetLinkDirectoriesBacktraces() const
-{
-  return cmMakeRange(this->impl->LinkDirectoriesBacktraces);
-}
-
-cmStringRange cmTarget::GetLinkImplementationEntries() const
+cmBTStringRange cmTarget::GetLinkImplementationEntries() const
 {
   return cmMakeRange(this->impl->LinkImplementationPropertyEntries);
 }
 
-cmBacktraceRange cmTarget::GetLinkImplementationBacktraces() const
-{
-  return cmMakeRange(this->impl->LinkImplementationPropertyBacktraces);
-}
-
 namespace {
 #define MAKE_PROP(PROP) const std::string prop##PROP = #PROP
 MAKE_PROP(C_STANDARD);
@@ -1270,75 +1200,57 @@ void cmTarget::StoreProperty(const std::string& prop, ValueType value)
 
   if (prop == propINCLUDE_DIRECTORIES) {
     this->impl->IncludeDirectoriesEntries.clear();
-    this->impl->IncludeDirectoriesBacktraces.clear();
     if (value) {
-      this->impl->IncludeDirectoriesEntries.emplace_back(value);
       cmListFileBacktrace lfbt = this->impl->Makefile->GetBacktrace();
-      this->impl->IncludeDirectoriesBacktraces.push_back(lfbt);
+      this->impl->IncludeDirectoriesEntries.emplace_back(value, lfbt);
     }
   } else if (prop == propCOMPILE_OPTIONS) {
     this->impl->CompileOptionsEntries.clear();
-    this->impl->CompileOptionsBacktraces.clear();
     if (value) {
-      this->impl->CompileOptionsEntries.emplace_back(value);
       cmListFileBacktrace lfbt = this->impl->Makefile->GetBacktrace();
-      this->impl->CompileOptionsBacktraces.push_back(lfbt);
+      this->impl->CompileOptionsEntries.emplace_back(value, lfbt);
     }
   } else if (prop == propCOMPILE_FEATURES) {
     this->impl->CompileFeaturesEntries.clear();
-    this->impl->CompileFeaturesBacktraces.clear();
     if (value) {
-      this->impl->CompileFeaturesEntries.emplace_back(value);
       cmListFileBacktrace lfbt = this->impl->Makefile->GetBacktrace();
-      this->impl->CompileFeaturesBacktraces.push_back(lfbt);
+      this->impl->CompileFeaturesEntries.emplace_back(value, lfbt);
     }
   } else if (prop == propCOMPILE_DEFINITIONS) {
     this->impl->CompileDefinitionsEntries.clear();
-    this->impl->CompileDefinitionsBacktraces.clear();
     if (value) {
-      this->impl->CompileDefinitionsEntries.emplace_back(value);
       cmListFileBacktrace lfbt = this->impl->Makefile->GetBacktrace();
-      this->impl->CompileDefinitionsBacktraces.push_back(lfbt);
+      this->impl->CompileDefinitionsEntries.emplace_back(value, lfbt);
     }
   } else if (prop == propLINK_OPTIONS) {
     this->impl->LinkOptionsEntries.clear();
-    this->impl->LinkOptionsBacktraces.clear();
     if (value) {
-      this->impl->LinkOptionsEntries.emplace_back(value);
       cmListFileBacktrace lfbt = this->impl->Makefile->GetBacktrace();
-      this->impl->LinkOptionsBacktraces.push_back(lfbt);
+      this->impl->LinkOptionsEntries.emplace_back(value, lfbt);
     }
   } else if (prop == propLINK_DIRECTORIES) {
     this->impl->LinkDirectoriesEntries.clear();
-    this->impl->LinkDirectoriesBacktraces.clear();
     if (value) {
-      this->impl->LinkDirectoriesEntries.emplace_back(value);
       cmListFileBacktrace lfbt = this->impl->Makefile->GetBacktrace();
-      this->impl->LinkDirectoriesBacktraces.push_back(lfbt);
+      this->impl->LinkDirectoriesEntries.emplace_back(value, lfbt);
     }
   } else if (prop == propPRECOMPILE_HEADERS) {
     this->impl->PrecompileHeadersEntries.clear();
-    this->impl->PrecompileHeadersBacktraces.clear();
     if (value) {
-      this->impl->PrecompileHeadersEntries.emplace_back(value);
       cmListFileBacktrace lfbt = this->impl->Makefile->GetBacktrace();
-      this->impl->PrecompileHeadersBacktraces.push_back(lfbt);
+      this->impl->PrecompileHeadersEntries.emplace_back(value, lfbt);
     }
   } else if (prop == propLINK_LIBRARIES) {
     this->impl->LinkImplementationPropertyEntries.clear();
-    this->impl->LinkImplementationPropertyBacktraces.clear();
     if (value) {
       cmListFileBacktrace lfbt = this->impl->Makefile->GetBacktrace();
-      this->impl->LinkImplementationPropertyEntries.emplace_back(value);
-      this->impl->LinkImplementationPropertyBacktraces.push_back(lfbt);
+      this->impl->LinkImplementationPropertyEntries.emplace_back(value, lfbt);
     }
   } else if (prop == propSOURCES) {
     this->impl->SourceEntries.clear();
-    this->impl->SourceBacktraces.clear();
     if (value) {
       cmListFileBacktrace lfbt = this->impl->Makefile->GetBacktrace();
-      this->impl->SourceEntries.emplace_back(value);
-      this->impl->SourceBacktraces.push_back(lfbt);
+      this->impl->SourceEntries.emplace_back(value, lfbt);
     }
   } else if (prop == propIMPORTED_GLOBAL) {
     if (!cmIsOn(value)) {
@@ -1443,39 +1355,33 @@ void cmTarget::AppendProperty(const std::string& prop,
   }
   if (prop == "INCLUDE_DIRECTORIES") {
     if (!value.empty()) {
-      this->impl->IncludeDirectoriesEntries.emplace_back(value);
       cmListFileBacktrace lfbt = this->impl->Makefile->GetBacktrace();
-      this->impl->IncludeDirectoriesBacktraces.push_back(lfbt);
+      this->impl->IncludeDirectoriesEntries.emplace_back(value, lfbt);
     }
   } else if (prop == "COMPILE_OPTIONS") {
     if (!value.empty()) {
-      this->impl->CompileOptionsEntries.emplace_back(value);
       cmListFileBacktrace lfbt = this->impl->Makefile->GetBacktrace();
-      this->impl->CompileOptionsBacktraces.push_back(lfbt);
+      this->impl->CompileOptionsEntries.emplace_back(value, lfbt);
     }
   } else if (prop == "COMPILE_FEATURES") {
     if (!value.empty()) {
-      this->impl->CompileFeaturesEntries.emplace_back(value);
       cmListFileBacktrace lfbt = this->impl->Makefile->GetBacktrace();
-      this->impl->CompileFeaturesBacktraces.push_back(lfbt);
+      this->impl->CompileFeaturesEntries.emplace_back(value, lfbt);
     }
   } else if (prop == "COMPILE_DEFINITIONS") {
     if (!value.empty()) {
-      this->impl->CompileDefinitionsEntries.emplace_back(value);
       cmListFileBacktrace lfbt = this->impl->Makefile->GetBacktrace();
-      this->impl->CompileDefinitionsBacktraces.push_back(lfbt);
+      this->impl->CompileDefinitionsEntries.emplace_back(value, lfbt);
     }
   } else if (prop == "LINK_OPTIONS") {
     if (!value.empty()) {
-      this->impl->LinkOptionsEntries.emplace_back(value);
       cmListFileBacktrace lfbt = this->impl->Makefile->GetBacktrace();
-      this->impl->LinkOptionsBacktraces.push_back(lfbt);
+      this->impl->LinkOptionsEntries.emplace_back(value, lfbt);
     }
   } else if (prop == "LINK_DIRECTORIES") {
     if (!value.empty()) {
-      this->impl->LinkDirectoriesEntries.emplace_back(value);
       cmListFileBacktrace lfbt = this->impl->Makefile->GetBacktrace();
-      this->impl->LinkDirectoriesBacktraces.push_back(lfbt);
+      this->impl->LinkDirectoriesEntries.emplace_back(value, lfbt);
     }
   } else if (prop == "PRECOMPILE_HEADERS") {
     if (this->GetProperty("PRECOMPILE_HEADERS_REUSE_FROM")) {
@@ -1487,20 +1393,17 @@ void cmTarget::AppendProperty(const std::string& prop,
       return;
     }
     if (!value.empty()) {
-      this->impl->PrecompileHeadersEntries.emplace_back(value);
       cmListFileBacktrace lfbt = this->impl->Makefile->GetBacktrace();
-      this->impl->PrecompileHeadersBacktraces.push_back(lfbt);
+      this->impl->PrecompileHeadersEntries.emplace_back(value, lfbt);
     }
   } else if (prop == "LINK_LIBRARIES") {
     if (!value.empty()) {
       cmListFileBacktrace lfbt = this->impl->Makefile->GetBacktrace();
-      this->impl->LinkImplementationPropertyEntries.emplace_back(value);
-      this->impl->LinkImplementationPropertyBacktraces.push_back(lfbt);
+      this->impl->LinkImplementationPropertyEntries.emplace_back(value, lfbt);
     }
   } else if (prop == "SOURCES") {
     cmListFileBacktrace lfbt = this->impl->Makefile->GetBacktrace();
-    this->impl->SourceEntries.emplace_back(value);
-    this->impl->SourceBacktraces.push_back(lfbt);
+    this->impl->SourceEntries.emplace_back(value, lfbt);
   } else if (cmHasLiteralPrefix(prop, "IMPORTED_LIBNAME")) {
     this->impl->Makefile->IssueMessage(
       MessageType::FATAL_ERROR, prop + " property may not be APPENDed.");
@@ -1550,70 +1453,46 @@ void cmTarget::AppendBuildInterfaceIncludes()
   }
 }
 
-void cmTarget::InsertInclude(std::string const& entry,
-                             cmListFileBacktrace const& bt, bool before)
+void cmTarget::InsertInclude(BT<std::string> const& entry, bool before)
 {
   auto position = before ? this->impl->IncludeDirectoriesEntries.begin()
                          : this->impl->IncludeDirectoriesEntries.end();
 
-  auto btPosition = before ? this->impl->IncludeDirectoriesBacktraces.begin()
-                           : this->impl->IncludeDirectoriesBacktraces.end();
-
   this->impl->IncludeDirectoriesEntries.insert(position, entry);
-  this->impl->IncludeDirectoriesBacktraces.insert(btPosition, bt);
 }
 
-void cmTarget::InsertCompileOption(std::string const& entry,
-                                   cmListFileBacktrace const& bt, bool before)
+void cmTarget::InsertCompileOption(BT<std::string> const& entry, bool before)
 {
   auto position = before ? this->impl->CompileOptionsEntries.begin()
                          : this->impl->CompileOptionsEntries.end();
 
-  auto btPosition = before ? this->impl->CompileOptionsBacktraces.begin()
-                           : this->impl->CompileOptionsBacktraces.end();
-
   this->impl->CompileOptionsEntries.insert(position, entry);
-  this->impl->CompileOptionsBacktraces.insert(btPosition, bt);
 }
 
-void cmTarget::InsertCompileDefinition(std::string const& entry,
-                                       cmListFileBacktrace const& bt)
+void cmTarget::InsertCompileDefinition(BT<std::string> const& entry)
 {
   this->impl->CompileDefinitionsEntries.push_back(entry);
-  this->impl->CompileDefinitionsBacktraces.push_back(bt);
 }
 
-void cmTarget::InsertLinkOption(std::string const& entry,
-                                cmListFileBacktrace const& bt, bool before)
+void cmTarget::InsertLinkOption(BT<std::string> const& entry, bool before)
 {
   auto position = before ? this->impl->LinkOptionsEntries.begin()
                          : this->impl->LinkOptionsEntries.end();
 
-  auto btPosition = before ? this->impl->LinkOptionsBacktraces.begin()
-                           : this->impl->LinkOptionsBacktraces.end();
-
   this->impl->LinkOptionsEntries.insert(position, entry);
-  this->impl->LinkOptionsBacktraces.insert(btPosition, bt);
 }
 
-void cmTarget::InsertLinkDirectory(std::string const& entry,
-                                   cmListFileBacktrace const& bt, bool before)
+void cmTarget::InsertLinkDirectory(BT<std::string> const& entry, bool before)
 {
   auto position = before ? this->impl->LinkDirectoriesEntries.begin()
                          : this->impl->LinkDirectoriesEntries.end();
 
-  auto btPosition = before ? this->impl->LinkDirectoriesBacktraces.begin()
-                           : this->impl->LinkDirectoriesBacktraces.end();
-
   this->impl->LinkDirectoriesEntries.insert(position, entry);
-  this->impl->LinkDirectoriesBacktraces.insert(btPosition, bt);
 }
 
-void cmTarget::InsertPrecompileHeader(std::string const& entry,
-                                      cmListFileBacktrace const& bt)
+void cmTarget::InsertPrecompileHeader(BT<std::string> const& entry)
 {
   this->impl->PrecompileHeadersEntries.push_back(entry);
-  this->impl->PrecompileHeadersBacktraces.push_back(bt);
 }
 
 static void cmTargetCheckLINK_INTERFACE_LIBRARIES(const std::string& prop,
diff --git a/Source/cmTarget.h b/Source/cmTarget.h
index de0c4e3..eced1ae 100644
--- a/Source/cmTarget.h
+++ b/Source/cmTarget.h
@@ -217,18 +217,12 @@ public:
   //! Get a backtrace from the creation of the target.
   cmListFileBacktrace const& GetBacktrace() const;
 
-  void InsertInclude(std::string const& entry, cmListFileBacktrace const& bt,
-                     bool before = false);
-  void InsertCompileOption(std::string const& entry,
-                           cmListFileBacktrace const& bt, bool before = false);
-  void InsertCompileDefinition(std::string const& entry,
-                               cmListFileBacktrace const& bt);
-  void InsertLinkOption(std::string const& entry,
-                        cmListFileBacktrace const& bt, bool before = false);
-  void InsertLinkDirectory(std::string const& entry,
-                           cmListFileBacktrace const& bt, bool before = false);
-  void InsertPrecompileHeader(std::string const& entry,
-                              cmListFileBacktrace const& bt);
+  void InsertInclude(BT<std::string> const& entry, bool before = false);
+  void InsertCompileOption(BT<std::string> const& entry, bool before = false);
+  void InsertCompileDefinition(BT<std::string> const& entry);
+  void InsertLinkOption(BT<std::string> const& entry, bool before = false);
+  void InsertLinkDirectory(BT<std::string> const& entry, bool before = false);
+  void InsertPrecompileHeader(BT<std::string> const& entry);
 
   void AppendBuildInterfaceIncludes();
 
@@ -248,32 +242,23 @@ public:
                                    std::string const& value,
                                    const std::string& feature);
 
-  cmStringRange GetIncludeDirectoriesEntries() const;
-  cmBacktraceRange GetIncludeDirectoriesBacktraces() const;
+  cmBTStringRange GetIncludeDirectoriesEntries() const;
 
-  cmStringRange GetCompileOptionsEntries() const;
-  cmBacktraceRange GetCompileOptionsBacktraces() const;
+  cmBTStringRange GetCompileOptionsEntries() const;
 
-  cmStringRange GetCompileFeaturesEntries() const;
-  cmBacktraceRange GetCompileFeaturesBacktraces() const;
+  cmBTStringRange GetCompileFeaturesEntries() const;
 
-  cmStringRange GetCompileDefinitionsEntries() const;
-  cmBacktraceRange GetCompileDefinitionsBacktraces() const;
+  cmBTStringRange GetCompileDefinitionsEntries() const;
 
-  cmStringRange GetPrecompileHeadersEntries() const;
-  cmBacktraceRange GetPrecompileHeadersBacktraces() const;
+  cmBTStringRange GetPrecompileHeadersEntries() const;
 
-  cmStringRange GetSourceEntries() const;
-  cmBacktraceRange GetSourceBacktraces() const;
+  cmBTStringRange GetSourceEntries() const;
 
-  cmStringRange GetLinkOptionsEntries() const;
-  cmBacktraceRange GetLinkOptionsBacktraces() const;
+  cmBTStringRange GetLinkOptionsEntries() const;
 
-  cmStringRange GetLinkDirectoriesEntries() const;
-  cmBacktraceRange GetLinkDirectoriesBacktraces() const;
+  cmBTStringRange GetLinkDirectoriesEntries() const;
 
-  cmStringRange GetLinkImplementationEntries() const;
-  cmBacktraceRange GetLinkImplementationBacktraces() const;
+  cmBTStringRange GetLinkImplementationEntries() const;
 
   std::string ImportedGetFullPath(const std::string& config,
                                   cmStateEnums::ArtifactType artifact) const;
diff --git a/Source/cmTargetCompileOptionsCommand.cxx b/Source/cmTargetCompileOptionsCommand.cxx
index dee2c10..8ca3842 100644
--- a/Source/cmTargetCompileOptionsCommand.cxx
+++ b/Source/cmTargetCompileOptionsCommand.cxx
@@ -37,7 +37,8 @@ private:
     }
 
     cmListFileBacktrace lfbt = this->Makefile->GetBacktrace();
-    tgt->InsertCompileOption(this->Join(content), lfbt, prepend);
+    tgt->InsertCompileOption(BT<std::string>(this->Join(content), lfbt),
+                             prepend);
     return true; // Successfully handled.
   }
 
diff --git a/Source/cmTargetIncludeDirectoriesCommand.cxx b/Source/cmTargetIncludeDirectoriesCommand.cxx
index 3897499..f31501e 100644
--- a/Source/cmTargetIncludeDirectoriesCommand.cxx
+++ b/Source/cmTargetIncludeDirectoriesCommand.cxx
@@ -63,7 +63,7 @@ bool TargetIncludeDirectoriesImpl::HandleDirectContent(
   bool system)
 {
   cmListFileBacktrace lfbt = this->Makefile->GetBacktrace();
-  tgt->InsertInclude(this->Join(content), lfbt, prepend);
+  tgt->InsertInclude(BT<std::string>(this->Join(content), lfbt), prepend);
   if (system) {
     std::string prefix = this->Makefile->GetCurrentSourceDirectory() + "/";
     std::set<std::string> sdirs;
diff --git a/Source/cmTargetLinkDirectoriesCommand.cxx b/Source/cmTargetLinkDirectoriesCommand.cxx
index 0c68d60..3ba27a8 100644
--- a/Source/cmTargetLinkDirectoriesCommand.cxx
+++ b/Source/cmTargetLinkDirectoriesCommand.cxx
@@ -34,7 +34,8 @@ private:
                            bool prepend, bool /*system*/) override
   {
     cmListFileBacktrace lfbt = this->Makefile->GetBacktrace();
-    tgt->InsertLinkDirectory(this->Join(content), lfbt, prepend);
+    tgt->InsertLinkDirectory(BT<std::string>(this->Join(content), lfbt),
+                             prepend);
     return true; // Successfully handled.
   }
 };
diff --git a/Source/cmTargetLinkOptionsCommand.cxx b/Source/cmTargetLinkOptionsCommand.cxx
index df9416f..3ea2d71 100644
--- a/Source/cmTargetLinkOptionsCommand.cxx
+++ b/Source/cmTargetLinkOptionsCommand.cxx
@@ -30,7 +30,7 @@ private:
                            bool prepend, bool /*system*/) override
   {
     cmListFileBacktrace lfbt = this->Makefile->GetBacktrace();
-    tgt->InsertLinkOption(this->Join(content), lfbt, prepend);
+    tgt->InsertLinkOption(BT<std::string>(this->Join(content), lfbt), prepend);
     return true; // Successfully handled.
   }