cmExportFileGenerator: Simplify collection of targets missing from export set

Store the list of missing target names in a member instead of threading
an explicit reference to it through the call stack.

11 files changed, 117 insertions, 157 deletions

diff --git a/Source/cmExportBuildAndroidMKGenerator.cxx b/Source/cmExportBuildAndroidMKGenerator.cxx
index 1441925..5d0b208 100644
--- a/Source/cmExportBuildAndroidMKGenerator.cxx
+++ b/Source/cmExportBuildAndroidMKGenerator.cxx
@@ -4,6 +4,7 @@
 
 #include <sstream>
 #include <utility>
+#include <vector>
 
 #include <cmext/algorithm>
 
@@ -60,7 +61,7 @@ void cmExportBuildAndroidMKGenerator::GenerateImportPropertyCode(
 }
 
 void cmExportBuildAndroidMKGenerator::GenerateMissingTargetsCheckCode(
-  std::ostream&, const std::vector<std::string>&)
+  std::ostream&)
 {
 }
 
diff --git a/Source/cmExportBuildAndroidMKGenerator.h b/Source/cmExportBuildAndroidMKGenerator.h
index 250564f..410d4c3 100644
--- a/Source/cmExportBuildAndroidMKGenerator.h
+++ b/Source/cmExportBuildAndroidMKGenerator.h
@@ -6,7 +6,6 @@
 
 #include <iosfwd>
 #include <string>
-#include <vector>
 
 #include "cmExportBuildFileGenerator.h"
 #include "cmExportFileGenerator.h"
@@ -56,8 +55,7 @@ protected:
     std::ostream& os, const std::string& config,
     cmGeneratorTarget const* target,
     ImportPropertyMap const& properties) override;
-  void GenerateMissingTargetsCheckCode(
-    std::ostream& os, const std::vector<std::string>& missingTargets) override;
+  void GenerateMissingTargetsCheckCode(std::ostream& os) override;
   void GenerateInterfaceProperties(
     cmGeneratorTarget const* target, std::ostream& os,
     const ImportPropertyMap& properties) override;
diff --git a/Source/cmExportBuildFileGenerator.cxx b/Source/cmExportBuildFileGenerator.cxx
index a47f1e5..f22c716 100644
--- a/Source/cmExportBuildFileGenerator.cxx
+++ b/Source/cmExportBuildFileGenerator.cxx
@@ -76,8 +76,6 @@ bool cmExportBuildFileGenerator::GenerateMainFile(std::ostream& os)
     this->GenerateExpectedTargetsCode(os, expectedTargets);
   }
 
-  std::vector<std::string> missingTargets;
-
   // Create all the imported targets.
   for (cmGeneratorTarget* gte : this->Exports) {
     this->GenerateImportTargetCode(os, gte, this->GetExportTargetType(gte));
@@ -88,34 +86,34 @@ bool cmExportBuildFileGenerator::GenerateMainFile(std::ostream& os)
 
     this->PopulateInterfaceProperty("INTERFACE_INCLUDE_DIRECTORIES", gte,
                                     cmGeneratorExpression::BuildInterface,
-                                    properties, missingTargets);
+                                    properties);
     this->PopulateInterfaceProperty("INTERFACE_SOURCES", gte,
                                     cmGeneratorExpression::BuildInterface,
-                                    properties, missingTargets);
+                                    properties);
     this->PopulateInterfaceProperty("INTERFACE_COMPILE_DEFINITIONS", gte,
                                     cmGeneratorExpression::BuildInterface,
-                                    properties, missingTargets);
+                                    properties);
     this->PopulateInterfaceProperty("INTERFACE_COMPILE_OPTIONS", gte,
                                     cmGeneratorExpression::BuildInterface,
-                                    properties, missingTargets);
+                                    properties);
     this->PopulateInterfaceProperty("INTERFACE_PRECOMPILE_HEADERS", gte,
                                     cmGeneratorExpression::BuildInterface,
-                                    properties, missingTargets);
+                                    properties);
     this->PopulateInterfaceProperty("INTERFACE_AUTOUIC_OPTIONS", gte,
                                     cmGeneratorExpression::BuildInterface,
-                                    properties, missingTargets);
+                                    properties);
     this->PopulateInterfaceProperty("INTERFACE_COMPILE_FEATURES", gte,
                                     cmGeneratorExpression::BuildInterface,
-                                    properties, missingTargets);
+                                    properties);
     this->PopulateInterfaceProperty("INTERFACE_LINK_OPTIONS", gte,
                                     cmGeneratorExpression::BuildInterface,
-                                    properties, missingTargets);
+                                    properties);
     this->PopulateInterfaceProperty("INTERFACE_LINK_DIRECTORIES", gte,
                                     cmGeneratorExpression::BuildInterface,
-                                    properties, missingTargets);
+                                    properties);
     this->PopulateInterfaceProperty("INTERFACE_LINK_DEPENDS", gte,
                                     cmGeneratorExpression::BuildInterface,
-                                    properties, missingTargets);
+                                    properties);
     this->PopulateInterfaceProperty("INTERFACE_POSITION_INDEPENDENT_CODE", gte,
                                     properties);
 
@@ -132,8 +130,7 @@ bool cmExportBuildFileGenerator::GenerateMainFile(std::ostream& os)
       gte->GetPolicyStatusCMP0022() != cmPolicies::OLD;
     if (newCMP0022Behavior) {
       this->PopulateInterfaceLinkLibrariesProperty(
-        gte, cmGeneratorExpression::BuildInterface, properties,
-        missingTargets);
+        gte, cmGeneratorExpression::BuildInterface, properties);
     }
     this->PopulateCompatibleInterfaceProperties(gte, properties);
 
@@ -144,17 +141,16 @@ bool cmExportBuildFileGenerator::GenerateMainFile(std::ostream& os)
 
   // Generate import file content for each configuration.
   for (std::string const& c : this->Configurations) {
-    this->GenerateImportConfig(os, c, missingTargets);
+    this->GenerateImportConfig(os, c);
   }
 
-  this->GenerateMissingTargetsCheckCode(os, missingTargets);
+  this->GenerateMissingTargetsCheckCode(os);
 
   return true;
 }
 
 void cmExportBuildFileGenerator::GenerateImportTargetsConfig(
-  std::ostream& os, const std::string& config, std::string const& suffix,
-  std::vector<std::string>& missingTargets)
+  std::ostream& os, const std::string& config, std::string const& suffix)
 {
   for (cmGeneratorTarget* target : this->Exports) {
     // Collect import properties for this target.
@@ -167,11 +163,10 @@ void cmExportBuildFileGenerator::GenerateImportTargetsConfig(
       // Get the rest of the target details.
       if (this->GetExportTargetType(target) !=
           cmStateEnums::INTERFACE_LIBRARY) {
-        this->SetImportDetailProperties(config, suffix, target, properties,
-                                        missingTargets);
+        this->SetImportDetailProperties(config, suffix, target, properties);
         this->SetImportLinkInterface(config, suffix,
                                      cmGeneratorExpression::BuildInterface,
-                                     target, properties, missingTargets);
+                                     target, properties);
       }
 
       // TODO: PUBLIC_HEADER_LOCATION
@@ -259,8 +254,8 @@ void cmExportBuildFileGenerator::SetImportLocationProperty(
 }
 
 void cmExportBuildFileGenerator::HandleMissingTarget(
-  std::string& link_libs, std::vector<std::string>& missingTargets,
-  cmGeneratorTarget const* depender, cmGeneratorTarget* dependee)
+  std::string& link_libs, cmGeneratorTarget const* depender,
+  cmGeneratorTarget* dependee)
 {
   // The target is not in the export.
   if (!this->AppendMode) {
@@ -275,7 +270,7 @@ void cmExportBuildFileGenerator::HandleMissingTarget(
 
       missingTarget += dependee->GetExportName();
       link_libs += missingTarget;
-      missingTargets.push_back(std::move(missingTarget));
+      this->MissingTargets.emplace_back(std::move(missingTarget));
       return;
     }
     // We are not appending, so all exported targets should be
diff --git a/Source/cmExportBuildFileGenerator.h b/Source/cmExportBuildFileGenerator.h
index a7985c7..3db8719 100644
--- a/Source/cmExportBuildFileGenerator.h
+++ b/Source/cmExportBuildFileGenerator.h
@@ -55,13 +55,11 @@ public:
 protected:
   // Implement virtual methods from the superclass.
   bool GenerateMainFile(std::ostream& os) override;
-  void GenerateImportTargetsConfig(
-    std::ostream& os, const std::string& config, std::string const& suffix,
-    std::vector<std::string>& missingTargets) override;
+  void GenerateImportTargetsConfig(std::ostream& os, const std::string& config,
+                                   std::string const& suffix) override;
   cmStateEnums::TargetType GetExportTargetType(
     cmGeneratorTarget const* target) const;
   void HandleMissingTarget(std::string& link_libs,
-                           std::vector<std::string>& missingTargets,
                            cmGeneratorTarget const* depender,
                            cmGeneratorTarget* dependee) override;
 
diff --git a/Source/cmExportFileGenerator.cxx b/Source/cmExportFileGenerator.cxx
index dc94e76..6d6df71 100644
--- a/Source/cmExportFileGenerator.cxx
+++ b/Source/cmExportFileGenerator.cxx
@@ -106,9 +106,8 @@ bool cmExportFileGenerator::GenerateImportFile()
   return result;
 }
 
-void cmExportFileGenerator::GenerateImportConfig(
-  std::ostream& os, const std::string& config,
-  std::vector<std::string>& missingTargets)
+void cmExportFileGenerator::GenerateImportConfig(std::ostream& os,
+                                                 const std::string& config)
 {
   // Construct the property configuration suffix.
   std::string suffix = "_";
@@ -119,7 +118,7 @@ void cmExportFileGenerator::GenerateImportConfig(
   }
 
   // Generate the per-config target information.
-  this->GenerateImportTargetsConfig(os, config, suffix, missingTargets);
+  this->GenerateImportTargetsConfig(os, config, suffix);
 }
 
 void cmExportFileGenerator::PopulateInterfaceProperty(
@@ -136,7 +135,7 @@ void cmExportFileGenerator::PopulateInterfaceProperty(
   const std::string& propName, const std::string& outputName,
   cmGeneratorTarget const* target,
   cmGeneratorExpression::PreprocessContext preprocessRule,
-  ImportPropertyMap& properties, std::vector<std::string>& missingTargets)
+  ImportPropertyMap& properties)
 {
   cmValue input = target->GetProperty(propName);
   if (input) {
@@ -149,8 +148,7 @@ void cmExportFileGenerator::PopulateInterfaceProperty(
     std::string prepro =
       cmGeneratorExpression::Preprocess(*input, preprocessRule);
     if (!prepro.empty()) {
-      this->ResolveTargetsInGeneratorExpressions(prepro, target,
-                                                 missingTargets);
+      this->ResolveTargetsInGeneratorExpressions(prepro, target);
       properties[outputName] = prepro;
     }
   }
@@ -170,7 +168,7 @@ void cmExportFileGenerator::GenerateRequiredCMakeVersion(
 bool cmExportFileGenerator::PopulateInterfaceLinkLibrariesProperty(
   cmGeneratorTarget const* target,
   cmGeneratorExpression::PreprocessContext preprocessRule,
-  ImportPropertyMap& properties, std::vector<std::string>& missingTargets)
+  ImportPropertyMap& properties)
 {
   if (!target->IsLinkable()) {
     return false;
@@ -185,8 +183,8 @@ bool cmExportFileGenerator::PopulateInterfaceLinkLibrariesProperty(
       std::string prepro =
         cmGeneratorExpression::Preprocess(*input, preprocessRule);
       if (!prepro.empty()) {
-        this->ResolveTargetsInGeneratorExpressions(
-          prepro, target, missingTargets, ReplaceFreeTargets);
+        this->ResolveTargetsInGeneratorExpressions(prepro, target,
+                                                   ReplaceFreeTargets);
         properties[linkIfaceProp] = prepro;
         hadINTERFACE_LINK_LIBRARIES = true;
       }
@@ -343,7 +341,7 @@ static void prefixItems(std::string& exportDirs)
 void cmExportFileGenerator::PopulateSourcesInterface(
   cmGeneratorTarget const* gt,
   cmGeneratorExpression::PreprocessContext preprocessRule,
-  ImportPropertyMap& properties, std::vector<std::string>& missingTargets)
+  ImportPropertyMap& properties)
 {
   assert(preprocessRule == cmGeneratorExpression::InstallInterface);
 
@@ -362,7 +360,7 @@ void cmExportFileGenerator::PopulateSourcesInterface(
   std::string prepro =
     cmGeneratorExpression::Preprocess(*input, preprocessRule, true);
   if (!prepro.empty()) {
-    this->ResolveTargetsInGeneratorExpressions(prepro, gt, missingTargets);
+    this->ResolveTargetsInGeneratorExpressions(prepro, gt);
 
     if (!checkInterfaceDirs(prepro, gt, propName)) {
       return;
@@ -374,8 +372,7 @@ void cmExportFileGenerator::PopulateSourcesInterface(
 void cmExportFileGenerator::PopulateIncludeDirectoriesInterface(
   cmGeneratorTarget const* target,
   cmGeneratorExpression::PreprocessContext preprocessRule,
-  ImportPropertyMap& properties, std::vector<std::string>& missingTargets,
-  cmTargetExport const& te)
+  ImportPropertyMap& properties, cmTargetExport const& te)
 {
   assert(preprocessRule == cmGeneratorExpression::InstallInterface);
 
@@ -422,7 +419,7 @@ void cmExportFileGenerator::PopulateIncludeDirectoriesInterface(
   std::string prepro =
     cmGeneratorExpression::Preprocess(includes, preprocessRule, true);
   if (!prepro.empty()) {
-    this->ResolveTargetsInGeneratorExpressions(prepro, target, missingTargets);
+    this->ResolveTargetsInGeneratorExpressions(prepro, target);
 
     if (!checkInterfaceDirs(prepro, target, propName)) {
       return;
@@ -434,7 +431,7 @@ void cmExportFileGenerator::PopulateIncludeDirectoriesInterface(
 void cmExportFileGenerator::PopulateLinkDependsInterface(
   cmGeneratorTarget const* gt,
   cmGeneratorExpression::PreprocessContext preprocessRule,
-  ImportPropertyMap& properties, std::vector<std::string>& missingTargets)
+  ImportPropertyMap& properties)
 {
   assert(preprocessRule == cmGeneratorExpression::InstallInterface);
 
@@ -453,7 +450,7 @@ void cmExportFileGenerator::PopulateLinkDependsInterface(
   std::string prepro =
     cmGeneratorExpression::Preprocess(*input, preprocessRule, true);
   if (!prepro.empty()) {
-    this->ResolveTargetsInGeneratorExpressions(prepro, gt, missingTargets);
+    this->ResolveTargetsInGeneratorExpressions(prepro, gt);
 
     if (!checkInterfaceDirs(prepro, gt, propName)) {
       return;
@@ -465,7 +462,7 @@ void cmExportFileGenerator::PopulateLinkDependsInterface(
 void cmExportFileGenerator::PopulateLinkDirectoriesInterface(
   cmGeneratorTarget const* gt,
   cmGeneratorExpression::PreprocessContext preprocessRule,
-  ImportPropertyMap& properties, std::vector<std::string>& missingTargets)
+  ImportPropertyMap& properties)
 {
   assert(preprocessRule == cmGeneratorExpression::InstallInterface);
 
@@ -484,7 +481,7 @@ void cmExportFileGenerator::PopulateLinkDirectoriesInterface(
   std::string prepro =
     cmGeneratorExpression::Preprocess(*input, preprocessRule, true);
   if (!prepro.empty()) {
-    this->ResolveTargetsInGeneratorExpressions(prepro, gt, missingTargets);
+    this->ResolveTargetsInGeneratorExpressions(prepro, gt);
 
     if (!checkInterfaceDirs(prepro, gt, propName)) {
       return;
@@ -496,10 +493,10 @@ void cmExportFileGenerator::PopulateLinkDirectoriesInterface(
 void cmExportFileGenerator::PopulateInterfaceProperty(
   const std::string& propName, cmGeneratorTarget const* target,
   cmGeneratorExpression::PreprocessContext preprocessRule,
-  ImportPropertyMap& properties, std::vector<std::string>& missingTargets)
+  ImportPropertyMap& properties)
 {
   this->PopulateInterfaceProperty(propName, propName, target, preprocessRule,
-                                  properties, missingTargets);
+                                  properties);
 }
 
 static void getPropertyContents(cmGeneratorTarget const* tgt,
@@ -604,9 +601,9 @@ void cmExportFileGenerator::GenerateInterfaceProperties(
   }
 }
 
-bool cmExportFileGenerator::AddTargetNamespace(
-  std::string& input, cmGeneratorTarget const* target,
-  cmLocalGenerator const* lg, std::vector<std::string>& missingTargets)
+bool cmExportFileGenerator::AddTargetNamespace(std::string& input,
+                                               cmGeneratorTarget const* target,
+                                               cmLocalGenerator const* lg)
 {
   cmGeneratorTarget::TargetOrString resolved =
     target->ResolveTargetReference(input, lg);
@@ -625,7 +622,7 @@ bool cmExportFileGenerator::AddTargetNamespace(
     input = this->Namespace + tgt->GetExportName();
   } else {
     std::string namespacedTarget;
-    this->HandleMissingTarget(namespacedTarget, missingTargets, target, tgt);
+    this->HandleMissingTarget(namespacedTarget, target, tgt);
     if (!namespacedTarget.empty()) {
       input = namespacedTarget;
     } else {
@@ -637,12 +634,11 @@ bool cmExportFileGenerator::AddTargetNamespace(
 
 void cmExportFileGenerator::ResolveTargetsInGeneratorExpressions(
   std::string& input, cmGeneratorTarget const* target,
-  std::vector<std::string>& missingTargets, FreeTargetsReplace replace)
+  FreeTargetsReplace replace)
 {
   cmLocalGenerator const* lg = target->GetLocalGenerator();
   if (replace == NoReplaceFreeTargets) {
-    this->ResolveTargetsInGeneratorExpression(input, target, lg,
-                                              missingTargets);
+    this->ResolveTargetsInGeneratorExpression(input, target, lg);
     return;
   }
   std::vector<std::string> parts;
@@ -655,10 +651,9 @@ void cmExportFileGenerator::ResolveTargetsInGeneratorExpressions(
       continue;
     }
     if (cmGeneratorExpression::Find(li) == std::string::npos) {
-      this->AddTargetNamespace(li, target, lg, missingTargets);
+      this->AddTargetNamespace(li, target, lg);
     } else {
-      this->ResolveTargetsInGeneratorExpression(li, target, lg,
-                                                missingTargets);
+      this->ResolveTargetsInGeneratorExpression(li, target, lg);
     }
     input += sep + li;
     sep = ";";
@@ -667,7 +662,7 @@ void cmExportFileGenerator::ResolveTargetsInGeneratorExpressions(
 
 void cmExportFileGenerator::ResolveTargetsInGeneratorExpression(
   std::string& input, cmGeneratorTarget const* target,
-  cmLocalGenerator const* lg, std::vector<std::string>& missingTargets)
+  cmLocalGenerator const* lg)
 {
   std::string::size_type pos = 0;
   std::string::size_type lastPos = pos;
@@ -691,7 +686,7 @@ void cmExportFileGenerator::ResolveTargetsInGeneratorExpression(
     std::string targetName =
       input.substr(nameStartPos, commaPos - nameStartPos);
 
-    if (this->AddTargetNamespace(targetName, target, lg, missingTargets)) {
+    if (this->AddTargetNamespace(targetName, target, lg)) {
       input.replace(nameStartPos, commaPos - nameStartPos, targetName);
     }
     lastPos = nameStartPos + targetName.size() + 1;
@@ -713,7 +708,7 @@ void cmExportFileGenerator::ResolveTargetsInGeneratorExpression(
                     "literal.";
       break;
     }
-    if (!this->AddTargetNamespace(targetName, target, lg, missingTargets)) {
+    if (!this->AddTargetNamespace(targetName, target, lg)) {
       errorString = "$<TARGET_NAME:...> requires its parameter to be a "
                     "reachable target.";
       break;
@@ -734,7 +729,7 @@ void cmExportFileGenerator::ResolveTargetsInGeneratorExpression(
     }
     std::string libName = input.substr(nameStartPos, endPos - nameStartPos);
     if (cmGeneratorExpression::IsValidTargetName(libName) &&
-        this->AddTargetNamespace(libName, target, lg, missingTargets)) {
+        this->AddTargetNamespace(libName, target, lg)) {
       input.replace(nameStartPos, endPos - nameStartPos, libName);
     }
     lastPos = nameStartPos + libName.size() + 1;
@@ -756,8 +751,7 @@ void cmExportFileGenerator::ReplaceInstallPrefix(std::string& /*unused*/)
 void cmExportFileGenerator::SetImportLinkInterface(
   const std::string& config, std::string const& suffix,
   cmGeneratorExpression::PreprocessContext preprocessRule,
-  cmGeneratorTarget const* target, ImportPropertyMap& properties,
-  std::vector<std::string>& missingTargets)
+  cmGeneratorTarget const* target, ImportPropertyMap& properties)
 {
   // Add the transitive link dependencies for this configuration.
   cmLinkInterface const* iface = target->GetLinkInterface(config, target);
@@ -769,7 +763,7 @@ void cmExportFileGenerator::SetImportLinkInterface(
     // Policy CMP0022 must not be NEW.
     this->SetImportLinkProperty(
       suffix, target, "IMPORTED_LINK_INTERFACE_LIBRARIES", iface->Libraries,
-      properties, missingTargets, ImportLinkPropertyTargetNames::Yes);
+      properties, ImportLinkPropertyTargetNames::Yes);
     return;
   }
 
@@ -808,7 +802,7 @@ void cmExportFileGenerator::SetImportLinkInterface(
   std::string prepro =
     cmGeneratorExpression::Preprocess(*propContent, preprocessRule);
   if (!prepro.empty()) {
-    this->ResolveTargetsInGeneratorExpressions(prepro, target, missingTargets,
+    this->ResolveTargetsInGeneratorExpressions(prepro, target,
                                                ReplaceFreeTargets);
     properties["IMPORTED_LINK_INTERFACE_LIBRARIES" + suffix] = prepro;
   }
@@ -816,8 +810,7 @@ void cmExportFileGenerator::SetImportLinkInterface(
 
 void cmExportFileGenerator::SetImportDetailProperties(
   const std::string& config, std::string const& suffix,
-  cmGeneratorTarget* target, ImportPropertyMap& properties,
-  std::vector<std::string>& missingTargets)
+  cmGeneratorTarget* target, ImportPropertyMap& properties)
 {
   // Get the makefile in which to lookup target information.
   cmMakefile* mf = target->Makefile;
@@ -848,12 +841,11 @@ void cmExportFileGenerator::SetImportDetailProperties(
         target->GetLinkInterface(config, target)) {
     this->SetImportLinkProperty(
       suffix, target, "IMPORTED_LINK_INTERFACE_LANGUAGES", iface->Languages,
-      properties, missingTargets, ImportLinkPropertyTargetNames::No);
+      properties, ImportLinkPropertyTargetNames::No);
 
-    std::vector<std::string> dummy;
     this->SetImportLinkProperty(
       suffix, target, "IMPORTED_LINK_DEPENDENT_LIBRARIES", iface->SharedDeps,
-      properties, dummy, ImportLinkPropertyTargetNames::Yes);
+      properties, ImportLinkPropertyTargetNames::Yes);
     if (iface->Multiplicity > 0) {
       std::string prop =
         cmStrCat("IMPORTED_LINK_INTERFACE_MULTIPLICITY", suffix);
@@ -894,8 +886,7 @@ template <typename T>
 void cmExportFileGenerator::SetImportLinkProperty(
   std::string const& suffix, cmGeneratorTarget const* target,
   const std::string& propName, std::vector<T> const& entries,
-  ImportPropertyMap& properties, std::vector<std::string>& missingTargets,
-  ImportLinkPropertyTargetNames targetNames)
+  ImportPropertyMap& properties, ImportLinkPropertyTargetNames targetNames)
 {
   // Skip the property if there are no entries.
   if (entries.empty()) {
@@ -914,7 +905,7 @@ void cmExportFileGenerator::SetImportLinkProperty(
 
     if (targetNames == ImportLinkPropertyTargetNames::Yes) {
       std::string temp = asString(l);
-      this->AddTargetNamespace(temp, target, lg, missingTargets);
+      this->AddTargetNamespace(temp, target, lg);
       link_entries += temp;
     } else {
       link_entries += asString(l);
@@ -1124,10 +1115,9 @@ void cmExportFileGenerator::GenerateImportPropertyCode(
      << "\n";
 }
 
-void cmExportFileGenerator::GenerateMissingTargetsCheckCode(
-  std::ostream& os, const std::vector<std::string>& missingTargets)
+void cmExportFileGenerator::GenerateMissingTargetsCheckCode(std::ostream& os)
 {
-  if (missingTargets.empty()) {
+  if (this->MissingTargets.empty()) {
     /* clang-format off */
     os << "# This file does not depend on other imported targets which have\n"
           "# been exported from the same project but in a separate "
@@ -1142,7 +1132,7 @@ void cmExportFileGenerator::GenerateMissingTargetsCheckCode(
         "foreach(_target ";
   /* clang-format on */
   std::set<std::string> emitted;
-  for (std::string const& missingTarget : missingTargets) {
+  for (std::string const& missingTarget : this->MissingTargets) {
     if (emitted.insert(missingTarget).second) {
       os << "\"" << missingTarget << "\" ";
     }
diff --git a/Source/cmExportFileGenerator.h b/Source/cmExportFileGenerator.h
index bde6f1b..d27a555 100644
--- a/Source/cmExportFileGenerator.h
+++ b/Source/cmExportFileGenerator.h
@@ -66,8 +66,7 @@ protected:
 
   // Generate per-configuration target information to the given output
   // stream.
-  void GenerateImportConfig(std::ostream& os, const std::string& config,
-                            std::vector<std::string>& missingTargets);
+  void GenerateImportConfig(std::ostream& os, const std::string& config);
 
   // Methods to implement export file code generation.
   virtual void GeneratePolicyHeaderCode(std::ostream& os);
@@ -88,8 +87,7 @@ protected:
     ImportPropertyMap const& properties,
     const std::set<std::string>& importedLocations);
   virtual void GenerateImportedFileCheckLoop(std::ostream& os);
-  virtual void GenerateMissingTargetsCheckCode(
-    std::ostream& os, const std::vector<std::string>& missingTargets);
+  virtual void GenerateMissingTargetsCheckCode(std::ostream& os);
 
   virtual void GenerateExpectedTargetsCode(std::ostream& os,
                                            const std::string& expectedTargets);
@@ -99,8 +97,7 @@ protected:
   void SetImportDetailProperties(const std::string& config,
                                  std::string const& suffix,
                                  cmGeneratorTarget* target,
-                                 ImportPropertyMap& properties,
-                                 std::vector<std::string>& missingTargets);
+                                 ImportPropertyMap& properties);
 
   enum class ImportLinkPropertyTargetNames
   {
@@ -113,31 +110,28 @@ protected:
                              const std::string& propName,
                              std::vector<T> const& entries,
                              ImportPropertyMap& properties,
-                             std::vector<std::string>& missingTargets,
                              ImportLinkPropertyTargetNames targetNames);
 
   /** Each subclass knows how to generate its kind of export file.  */
   virtual bool GenerateMainFile(std::ostream& os) = 0;
 
   /** Each subclass knows where the target files are located.  */
-  virtual void GenerateImportTargetsConfig(
-    std::ostream& os, const std::string& config, std::string const& suffix,
-    std::vector<std::string>& missingTargets) = 0;
+  virtual void GenerateImportTargetsConfig(std::ostream& os,
+                                           const std::string& config,
+                                           std::string const& suffix) = 0;
 
   /** Each subclass knows how to deal with a target that is  missing from an
    *  export set.  */
   virtual void HandleMissingTarget(std::string& link_libs,
-                                   std::vector<std::string>& missingTargets,
                                    cmGeneratorTarget const* depender,
                                    cmGeneratorTarget* dependee) = 0;
   void PopulateInterfaceProperty(const std::string&,
                                  cmGeneratorTarget const* target,
                                  cmGeneratorExpression::PreprocessContext,
-                                 ImportPropertyMap& properties,
-                                 std::vector<std::string>& missingTargets);
+                                 ImportPropertyMap& properties);
   bool PopulateInterfaceLinkLibrariesProperty(
     cmGeneratorTarget const* target, cmGeneratorExpression::PreprocessContext,
-    ImportPropertyMap& properties, std::vector<std::string>& missingTargets);
+    ImportPropertyMap& properties);
   void PopulateInterfaceProperty(const std::string& propName,
                                  cmGeneratorTarget const* target,
                                  ImportPropertyMap& properties);
@@ -149,26 +143,24 @@ protected:
   void PopulateIncludeDirectoriesInterface(
     cmGeneratorTarget const* target,
     cmGeneratorExpression::PreprocessContext preprocessRule,
-    ImportPropertyMap& properties, std::vector<std::string>& missingTargets,
-    cmTargetExport const& te);
+    ImportPropertyMap& properties, cmTargetExport const& te);
   void PopulateSourcesInterface(
     cmGeneratorTarget const* target,
     cmGeneratorExpression::PreprocessContext preprocessRule,
-    ImportPropertyMap& properties, std::vector<std::string>& missingTargets);
+    ImportPropertyMap& properties);
   void PopulateLinkDirectoriesInterface(
     cmGeneratorTarget const* target,
     cmGeneratorExpression::PreprocessContext preprocessRule,
-    ImportPropertyMap& properties, std::vector<std::string>& missingTargets);
+    ImportPropertyMap& properties);
   void PopulateLinkDependsInterface(
     cmGeneratorTarget const* target,
     cmGeneratorExpression::PreprocessContext preprocessRule,
-    ImportPropertyMap& properties, std::vector<std::string>& missingTargets);
+    ImportPropertyMap& properties);
 
   void SetImportLinkInterface(
     const std::string& config, std::string const& suffix,
     cmGeneratorExpression::PreprocessContext preprocessRule,
-    cmGeneratorTarget const* target, ImportPropertyMap& properties,
-    std::vector<std::string>& missingTargets);
+    cmGeneratorTarget const* target, ImportPropertyMap& properties);
 
   enum FreeTargetsReplace
   {
@@ -178,7 +170,6 @@ protected:
 
   void ResolveTargetsInGeneratorExpressions(
     std::string& input, cmGeneratorTarget const* target,
-    std::vector<std::string>& missingTargets,
     FreeTargetsReplace replace = NoReplaceFreeTargets);
 
   virtual void GenerateRequiredCMakeVersion(std::ostream& os,
@@ -216,20 +207,20 @@ protected:
   // The set of targets included in the export.
   std::set<cmGeneratorTarget*> ExportedTargets;
 
+  std::vector<std::string> MissingTargets;
+
 private:
   void PopulateInterfaceProperty(const std::string&, const std::string&,
                                  cmGeneratorTarget const* target,
                                  cmGeneratorExpression::PreprocessContext,
-                                 ImportPropertyMap& properties,
-                                 std::vector<std::string>& missingTargets);
+                                 ImportPropertyMap& properties);
 
   bool AddTargetNamespace(std::string& input, cmGeneratorTarget const* target,
-                          cmLocalGenerator const* lg,
-                          std::vector<std::string>& missingTargets);
+                          cmLocalGenerator const* lg);
 
-  void ResolveTargetsInGeneratorExpression(
-    std::string& input, cmGeneratorTarget const* target,
-    cmLocalGenerator const* lg, std::vector<std::string>& missingTargets);
+  void ResolveTargetsInGeneratorExpression(std::string& input,
+                                           cmGeneratorTarget const* target,
+                                           cmLocalGenerator const* lg);
 
   virtual void ReplaceInstallPrefix(std::string& input);
 
diff --git a/Source/cmExportInstallAndroidMKGenerator.cxx b/Source/cmExportInstallAndroidMKGenerator.cxx
index 80f776e..4e4f8a1 100644
--- a/Source/cmExportInstallAndroidMKGenerator.cxx
+++ b/Source/cmExportInstallAndroidMKGenerator.cxx
@@ -5,6 +5,7 @@
 #include <cstddef>
 #include <memory>
 #include <ostream>
+#include <vector>
 
 #include "cmExportBuildAndroidMKGenerator.h"
 #include "cmExportSet.h"
@@ -86,7 +87,7 @@ void cmExportInstallAndroidMKGenerator::GenerateImportPropertyCode(
 }
 
 void cmExportInstallAndroidMKGenerator::GenerateMissingTargetsCheckCode(
-  std::ostream&, const std::vector<std::string>&)
+  std::ostream&)
 {
 }
 
@@ -132,7 +133,7 @@ void cmExportInstallAndroidMKGenerator::GenerateImportedFileChecksCode(
 }
 
 bool cmExportInstallAndroidMKGenerator::GenerateImportFileConfig(
-  const std::string&, std::vector<std::string>&)
+  const std::string&)
 {
   return true;
 }
diff --git a/Source/cmExportInstallAndroidMKGenerator.h b/Source/cmExportInstallAndroidMKGenerator.h
index 40978e0..c05751a 100644
--- a/Source/cmExportInstallAndroidMKGenerator.h
+++ b/Source/cmExportInstallAndroidMKGenerator.h
@@ -7,7 +7,6 @@
 #include <iosfwd>
 #include <set>
 #include <string>
-#include <vector>
 
 #include "cmExportFileGenerator.h"
 #include "cmExportInstallFileGenerator.h"
@@ -50,8 +49,7 @@ protected:
     std::ostream& os, const std::string& config,
     cmGeneratorTarget const* target,
     ImportPropertyMap const& properties) override;
-  void GenerateMissingTargetsCheckCode(
-    std::ostream& os, const std::vector<std::string>& missingTargets) override;
+  void GenerateMissingTargetsCheckCode(std::ostream& os) override;
   void GenerateInterfaceProperties(
     cmGeneratorTarget const* target, std::ostream& os,
     const ImportPropertyMap& properties) override;
@@ -65,6 +63,5 @@ protected:
     std::ostream& os, cmGeneratorTarget* target,
     ImportPropertyMap const& properties,
     const std::set<std::string>& importedLocations) override;
-  bool GenerateImportFileConfig(const std::string& config,
-                                std::vector<std::string>&) override;
+  bool GenerateImportFileConfig(const std::string& config) override;
 };
diff --git a/Source/cmExportInstallFileGenerator.cxx b/Source/cmExportInstallFileGenerator.cxx
index f232440..0c41946 100644
--- a/Source/cmExportInstallFileGenerator.cxx
+++ b/Source/cmExportInstallFileGenerator.cxx
@@ -71,8 +71,6 @@ bool cmExportInstallFileGenerator::GenerateMainFile(std::ostream& os)
   // Compute the relative import prefix for the file
   this->GenerateImportPrefix(os);
 
-  std::vector<std::string> missingTargets;
-
   bool require2_8_12 = false;
   bool require3_0_0 = false;
   bool require3_1_0 = false;
@@ -90,35 +88,34 @@ bool cmExportInstallFileGenerator::GenerateMainFile(std::ostream& os)
     ImportPropertyMap properties;
 
     this->PopulateIncludeDirectoriesInterface(
-      gt, cmGeneratorExpression::InstallInterface, properties, missingTargets,
-      *te);
+      gt, cmGeneratorExpression::InstallInterface, properties, *te);
     this->PopulateSourcesInterface(gt, cmGeneratorExpression::InstallInterface,
-                                   properties, missingTargets);
+                                   properties);
     this->PopulateInterfaceProperty("INTERFACE_SYSTEM_INCLUDE_DIRECTORIES", gt,
                                     cmGeneratorExpression::InstallInterface,
-                                    properties, missingTargets);
+                                    properties);
     this->PopulateInterfaceProperty("INTERFACE_COMPILE_DEFINITIONS", gt,
                                     cmGeneratorExpression::InstallInterface,
-                                    properties, missingTargets);
+                                    properties);
     this->PopulateInterfaceProperty("INTERFACE_COMPILE_OPTIONS", gt,
                                     cmGeneratorExpression::InstallInterface,
-                                    properties, missingTargets);
+                                    properties);
     this->PopulateInterfaceProperty("INTERFACE_PRECOMPILE_HEADERS", gt,
                                     cmGeneratorExpression::InstallInterface,
-                                    properties, missingTargets);
+                                    properties);
     this->PopulateInterfaceProperty("INTERFACE_AUTOUIC_OPTIONS", gt,
                                     cmGeneratorExpression::InstallInterface,
-                                    properties, missingTargets);
+                                    properties);
     this->PopulateInterfaceProperty("INTERFACE_COMPILE_FEATURES", gt,
                                     cmGeneratorExpression::InstallInterface,
-                                    properties, missingTargets);
+                                    properties);
     this->PopulateInterfaceProperty("INTERFACE_LINK_OPTIONS", gt,
                                     cmGeneratorExpression::InstallInterface,
-                                    properties, missingTargets);
+                                    properties);
     this->PopulateLinkDirectoriesInterface(
-      gt, cmGeneratorExpression::InstallInterface, properties, missingTargets);
+      gt, cmGeneratorExpression::InstallInterface, properties);
     this->PopulateLinkDependsInterface(
-      gt, cmGeneratorExpression::InstallInterface, properties, missingTargets);
+      gt, cmGeneratorExpression::InstallInterface, properties);
 
     std::string errorMessage;
     if (!this->PopulateExportProperties(gt, properties, errorMessage)) {
@@ -131,8 +128,7 @@ bool cmExportInstallFileGenerator::GenerateMainFile(std::ostream& os)
       gt->GetPolicyStatusCMP0022() != cmPolicies::OLD;
     if (newCMP0022Behavior) {
       if (this->PopulateInterfaceLinkLibrariesProperty(
-            gt, cmGeneratorExpression::InstallInterface, properties,
-            missingTargets) &&
+            gt, cmGeneratorExpression::InstallInterface, properties) &&
           !this->ExportOld) {
         require2_8_12 = true;
       }
@@ -174,13 +170,13 @@ bool cmExportInstallFileGenerator::GenerateMainFile(std::ostream& os)
   // Don't do this if we only export INTERFACE_LIBRARY targets.
   if (requiresConfigFiles) {
     for (std::string const& c : this->Configurations) {
-      if (!this->GenerateImportFileConfig(c, missingTargets)) {
+      if (!this->GenerateImportFileConfig(c)) {
         result = false;
       }
     }
   }
 
-  this->GenerateMissingTargetsCheckCode(os, missingTargets);
+  this->GenerateMissingTargetsCheckCode(os);
 
   return result;
 }
@@ -273,7 +269,7 @@ void cmExportInstallFileGenerator::ReplaceInstallPrefix(std::string& input)
 }
 
 bool cmExportInstallFileGenerator::GenerateImportFileConfig(
-  const std::string& config, std::vector<std::string>& missingTargets)
+  const std::string& config)
 {
   // Skip configurations not enabled for this export.
   if (!this->IEGen->InstallsForConfig(config)) {
@@ -305,7 +301,7 @@ bool cmExportInstallFileGenerator::GenerateImportFileConfig(
   this->GenerateImportHeaderCode(os, config);
 
   // Generate the per-config target information.
-  this->GenerateImportConfig(os, config, missingTargets);
+  this->GenerateImportConfig(os, config);
 
   // End with the import file footer.
   this->GenerateImportFooterCode(os);
@@ -317,8 +313,7 @@ bool cmExportInstallFileGenerator::GenerateImportFileConfig(
 }
 
 void cmExportInstallFileGenerator::GenerateImportTargetsConfig(
-  std::ostream& os, const std::string& config, std::string const& suffix,
-  std::vector<std::string>& missingTargets)
+  std::ostream& os, const std::string& config, std::string const& suffix)
 {
   // Add each target in the set to the export.
   for (std::unique_ptr<cmTargetExport> const& te :
@@ -350,12 +345,11 @@ void cmExportInstallFileGenerator::GenerateImportTargetsConfig(
     if (!properties.empty()) {
       // Get the rest of the target details.
       cmGeneratorTarget* gtgt = te->Target;
-      this->SetImportDetailProperties(config, suffix, gtgt, properties,
-                                      missingTargets);
+      this->SetImportDetailProperties(config, suffix, gtgt, properties);
 
       this->SetImportLinkInterface(config, suffix,
                                    cmGeneratorExpression::InstallInterface,
-                                   gtgt, properties, missingTargets);
+                                   gtgt, properties);
 
       // TODO: PUBLIC_HEADER_LOCATION
       // This should wait until the build feature propagation stuff
@@ -454,8 +448,8 @@ cmStateEnums::TargetType cmExportInstallFileGenerator::GetExportTargetType(
 }
 
 void cmExportInstallFileGenerator::HandleMissingTarget(
-  std::string& link_libs, std::vector<std::string>& missingTargets,
-  cmGeneratorTarget const* depender, cmGeneratorTarget* dependee)
+  std::string& link_libs, cmGeneratorTarget const* depender,
+  cmGeneratorTarget* dependee)
 {
   const std::string name = dependee->GetName();
   cmGlobalGenerator* gg = dependee->GetLocalGenerator()->GetGlobalGenerator();
@@ -466,7 +460,7 @@ void cmExportInstallFileGenerator::HandleMissingTarget(
 
     missingTarget += dependee->GetExportName();
     link_libs += missingTarget;
-    missingTargets.push_back(std::move(missingTarget));
+    this->MissingTargets.emplace_back(std::move(missingTarget));
   } else {
     // All exported targets should be known here and should be unique.
     // This is probably user-error.
diff --git a/Source/cmExportInstallFileGenerator.h b/Source/cmExportInstallFileGenerator.h
index 9374c6b..86fb505 100644
--- a/Source/cmExportInstallFileGenerator.h
+++ b/Source/cmExportInstallFileGenerator.h
@@ -57,13 +57,11 @@ public:
 protected:
   // Implement virtual methods from the superclass.
   bool GenerateMainFile(std::ostream& os) override;
-  void GenerateImportTargetsConfig(
-    std::ostream& os, const std::string& config, std::string const& suffix,
-    std::vector<std::string>& missingTargets) override;
+  void GenerateImportTargetsConfig(std::ostream& os, const std::string& config,
+                                   std::string const& suffix) override;
   cmStateEnums::TargetType GetExportTargetType(
     cmTargetExport const* targetExport) const;
   void HandleMissingTarget(std::string& link_libs,
-                           std::vector<std::string>& missingTargets,
                            cmGeneratorTarget const* depender,
                            cmGeneratorTarget* dependee) override;
 
@@ -85,8 +83,7 @@ protected:
   virtual void CleanupTemporaryVariables(std::ostream&);
 
   /** Generate a per-configuration file for the targets.  */
-  virtual bool GenerateImportFileConfig(
-    const std::string& config, std::vector<std::string>& missingTargets);
+  virtual bool GenerateImportFileConfig(const std::string& config);
 
   /** Fill in properties indicating installed file locations.  */
   void SetImportLocationProperty(const std::string& config,
diff --git a/Source/cmExportTryCompileFileGenerator.h b/Source/cmExportTryCompileFileGenerator.h
index 8a1fd7e..1dd8a20 100644
--- a/Source/cmExportTryCompileFileGenerator.h
+++ b/Source/cmExportTryCompileFileGenerator.h
@@ -33,12 +33,10 @@ protected:
   bool GenerateMainFile(std::ostream& os) override;
 
   void GenerateImportTargetsConfig(std::ostream&, const std::string&,
-                                   std::string const&,
-                                   std::vector<std::string>&) override
+                                   std::string const&) override
   {
   }
-  void HandleMissingTarget(std::string&, std::vector<std::string>&,
-                           cmGeneratorTarget const*,
+  void HandleMissingTarget(std::string&, cmGeneratorTarget const*,
                            cmGeneratorTarget*) override
   {
   }