cmCustomCommand: Track main dependency explicitly

Store the main dependency as the first entry in the dependency list plus
a boolean member indicating its existence.  Note that this slightly
changes existing behavior: the main dependency was previously the last
entry of the dependency list.

14 files changed, 64 insertions, 60 deletions

diff --git a/Source/cmAddCustomCommandCommand.cxx b/Source/cmAddCustomCommandCommand.cxx
index 0798ed4..831e9c7 100644
--- a/Source/cmAddCustomCommandCommand.cxx
+++ b/Source/cmAddCustomCommandCommand.cxx
@@ -335,9 +335,10 @@ bool cmAddCustomCommandCommand(std::vector<std::string> const& args,
   } else if (target.empty()) {
     // Target is empty, use the output.
     cc->SetOutputs(output);
+    cc->SetMainDependency(main_dependency);
     cc->SetDepends(depends);
     cc->SetImplicitDepends(implicit_depends);
-    mf.AddCustomCommandToOutput(main_dependency, std::move(cc));
+    mf.AddCustomCommandToOutput(std::move(cc));
   } else if (!byproducts.empty()) {
     status.SetError("BYPRODUCTS may not be specified with SOURCE signatures");
     return false;
diff --git a/Source/cmCPluginAPI.cxx b/Source/cmCPluginAPI.cxx
index 9714e16..1b11f20 100644
--- a/Source/cmCPluginAPI.cxx
+++ b/Source/cmCPluginAPI.cxx
@@ -302,9 +302,10 @@ static void CCONV cmAddCustomCommandToOutput(void* arg, const char* output,
   // Pass the call to the makefile instance.
   auto cc = cm::make_unique<cmCustomCommand>();
   cc->SetOutputs(output);
+  cc->SetMainDependency(main_dependency);
   cc->SetDepends(depends2);
   cc->SetCommandLines(commandLines);
-  mf->AddCustomCommandToOutput(main_dependency, std::move(cc));
+  mf->AddCustomCommandToOutput(std::move(cc));
 }
 
 static void CCONV cmAddCustomCommandToTarget(void* arg, const char* target,
diff --git a/Source/cmCustomCommand.cxx b/Source/cmCustomCommand.cxx
index f009632..68c65bb 100644
--- a/Source/cmCustomCommand.cxx
+++ b/Source/cmCustomCommand.cxx
@@ -2,6 +2,7 @@
    file Copyright.txt or https://cmake.org/licensing for details.  */
 #include "cmCustomCommand.h"
 
+#include <cassert>
 #include <utility>
 
 #include <cmext/algorithm>
@@ -38,9 +39,32 @@ const std::vector<std::string>& cmCustomCommand::GetDepends() const
 
 void cmCustomCommand::SetDepends(std::vector<std::string> depends)
 {
+  if (this->HasMainDependency_) {
+    depends.insert(depends.begin(), std::move(this->Depends[0]));
+  }
+
   Depends = std::move(depends);
 }
 
+const std::string& cmCustomCommand::GetMainDependency() const
+{
+  assert(this->HasMainDependency_);
+  return this->Depends[0];
+}
+
+void cmCustomCommand::SetMainDependency(std::string main_dependency)
+{
+  if (this->HasMainDependency_) {
+    assert(!main_dependency.empty());
+    this->Depends[0] = std::move(main_dependency);
+  } else if (main_dependency.empty()) {
+    // Do nothing.
+  } else {
+    this->Depends.insert(this->Depends.begin(), std::move(main_dependency));
+    this->HasMainDependency_ = true;
+  }
+}
+
 const cmCustomCommandLines& cmCustomCommand::GetCommandLines() const
 {
   return this->CommandLines;
diff --git a/Source/cmCustomCommand.h b/Source/cmCustomCommand.h
index 5ae26dd..5533847 100644
--- a/Source/cmCustomCommand.h
+++ b/Source/cmCustomCommand.h
@@ -38,6 +38,10 @@ public:
   const std::vector<std::string>& GetDepends() const;
   void SetDepends(std::vector<std::string> depends);
 
+  bool HasMainDependency() const { return this->HasMainDependency_; }
+  const std::string& GetMainDependency() const;
+  void SetMainDependency(std::string main_dependency);
+
   /** Get the working directory.  */
   std::string const& GetWorkingDirectory() const
   {
@@ -130,5 +134,6 @@ private:
   bool UsesTerminal = false;
   bool CommandExpandLists = false;
   bool StdPipesUTF8 = false;
+  bool HasMainDependency_ = false;
   cmPolicies::PolicyStatus CMP0116Status = cmPolicies::WARN;
 };
diff --git a/Source/cmFLTKWrapUICommand.cxx b/Source/cmFLTKWrapUICommand.cxx
index 47dd709..80c069f 100644
--- a/Source/cmFLTKWrapUICommand.cxx
+++ b/Source/cmFLTKWrapUICommand.cxx
@@ -98,7 +98,6 @@ bool cmFLTKWrapUICommand(std::vector<std::string> const& args,
       });
 
       // Add command for generating the .h and .cxx files
-      std::string no_main_dependency;
 
       auto hcc = cm::make_unique<cmCustomCommand>();
       hcc->SetDepends(depends);
@@ -106,10 +105,10 @@ bool cmFLTKWrapUICommand(std::vector<std::string> const& args,
       auto ccc = cm::make_unique<cmCustomCommand>(*hcc);
 
       hcc->SetOutputs(cxxres);
-      mf.AddCustomCommandToOutput(no_main_dependency, std::move(hcc));
+      mf.AddCustomCommandToOutput(std::move(hcc));
 
       ccc->SetOutputs(hname);
-      mf.AddCustomCommandToOutput(no_main_dependency, std::move(ccc));
+      mf.AddCustomCommandToOutput(std::move(ccc));
 
       cmSourceFile* sf = mf.GetSource(cxxres);
       sf->AddDepend(hname);
diff --git a/Source/cmGlobalVisualStudio8Generator.cxx b/Source/cmGlobalVisualStudio8Generator.cxx
index 4e53dff..dbd2de9 100644
--- a/Source/cmGlobalVisualStudio8Generator.cxx
+++ b/Source/cmGlobalVisualStudio8Generator.cxx
@@ -254,7 +254,6 @@ bool cmGlobalVisualStudio8Generator::AddCheckTarget()
     // file as the main dependency because it would get
     // overwritten by the CreateVCProjBuildRule.
     // (this could be avoided with per-target source files)
-    std::string no_main_dependency;
     cc = cm::make_unique<cmCustomCommand>();
     cc->SetOutputs(stamps);
     cc->SetDepends(listFiles);
@@ -263,8 +262,8 @@ bool cmGlobalVisualStudio8Generator::AddCheckTarget()
     cc->SetCMP0116Status(cmPolicies::NEW);
     cc->SetEscapeOldStyle(false);
     cc->SetStdPipesUTF8(stdPipesUTF8);
-    if (cmSourceFile* file = lg.AddCustomCommandToOutput(
-          no_main_dependency, std::move(cc), true)) {
+    if (cmSourceFile* file =
+          lg.AddCustomCommandToOutput(std::move(cc), true)) {
       gt->AddSource(file->ResolveFullPath());
     } else {
       cmSystemTools::Error("Error adding rule for " + stamps[0]);
diff --git a/Source/cmLocalGenerator.cxx b/Source/cmLocalGenerator.cxx
index a07e298..5b3aad3 100644
--- a/Source/cmLocalGenerator.cxx
+++ b/Source/cmLocalGenerator.cxx
@@ -1072,8 +1072,7 @@ cmTarget* cmLocalGenerator::AddCustomCommandToTarget(
 }
 
 cmSourceFile* cmLocalGenerator::AddCustomCommandToOutput(
-  const std::string& main_dependency, std::unique_ptr<cmCustomCommand> cc,
-  bool replace)
+  std::unique_ptr<cmCustomCommand> cc, bool replace)
 {
   // Make sure there is at least one output.
   if (cc->GetOutputs().empty()) {
@@ -1083,8 +1082,7 @@ cmSourceFile* cmLocalGenerator::AddCustomCommandToOutput(
 
   cc->SetBacktrace(this->DirectoryBacktrace);
   return detail::AddCustomCommandToOutput(*this, cmCommandOrigin::Generator,
-                                          main_dependency, std::move(cc),
-                                          replace);
+                                          std::move(cc), replace);
 }
 
 cmTarget* cmLocalGenerator::AddUtilityCommand(
@@ -2724,7 +2722,6 @@ void cmLocalGenerator::CopyPchCompilePdb(
       configGenex(cmStrCat("-DPDB_PREFIX=", pdb_prefix)), configGenex("-P"),
       configGenex(copy_script) });
 
-  const std::string no_main_dependency;
   const char* no_message = "";
 
   std::vector<std::string> outputs;
@@ -2744,8 +2741,7 @@ void cmLocalGenerator::CopyPchCompilePdb(
       cmObjectLibraryCommands::Accept);
   } else {
     cc->SetOutputs(outputs);
-    cmSourceFile* copy_rule =
-      this->AddCustomCommandToOutput(no_main_dependency, std::move(cc));
+    cmSourceFile* copy_rule = this->AddCustomCommandToOutput(std::move(cc));
 
     if (copy_rule) {
       target->AddSource(copy_rule->ResolveFullPath());
@@ -4011,7 +4007,6 @@ std::string ComputeCustomCommandRuleFileName(cmLocalGenerator& lg,
 }
 
 cmSourceFile* AddCustomCommand(cmLocalGenerator& lg, cmCommandOrigin origin,
-                               const std::string& main_dependency,
                                std::unique_ptr<cmCustomCommand> cc,
                                bool replace)
 {
@@ -4023,7 +4018,8 @@ cmSourceFile* AddCustomCommand(cmLocalGenerator& lg, cmCommandOrigin origin,
 
   // Choose a source file on which to store the custom command.
   cmSourceFile* file = nullptr;
-  if (!commandLines.empty() && !main_dependency.empty()) {
+  if (!commandLines.empty() && cc->HasMainDependency()) {
+    const auto& main_dependency = cc->GetMainDependency();
     // The main dependency was specified.  Use it unless a different
     // custom command already used it.
     file = mf->GetSource(main_dependency);
@@ -4073,11 +4069,6 @@ cmSourceFile* AddCustomCommand(cmLocalGenerator& lg, cmCommandOrigin origin,
 
   // Attach the custom command to the file.
   if (file) {
-    // Construct a complete list of dependencies.
-    if (!main_dependency.empty()) {
-      cc->AppendDepends({ main_dependency });
-    }
-
     cc->SetEscapeAllowMakeVars(true);
 
     lg.AddSourceOutputs(file, outputs, cmLocalGenerator::OutputRole::Primary,
@@ -4142,11 +4133,10 @@ void AddCustomCommandToTarget(cmLocalGenerator& lg, cmCommandOrigin origin,
 
 cmSourceFile* AddCustomCommandToOutput(cmLocalGenerator& lg,
                                        cmCommandOrigin origin,
-                                       const std::string& main_dependency,
                                        std::unique_ptr<cmCustomCommand> cc,
                                        bool replace)
 {
-  return AddCustomCommand(lg, origin, main_dependency, std::move(cc), replace);
+  return AddCustomCommand(lg, origin, std::move(cc), replace);
 }
 
 void AppendCustomCommandToOutput(cmLocalGenerator& lg,
@@ -4206,10 +4196,8 @@ void AddUtilityCommand(cmLocalGenerator& lg, cmCommandOrigin origin,
     lg.CreateUtilityOutput(target->GetName(), byproducts, lfbt);
   cc->SetOutputs(output);
 
-  std::string no_main_dependency;
-  cmSourceFile* rule =
-    AddCustomCommand(lg, origin, no_main_dependency, std::move(cc),
-                     /*replace=*/false);
+  cmSourceFile* rule = AddCustomCommand(lg, origin, std::move(cc),
+                                        /*replace=*/false);
   if (rule) {
     lg.AddTargetByproducts(target, byproducts, lfbt, origin);
   }
diff --git a/Source/cmLocalGenerator.h b/Source/cmLocalGenerator.h
index 5793f29..c73cd62 100644
--- a/Source/cmLocalGenerator.h
+++ b/Source/cmLocalGenerator.h
@@ -330,8 +330,7 @@ public:
   /**
    * Add a custom command to a source file.
    */
-  cmSourceFile* AddCustomCommandToOutput(const std::string& main_dependency,
-                                         std::unique_ptr<cmCustomCommand> cc,
+  cmSourceFile* AddCustomCommandToOutput(std::unique_ptr<cmCustomCommand> cc,
                                          bool replace = false);
 
   /**
@@ -683,7 +682,6 @@ void AddCustomCommandToTarget(cmLocalGenerator& lg, cmCommandOrigin origin,
 
 cmSourceFile* AddCustomCommandToOutput(cmLocalGenerator& lg,
                                        cmCommandOrigin origin,
-                                       const std::string& main_dependency,
                                        std::unique_ptr<cmCustomCommand> cc,
                                        bool replace);
 
diff --git a/Source/cmLocalVisualStudio7Generator.cxx b/Source/cmLocalVisualStudio7Generator.cxx
index c40e33e..dc9dcc7 100644
--- a/Source/cmLocalVisualStudio7Generator.cxx
+++ b/Source/cmLocalVisualStudio7Generator.cxx
@@ -129,7 +129,6 @@ void cmLocalVisualStudio7Generator::FixGlobalTargets()
     if (l->GetType() == cmStateEnums::GLOBAL_TARGET) {
       cmCustomCommandLines force_commands =
         cmMakeSingleCommandLine({ "cd", "." });
-      std::string no_main_dependency;
       std::string force = cmStrCat(this->GetCurrentBinaryDirectory(),
                                    "/CMakeFiles/", l->GetName(), "_force");
       if (cmSourceFile* sf =
@@ -141,8 +140,8 @@ void cmLocalVisualStudio7Generator::FixGlobalTargets()
       cc->SetCommandLines(force_commands);
       cc->SetComment(" ");
       cc->SetCMP0116Status(cmPolicies::NEW);
-      if (cmSourceFile* file = this->AddCustomCommandToOutput(
-            no_main_dependency, std::move(cc), true)) {
+      if (cmSourceFile* file =
+            this->AddCustomCommandToOutput(std::move(cc), true)) {
         l->AddSource(file->ResolveFullPath());
       }
     }
@@ -266,13 +265,14 @@ cmSourceFile* cmLocalVisualStudio7Generator::CreateVCProjBuildRule()
   std::string comment = cmStrCat("Building Custom Rule ", makefileIn);
   auto cc = cm::make_unique<cmCustomCommand>();
   cc->SetOutputs(stampName);
+  cc->SetMainDependency(makefileIn);
   cc->SetDepends(listFiles);
   cc->SetCommandLines(commandLines);
   cc->SetComment(comment.c_str());
   cc->SetCMP0116Status(cmPolicies::NEW);
   cc->SetEscapeOldStyle(false);
   cc->SetStdPipesUTF8(true);
-  this->AddCustomCommandToOutput(makefileIn, std::move(cc), true);
+  this->AddCustomCommandToOutput(std::move(cc), true);
   if (cmSourceFile* file = this->Makefile->GetSource(makefileIn)) {
     // Finalize the source file path now since we're adding this after
     // the generator validated all project-named sources.
diff --git a/Source/cmMakefile.cxx b/Source/cmMakefile.cxx
index 950fa7b..cc687b1 100644
--- a/Source/cmMakefile.cxx
+++ b/Source/cmMakefile.cxx
@@ -1087,8 +1087,8 @@ cmTarget* cmMakefile::AddCustomCommandToTarget(
 }
 
 void cmMakefile::AddCustomCommandToOutput(
-  const std::string& main_dependency, std::unique_ptr<cmCustomCommand> cc,
-  const CommandSourceCallback& callback, bool replace)
+  std::unique_ptr<cmCustomCommand> cc, const CommandSourceCallback& callback,
+  bool replace)
 {
   const auto& outputs = cc->GetOutputs();
   const auto& byproducts = cc->GetByproducts();
@@ -1119,8 +1119,7 @@ void cmMakefile::AddCustomCommandToOutput(
       BacktraceGuard guard(this->Backtrace, lfbt);
       tcc->SetBacktrace(lfbt);
       cmSourceFile* sf = detail::AddCustomCommandToOutput(
-        lg, cmCommandOrigin::Project, main_dependency, std::move(tcc),
-        replace);
+        lg, cmCommandOrigin::Project, std::move(tcc), replace);
       if (callback && sf) {
         callback(sf);
       }
@@ -1178,19 +1177,17 @@ void cmMakefile::AddCustomCommandOldStyle(
     for (std::string const& output : outputs) {
       auto cc1 = cm::make_unique<cmCustomCommand>(*cc);
       cc1->SetOutputs(output);
-      this->AddCustomCommandToOutput(source, std::move(cc1),
-                                     addRuleFileToTarget);
+      cc1->SetMainDependency(source);
+      this->AddCustomCommandToOutput(std::move(cc1), addRuleFileToTarget);
     }
   } else {
-    std::string no_main_dependency;
     cc->AppendDepends({ source });
 
     // The source may not be a real file.  Do not use a main dependency.
     for (std::string const& output : outputs) {
       auto cc1 = cm::make_unique<cmCustomCommand>(*cc);
       cc1->SetOutputs(output);
-      this->AddCustomCommandToOutput(no_main_dependency, std::move(cc1),
-                                     addRuleFileToTarget);
+      this->AddCustomCommandToOutput(std::move(cc1), addRuleFileToTarget);
     }
   }
 }
diff --git a/Source/cmMakefile.h b/Source/cmMakefile.h
index af18230..85988b8 100644
--- a/Source/cmMakefile.h
+++ b/Source/cmMakefile.h
@@ -212,7 +212,7 @@ public:
    * Dispatch adding a custom command to a source file.
    */
   void AddCustomCommandToOutput(
-    const std::string& main_dependency, std::unique_ptr<cmCustomCommand> cc,
+    std::unique_ptr<cmCustomCommand> cc,
     const CommandSourceCallback& callback = nullptr, bool replace = false);
   void AddCustomCommandOldStyle(const std::string& target,
                                 const std::vector<std::string>& outputs,
diff --git a/Source/cmQTWrapCPPCommand.cxx b/Source/cmQTWrapCPPCommand.cxx
index b489944..58cf514 100644
--- a/Source/cmQTWrapCPPCommand.cxx
+++ b/Source/cmQTWrapCPPCommand.cxx
@@ -75,13 +75,12 @@ bool cmQTWrapCPPCommand(std::vector<std::string> const& args,
       depends.push_back(moc_exe);
       depends.push_back(hname);
 
-      std::string no_main_dependency;
       auto cc = cm::make_unique<cmCustomCommand>();
       cc->SetOutputs(newName);
       cc->SetDepends(depends);
       cc->SetCommandLines(commandLines);
       cc->SetComment("Qt Wrapped File");
-      mf.AddCustomCommandToOutput(no_main_dependency, std::move(cc));
+      mf.AddCustomCommandToOutput(std::move(cc));
     }
   }
 
diff --git a/Source/cmQTWrapUICommand.cxx b/Source/cmQTWrapUICommand.cxx
index 4d65f33..8b2a42c 100644
--- a/Source/cmQTWrapUICommand.cxx
+++ b/Source/cmQTWrapUICommand.cxx
@@ -88,19 +88,18 @@ bool cmQTWrapUICommand(std::vector<std::string> const& args,
 
       std::vector<std::string> depends;
       depends.push_back(uiName);
-      std::string no_main_dependency;
       auto cc = cm::make_unique<cmCustomCommand>();
       cc->SetOutputs(hName);
       cc->SetDepends(depends);
       cc->SetCommandLines(hCommandLines);
-      mf.AddCustomCommandToOutput(no_main_dependency, std::move(cc));
+      mf.AddCustomCommandToOutput(std::move(cc));
 
       depends.push_back(hName);
       cc = cm::make_unique<cmCustomCommand>();
       cc->SetOutputs(cxxName);
       cc->SetDepends(depends);
       cc->SetCommandLines(cxxCommandLines);
-      mf.AddCustomCommandToOutput(no_main_dependency, std::move(cc));
+      mf.AddCustomCommandToOutput(std::move(cc));
 
       depends.clear();
       depends.push_back(hName);
@@ -108,7 +107,7 @@ bool cmQTWrapUICommand(std::vector<std::string> const& args,
       cc->SetOutputs(mocName);
       cc->SetDepends(depends);
       cc->SetCommandLines(mocCommandLines);
-      mf.AddCustomCommandToOutput(no_main_dependency, std::move(cc));
+      mf.AddCustomCommandToOutput(std::move(cc));
     }
   }
 
diff --git a/Source/cmQtAutoGenInitializer.cxx b/Source/cmQtAutoGenInitializer.cxx
index c2a37fe..a01e6ae 100644
--- a/Source/cmQtAutoGenInitializer.cxx
+++ b/Source/cmQtAutoGenInitializer.cxx
@@ -1230,7 +1230,6 @@ bool cmQtAutoGenInitializer::InitAutogenTarget()
 
       // Add a rule file to cause the target to build if a dependency has
       // changed, which will trigger the pre-build command to run autogen
-      std::string no_main_dependency;
       auto cc = cm::make_unique<cmCustomCommand>();
       cc->SetOutputs(timestampFileGenex);
       cc->SetDepends(uicDependencies);
@@ -1239,8 +1238,7 @@ bool cmQtAutoGenInitializer::InitAutogenTarget()
       cc->SetCMP0116Status(cmPolicies::NEW);
       cc->SetEscapeOldStyle(false);
       cc->SetStdPipesUTF8(stdPipesUTF8);
-      this->LocalGen->AddCustomCommandToOutput(no_main_dependency,
-                                               std::move(cc));
+      this->LocalGen->AddCustomCommandToOutput(std::move(cc));
     }
 
     // Add the pre-build command directly to bypass the OBJECT_LIBRARY
@@ -1362,7 +1360,6 @@ bool cmQtAutoGenInitializer::InitAutogenTarget()
         { cmSystemTools::GetCMakeCommand(), "-E", "touch", outputFile }));
 
       this->AddGeneratedSource(outputFile, this->Moc);
-      const std::string no_main_dependency;
       cc = cm::make_unique<cmCustomCommand>();
       cc->SetOutputs(outputFile);
       cc->SetByproducts(timestampByproducts);
@@ -1374,8 +1371,7 @@ bool cmQtAutoGenInitializer::InitAutogenTarget()
       cc->SetEscapeOldStyle(false);
       cc->SetDepfile(this->AutogenTarget.DepFile);
       cc->SetStdPipesUTF8(stdPipesUTF8);
-      this->LocalGen->AddCustomCommandToOutput(no_main_dependency,
-                                               std::move(cc));
+      this->LocalGen->AddCustomCommandToOutput(std::move(cc));
 
       // Alter variables for the autogen target which now merely wraps the
       // custom command
@@ -1524,12 +1520,10 @@ bool cmQtAutoGenInitializer::InitRccTargets()
         if (!this->Rcc.ExecutableTargetName.empty()) {
           ccDepends.push_back(this->Rcc.ExecutableTargetName);
         }
-        std::string no_main_dependency;
         cc->SetOutputs(ccOutput);
         cc->SetByproducts(ccByproducts);
         cc->SetDepends(ccDepends);
-        this->LocalGen->AddCustomCommandToOutput(no_main_dependency,
-                                                 std::move(cc));
+        this->LocalGen->AddCustomCommandToOutput(std::move(cc));
       }
       // Reconfigure when .qrc file changes
       this->Makefile->AddCMakeDependFile(qrc.QrcFile);