cmOutputConverter: Always set relative path top source and binary together

Refactor to set both at once so we have a single place in the code that
knows both have been set.

Source/cmGlobalNinjaGenerator.cxx

@@ -2495,8 +2495,7 @@ bool cmGlobalNinjaGenerator::WriteDyndepFile(
     snapshot.GetDirectory().SetCurrentBinary(dir_cur_bld);
     auto mfd = cm::make_unique<cmMakefile>(this, snapshot);
     auto lgd = this->CreateLocalGenerator(mfd.get());
-    lgd->SetRelativePathTopSource(dir_top_src);
-    lgd->SetRelativePathTopBinary(dir_top_bld);
+    lgd->SetRelativePathTop(dir_top_src, dir_top_bld);
     this->Makefiles.push_back(std::move(mfd));
     this->LocalGenerators.push_back(std::move(lgd));
   }

Source/cmLocalUnixMakefileGenerator3.cxx

@@ -1508,13 +1508,12 @@ bool cmLocalUnixMakefileGenerator3::ScanDependencies(
     }
 
     // Setup relative path top directories.
-    if (cmValue relativePathTopSource =
-          mf->GetDefinition("CMAKE_RELATIVE_PATH_TOP_SOURCE")) {
-      this->SetRelativePathTopSource(*relativePathTopSource);
-    }
-    if (cmValue relativePathTopBinary =
-          mf->GetDefinition("CMAKE_RELATIVE_PATH_TOP_BINARY")) {
-      this->SetRelativePathTopBinary(*relativePathTopBinary);
+    cmValue relativePathTopSource =
+      mf->GetDefinition("CMAKE_RELATIVE_PATH_TOP_SOURCE");
+    cmValue relativePathTopBinary =
+      mf->GetDefinition("CMAKE_RELATIVE_PATH_TOP_BINARY");
+    if (relativePathTopSource && relativePathTopBinary) {
+      this->SetRelativePathTop(*relativePathTopSource, *relativePathTopBinary);
     }
   } else {
     cmSystemTools::Error("Directory Information file not found");

Source/cmOutputConverter.cxx

@@ -79,14 +79,11 @@ std::string const& cmOutputConverter::GetRelativePathTopBinary() const
   return this->RelativePathTopBinary;
 }
 
-void cmOutputConverter::SetRelativePathTopSource(std::string const& top)
+void cmOutputConverter::SetRelativePathTop(std::string const& topSource,
+                                           std::string const& topBinary)
 {
-  this->RelativePathTopSource = top;
-}
-
-void cmOutputConverter::SetRelativePathTopBinary(std::string const& top)
-{
-  this->RelativePathTopBinary = top;
+  this->RelativePathTopSource = topSource;
+  this->RelativePathTopBinary = topBinary;
 }
 
 std::string cmOutputConverter::MaybeRelativeTo(

Source/cmOutputConverter.h

@@ -29,8 +29,8 @@ public:
 
   std::string const& GetRelativePathTopSource() const;
   std::string const& GetRelativePathTopBinary() const;
-  void SetRelativePathTopSource(std::string const& top);
-  void SetRelativePathTopBinary(std::string const& top);
+  void SetRelativePathTop(std::string const& topSource,
+                          std::string const& topBinary);
 
   enum OutputFormat
   {

Source/cmcmd.cxx

@@ -1286,8 +1286,7 @@ int cmcmd::ExecuteCMakeCommand(std::vector<std::string> const& args,
         // FIXME: With advanced add_subdirectory usage, these are
         // not necessarily the same as the generator originally used.
         // We should pass all these directories through an info file.
-        lgd->SetRelativePathTopSource(homeDir);
-        lgd->SetRelativePathTopBinary(homeOutDir);
+        lgd->SetRelativePathTop(homeDir, homeOutDir);
 
         // Actually scan dependencies.
         return lgd->UpdateDependencies(depInfo, verbose, color) ? 0 : 2;
@@ -1569,8 +1568,7 @@ int cmcmd::ExecuteCMakeCommand(std::vector<std::string> const& args,
         // FIXME: With advanced add_subdirectory usage, these are
         // not necessarily the same as the generator originally used.
         // We should pass all these directories through an info file.
-        lgd->SetRelativePathTopSource(homeDir);
-        lgd->SetRelativePathTopBinary(homeOutDir);
+        lgd->SetRelativePathTop(homeDir, homeOutDir);
 
         return cmTransformDepfile(format, *lgd, args[8], args[9]) ? 0 : 2;
       }