Xcode: Each target dependency edge needs a unique object (#13935)

Generate a unique PBXTargetDependency and PBXContainerItemProxy for
every edge in the dependency graph as required by the Xcode format.
Xcode only accidentally loads project files that re-use the same
PBXTargetDependency for every edge leading to a single target.  If one
is removed by hand in the IDE then Xcode may crash due to dangling
references from the others.

Since cmGlobalXCodeGenerator::AddDependTarget is called exactly once for
every edge in the target dependency graph we do not need to keep track
of which edges have been visited to avoid generating duplicates.

3 files changed, 19 insertions, 33 deletions

diff --git a/Source/cmGlobalXCodeGenerator.cxx b/Source/cmGlobalXCodeGenerator.cxx
index fb8eafc..d836290 100644
--- a/Source/cmGlobalXCodeGenerator.cxx
+++ b/Source/cmGlobalXCodeGenerator.cxx
@@ -2517,29 +2517,25 @@ std::string cmGlobalXCodeGenerator::GetOrCreateId(const char* name,
 void cmGlobalXCodeGenerator::AddDependTarget(cmXCodeObject* target,
                                              cmXCodeObject* dependTarget)
 {
-  cmXCodeObject* targetdep = dependTarget->GetPBXTargetDependency();
-  if(!targetdep)
-    {
-    cmXCodeObject* container =
-      this->CreateObject(cmXCodeObject::PBXContainerItemProxy);
-    container->SetComment("PBXContainerItemProxy");
-    container->AddAttribute("containerPortal",
-                            this->CreateObjectReference(this->RootObject));
-    container->AddAttribute("proxyType", this->CreateString("1"));
-    container->AddAttribute("remoteGlobalIDString",
-                            this->CreateObjectReference(dependTarget));
-    container->AddAttribute("remoteInfo",
-                            this->CreateString(
-                              dependTarget->GetTarget()->GetName()));
-    targetdep =
-      this->CreateObject(cmXCodeObject::PBXTargetDependency);
-    targetdep->SetComment("PBXTargetDependency");
-    targetdep->AddAttribute("target",
-                            this->CreateObjectReference(dependTarget));
-    targetdep->AddAttribute("targetProxy",
-                            this->CreateObjectReference(container));
-    dependTarget->SetPBXTargetDependency(targetdep);
-    }
+  // This is called once for every edge in the target dependency graph.
+  cmXCodeObject* container =
+    this->CreateObject(cmXCodeObject::PBXContainerItemProxy);
+  container->SetComment("PBXContainerItemProxy");
+  container->AddAttribute("containerPortal",
+                          this->CreateObjectReference(this->RootObject));
+  container->AddAttribute("proxyType", this->CreateString("1"));
+  container->AddAttribute("remoteGlobalIDString",
+                          this->CreateObjectReference(dependTarget));
+  container->AddAttribute("remoteInfo",
+                          this->CreateString(
+                            dependTarget->GetTarget()->GetName()));
+  cmXCodeObject* targetdep =
+    this->CreateObject(cmXCodeObject::PBXTargetDependency);
+  targetdep->SetComment("PBXTargetDependency");
+  targetdep->AddAttribute("target",
+                          this->CreateObjectReference(dependTarget));
+  targetdep->AddAttribute("targetProxy",
+                          this->CreateObjectReference(container));
 
   cmXCodeObject* depends = target->GetObject("dependencies");
   if(!depends)
diff --git a/Source/cmXCodeObject.cxx b/Source/cmXCodeObject.cxx
index de150ee..6abf6bf 100644
--- a/Source/cmXCodeObject.cxx
+++ b/Source/cmXCodeObject.cxx
@@ -38,7 +38,6 @@ cmXCodeObject::~cmXCodeObject()
 cmXCodeObject::cmXCodeObject(PBXType ptype, Type type)
 {
   this->Version = 15;
-  this->PBXTargetDependencyValue = 0;
   this->Target = 0;
   this->Object =0;
 
diff --git a/Source/cmXCodeObject.h b/Source/cmXCodeObject.h
index bb2d5b2..b89f78c 100644
--- a/Source/cmXCodeObject.h
+++ b/Source/cmXCodeObject.h
@@ -120,14 +120,6 @@ public:
       return 0;
     }
 
-  cmXCodeObject* GetPBXTargetDependency()
-    {
-      return this->PBXTargetDependencyValue;
-    }
-  void SetPBXTargetDependency(cmXCodeObject* d)
-    {
-      this->PBXTargetDependencyValue = d;
-    }
   void CopyAttributes(cmXCodeObject* );
 
   void AddDependLibrary(const char* configName,
@@ -170,7 +162,6 @@ protected:
   cmStdString Comment;
   cmStdString String;
   cmXCodeObject* Object;
-  cmXCodeObject* PBXTargetDependencyValue;
   std::vector<cmXCodeObject*> List;
   std::map<cmStdString, StringVec> DependLibraries;
   std::map<cmStdString, StringVec> DependTargets;