ENH: Move CMP0004 check into cmTarget

This moves code implementing policy CMP0004 into cmTarget::CheckCMP0004.
The implementation is slightly simpler and can be re-used outside of
cmComputeLinkDepends.

Source/cmComputeLinkDepends.cxx

@@ -553,7 +553,7 @@ cmComputeLinkDepends::AddLinkEntries(int depender_index,
     {
     // Skip entries that will resolve to the target getting linked or
     // are empty.
-    std::string item = this->CleanItemName(*li);
+    std::string item = this->Target->CheckCMP0004(*li);
     if(item == this->Target->GetName() || item.empty())
       {
       continue;
@@ -605,66 +605,6 @@ cmComputeLinkDepends::AddLinkEntries(int depender_index,
     }
 }
 
-//----------------------------------------------------------------------------
-std::string cmComputeLinkDepends::CleanItemName(std::string const& item)
-{
-  // Strip whitespace off the library names because we used to do this
-  // in case variables were expanded at generate time.  We no longer
-  // do the expansion but users link to libraries like " ${VAR} ".
-  std::string lib = item;
-  std::string::size_type pos = lib.find_first_not_of(" \t\r\n");
-  if(pos != lib.npos)
-    {
-    lib = lib.substr(pos, lib.npos);
-    }
-  pos = lib.find_last_not_of(" \t\r\n");
-  if(pos != lib.npos)
-    {
-    lib = lib.substr(0, pos+1);
-    }
-  if(lib != item)
-    {
-    switch(this->Target->GetPolicyStatusCMP0004())
-      {
-      case cmPolicies::WARN:
-        {
-        cmOStringStream w;
-        w << (this->Makefile->GetPolicies()
-              ->GetPolicyWarning(cmPolicies::CMP0004)) << "\n"
-          << "Target \"" << this->Target->GetName() << "\" links to item \""
-          << item << "\" which has leading or trailing whitespace.";
-        this->CMakeInstance->IssueMessage(cmake::AUTHOR_WARNING, w.str(),
-                                          this->Target->GetBacktrace());
-        }
-      case cmPolicies::OLD:
-        break;
-      case cmPolicies::NEW:
-        {
-        cmOStringStream e;
-        e << "Target \"" << this->Target->GetName() << "\" links to item \""
-          << item << "\" which has leading or trailing whitespace.  "
-          << "This is now an error according to policy CMP0004.";
-        this->CMakeInstance->IssueMessage(cmake::FATAL_ERROR, e.str(),
-                                          this->Target->GetBacktrace());
-        }
-        break;
-      case cmPolicies::REQUIRED_IF_USED:
-      case cmPolicies::REQUIRED_ALWAYS:
-        {
-        cmOStringStream e;
-        e << (this->Makefile->GetPolicies()
-              ->GetRequiredPolicyError(cmPolicies::CMP0004)) << "\n"
-          << "Target \"" << this->Target->GetName() << "\" links to item \""
-          << item << "\" which has leading or trailing whitespace.";
-        this->CMakeInstance->IssueMessage(cmake::FATAL_ERROR, e.str(),
-                                          this->Target->GetBacktrace());
-        }
-        break;
-      }
-    }
-  return lib;
-}
-
 //----------------------------------------------------------------------------
 cmTarget* cmComputeLinkDepends::FindTargetToLink(int depender_index,
                                                  const char* name)

Source/cmComputeLinkDepends.h

@@ -87,7 +87,6 @@ private:
                             LinkLibraryVectorType const& libs);
   void AddLinkEntries(int depender_index,
                       std::vector<std::string> const& libs);
-  std::string CleanItemName(std::string const& item);
   cmTarget* FindTargetToLink(int depender_index, const char* name);
 
   // One entry for each unique item.

Source/cmTarget.cxx

@@ -3814,6 +3814,65 @@ cmTarget::ComputeLinkInterface(const char* config)
   return iface;
 }
 
+//----------------------------------------------------------------------------
+std::string cmTarget::CheckCMP0004(std::string const& item)
+{
+  // Strip whitespace off the library names because we used to do this
+  // in case variables were expanded at generate time.  We no longer
+  // do the expansion but users link to libraries like " ${VAR} ".
+  std::string lib = item;
+  std::string::size_type pos = lib.find_first_not_of(" \t\r\n");
+  if(pos != lib.npos)
+    {
+    lib = lib.substr(pos, lib.npos);
+    }
+  pos = lib.find_last_not_of(" \t\r\n");
+  if(pos != lib.npos)
+    {
+    lib = lib.substr(0, pos+1);
+    }
+  if(lib != item)
+    {
+    cmake* cm = this->Makefile->GetCMakeInstance();
+    switch(this->PolicyStatusCMP0004)
+      {
+      case cmPolicies::WARN:
+        {
+        cmOStringStream w;
+        w << (this->Makefile->GetPolicies()
+              ->GetPolicyWarning(cmPolicies::CMP0004)) << "\n"
+          << "Target \"" << this->GetName() << "\" links to item \""
+          << item << "\" which has leading or trailing whitespace.";
+        cm->IssueMessage(cmake::AUTHOR_WARNING, w.str(),
+                         this->GetBacktrace());
+        }
+      case cmPolicies::OLD:
+        break;
+      case cmPolicies::NEW:
+        {
+        cmOStringStream e;
+        e << "Target \"" << this->GetName() << "\" links to item \""
+          << item << "\" which has leading or trailing whitespace.  "
+          << "This is now an error according to policy CMP0004.";
+        cm->IssueMessage(cmake::FATAL_ERROR, e.str(), this->GetBacktrace());
+        }
+        break;
+      case cmPolicies::REQUIRED_IF_USED:
+      case cmPolicies::REQUIRED_ALWAYS:
+        {
+        cmOStringStream e;
+        e << (this->Makefile->GetPolicies()
+              ->GetRequiredPolicyError(cmPolicies::CMP0004)) << "\n"
+          << "Target \"" << this->GetName() << "\" links to item \""
+          << item << "\" which has leading or trailing whitespace.";
+        cm->IssueMessage(cmake::FATAL_ERROR, e.str(), this->GetBacktrace());
+        }
+        break;
+      }
+    }
+  return lib;
+}
+
 //----------------------------------------------------------------------------
 cmComputeLinkInformation*
 cmTarget::GetLinkInformation(const char* config)

Source/cmTarget.h

@@ -260,6 +260,10 @@ public:
       such dependencies or for static libraries.  */
   cmTargetLinkInterface const* GetLinkInterface(const char* config);
 
+  /** Strip off leading and trailing whitespace from an item named in
+      the link dependencies of this target.  */
+  std::string CheckCMP0004(std::string const& item);
+
   /** Get the directory in which this target will be built.  If the
       configuration name is given then the generator will add its
       subdirectory for that configuration.  Otherwise just the canonical