ENH: Make link interface mode more distinct

Rename the recently added INTERFACE mode of the target_link_libraries()
command to LINK_INTERFACE_LIBRARIES.  This makes it much more distinct
from a normal call to the command, and clearly states its connection to
the property of the same name.  Also require the option to appear
immediately after the target name to make it a mode rather than an
option.

Source/cmTargetLinkLibrariesCommand.cxx

@@ -64,15 +64,22 @@ bool cmTargetLinkLibrariesCommand
 
   // add libraries, nothe that there is an optional prefix 
   // of debug and optimized than can be used
-  std::vector<std::string>::const_iterator i = args.begin();
-  
-  for(++i; i != args.end(); ++i)
+  for(unsigned int i=1; i < args.size(); ++i)
     {
-    if(*i == "INTERFACE")
+    if(args[i] == "LINK_INTERFACE_LIBRARIES")
       {
       this->DoingInterface = true;
+      if(i != 1)
+        {
+        this->Makefile->IssueMessage(
+          cmake::FATAL_ERROR,
+          "The LINK_INTERFACE_LIBRARIES option must appear as the second "
+          "argument, just after the target name."
+          );
+        return true;
+        }
       }
-    else if(*i == "debug")
+    else if(args[i] == "debug")
       {
       if(haveLLT)
         {
@@ -81,7 +88,7 @@ bool cmTargetLinkLibrariesCommand
       llt = cmTarget::DEBUG;
       haveLLT = true;
       }
-    else if(*i == "optimized")
+    else if(args[i] == "optimized")
       {
       if(haveLLT)
         {
@@ -90,7 +97,7 @@ bool cmTargetLinkLibrariesCommand
       llt = cmTarget::OPTIMIZED;
       haveLLT = true;
       }
-    else if(*i == "general")
+    else if(args[i] == "general")
       {
       if(haveLLT)
         {
@@ -103,7 +110,7 @@ bool cmTargetLinkLibrariesCommand
       {
       // The link type was specified by the previous argument.
       haveLLT = false;
-      this->HandleLibrary(i->c_str(), llt);
+      this->HandleLibrary(args[i].c_str(), llt);
       }
     else
       {
@@ -129,7 +136,7 @@ bool cmTargetLinkLibrariesCommand
           llt = cmTarget::OPTIMIZED;
           }
         }
-      this->HandleLibrary(i->c_str(), llt);
+      this->HandleLibrary(args[i].c_str(), llt);
       }
     } 
 

Source/cmTargetLinkLibrariesCommand.h

@@ -64,7 +64,7 @@ public:
   virtual const char* GetFullDocumentation()
     {
     return
-      "  target_link_libraries(<target> [INTERFACE]\n"
+      "  target_link_libraries(<target> [lib1 [lib2 [...]]]\n"
       "                        [[debug|optimized|general] <lib>] ...)\n"
       "Specify a list of libraries to be linked into the specified target.  "
       "If any library name matches that of a target in the current project "
@@ -90,7 +90,9 @@ public:
       "See the LINK_INTERFACE_LIBRARIES target property to override the "
       "set of transitive link dependencies for a target."
       "\n"
-      "The INTERFACE option tells the command to append the libraries "
+      "  target_link_libraries(<target> LINK_INTERFACE_LIBRARIES\n"
+      "                        [[debug|optimized|general] <lib>] ...)\n"
+      "The LINK_INTERFACE_LIBRARIES mode appends the libraries "
       "to the LINK_INTERFACE_LIBRARIES and LINK_INTERFACE_LIBRARIES_DEBUG "
       "target properties instead of using them for linking.  "
       "Libraries specified as \"debug\" are appended to the "

Tests/ExportImport/Export/CMakeLists.txt

@@ -54,7 +54,8 @@ add_library(testLib4libopt STATIC testLib4libdbg.c testLib4libopt${VS6}.c)
 set_property(TARGET testLib4libdbg PROPERTY COMPILE_DEFINITIONS LIB_DBG)
 set_property(TARGET testLib4libopt PROPERTY COMPILE_DEFINITIONS LIB_OPT)
 target_link_libraries(testLib4
-  INTERFACE testLib4lib debug testLib4libdbg optimized testLib4libopt
+  LINK_INTERFACE_LIBRARIES
+  testLib4lib debug testLib4libdbg optimized testLib4libopt
   )
 
 add_executable(testExe3 testExe3.c)