Remove CMAKE_USE_RELATIVE_PATHS variable.

The test for this variable was removed in commit v2.8.8~330^2~7 (complex:
Remove ancient unused ComplexRelativePaths test, 2011-12-23).

Commit v3.1.0-rc1~425^2~2 (backtrace: Convert to local paths in
IssueMessage, 2014-03-12) appears to have accidentally made some backtraces
print relative paths with the variable because conversions which used to be
done at configure time, before the variable had an effect are now potentially
done at generate time.

The documentation of the variable says not to use it, and the docs are wrong in
that the variable actually applies in per-directory scope.

The read of the variable makes it harder to split conversion methods from
cmLocalGenerator where they don't belong.  Remove it now.

Help/release/dev/remove-CMAKE_USE_RELATIVE_PATHS.rst

@@ -0,0 +1,5 @@
+remove-CMAKE_USE_RELATIVE_PATHS
+-------------------------------
+
+* The :variable:`CMAKE_USE_RELATIVE_PATHS` variable no longer has any
+  effect.  Previously it was partially implemented and unreliable.

Help/variable/CMAKE_USE_RELATIVE_PATHS.rst

@@ -1,10 +1,5 @@
 CMAKE_USE_RELATIVE_PATHS
 ------------------------
 
-Use relative paths (May not work!).
-
-If this is set to TRUE, then CMake will use relative paths between the
-source and binary tree.  This option does not work for more
-complicated projects, and relative paths are used when possible.  In
-general, it is not possible to move CMake generated makefiles to a
-different location regardless of the value of this variable.
+This variable has no effect.  The partially implemented effect it
+had in previous releases was removed in CMake 3.4.

Source/cmGlobalXCodeGenerator.cxx

@@ -3804,33 +3804,13 @@ void cmGlobalXCodeGenerator::GetDocumentation(cmDocumentationEntry& entry)
 //----------------------------------------------------------------------------
 std::string cmGlobalXCodeGenerator::ConvertToRelativeForMake(const char* p)
 {
-  if ( !this->CurrentMakefile->IsOn("CMAKE_USE_RELATIVE_PATHS") )
-    {
-    return cmSystemTools::ConvertToOutputPath(p);
-    }
-  else
-    {
-    std::string ret =
-      this->CurrentLocalGenerator->
-        ConvertToRelativePath(this->CurrentOutputDirectoryComponents, p);
-    return cmSystemTools::ConvertToOutputPath(ret.c_str());
-    }
+  return cmSystemTools::ConvertToOutputPath(p);
 }
 
 //----------------------------------------------------------------------------
 std::string cmGlobalXCodeGenerator::ConvertToRelativeForXCode(const char* p)
 {
-  if ( !this->CurrentMakefile->IsOn("CMAKE_USE_RELATIVE_PATHS") )
-    {
-    return cmSystemTools::ConvertToOutputPath(p);
-    }
-  else
-    {
-    std::string ret =
-      this->CurrentLocalGenerator->
-        ConvertToRelativePath(this->ProjectOutputDirectoryComponents, p);
-    return cmSystemTools::ConvertToOutputPath(ret.c_str());
-    }
+  return cmSystemTools::ConvertToOutputPath(p);
 }
 
 //----------------------------------------------------------------------------

Source/cmLocalGenerator.cxx

@@ -59,7 +59,6 @@ cmLocalGenerator::cmLocalGenerator(cmGlobalGenerator* gg,
   this->Makefile = new cmMakefile(this);
 
   this->LinkScriptShell = false;
-  this->UseRelativePaths = false;
   this->Configured = false;
   this->EmitUniversalBinaryFlags = true;
   this->BackwardsCompatibility = 0;
@@ -137,10 +136,6 @@ void cmLocalGenerator::Configure()
 
   this->Makefile->AddCMakeDependFilesFromUser();
 
-  // Check whether relative paths should be used for optionally
-  // relative paths.
-  this->UseRelativePaths = this->Makefile->IsOn("CMAKE_USE_RELATIVE_PATHS");
-
   this->ComputeObjectMaxPath();
 
   this->Configured = true;
@@ -2705,7 +2700,7 @@ std::string cmLocalGenerator::Convert(const std::string& source,
   // Convert the path to a relative path.
   std::string result = source;
 
-  if (!optional || this->UseRelativePaths)
+  if (!optional)
     {
     switch (relative)
       {
@@ -2786,7 +2781,7 @@ std::string cmLocalGenerator::Convert(RelativeRoot remote,
   // The relative root must have a path (i.e. not FULL or NONE)
   assert(remotePath != 0);
 
-  if(!local.empty() && (!optional || this->UseRelativePaths))
+  if(!local.empty() && !optional)
     {
     std::vector<std::string> components;
     cmSystemTools::SplitPath(local, components);

Source/cmLocalGenerator.h

@@ -127,8 +127,7 @@ public:
   const char* GetRelativeRootPath(RelativeRoot relroot);
 
   /**
-   * Convert the given path to an output path that is optionally
-   * relative based on the cache option CMAKE_USE_RELATIVE_PATHS.  The
+   * Convert the given path to an output path.  The
    * remote path must use forward slashes and not already be escaped
    * or quoted.
    */
@@ -460,7 +459,6 @@ protected:
   std::set<cmTarget const*> WarnCMP0063;
 
   bool LinkScriptShell;
-  bool UseRelativePaths;
   bool Configured;
   bool EmitUniversalBinaryFlags;
 

Source/cmMakefileTargetGenerator.cxx

@@ -614,13 +614,7 @@ cmMakefileTargetGenerator
     }
 
   // Get the output paths for source and object files.
-  std::string sourceFile = source.GetFullPath();
-  if(this->LocalGenerator->UseRelativePaths)
-    {
-    sourceFile = this->Convert(sourceFile,
-                               cmLocalGenerator::START_OUTPUT);
-    }
-  sourceFile = this->Convert(sourceFile,
+  std::string sourceFile = this->Convert(source.GetFullPath(),
                              cmLocalGenerator::NONE,
                              cmLocalGenerator::SHELL);
 

Source/cmake.cxx

@@ -1437,20 +1437,6 @@ int cmake::ActualConfigure()
          cmState::PATH);
       }
     }
-  if(!this->State
-          ->GetInitializedCacheValue("CMAKE_USE_RELATIVE_PATHS"))
-    {
-    this->State->AddCacheEntry
-      ("CMAKE_USE_RELATIVE_PATHS", "OFF",
-       "If true, cmake will use relative paths in makefiles and projects.",
-       cmState::BOOL);
-    if (!this->State->GetCacheEntryProperty("CMAKE_USE_RELATIVE_PATHS",
-                                                    "ADVANCED"))
-      {
-      this->State->SetCacheEntryProperty("CMAKE_USE_RELATIVE_PATHS",
-                                                 "ADVANCED", "1");
-      }
-    }
 
   if(cmSystemTools::GetFatalErrorOccured())
     {