From 87342c189915ba27f9e122a4196e51404ff5ee11 Mon Sep 17 00:00:00 2001
From: Bartosz Kosiorek <gang65@poczta.onet.pl>
Date: Thu, 28 Jan 2016 10:52:15 +0100
Subject: [PATCH] Distinguish between warnings, when target is not exist, and
 from when target was not defined in current directory.

---
 Help/command/add_custom_command.rst  |  7 ++++++-
 Help/command/get_target_property.rst |  2 +-
 Help/command/if.rst                  |  6 ++++--
 Help/policy/CMP0040.rst              | 18 ++++++++++--------
 Source/cmMakefile.cxx                |  9 ++++++++-
 5 files changed, 29 insertions(+), 13 deletions(-)

diff --git a/Help/command/add_custom_command.rst b/Help/command/add_custom_command.rst
index ecbf9dd..5c958b7 100644
--- a/Help/command/add_custom_command.rst
+++ b/Help/command/add_custom_command.rst
@@ -188,7 +188,11 @@ target is already built, the command will not execute.
                      [VERBATIM] [USES_TERMINAL])
 
 This defines a new command that will be associated with building the
-specified target.  When the command will happen is determined by which
+specified ``TARGET``. ``TARGET`` name must be defined in current 
+directory. If the target is not property defined, the warning will 
+be displayed according to :policy:`CMP0040`.
+ 
+When the command will happen is determined by which
 of the following is specified:
 
 ``PRE_BUILD``
@@ -203,3 +207,4 @@ of the following is specified:
   :command:`add_custom_target` command.
 ``POST_BUILD``
   Run after all other rules within the target have been executed.
+
diff --git a/Help/command/get_target_property.rst b/Help/command/get_target_property.rst
index 7798252..2a72c3a 100644
--- a/Help/command/get_target_property.rst
+++ b/Help/command/get_target_property.rst
@@ -13,6 +13,6 @@ the variable ``VAR``.  If the property is not found, ``VAR`` will be set to
 Properties are usually used to control how a target is built, but some
 query the target instead.  This command can get properties for any
 target so far created.  The targets do not need to be in the current
-CMakeLists.txt file.
+``CMakeLists.txt`` file.
 
 See also the more general :command:`get_property` command.
diff --git a/Help/command/if.rst b/Help/command/if.rst
index 2465bde..5b0a7aa 100644
--- a/Help/command/if.rst
+++ b/Help/command/if.rst
@@ -69,7 +69,9 @@ Possible expressions are:
 ``if(TARGET target-name)``
  True if the given name is an existing logical target name such as those
  created by the :command:`add_executable`, :command:`add_library`, or
- :command:`add_custom_target` commands.
+ :command:`add_custom_target` commands. Expression do not check if 
+ target is defined in current directory, and cannot be used to check 
+ if command :command:`add_custom_command` could be used.
 
 ``if(TEST test-name)``
  True if the given name is an existing test name created by the
@@ -80,7 +82,7 @@ Possible expressions are:
  only for full paths.
 
 ``if(file1 IS_NEWER_THAN file2)``
- True if file1 is newer than file2 or if one of the two files doesn't
+ True if ``file1`` is newer than ``file2`` or if one of the two files doesn't
  exist.  Behavior is well-defined only for full paths.  If the file
  time stamps are exactly the same, an ``IS_NEWER_THAN`` comparison returns
  true, so that any dependent build operations will occur in the event
diff --git a/Help/policy/CMP0040.rst b/Help/policy/CMP0040.rst
index e746c03..eea9702 100644
--- a/Help/policy/CMP0040.rst
+++ b/Help/policy/CMP0040.rst
@@ -1,18 +1,20 @@
 CMP0040
 -------
 
-The target in the TARGET signature of add_custom_command() must exist.
+The target in the ``TARGET`` signature of :command:`add_custom_command` 
+must exist and must be defined in current directory.
 
 CMake 2.8.12 and lower silently ignored a custom command created with
-the TARGET signature of :command:`add_custom_command`
-if the target is unknown.
+the ``TARGET`` signature of :command:`add_custom_command`
+if the target is unknown or was defined outside directory.
 
-The OLD behavior for this policy is to ignore custom commands
-for unknown targets. The NEW behavior for this policy is to report an error
-if the target referenced in :command:`add_custom_command` is unknown.
+The ``OLD`` behavior for this policy is to ignore custom commands
+for unknown targets.  The ``NEW`` behavior for this policy is to report an error
+if the target referenced in :command:`add_custom_command` is unknown, 
+or defined outside current directory.
 
 This policy was introduced in CMake version 3.0.  CMake version
-|release| warns when the policy is not set and uses OLD behavior.  Use
-the cmake_policy command to set it to OLD or NEW explicitly.
+|release| warns when the policy is not set and uses ``OLD`` behavior.  Use
+the :command:`cmake_policy` command to set it to ``OLD`` or ``NEW`` explicitly.
 
 .. include:: DEPRECATED.txt
diff --git a/Source/cmMakefile.cxx b/Source/cmMakefile.cxx
index ba0d672..0690eb4 100644
--- a/Source/cmMakefile.cxx
+++ b/Source/cmMakefile.cxx
@@ -791,7 +791,14 @@ cmMakefile::AddCustomCommandToTarget(const std::string& target,
 
     if(issueMessage)
       {
-      e << "The target name \"" << target << "\" is unknown in this context.";
+      if(this->FindTargetToUse(target))
+        {
+        e << "add_custom_command() is unable to use target \"" << target << "\", which was defined outside current directory.";
+        }
+      else
+        {
+        e << "The target name \"" << target << "\" is unknown in this context, and cannot be used by add_custom_command().";  
+        }
       IssueMessage(messageType, e.str());
       }
 
-- 
2.5.0