LINK_DIRECTORIES target property: add policy for absolute paths check.

Help/manual/cmake-policies.7.rst

@@ -57,6 +57,7 @@ Policies Introduced by CMake 3.13
 .. toctree::
    :maxdepth: 1
 
+   CMP0081: Relative paths not allowed in LINK_DIRECTORIES target property. </policy/CMP0081>
    CMP0080: BundleUtilities cannot be included at configure time. </policy/CMP0080>
    CMP0079: target_link_libraries allows use with targets in other directories. </policy/CMP0079>
    CMP0078: UseSWIG generates standard target names. </policy/CMP0078>

Help/policy/CMP0081.rst

@@ -0,0 +1,22 @@
+CMP0081
+-------
+
+Relative paths not allowed in :prop_tgt:`LINK_DIRECTORIES` target property.
+
+CMake 3.12 and lower allowed the :prop_dir:`LINK_DIRECTORIES` directory
+property to contain relative paths.  The base path for such relative
+entries is not well defined.  CMake 3.13 and later will issue a
+``FATAL_ERROR`` if the :prop_tgt:`LINK_DIRECTORIES` target property
+(which is initialized by the :prop_dir:`LINK_DIRECTORIES` directory property)
+contains a relative path.
+
+The ``OLD`` behavior for this policy is not to warn about relative paths
+in the :prop_tgt:`LINK_DIRECTORIES` target property.  The ``NEW`` behavior for
+this policy is to issue a ``FATAL_ERROR`` if :prop_tgt:`LINK_DIRECTORIES`
+contains a relative path.
+
+This policy was introduced in CMake version 3.13.  CMake version
+|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

Help/release/dev/LINK_DIRECTORIES-policy.rst

@@ -0,0 +1,5 @@
+LINK_DIRECTORIES-policy
+-----------------------
+
+* The :prop_tgt:`LINK_DIRECTORIES` target property expects absolute paths.
+  See policy :policy:`CMP0081`.

Source/cmGeneratorTarget.cxx

@@ -3091,14 +3091,38 @@ void processLinkDirectories(
     for (std::string& entryDirectory : entryDirectories) {
       if (!cmSystemTools::FileIsFullPath(entryDirectory)) {
         std::ostringstream e;
+        bool noMessage = false;
+        cmake::MessageType messageType = cmake::FATAL_ERROR;
         if (!targetName.empty()) {
           /* clang-format off */
           e << "Target \"" << targetName << "\" contains relative "
             "path in its INTERFACE_LINK_DIRECTORIES:\n"
             "  \"" << entryDirectory << "\"";
           /* clang-format on */
-          tgt->GetLocalGenerator()->IssueMessage(cmake::FATAL_ERROR, e.str());
+        } else {
-          return;
+          switch (tgt->GetPolicyStatusCMP0081()) {
+            case cmPolicies::WARN: {
+              e << cmPolicies::GetPolicyWarning(cmPolicies::CMP0081) << "\n";
+              messageType = cmake::AUTHOR_WARNING;
+            } break;
+            case cmPolicies::OLD:
+              noMessage = true;
+              break;
+            case cmPolicies::REQUIRED_IF_USED:
+            case cmPolicies::REQUIRED_ALWAYS:
+            case cmPolicies::NEW:
+              // Issue the fatal message.
+              break;
+          }
+          e << "Found relative path while evaluating link directories of "
+               "\""
+            << tgt->GetName() << "\":\n  \"" << entryDirectory << "\"\n";
+        }
+        if (!noMessage) {
+          tgt->GetLocalGenerator()->IssueMessage(messageType, e.str());
+          if (messageType == cmake::FATAL_ERROR) {
+            return;
+          }
         }
       }
 

Source/cmPolicies.h

@@ -237,7 +237,10 @@ class cmMakefile;
     13, 0, cmPolicies::WARN)                                                  \
   SELECT(POLICY, CMP0080,                                                     \
          "BundleUtilities cannot be included at configure time", 3, 13, 0,    \
-         cmPolicies::WARN)
+         cmPolicies::WARN)                                                    \
+  SELECT(POLICY, CMP0081,                                                     \
+         "Relative paths not allowed in LINK_DIRECTORIES target property.",   \
+         3, 13, 0, cmPolicies::WARN)
 
 #define CM_SELECT_ID(F, A1, A2, A3, A4, A5, A6) F(A1)
 #define CM_FOR_EACH_POLICY_ID(POLICY)                                         \
@@ -263,7 +266,8 @@ class cmMakefile;
   F(CMP0068)                                                                  \
   F(CMP0069)                                                                  \
   F(CMP0073)                                                                  \
-  F(CMP0076)
+  F(CMP0076)                                                                  \
+  F(CMP0081)
 
 /** \class cmPolicies
  * \brief Handles changes in CMake behavior and policies

Tests/RunCMake/CMP0081/CMP0081-Common.cmake

@@ -0,0 +1,5 @@
+
+enable_language(CXX)
+
+add_library(foo SHARED empty.cpp)
+set_target_properties(foo PROPERTIES LINK_DIRECTORIES "../lib")

Tests/RunCMake/CMP0081/CMP0081-NEW-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/CMP0081/CMP0081-NEW-stderr.txt

@@ -0,0 +1,4 @@
+CMake Error in CMakeLists.txt:
+  Found relative path while evaluating link directories of "foo":
+
+    "../lib"

Tests/RunCMake/CMP0081/CMP0081-NEW.cmake

@@ -0,0 +1,4 @@
+
+cmake_policy(SET CMP0081 NEW)
+
+include (CMP0081-Common.cmake)

Tests/RunCMake/CMP0081/CMP0081-OLD-result.txt

@@ -0,0 +1 @@
+0

Tests/RunCMake/CMP0081/CMP0081-OLD.cmake

@@ -0,0 +1,4 @@
+
+cmake_policy(SET CMP0081 OLD)
+
+include (CMP0081-Common.cmake)

Tests/RunCMake/CMP0081/CMP0081-WARN-result.txt

@@ -0,0 +1 @@
+0

Tests/RunCMake/CMP0081/CMP0081-WARN-stderr.txt

@@ -0,0 +1,10 @@
+CMake Warning \(dev\) in CMakeLists.txt:
+  Policy CMP0081 is not set: Relative paths not allowed in LINK_DIRECTORIES
+  target property.  Run "cmake --help-policy CMP0081" for policy details.
+  Use the cmake_policy command to set the policy and suppress this warning.
+
+  Found relative path while evaluating link directories of "foo":
+
+    "../lib"
+
+This warning is for project developers.  Use -Wno-dev to suppress it.

Tests/RunCMake/CMP0081/CMP0081-WARN.cmake

@@ -0,0 +1,2 @@
+
+include (CMP0081-Common.cmake)

Tests/RunCMake/CMP0081/CMakeLists.txt

@@ -0,0 +1,3 @@
+cmake_minimum_required(VERSION 3.1)
+project(${RunCMake_TEST} NONE)
+include(${RunCMake_TEST}.cmake)

Tests/RunCMake/CMP0081/RunCMakeTest.cmake

@@ -0,0 +1,5 @@
+include(RunCMake)
+
+run_cmake(CMP0081-OLD)
+run_cmake(CMP0081-NEW)
+run_cmake(CMP0081-WARN)

Tests/RunCMake/CMP0081/empty.cpp

@@ -0,0 +1,7 @@
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+  int empty()
+{
+  return 0;
+}

Tests/RunCMake/CMakeLists.txt

@@ -106,6 +106,7 @@ if(CMAKE_SYSTEM_NAME MATCHES Darwin AND CMAKE_SHARED_LIBRARY_RUNTIME_C_FLAG)
   add_RunCMake_test(CMP0068)
 endif()
 add_RunCMake_test(CMP0069)
+add_RunCMake_test(CMP0081)
 
 # The test for Policy 65 requires the use of the
 # CMAKE_SHARED_LIBRARY_LINK_CXX_FLAGS variable, which both the VS and Xcode

Tests/RunCMake/TargetPolicies/PolicyList-stderr.txt

@@ -25,6 +25,7 @@
    \* CMP0069
    \* CMP0073
    \* CMP0076
+   \* CMP0081
 
 Call Stack \(most recent call first\):
   CMakeLists.txt:3 \(include\)