cmTarget: Evaluate CMP0026 and CMP0051 in calling context

These policies should be checked at the call site that tries to access
the LOCATION or SOURCES property, not the directory scope containing the
target.  Thread the caller context through cmTarget::GetProperty to use
for checking the policy setting and emitting a diagnostic with proper
backtrace.

Extend the RunCMake.CMP0026 and RunCMake.CMP0051 tests with
cross-directory cases.

Source/cmGetPropertyCommand.cxx

@@ -302,7 +302,8 @@ bool cmGetPropertyCommand::HandleTargetMode()
     }
   if(cmTarget* target = this->Makefile->FindTargetToUse(this->Name))
     {
-    return this->StoreResult(target->GetProperty(this->PropertyName));
+    return this->StoreResult(target->GetProperty(this->PropertyName,
+                                                 this->Makefile));
     }
   else
     {

Source/cmGetTargetPropertyCommand.cxx

@@ -38,7 +38,7 @@ bool cmGetTargetPropertyCommand
   else if(cmTarget* tgt = this->Makefile->FindTargetToUse(targetName))
     {
     cmTarget& target = *tgt;
-    const char* prop_cstr = target.GetProperty(args[2]);
+    const char* prop_cstr = target.GetProperty(args[2], this->Makefile);
     if(prop_cstr)
       {
       prop = prop_cstr;

Source/cmTarget.cxx

@@ -3178,7 +3178,7 @@ const char* cmTarget::GetFeature(const std::string& feature,
 }
 
 //----------------------------------------------------------------------------
-bool cmTarget::HandleLocationPropertyPolicy() const
+bool cmTarget::HandleLocationPropertyPolicy(cmMakefile* context) const
 {
   if (this->IsImported())
     {
@@ -3187,7 +3187,7 @@ bool cmTarget::HandleLocationPropertyPolicy() const
   cmOStringStream e;
   const char *modal = 0;
   cmake::MessageType messageType = cmake::AUTHOR_WARNING;
-  switch (this->Makefile->GetPolicyStatus(cmPolicies::CMP0026))
+  switch (context->GetPolicyStatus(cmPolicies::CMP0026))
     {
     case cmPolicies::WARN:
       e << (this->Makefile->GetPolicies()
@@ -3208,7 +3208,7 @@ bool cmTarget::HandleLocationPropertyPolicy() const
       << this->GetName() << "\".  Use the target name directly with "
       "add_custom_command, or use the generator expression $<TARGET_FILE>, "
       "as appropriate.\n";
-    this->Makefile->IssueMessage(messageType, e.str());
+    context->IssueMessage(messageType, e.str());
     }
 
   return messageType != cmake::FATAL_ERROR;
@@ -3216,6 +3216,13 @@ bool cmTarget::HandleLocationPropertyPolicy() const
 
 //----------------------------------------------------------------------------
 const char *cmTarget::GetProperty(const std::string& prop) const
+{
+  return this->GetProperty(prop, this->Makefile);
+}
+
+//----------------------------------------------------------------------------
+const char *cmTarget::GetProperty(const std::string& prop,
+                                  cmMakefile* context) const
 {
   if (this->GetType() == INTERFACE_LIBRARY
       && !whiteListedInterfaceProperty(prop))
@@ -3223,7 +3230,7 @@ const char *cmTarget::GetProperty(const std::string& prop) const
     cmOStringStream e;
     e << "INTERFACE_LIBRARY targets may only have whitelisted properties.  "
          "The property \"" << prop << "\" is not allowed.";
-    this->Makefile->IssueMessage(cmake::FATAL_ERROR, e.str());
+    context->IssueMessage(cmake::FATAL_ERROR, e.str());
     return 0;
     }
 
@@ -3242,7 +3249,7 @@ const char *cmTarget::GetProperty(const std::string& prop) const
     {
     if(prop == "LOCATION")
       {
-      if (!this->HandleLocationPropertyPolicy())
+      if (!this->HandleLocationPropertyPolicy(context))
         {
         return 0;
         }
@@ -3263,7 +3270,7 @@ const char *cmTarget::GetProperty(const std::string& prop) const
     // Support "LOCATION_<CONFIG>".
     if(cmHasLiteralPrefix(prop, "LOCATION_"))
       {
-      if (!this->HandleLocationPropertyPolicy())
+      if (!this->HandleLocationPropertyPolicy(context))
         {
         return 0;
         }
@@ -3278,7 +3285,7 @@ const char *cmTarget::GetProperty(const std::string& prop) const
       std::string configName(prop.c_str(), prop.size() - 9);
       if(configName != "IMPORTED")
         {
-        if (!this->HandleLocationPropertyPolicy())
+        if (!this->HandleLocationPropertyPolicy(context))
           {
           return 0;
           }
@@ -3416,7 +3423,7 @@ const char *cmTarget::GetProperty(const std::string& prop) const
           bool noMessage = true;
           cmOStringStream e;
           cmake::MessageType messageType = cmake::AUTHOR_WARNING;
-          switch(this->Makefile->GetPolicyStatus(cmPolicies::CMP0051))
+          switch(context->GetPolicyStatus(cmPolicies::CMP0051))
             {
             case cmPolicies::WARN:
               e << (this->Makefile->GetPolicies()
@@ -3437,7 +3444,7 @@ const char *cmTarget::GetProperty(const std::string& prop) const
             "read at configure time.  Code reading that property needs to be "
             "adapted to ignore the generator expression using the "
             "string(GENEX_STRIP) command.";
-            this->Makefile->IssueMessage(messageType, e.str());
+            context->IssueMessage(messageType, e.str());
             }
           if (addContent)
             {

Source/cmTarget.h

@@ -231,6 +231,7 @@ public:
   void AppendProperty(const std::string&  prop, const char* value,
           bool asString=false);
   const char *GetProperty(const std::string& prop) const;
+  const char *GetProperty(const std::string& prop, cmMakefile* context) const;
   bool GetPropertyAsBool(const std::string& prop) const;
   void CheckProperty(const std::string& prop, cmMakefile* context) const;
 
@@ -587,7 +588,7 @@ public:
                             const std::string &compatibilityType) const;
 
 private:
-  bool HandleLocationPropertyPolicy() const;
+  bool HandleLocationPropertyPolicy(cmMakefile* context) const;
 
   // The set of include directories that are marked as system include
   // directories.

Tests/RunCMake/CMP0026/CMP0026-WARN-Dir/CMakeLists.txt

@@ -0,0 +1 @@
+add_library(otherlib ../empty.cpp)

Tests/RunCMake/CMP0026/CMP0026-WARN-stderr.txt

@@ -10,3 +10,16 @@ CMake Warning \(dev\) at CMP0026-WARN.cmake:5 \(get_target_property\):
 Call Stack \(most recent call first\):
   CMakeLists.txt:3 \(include\)
 This warning is for project developers.  Use -Wno-dev to suppress it.
++
+CMake Warning \(dev\) at CMP0026-WARN.cmake:8 \(get_target_property\):
+  Policy CMP0026 is not set: Disallow use of the LOCATION target property.
+  Run "cmake --help-policy CMP0026" for policy details.  Use the cmake_policy
+  command to set the policy and suppress this warning.
+
+  The LOCATION property should not be read from target "otherlib".  Use the
+  target name directly with add_custom_command, or use the generator
+  expression \$<TARGET_FILE>, as appropriate.
+
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
+This warning is for project developers.  Use -Wno-dev to suppress it.

Tests/RunCMake/CMP0026/CMP0026-WARN.cmake

@@ -3,3 +3,6 @@ enable_language(CXX)
 
 add_library(somelib empty.cpp)
 get_target_property(_loc somelib LOCATION)
+
+add_subdirectory(CMP0026-WARN-Dir)
+get_target_property(_loc otherlib LOCATION)

Tests/RunCMake/CMP0051/CMP0051-WARN-Dir/CMakeLists.txt

@@ -0,0 +1 @@
+add_library(empty2 ../empty.cpp $<TARGET_OBJECTS:objects>)

Tests/RunCMake/CMP0051/CMP0051-WARN-stderr.txt

@@ -12,4 +12,20 @@ Call Stack \(most recent call first\):
   CMakeLists.txt:3 \(include\)
 This warning is for project developers.  Use -Wno-dev to suppress it.
 
-Sources: "empty.cpp"$
+Sources: "empty.cpp"
+*
+CMake Warning \(dev\) at CMP0051-WARN.cmake:12 \(get_target_property\):
+  Policy CMP0051 is not set: List TARGET_OBJECTS in SOURCES target property.
+  Run "cmake --help-policy CMP0051" for policy details.  Use the cmake_policy
+  command to set the policy and suppress this warning.
+
+  Target "empty2" contains \$<TARGET_OBJECTS> generator expression in its
+  sources list.  This content was not previously part of the SOURCES property
+  when that property was read at configure time.  Code reading that property
+  needs to be adapted to ignore the generator expression using the
+  string\(GENEX_STRIP\) command.
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
+This warning is for project developers.  Use -Wno-dev to suppress it.
+
+Sources: "../empty.cpp"$

Tests/RunCMake/CMP0051/CMP0051-WARN.cmake

@@ -6,3 +6,9 @@ add_library(empty empty.cpp $<TARGET_OBJECTS:objects>)
 get_target_property(srcs empty SOURCES)
 
 message("Sources: \"${srcs}\"")
+
+add_subdirectory(CMP0051-WARN-Dir)
+
+get_target_property(srcs empty2 SOURCES)
+
+message("Sources: \"${srcs}\"")