AddDependencies: new policy requires dependencies to exist

Added new policy CMP0046 which requires dependencies added by
add_dependencies() to actually exist.

Help/manual/cmake-policies.7.rst

@@ -97,3 +97,4 @@ All Policies
    /policy/CMP0043
    /policy/CMP0044
    /policy/CMP0045
+   /policy/CMP0046

Help/policy/CMP0046.rst

@@ -0,0 +1,17 @@
+CMP0046
+-------
+
+Error on non-existent dependency in add_dependencies.
+
+CMake 2.8.12 and lower silently ignored non-existent dependencies
+listed in the :command:`add_dependencies` command.
+
+The OLD behavior for this policy is to silently ignore non-existent
+dependencies. The NEW behavior for this policy is to report an error
+if non-existent dependencies are listed in the :command:`add_dependencies`
+command.
+
+This policy was introduced in CMake version 3.0.0.
+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.

Source/cmAddDependenciesCommand.cxx

@@ -46,7 +46,7 @@ bool cmAddDependenciesCommand
     ++s; // skip over target_name
     for (; s != args.end(); ++s)
       {
-      target->AddUtility(s->c_str());
+      target->AddUtility(s->c_str(), this->Makefile);
       }
     }
   else

Source/cmComputeTargetDepends.cxx

@@ -343,6 +343,45 @@ void cmComputeTargetDepends::AddTargetDepend(int depender_index,
   cmTarget const* dependee =
     depender->GetMakefile()->FindTargetToUse(dependee_name);
 
+  if(!dependee && !linking &&
+    (depender->GetType() != cmTarget::GLOBAL_TARGET))
+    {
+    cmMakefile *makefile = depender->GetMakefile();
+    cmake::MessageType messageType = cmake::AUTHOR_WARNING;
+    bool issueMessage = false;
+    switch(makefile->GetPolicyStatus(cmPolicies::CMP0046))
+      {
+      case cmPolicies::WARN:
+        issueMessage = true;
+      case cmPolicies::OLD:
+        break;
+      case cmPolicies::NEW:
+      case cmPolicies::REQUIRED_IF_USED:
+      case cmPolicies::REQUIRED_ALWAYS:
+        issueMessage = true;
+        messageType = cmake::FATAL_ERROR;
+      }
+    if(issueMessage)
+      {
+      cmake* cm = this->GlobalGenerator->GetCMakeInstance();
+      cmOStringStream e;
+      e << (makefile->GetPolicies()
+        ->GetPolicyWarning(cmPolicies::CMP0046)) << "\n";
+      e << "The dependency target \"" <<  dependee_name
+        << "\" of target \"" << depender->GetName() << "\" does not exist.";
+
+      cmListFileBacktrace nullBacktrace;
+      cmListFileBacktrace const* backtrace =
+        depender->GetUtilityBacktrace(dependee_name);
+      if(!backtrace)
+        {
+        backtrace = &nullBacktrace;
+        }
+
+      cm->IssueMessage(messageType, e.str(), *backtrace);
+      }
+    }
+
   // Skip targets that will not really be linked.  This is probably a
   // name conflict between an external library and an executable
   // within the project.

Source/cmPolicies.cxx

@@ -331,6 +331,11 @@ cmPolicies::cmPolicies()
     CMP0045, "CMP0045",
     "Error on non-existent target in get_target_property.",
     3,0,0,0, cmPolicies::WARN);
+
+  this->DefinePolicy(
+    CMP0046, "CMP0046",
+    "Error on non-existent dependency in add_dependencies.",
+    3,0,0,0, cmPolicies::WARN);
 }
 
 cmPolicies::~cmPolicies()

Source/cmPolicies.h

@@ -99,6 +99,7 @@ public:
     CMP0043, ///< Ignore COMPILE_DEFINITIONS_<Config> properties
     CMP0044, ///< Case sensitive <LANG>_COMPILER_ID generator expressions
     CMP0045, ///< Error on non-existent target in get_target_property
+    CMP0046, ///< Error on non-existent dependency in add_dependencies
 
     /** \brief Always the last entry.
      *

Source/cmTarget.cxx

@@ -401,6 +401,26 @@ void cmTarget::SetMakefile(cmMakefile* mf)
   this->SetPropertyDefault("JOB_POOL_LINK", 0);
 }
 
+//----------------------------------------------------------------------------
+void cmTarget::AddUtility(const char *u, cmMakefile *makefile)
+{
+  this->Utilities.insert(u);
+  if(makefile)
+  {
+    makefile->GetBacktrace(UtilityBacktraces[u]);
+  }
+}
+
+//----------------------------------------------------------------------------
+cmListFileBacktrace const* cmTarget::GetUtilityBacktrace(const char *u) const
+{
+  std::map<cmStdString, cmListFileBacktrace>::const_iterator i =
+    this->UtilityBacktraces.find(u);
+  if(i == this->UtilityBacktraces.end()) return 0;
+
+  return &i->second;
+}
+
 //----------------------------------------------------------------------------
 void cmTarget::FinishConfigure()
 {

Source/cmTarget.h

@@ -242,9 +242,10 @@ public:
    * name as would be specified to the ADD_EXECUTABLE or UTILITY_SOURCE
    * commands. It is not a full path nor does it have an extension.
    */
-  void AddUtility(const char* u) { this->Utilities.insert(u);}
+  void AddUtility(const char* u, cmMakefile *makefile = 0);
   ///! Get the utilities used by this target
   std::set<cmStdString>const& GetUtilities() const { return this->Utilities; }
+  cmListFileBacktrace const* GetUtilityBacktrace(const char* u) const;
 
   /** Finalize the target at the end of the Configure step.  */
   void FinishConfigure();
@@ -691,6 +692,7 @@ private:
   std::string RuntimeInstallPath;
   mutable std::string ExportMacro;
   std::set<cmStdString> Utilities;
+  std::map<cmStdString, cmListFileBacktrace> UtilityBacktraces;
   bool RecordDependencies;
   mutable cmPropertyMap Properties;
   LinkLibraryVectorType OriginalLinkLibraries;

Tests/RunCMake/CMP0046/CMP0046-NEW-existing-dependency-stderr.txt

@@ -0,0 +1 @@
+^$

Tests/RunCMake/CMP0046/CMP0046-NEW-existing-dependency.cmake

@@ -0,0 +1,5 @@
+cmake_policy(SET CMP0046 NEW)
+
+add_custom_target(foo)
+add_custom_target(bar)
+add_dependencies(foo bar)

Tests/RunCMake/CMP0046/CMP0046-NEW-missing-dependency-result.txt

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

Tests/RunCMake/CMP0046/CMP0046-NEW-missing-dependency-stderr.txt

@@ -0,0 +1,8 @@
+CMake Error at CMP0046-NEW-missing-dependency.cmake:4 \(add_dependencies\):
+  Policy CMP0046 is not set: Error on non-existent dependency in
+  add_dependencies.  Run "cmake --help-policy CMP0046" for policy details.
+  Use the cmake_policy command to set the policy and suppress this warning.
++
+  The dependency target "bar" of target "foo" does not exist.
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)

Tests/RunCMake/CMP0046/CMP0046-NEW-missing-dependency.cmake

@@ -0,0 +1,4 @@
+cmake_policy(SET CMP0046 NEW)
+
+add_custom_target(foo)
+add_dependencies(foo bar)

Tests/RunCMake/CMP0046/CMP0046-OLD-existing-dependency-stderr.txt

@@ -0,0 +1 @@
+^$

Tests/RunCMake/CMP0046/CMP0046-OLD-existing-dependency.cmake

@@ -0,0 +1,5 @@
+cmake_policy(SET CMP0046 OLD)
+
+add_custom_target(foo)
+add_custom_target(bar)
+add_dependencies(foo bar)

Tests/RunCMake/CMP0046/CMP0046-OLD-missing-dependency-stderr.txt

@@ -0,0 +1 @@
+^$

Tests/RunCMake/CMP0046/CMP0046-OLD-missing-dependency.cmake

@@ -0,0 +1,4 @@
+cmake_policy(SET CMP0046 OLD)
+
+add_custom_target(foo)
+add_dependencies(foo bar)

Tests/RunCMake/CMP0046/CMP0046-WARN-missing-dependency-stderr.txt

@@ -0,0 +1,9 @@
+CMake Warning \(dev\) at CMP0046-WARN-missing-dependency.cmake:2 \(add_dependencies\):
+  Policy CMP0046 is not set: Error on non-existent dependency in
+  add_dependencies.  Run "cmake --help-policy CMP0046" for policy details.
+  Use the cmake_policy command to set the policy and suppress this warning.
++
+  The dependency target "bar" of target "foo" does not exist.
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
+This warning is for project developers.  Use -Wno-dev to suppress it.

Tests/RunCMake/CMP0046/CMP0046-WARN-missing-dependency.cmake

@@ -0,0 +1,2 @@
+add_custom_target(foo)
+add_dependencies(foo bar)

Tests/RunCMake/CMP0046/CMakeLists.txt

@@ -0,0 +1,3 @@
+cmake_minimum_required(VERSION 2.8.12)
+project(${RunCMake_TEST} CXX)
+include(${RunCMake_TEST}.cmake NO_POLICY_SCOPE)

Tests/RunCMake/CMP0046/RunCMakeTest.cmake

@@ -0,0 +1,8 @@
+include(RunCMake)
+
+run_cmake(CMP0046-OLD-missing-dependency)
+run_cmake(CMP0046-NEW-missing-dependency)
+run_cmake(CMP0046-WARN-missing-dependency)
+
+run_cmake(CMP0046-OLD-existing-dependency)
+run_cmake(CMP0046-NEW-existing-dependency)

Tests/RunCMake/CMakeLists.txt

@@ -66,6 +66,7 @@ if(CMAKE_SYSTEM_NAME MATCHES Darwin AND CMAKE_SHARED_LIBRARY_RUNTIME_C_FLAG)
 endif()
 add_RunCMake_test(CMP0043)
 add_RunCMake_test(CMP0045)
+add_RunCMake_test(CMP0046)
 add_RunCMake_test(CTest)
 if(UNIX AND "${CMAKE_TEST_GENERATOR}" MATCHES "Unix Makefiles")
   add_RunCMake_test(CompilerChange)