From 2600e923a66a86784f756c7d5b9a8b06c5848576 Mon Sep 17 00:00:00 2001
From: Stephen Kelly <steveire@gmail.com>
Date: Wed, 19 Mar 2014 15:50:01 +0100
Subject: [PATCH] Disallow INTERFACE libraries with add_custom_command(TARGET).

Don't attempt to trace their dependencies.
---
 Source/cmLocalGenerator.cxx                               | 3 ++-
 Source/cmMakefile.cxx                                     | 8 ++++++++
 Tests/RunCMake/interface_library/RunCMakeTest.cmake       | 1 +
 .../add_custom_command-TARGET-result.txt                  | 1 +
 .../add_custom_command-TARGET-stderr.txt                  | 5 +++++
 .../interface_library/add_custom_command-TARGET.cmake     | 6 ++++++
 6 files changed, 23 insertions(+), 1 deletion(-)
 create mode 100644 Tests/RunCMake/interface_library/add_custom_command-TARGET-result.txt
 create mode 100644 Tests/RunCMake/interface_library/add_custom_command-TARGET-stderr.txt
 create mode 100644 Tests/RunCMake/interface_library/add_custom_command-TARGET.cmake

diff --git a/Source/cmLocalGenerator.cxx b/Source/cmLocalGenerator.cxx
index aca195c57..7890379ee 100644
--- a/Source/cmLocalGenerator.cxx
+++ b/Source/cmLocalGenerator.cxx
@@ -263,7 +263,8 @@ void cmLocalGenerator::TraceDependencies()
   for(cmGeneratorTargetsType::iterator t = targets.begin();
       t != targets.end(); ++t)
     {
-    if (t->second->Target->IsImported())
+    if (t->second->Target->IsImported()
+        || t->second->Target->GetType() == cmTarget::INTERFACE_LIBRARY)
       {
       continue;
       }
diff --git a/Source/cmMakefile.cxx b/Source/cmMakefile.cxx
index f248c57e7..10137ec8b 100644
--- a/Source/cmMakefile.cxx
+++ b/Source/cmMakefile.cxx
@@ -926,6 +926,14 @@ cmMakefile::AddCustomCommandToTarget(const char* target,
     this->IssueMessage(cmake::FATAL_ERROR, e.str());
     return;
     }
+  if(ti->second.GetType() == cmTarget::INTERFACE_LIBRARY)
+    {
+    cmOStringStream e;
+    e << "Target \"" << target << "\" is an INTERFACE library "
+      "that may not have PRE_BUILD, PRE_LINK, or POST_BUILD commands.";
+    this->IssueMessage(cmake::FATAL_ERROR, e.str());
+    return;
+    }
   // Add the command to the appropriate build step for the target.
   std::vector<std::string> no_output;
   cmCustomCommand cc(this, no_output, depends,
diff --git a/Tests/RunCMake/interface_library/RunCMakeTest.cmake b/Tests/RunCMake/interface_library/RunCMakeTest.cmake
index 3c457c5ba..08e81c6c8 100644
--- a/Tests/RunCMake/interface_library/RunCMakeTest.cmake
+++ b/Tests/RunCMake/interface_library/RunCMakeTest.cmake
@@ -8,3 +8,4 @@ run_cmake(invalid_signature)
 run_cmake(global-interface)
 run_cmake(genex_link)
 run_cmake(add_dependencies)
+run_cmake(add_custom_command-TARGET)
diff --git a/Tests/RunCMake/interface_library/add_custom_command-TARGET-result.txt b/Tests/RunCMake/interface_library/add_custom_command-TARGET-result.txt
new file mode 100644
index 000000000..d00491fd7
--- /dev/null
+++ b/Tests/RunCMake/interface_library/add_custom_command-TARGET-result.txt
@@ -0,0 +1 @@
+1
diff --git a/Tests/RunCMake/interface_library/add_custom_command-TARGET-stderr.txt b/Tests/RunCMake/interface_library/add_custom_command-TARGET-stderr.txt
new file mode 100644
index 000000000..c09526265
--- /dev/null
+++ b/Tests/RunCMake/interface_library/add_custom_command-TARGET-stderr.txt
@@ -0,0 +1,5 @@
+CMake Error at add_custom_command-TARGET.cmake:4 \(add_custom_command\):
+  Target "iface" is an INTERFACE library that may not have PRE_BUILD,
+  PRE_LINK, or POST_BUILD commands.
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
diff --git a/Tests/RunCMake/interface_library/add_custom_command-TARGET.cmake b/Tests/RunCMake/interface_library/add_custom_command-TARGET.cmake
new file mode 100644
index 000000000..a5136eff8
--- /dev/null
+++ b/Tests/RunCMake/interface_library/add_custom_command-TARGET.cmake
@@ -0,0 +1,6 @@
+
+add_library(iface INTERFACE)
+
+add_custom_command(TARGET iface
+  COMMAND "${CMAKE_COMMAND}" -E echo test
+)