From ff015ee11e66388f50f9a1350e2731e7a240ccb1 Mon Sep 17 00:00:00 2001
From: Stephen Kelly <steveire@gmail.com>
Date: Fri, 14 Jun 2013 16:25:29 +0200
Subject: [PATCH] Genex: Report error if a target file is needed to evaluate
 link libraries.

Constructs such as

 target_link_libraries(foo $<$<STREQUAL:$<TARGET_FILE:foo>,foo.so>:bar>)

segfault before this patch.
---
 Source/cmGeneratorExpressionEvaluator.cxx                | 9 ++++++++-
 Tests/RunCMake/Languages/RunCMakeTest.cmake              | 2 ++
 .../link-libraries-TARGET_FILE-genex-ok-result.txt       | 1 +
 .../Languages/link-libraries-TARGET_FILE-genex-ok.cmake  | 6 ++++++
 .../link-libraries-TARGET_FILE-genex-result.txt          | 1 +
 .../link-libraries-TARGET_FILE-genex-stderr.txt          | 7 +++++++
 .../Languages/link-libraries-TARGET_FILE-genex.cmake     | 4 ++++
 7 files changed, 29 insertions(+), 1 deletion(-)
 create mode 100644 Tests/RunCMake/Languages/link-libraries-TARGET_FILE-genex-ok-result.txt
 create mode 100644 Tests/RunCMake/Languages/link-libraries-TARGET_FILE-genex-ok.cmake
 create mode 100644 Tests/RunCMake/Languages/link-libraries-TARGET_FILE-genex-result.txt
 create mode 100644 Tests/RunCMake/Languages/link-libraries-TARGET_FILE-genex-stderr.txt
 create mode 100644 Tests/RunCMake/Languages/link-libraries-TARGET_FILE-genex.cmake

diff --git a/Source/cmGeneratorExpressionEvaluator.cxx b/Source/cmGeneratorExpressionEvaluator.cxx
index cd0d26b33..f57e683c2 100644
--- a/Source/cmGeneratorExpressionEvaluator.cxx
+++ b/Source/cmGeneratorExpressionEvaluator.cxx
@@ -1100,7 +1100,7 @@ struct TargetFilesystemArtifact : public cmGeneratorExpressionNode
   std::string Evaluate(const std::vector<std::string> &parameters,
                        cmGeneratorExpressionContext *context,
                        const GeneratorExpressionContent *content,
-                       cmGeneratorExpressionDAGChecker *) const
+                       cmGeneratorExpressionDAGChecker *dagChecker) const
   {
     // Lookup the referenced target.
     std::string name = *parameters.begin();
@@ -1125,6 +1125,13 @@ struct TargetFilesystemArtifact : public cmGeneratorExpressionNode
                   "Target \"" + name + "\" is not an executable or library.");
       return std::string();
       }
+    if (dagChecker && dagChecker->EvaluatingLinkLibraries(name.c_str()))
+      {
+      ::reportError(context, content->GetOriginalExpression(),
+                    "Expressions which require the linker language may not "
+                    "be used while evaluating link libraries");
+      return std::string();
+      }
     context->DependTargets.insert(target);
     context->AllTargets.insert(target);
 
diff --git a/Tests/RunCMake/Languages/RunCMakeTest.cmake b/Tests/RunCMake/Languages/RunCMakeTest.cmake
index 59ef5dc09..6517a8105 100644
--- a/Tests/RunCMake/Languages/RunCMakeTest.cmake
+++ b/Tests/RunCMake/Languages/RunCMakeTest.cmake
@@ -2,3 +2,5 @@ include(RunCMake)
 
 run_cmake(NoLangSHARED)
 run_cmake(LINK_LANGUAGE-genex)
+run_cmake(link-libraries-TARGET_FILE-genex)
+run_cmake(link-libraries-TARGET_FILE-genex-ok)
diff --git a/Tests/RunCMake/Languages/link-libraries-TARGET_FILE-genex-ok-result.txt b/Tests/RunCMake/Languages/link-libraries-TARGET_FILE-genex-ok-result.txt
new file mode 100644
index 000000000..573541ac9
--- /dev/null
+++ b/Tests/RunCMake/Languages/link-libraries-TARGET_FILE-genex-ok-result.txt
@@ -0,0 +1 @@
+0
diff --git a/Tests/RunCMake/Languages/link-libraries-TARGET_FILE-genex-ok.cmake b/Tests/RunCMake/Languages/link-libraries-TARGET_FILE-genex-ok.cmake
new file mode 100644
index 000000000..f0fd6e5aa
--- /dev/null
+++ b/Tests/RunCMake/Languages/link-libraries-TARGET_FILE-genex-ok.cmake
@@ -0,0 +1,6 @@
+
+enable_language(CXX)
+
+add_library(foo SHARED empty.cpp)
+add_library(bar SHARED empty.cpp)
+target_link_libraries(foo $<$<STREQUAL:$<TARGET_FILE:bar>,anything>:bar>)
diff --git a/Tests/RunCMake/Languages/link-libraries-TARGET_FILE-genex-result.txt b/Tests/RunCMake/Languages/link-libraries-TARGET_FILE-genex-result.txt
new file mode 100644
index 000000000..d00491fd7
--- /dev/null
+++ b/Tests/RunCMake/Languages/link-libraries-TARGET_FILE-genex-result.txt
@@ -0,0 +1 @@
+1
diff --git a/Tests/RunCMake/Languages/link-libraries-TARGET_FILE-genex-stderr.txt b/Tests/RunCMake/Languages/link-libraries-TARGET_FILE-genex-stderr.txt
new file mode 100644
index 000000000..2d7a3c9d6
--- /dev/null
+++ b/Tests/RunCMake/Languages/link-libraries-TARGET_FILE-genex-stderr.txt
@@ -0,0 +1,7 @@
+CMake Error:
+  Error evaluating generator expression:
+
+    \$<TARGET_FILE:foo>
+
+  Expressions which require the linker language may not be used while
+  evaluating link libraries
diff --git a/Tests/RunCMake/Languages/link-libraries-TARGET_FILE-genex.cmake b/Tests/RunCMake/Languages/link-libraries-TARGET_FILE-genex.cmake
new file mode 100644
index 000000000..eca73e977
--- /dev/null
+++ b/Tests/RunCMake/Languages/link-libraries-TARGET_FILE-genex.cmake
@@ -0,0 +1,4 @@
+
+add_library(foo SHARED empty.cpp)
+add_library(bar SHARED empty.cpp)
+target_link_libraries(foo $<$<STREQUAL:$<TARGET_FILE:foo>,anything>:bar>)