13 files changed, 130 insertions, 1 deletions

diff --git a/Help/manual/cmake-policies.7.rst b/Help/manual/cmake-policies.7.rst
index 2181f88..e9c31a7 100644
--- a/Help/manual/cmake-policies.7.rst
+++ b/Help/manual/cmake-policies.7.rst
@@ -93,3 +93,4 @@ All Policies
    /policy/CMP0041
    /policy/CMP0042
    /policy/CMP0043
+   /policy/CMP0044
diff --git a/Help/policy/CMP0044.rst b/Help/policy/CMP0044.rst
new file mode 100644
index 0000000..edbadf5
--- /dev/null
+++ b/Help/policy/CMP0044.rst
@@ -0,0 +1,19 @@
+CMP0044
+-------
+
+Case sensitive ``<LANG>_COMPILER_ID`` generator expressions
+
+CMake 2.8.12 introduced the ``<LANG>_COMPILER_ID``
+:manual:`generator expressions <cmake-generator-expressions(7)>` to allow
+comparison of the :variable:`CMAKE_<LANG>_COMPILER_ID` with a test value.  The
+possible valid values are lowercase, but the comparison with the test value
+was performed case-insensitively.
+
+The OLD behavior for this policy is to perform a case-insensitive comparison
+with the value in the ``<LANG>_COMPILER_ID`` expression. The NEW behavior
+for this policy is to perform a case-sensitive comparison with the value in
+the ``<LANG>_COMPILER_ID`` expression.
+
+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.
diff --git a/Source/cmGeneratorExpressionEvaluator.cxx b/Source/cmGeneratorExpressionEvaluator.cxx
index 80b16d3..1feb03a 100644
--- a/Source/cmGeneratorExpressionEvaluator.cxx
+++ b/Source/cmGeneratorExpressionEvaluator.cxx
@@ -412,10 +412,32 @@ struct CompilerIdNode : public cmGeneratorExpressionNode
       return parameters.front().empty() ? "1" : "0";
       }
 
-    if (cmsysString_strcasecmp(parameters.begin()->c_str(), compilerId) == 0)
+    if (strcmp(parameters.begin()->c_str(), compilerId) == 0)
       {
       return "1";
       }
+
+    if (cmsysString_strcasecmp(parameters.begin()->c_str(), compilerId) == 0)
+      {
+      switch(context->Makefile->GetPolicyStatus(cmPolicies::CMP0044))
+        {
+        case cmPolicies::WARN:
+          {
+          cmOStringStream e;
+          e << context->Makefile->GetPolicies()
+                      ->GetPolicyWarning(cmPolicies::CMP0044);
+          context->Makefile->GetCMakeInstance()
+                 ->IssueMessage(cmake::AUTHOR_WARNING,
+                                e.str().c_str(), context->Backtrace);
+          }
+        case cmPolicies::OLD:
+          return "1";
+        case cmPolicies::NEW:
+        case cmPolicies::REQUIRED_ALWAYS:
+        case cmPolicies::REQUIRED_IF_USED:
+          break;
+        }
+      }
     return "0";
   }
 };
diff --git a/Source/cmPolicies.cxx b/Source/cmPolicies.cxx
index 32c1476..c9dacaf 100644
--- a/Source/cmPolicies.cxx
+++ b/Source/cmPolicies.cxx
@@ -321,6 +321,11 @@ cmPolicies::cmPolicies()
     CMP0043, "CMP0043",
     "Ignore COMPILE_DEFINITIONS_<Config> properties.",
     3,0,0,0, cmPolicies::WARN);
+
+  this->DefinePolicy(
+    CMP0044, "CMP0044",
+    "Case sensitive <LANG>_COMPILER_ID generator expressions.",
+    3,0,0,0, cmPolicies::WARN);
 }
 
 cmPolicies::~cmPolicies()
diff --git a/Source/cmPolicies.h b/Source/cmPolicies.h
index 3c8200f..0d7327f 100644
--- a/Source/cmPolicies.h
+++ b/Source/cmPolicies.h
@@ -97,6 +97,7 @@ public:
     CMP0041, ///< Error on relative include with generator expression
     CMP0042, ///< Enable MACOSX_RPATH by default
     CMP0043, ///< Ignore COMPILE_DEFINITIONS_<Config> properties
+    CMP0044, ///< Case sensitive <LANG>_COMPILER_ID generator expressions
 
     /** \brief Always the last entry.
      *
diff --git a/Tests/GeneratorExpression/CMP0044/CMakeLists.txt b/Tests/GeneratorExpression/CMP0044/CMakeLists.txt
new file mode 100644
index 0000000..309a8cc
--- /dev/null
+++ b/Tests/GeneratorExpression/CMP0044/CMakeLists.txt
@@ -0,0 +1,19 @@
+
+string(TOLOWER ${CMAKE_C_COMPILER_ID} lc_test)
+if (lc_test STREQUAL CMAKE_C_COMPILER_ID)
+  string(TOUPPER ${CMAKE_C_COMPILER_ID} lc_test)
+  if (lc_test STREQUAL CMAKE_C_COMPILER_ID)
+    message(SEND_ERROR "Try harder.")
+  endif()
+endif()
+
+if (CMP0044_TYPE)
+  cmake_policy(SET CMP0044 ${CMP0044_TYPE})
+endif()
+
+add_library(cmp0044-check-${CMP0044_TYPE} cmp0044-check.cpp)
+target_compile_definitions(cmp0044-check-${CMP0044_TYPE}
+  PRIVATE
+    Result=$<C_COMPILER_ID:${lc_test}>
+    Type_Is_${CMP0044_TYPE}
+)
diff --git a/Tests/GeneratorExpression/CMP0044/cmp0044-check.cpp b/Tests/GeneratorExpression/CMP0044/cmp0044-check.cpp
new file mode 100644
index 0000000..2356bc4
--- /dev/null
+++ b/Tests/GeneratorExpression/CMP0044/cmp0044-check.cpp
@@ -0,0 +1,26 @@
+
+#ifdef Type_Is_
+#  if !Result
+#    error Result should be 1 in WARN mode
+#  endif
+#endif
+
+#ifdef Type_Is_NEW
+#  if Result
+#    error Result should be 0 in NEW mode
+#  endif
+#endif
+
+#ifdef Type_Is_OLD
+#  if !Result
+#    error Result should be 1 in OLD mode
+#  endif
+#endif
+
+#if !defined(Type_Is_) && !defined(Type_Is_OLD) && !defined(Type_Is_NEW)
+#error No expected definition present
+#endif
+
+void foo(void)
+{
+}
diff --git a/Tests/GeneratorExpression/CMakeLists.txt b/Tests/GeneratorExpression/CMakeLists.txt
index 3b85dc3..a0e34ef 100644
--- a/Tests/GeneratorExpression/CMakeLists.txt
+++ b/Tests/GeneratorExpression/CMakeLists.txt
@@ -252,3 +252,9 @@ endforeach()
 add_test(echo-old-style echo "\$<CONFIGURATION>")
 set_property(TEST echo-old-style PROPERTY
     PASS_REGULAR_EXPRESSION "^\\$<CONFIGURATION>\n$")
+
+add_subdirectory(CMP0044 ${CMAKE_BINARY_DIR}/CMP0044-WARN)
+set(CMP0044_TYPE NEW)
+add_subdirectory(CMP0044 ${CMAKE_BINARY_DIR}/CMP0044-NEW)
+set(CMP0044_TYPE OLD)
+add_subdirectory(CMP0044 ${CMAKE_BINARY_DIR}/CMP0044-OLD)
diff --git a/Tests/RunCMake/CMP0043/CMakeLists.txt b/Tests/RunCMake/CMP0043/CMakeLists.txt
index 11ea636..b465c88 100644
--- a/Tests/RunCMake/CMP0043/CMakeLists.txt
+++ b/Tests/RunCMake/CMP0043/CMakeLists.txt
@@ -1,3 +1,7 @@
 cmake_minimum_required(VERSION 2.8)
 project(${RunCMake_TEST} CXX)
 include(${RunCMake_TEST}.cmake NO_POLICY_SCOPE)
+
+if(CMAKE_BUILD_TYPE)
+  # Dummy variable use
+endif()
diff --git a/Tests/RunCMake/GeneratorExpression/CMP0044-WARN-result.txt b/Tests/RunCMake/GeneratorExpression/CMP0044-WARN-result.txt
new file mode 100644
index 0000000..573541a
--- /dev/null
+++ b/Tests/RunCMake/GeneratorExpression/CMP0044-WARN-result.txt
@@ -0,0 +1 @@
+0
diff --git a/Tests/RunCMake/GeneratorExpression/CMP0044-WARN-stderr.txt b/Tests/RunCMake/GeneratorExpression/CMP0044-WARN-stderr.txt
new file mode 100644
index 0000000..2079c12
--- /dev/null
+++ b/Tests/RunCMake/GeneratorExpression/CMP0044-WARN-stderr.txt
@@ -0,0 +1,7 @@
+CMake Warning \(dev\) at CMP0044-WARN.cmake:13 \(target_compile_definitions\):
+  Policy CMP0044 is not set: Case sensitive <LANG>_COMPILER_ID generator
+  expressions.  Run "cmake --help-policy CMP0044" for policy details.  Use
+  the cmake_policy command to set the policy and suppress this warning.
+Call Stack \(most recent call first\):
+  CMakeLists.txt:3 \(include\)
+This warning is for project developers.  Use -Wno-dev to suppress it.
diff --git a/Tests/RunCMake/GeneratorExpression/CMP0044-WARN.cmake b/Tests/RunCMake/GeneratorExpression/CMP0044-WARN.cmake
new file mode 100644
index 0000000..d5b85c9
--- /dev/null
+++ b/Tests/RunCMake/GeneratorExpression/CMP0044-WARN.cmake
@@ -0,0 +1,17 @@
+
+project(CMP0044-WARN)
+
+string(TOLOWER ${CMAKE_C_COMPILER_ID} lc_test)
+if (lc_test STREQUAL CMAKE_C_COMPILER_ID)
+  string(TOUPPER ${CMAKE_C_COMPILER_ID} lc_test)
+  if (lc_test STREQUAL CMAKE_C_COMPILER_ID)
+    message(SEND_ERROR "Try harder.")
+  endif()
+endif()
+
+add_library(cmp0044-check empty.c)
+target_compile_definitions(cmp0044-check
+  PRIVATE
+    Result=$<C_COMPILER_ID:${lc_test}>
+    Type_Is_${CMP0044_TYPE}
+)
diff --git a/Tests/RunCMake/GeneratorExpression/RunCMakeTest.cmake b/Tests/RunCMake/GeneratorExpression/RunCMakeTest.cmake
index 54d5064..f3f99ed 100644
--- a/Tests/RunCMake/GeneratorExpression/RunCMakeTest.cmake
+++ b/Tests/RunCMake/GeneratorExpression/RunCMakeTest.cmake
@@ -9,3 +9,4 @@ run_cmake(BadZero)
 run_cmake(BadTargetName)
 run_cmake(BadTargetTypeObject)
 run_cmake(BadInstallPrefix)
+run_cmake(CMP0044-WARN)