Xcode: Teach XCODE_ATTRIBUTE target properties about generator expressions

Signed-off-by: Gregor Jasny <gjasny@googlemail.com>

Tests/RunCMake/XcodeProject/RunCMakeTest.cmake

@@ -1,3 +1,5 @@
 include(RunCMake)
 
 run_cmake(XcodeFileType)
+run_cmake(XcodeAttributeGenex)
+run_cmake(XcodeAttributeGenexError)

Tests/RunCMake/XcodeProject/XcodeAttributeGenex-check.cmake

@@ -0,0 +1,7 @@
+set(expect "TEST_HOST = \"[^;\"]*Tests/RunCMake/XcodeProject/XcodeAttributeGenex-build/[^;\"/]*/some\"")
+file(STRINGS ${RunCMake_TEST_BINARY_DIR}/XcodeAttributeGenex.xcodeproj/project.pbxproj actual
+     REGEX "TEST_HOST = .*;" LIMIT_COUNT 1)
+if(NOT "${actual}" MATCHES "${expect}")
+  message(SEND_ERROR "The actual project contains the line:\n ${actual}\n"
+    "which does not match expected regex:\n ${expect}\n")
+endif()

Tests/RunCMake/XcodeProject/XcodeAttributeGenex.cmake

@@ -0,0 +1,4 @@
+enable_language(C)
+add_executable(some main.c)
+add_executable(another main.c)
+set_property(TARGET another PROPERTY XCODE_ATTRIBUTE_TEST_HOST "$<TARGET_FILE:some>")

Tests/RunCMake/XcodeProject/XcodeAttributeGenexError-result.txt

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

Tests/RunCMake/XcodeProject/XcodeAttributeGenexError-stderr.txt

@@ -0,0 +1,6 @@
+CMake Error:
+  Error evaluating generator expression:
+
+    \$<NOTAGENEX>
+
+  Expression did not evaluate to a known generator expression

Tests/RunCMake/XcodeProject/XcodeAttributeGenexError.cmake

@@ -0,0 +1,4 @@
+enable_language(C)
+add_executable(some main.c)
+add_executable(another main.c)
+set_property(TARGET another PROPERTY XCODE_ATTRIBUTE_TEST_HOST "$<NOTAGENEX>")