ENH: add a test to make sure Xcode does not break again

Tests/BuildDepends/CMakeLists.txt

@@ -0,0 +1,45 @@
+# this test creates a static library and an executable
+# the source to the library is then changed 
+# and the build is done on the executable and if things
+# are working the executable should relink with the new
+# value.  The subdir Project contains the CMakelists.txt
+# and source files for the test project. 
+project(BuildDepends)
+make_directory(${BuildDepends_BINARY_DIR}/Project)
+write_file(${BuildDepends_BINARY_DIR}/Project/foo.c 
+  "const char* foo() { return \"foo\";}" )
+try_compile(RESULT 
+  ${BuildDepends_BINARY_DIR}/Project
+  ${BuildDepends_SOURCE_DIR}/Project
+  testRebuild
+  OUTPUT_VARIABLE OUTPUT)
+
+set(bar ${BuildDepends_BINARY_DIR}/Project/bar.exe)
+if(EXISTS ${BuildDepends_BINARY_DIR}/Project/Debug/bar.exe )
+  set(bar ${BuildDepends_BINARY_DIR}/Project/Debug/bar.exe)
+endif(EXISTS ${BuildDepends_BINARY_DIR}/Project/Debug/bar.exe )
+  
+execute_process(COMMAND ${bar} OUTPUT_VARIABLE out)
+message("${out}")
+if("${out}" STREQUAL "foo")
+  message("Worked!")
+else("${out}" STREQUAL "foo")
+  message(SEND_ERROR "Program did not rebuild with changed file")
+endif("${out}" STREQUAL "foo")
+
+write_file(${BuildDepends_BINARY_DIR}/Project/foo.c 
+  "const char* foo() { return \"foo changed\";}" )
+try_compile(RESULT 
+  ${BuildDepends_BINARY_DIR}/Project
+  ${BuildDepends_SOURCE_DIR}/Project
+  testRebuild
+  OUTPUT_VARIABLE OUTPUT)
+
+execute_process(COMMAND ${bar} OUTPUT_VARIABLE out)
+message("${out}")
+
+if("${out}" STREQUAL "foo changed")
+  message("Worked!")
+else("${out}" STREQUAL "foo changed")
+  message(SEND_ERROR "Program did not rebuild with changed file")
+endif("${out}" STREQUAL "foo changed")

Tests/BuildDepends/Project/CMakeLists.txt

@@ -0,0 +1,4 @@
+project(testRebuild)
+add_library(foo STATIC ${testRebuild_BINARY_DIR}/foo.c)
+add_executable(bar bar.c)
+target_link_libraries(bar foo)

Tests/BuildDepends/Project/bar.c

@@ -0,0 +1,8 @@
+#include "stdio.h"
+
+const char* foo();
+int main()
+{
+  printf("%s", foo());
+  return 0;
+}