cmake: Remove check for files not in build list.

[arsenm]

Summary

I don't see what value this provides. It does globbing for
files to build, and still requires manually listing the files.
emacs by default creates backup files in the same directory if you
make changes without saving, resulting in really irritating
build errors from the "found unknown source file .#Foo.cpp"

I also don't think it's consistently used, since this
doesn't seems to happen for some subset of directories.

[arsenm]

Ping

[arsenm]

Insert a check for backup files instead. Skip files that begin with the normal "." for unix hidden files

[arsenm]

Ping

[arsenm]

Ping

[dexonsmith]

This looks like it matches our consensus, but I'm not entirely
comfortable signing off on cmake stuff. Can any build gurus take a look
at this and confirm it does what the comment says?

[chandlerc]

Please commit with the condition rewritten as suggested or something similar (provided that you test it works, I didn't try out my cmake scribble here).

cmake/modules/LLVMProcessSources.cmake

66

While regexs are a bit heavy handed, i think this is simpler as:

if (NOT "${fn}" MATCHES "^\.")

Otherwise, this looks fine.

[arsenm]

r216941 with the regex (which needed another backslash)

cmake/modules/LLVMProcessSources.cmake

 endfunction(llvm_process_sources)
 
 
 function(llvm_check_source_file_list)
   set(listed ${ARGN})
   file(GLOB globbed *.c *.cpp)
   foreach(g ${globbed})
     get_filename_component(fn ${g} NAME)
+
+    # Don't reject hidden files. Some editors create backups in the
+    # same directory as the file.
+    string(SUBSTRING ${fn} 0 1 first_char)
+    if(NOT ${first_char} STREQUAL ".")
       list(FIND LLVM_OPTIONAL_SOURCES ${fn} idx)
       if( idx LESS 0 )
         list(FIND listed ${fn} idx)
         if( idx LESS 0 )
           message(SEND_ERROR "Found unknown source file ${g}
 Please update ${CMAKE_CURRENT_LIST_FILE}\n")
         endif()
       endif()
+    endif()
   endforeach()
 endfunction(llvm_check_source_file_list)