CMake: Detect gv, circo, twopi, neato, fdo, dot and dotty.

Patch by Arnaud Allard de Grandmaison!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86547 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/cmake/config-ix.cmake b/cmake/config-ix.cmake
index dc57a13..ca5e0bf 100755
--- a/cmake/config-ix.cmake
+++ b/cmake/config-ix.cmake
@@ -127,13 +127,26 @@
 check_type_exists(u_int64_t "${headers}" HAVE_U_INT64_T)
 
 # available programs checks
-find_program(DOTTY_EXECUTABLE dotty)
-if(DOTTY_EXECUTABLE)
-  set(HAVE_DOTTY 1)
-  set(LLVM_PATH_DOTTY ${DOTTY_EXECUTABLE})
-  mark_as_advanced(HAVE_DOTTY)
-  mark_as_advanced(LLVM_PATH_DOTTY)
-endif()
+function(llvm_find_program name)
+  string(TOUPPER ${name} NAME)
+  find_program(LLVM_PATH_${NAME} ${name})
+  mark_as_advanced(LLVM_PATH_${NAME})
+  if(LLVM_PATH_${NAME})
+    set(HAVE_${NAME} 1 CACHE INTERNAL "Is ${name} available ?")
+    mark_as_advanced(HAVE_${NAME})
+  else(LLVM_PATH_${NAME})
+    set(HAVE_${NAME} "" CACHE INTERNAL "Is ${name} available ?")
+    unset(LLVM_PATH_${NAME} CACHE)
+  endif(LLVM_PATH_${NAME})
+endfunction()
+
+llvm_find_program(gv)
+llvm_find_program(circo)
+llvm_find_program(twopi)
+llvm_find_program(neato)
+llvm_find_program(fdp)
+llvm_find_program(dot)
+llvm_find_program(dotty)
 
 # Define LLVM_MULTITHREADED if gcc atomic builtins exists.
 include(CheckAtomic)