# HG changeset patch
# User Frits van Bommel <fvbommel wxs.nl>
# Date 1244038188 -7200
# Node ID 230765fc82f4bed913f37717e967410b1e55c680
# Parent  da3262e901b41207c24df56cdef723b0c6e23a26
Emit nicer error messages when the user didn't set LLVM_REV and autodetection
didn't find a suitable revision or when the LLVM revision in use is too old.

diff -r da3262e901b4 -r 230765fc82f4 revisions.pl.in
--- a/revisions.pl.in	Wed Jun 03 15:26:58 2009 +0200
+++ b/revisions.pl.in	Wed Jun 03 16:09:48 2009 +0200
@@ -62,13 +62,19 @@
 }
 
 # Allow the user to manually define it on the command line...
-$out = qq!#ifndef LLVM_REV
+$out = qq@#ifndef LLVM_REV
 
 // LLVM svn revision number, used to adapt to changes in LLVM
 // (Is 0 if LLVM is not an SVN trunk version)
 #define LLVM_REV $llvm_rev_nr
 
-#endif // LLVM_REV\n!;
+#endif // LLVM_REV
+
+#if !LLVM_REV
+#error "You need to add '-DLLVM_REV=<your-llvm-rev>' to CMAKE_CXX_FLAGS in the cmake configuration"
+#elif LLVM_REV < 67588
+#error "Please update to a more recent LLVM version"
+#endif\n@;
 
 $old = "";
 open $revh, "llvm-version.h" and $old = join "", <$revh>;