[opt-viewer] Handle column number 0

The asm-printer now emits remarks with function location which have
unspecified (0) source column number.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296547 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/utils/opt-viewer/opt-viewer.py b/utils/opt-viewer/opt-viewer.py
index d56e295425f2d76a09bb7a51d77f652a7ab69edf..597c7031069f933edf8fe605f0d46606c0cb6a96 100755 (executable)
--- a/utils/opt-viewer/opt-viewer.py
+++ b/utils/opt-viewer/opt-viewer.py
@@ -217,7 +217,7 @@ class SourceFileRenderer:
 
         # Column is the number of characters *including* tabs, keep those and
         # replace everything else with spaces.
-        indent = line[:r.Column - 1]
+        indent = line[:max(r.Column, 1) - 1]
         indent = re.sub('\S', ' ', indent)
 
         print('''