Add --color_warnings to make warnings/errors like clang

This adds new (WARN|KATI_WARN|ERROR)_LOC log macro variants that take a
location as the first argument, and will prefix that location
information to the warning/error lines.

When --color_warnings is enabled, it reformats them to have a standard
warning:/error: infix, and adds colors in order to match the
warnings/errors produced by clang.

1 files changed, 7 insertions, 0 deletions

diff --git a/strutil.cc b/strutil.cc
index b094198..632d151 100644
--- a/strutil.cc
+++ b/strutil.cc
@@ -174,6 +174,13 @@ bool HasWord(StringPiece str, StringPiece w) {
   return true;
 }
 
+StringPiece TrimPrefix(StringPiece str, StringPiece prefix) {
+  ssize_t size_diff = str.size() - prefix.size();
+  if (size_diff < 0 || str.substr(0, prefix.size()) != prefix)
+    return str;
+  return str.substr(prefix.size());
+}
+
 StringPiece TrimSuffix(StringPiece str, StringPiece suffix) {
   ssize_t size_diff = str.size() - suffix.size();
   if (size_diff < 0 || str.substr(size_diff) != suffix)