diff options
| -rw-r--r-- | build2/cc/lexer.cxx | 18 | ||||
| -rw-r--r-- | build2/cc/lexer.hxx | 1 |
2 files changed, 17 insertions, 2 deletions
diff --git a/build2/cc/lexer.cxx b/build2/cc/lexer.cxx index 7ab1a57..0615941 100644 --- a/build2/cc/lexer.cxx +++ b/build2/cc/lexer.cxx @@ -809,7 +809,12 @@ namespace build2 { const location l (&name_, c.line, c.column); - string s (move (log_file_).string ()); // Move string rep out. + // It is common to have a large number of #line directives that don't + // change the file (they seem to be used to track macro locations or + // some such). So we are going to optimize for this by comparing the + // current path to what's in #line. + // + string& s (tmp_file_); s.clear (); for (char p ('\0'); p != '\"'; ) // Previous character. @@ -867,7 +872,16 @@ namespace build2 } } - log_file_ = path (move (s)); // Move back in. + if (log_file_.string () == s) + return; + + // Swap the two string buffers. + // + { + string r (move (log_file_).string ()); // Move string rep out. + r.swap (s); + log_file_ = path (move (r)); // Move back in. + } // If the path is relative, then prefix it with the current working // directory. Failed that, we will end up with different checksums for diff --git a/build2/cc/lexer.hxx b/build2/cc/lexer.hxx index aa24f6a..9dab12b 100644 --- a/build2/cc/lexer.hxx +++ b/build2/cc/lexer.hxx @@ -170,6 +170,7 @@ namespace build2 path log_file_; optional<uint64_t> log_line_; + string tmp_file_; sha256 cs_; }; |