This patch implements an AST matching framework that allows to write

tools that match on the C++ ASTs. The main interface is in ASTMatchers.h,
an example implementation of a tool that removes redundant .c_str() calls
is in the example RemoveCStrCalls.cpp.

Various contributions:
Zhanyong Wan, Chandler Carruth, Marcin Kowalczyk, Wei Xu, James Dennett.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@132374 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 50 insertions, 0 deletions

diff --git a/examples/Tooling/replace.py b/examples/Tooling/replace.py
new file mode 100755
index 0000000000..a738dea70c
--- /dev/null
+++ b/examples/Tooling/replace.py
@@ -0,0 +1,50 @@
+#!/usr/bin/env python
+
+#===- replace.py - Applying code rewrites --------------------*- python -*--===#
+#
+#                     The LLVM Compiler Infrastructure
+#
+# This file is distributed under the University of Illinois Open Source
+# License. See LICENSE.TXT for details.
+#
+#===------------------------------------------------------------------------===#
+#
+# This script applies the rewrites generated by replace-cstr-calls on a source
+# tree.
+#
+# Usage:
+#   ./replace.py < /path/to/replace-cstr-calls-output
+#
+#===------------------------------------------------------------------------===#
+
+import fileinput
+import re
+import sys
+
+for line in sys.stdin.readlines():
+  # The format is:
+  # <file>:<start_line>:<start_column>:<end_line>:<end_column>:<replacement>
+  # FIXME: This currently does not support files with colons, we'll need to
+  # figure out a format when we implement more refactoring support.
+  match = re.match(r'(.*):(\d+):(\d+):(\d+):(\d+):(.*)$', line)
+  if match is not None:
+    file_name = match.group(1)
+    start_line, start_column = int(match.group(2)), int(match.group(3))
+    end_line, end_column = int(match.group(4)), int(match.group(5))
+    replacement = match.group(6)
+    if start_line != end_line:
+      print ('Skipping match "%s": only single line ' +
+             'replacements are supported') % line.strip()
+      continue
+    try:
+      replace_file = fileinput.input(file_name, inplace=1)
+      for replace_line in replace_file:
+        # FIXME: Looping over the file for each replacement is both inefficient
+        # and incorrect if replacements add or remove lines.
+        if replace_file.lineno() == start_line:
+          sys.stdout.write(replace_line[:start_column-1] + replacement +
+                           replace_line[end_column:])
+        else:
+          sys.stdout.write(replace_line)
+    except OSError, e:
+      print 'Cannot open %s for editing' % file_name