[clang] [libclang/python] Expose Rewriter to the python binding (PR #77269)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Jimmy Z (jimmy-zx)

<details>
<summary>Changes</summary>

Exposes `CXRewriter` API to the python binding as in https://github.com/llvm/llvm-project/commit/69e5abb57b70570cf04671a93246e5e624023650.

---
Full diff: https://github.com/llvm/llvm-project/pull/77269.diff


2 Files Affected:

- (modified) clang/bindings/python/clang/cindex.py (+62) 
- (added) clang/bindings/python/tests/cindex/test_rewrite.py (+75) 


``````````diff
diff --git a/clang/bindings/python/clang/cindex.py b/clang/bindings/python/clang/cindex.py
index d780ee353a133c..ced449180d98fc 100644
--- a/clang/bindings/python/clang/cindex.py
+++ b/clang/bindings/python/clang/cindex.py
@@ -3531,6 +3531,61 @@ def cursor(self):
         return cursor
 
 
+class Rewriter(ClangObject):
+    """
+    The Rewriter is a wrapper class around clang::Rewriter
+
+    It enables rewriting buffers.
+    """
+
+    @staticmethod
+    def create(tu):
+        """
+        Creates a new Rewriter
+        Parameters:
+        tu -- The translation unit for the target AST.
+        """
+        return Rewriter(conf.lib.clang_CXRewriter_create(tu))
+
+    def __init__(self, ptr):
+        ClangObject.__init__(self, ptr)
+
+    def __del__(self):
+        conf.lib.clang_CXRewriter_dispose(self)
+
+    def insertTextBefore(self, loc, insert):
+        """
+        Insert the specified string at the specified location in the original buffer.
+        """
+        conf.lib.clang_CXRewriter_insertTextBefore(self, loc, insert)
+
+    def replaceText(self, toBeReplaced, replacement):
+        """
+        This method replaces a range of characters in the input buffer with a new string.
+        """
+        conf.lib.clang_CXRewriter_replaceText(self, toBeReplaced, replacement)
+
+    def removeText(self, toBeRemoved):
+        """
+        Remove the specified text region.
+        """
+        conf.lib.clang_CXRewriter_removeText(self, toBeRemoved)
+
+    def overwriteChangedFiles(self):
+        """
+        Save all changed files to disk.
+
+        Returns 1 if any files were not saved successfully, returns 0 otherwise.
+        """
+        return conf.lib.clang_CXRewriter_overwriteChangedFiles(self)
+
+    def writeMainFileToStdOut(self):
+        """
+        Writes the main file to stdout.
+        """
+        conf.lib.clang_CXRewriter_writeMainFileToStdOut(self)
+
+
 # Now comes the plumbing to hook up the C library.
 
 # Register callback types in common container.
@@ -3596,6 +3651,13 @@ def cursor(self):
     ("clang_codeCompleteGetNumDiagnostics", [CodeCompletionResults], c_int),
     ("clang_createIndex", [c_int, c_int], c_object_p),
     ("clang_createTranslationUnit", [Index, c_interop_string], c_object_p),
+    ("clang_CXRewriter_create", [TranslationUnit], c_object_p),
+    ("clang_CXRewriter_dispose", [Rewriter]),
+    ("clang_CXRewriter_insertTextBefore", [Rewriter, SourceLocation, c_interop_string]),
+    ("clang_CXRewriter_overwriteChangedFiles", [Rewriter], c_int),
+    ("clang_CXRewriter_removeText", [Rewriter, SourceRange]),
+    ("clang_CXRewriter_replaceText", [Rewriter, SourceRange, c_interop_string]),
+    ("clang_CXRewriter_writeMainFileToStdOut", [Rewriter]),
     ("clang_CXXConstructor_isConvertingConstructor", [Cursor], bool),
     ("clang_CXXConstructor_isCopyConstructor", [Cursor], bool),
     ("clang_CXXConstructor_isDefaultConstructor", [Cursor], bool),
diff --git a/clang/bindings/python/tests/cindex/test_rewrite.py b/clang/bindings/python/tests/cindex/test_rewrite.py
new file mode 100644
index 00000000000000..2c5f904ce50bdc
--- /dev/null
+++ b/clang/bindings/python/tests/cindex/test_rewrite.py
@@ -0,0 +1,75 @@
+import sys
+import io
+import unittest
+import tempfile
+
+from clang.cindex import (
+    Rewriter,
+    TranslationUnit,
+    Config,
+    File,
+    SourceLocation,
+    SourceRange,
+)
+
+
+class TestRewrite(unittest.TestCase):
+    code = """
+int test1;
+
+void test2(void);
+
+int f(int c) {
+    return c;
+}
+"""
+
+    def setUp(self):
+        self.tmp = tempfile.NamedTemporaryFile(suffix=".cpp", buffering=0)
+        self.tmp.write(TestRewrite.code.encode("utf-8"))
+        self.tmp.flush()
+        self.tu = TranslationUnit.from_source(self.tmp.name)
+        self.rew = Rewriter.create(self.tu)
+        self.file = File.from_name(self.tu, self.tmp.name)
+
+    def tearDown(self):
+        self.tmp.close()
+
+    def test_insert(self):
+        snip = "#include <cstdio>\n"
+
+        beginning = SourceLocation.from_offset(self.tu, self.file, 0)
+        self.rew.insertTextBefore(beginning, snip)
+        self.rew.overwriteChangedFiles()
+
+        with open(self.tmp.name, "r", encoding="utf-8") as f:
+            self.assertEqual(f.read(), snip + TestRewrite.code)
+
+    def test_replace(self):
+        pattern = "test2"
+        replacement = "func"
+
+        offset = TestRewrite.code.find(pattern)
+        pattern_range = SourceRange.from_locations(
+            SourceLocation.from_offset(self.tu, self.file, offset),
+            SourceLocation.from_offset(self.tu, self.file, offset + len(pattern)),
+        )
+        self.rew.replaceText(pattern_range, replacement)
+        self.rew.overwriteChangedFiles()
+
+        with open(self.tmp.name, "r", encoding="utf-8") as f:
+            self.assertEqual(f.read(), TestRewrite.code.replace(pattern, replacement))
+
+    def test_remove(self):
+        pattern = "int c"
+
+        offset = TestRewrite.code.find(pattern)
+        pattern_range = SourceRange.from_locations(
+            SourceLocation.from_offset(self.tu, self.file, offset),
+            SourceLocation.from_offset(self.tu, self.file, offset + len(pattern)),
+        )
+        self.rew.removeText(pattern_range)
+        self.rew.overwriteChangedFiles()
+
+        with open(self.tmp.name, "r", encoding="utf-8") as f:
+            self.assertEqual(f.read(), TestRewrite.code.replace(pattern, ""))

``````````

</details>


https://github.com/llvm/llvm-project/pull/77269