1 //===- unittests/Rewrite/RewriteBufferTest.cpp - RewriteBuffer tests ------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8
9 #include "clang/Rewrite/Core/RewriteBuffer.h"
10 #include "gtest/gtest.h"
11
12 using namespace llvm;
13 using namespace clang;
14
15 namespace {
16
17 #define EXPECT_OUTPUT(Buf, Output) EXPECT_EQ(Output, writeOutput(Buf))
18
writeOutput(const RewriteBuffer & Buf)19 static std::string writeOutput(const RewriteBuffer &Buf) {
20 std::string Result;
21 raw_string_ostream OS(Result);
22 Buf.write(OS);
23 OS.flush();
24 return Result;
25 }
26
tagRange(unsigned Offset,unsigned Len,StringRef tagName,RewriteBuffer & Buf)27 static void tagRange(unsigned Offset, unsigned Len, StringRef tagName,
28 RewriteBuffer &Buf) {
29 std::string BeginTag;
30 raw_string_ostream(BeginTag) << '<' << tagName << '>';
31 std::string EndTag;
32 raw_string_ostream(EndTag) << "</" << tagName << '>';
33
34 Buf.InsertTextAfter(Offset, BeginTag);
35 Buf.InsertTextBefore(Offset+Len, EndTag);
36 }
37
TEST(RewriteBuffer,TagRanges)38 TEST(RewriteBuffer, TagRanges) {
39 StringRef Input = "hello world";
40 const char *Output = "<outer><inner>hello</inner></outer> ";
41
42 RewriteBuffer Buf;
43 Buf.Initialize(Input);
44 StringRef RemoveStr = "world";
45 size_t Pos = Input.find(RemoveStr);
46 Buf.RemoveText(Pos, RemoveStr.size());
47
48 StringRef TagStr = "hello";
49 Pos = Input.find(TagStr);
50 tagRange(Pos, TagStr.size(), "outer", Buf);
51 tagRange(Pos, TagStr.size(), "inner", Buf);
52
53 EXPECT_OUTPUT(Buf, Output);
54 }
55
TEST(RewriteBuffer,DISABLED_RemoveLineIfEmpty_XFAIL)56 TEST(RewriteBuffer, DISABLED_RemoveLineIfEmpty_XFAIL) {
57 StringRef Input = "def\n"
58 "ghi\n"
59 "jkl\n";
60 RewriteBuffer Buf;
61 Buf.Initialize(Input);
62
63 // Insert "abc\n" at the start.
64 Buf.InsertText(0, "abc\n");
65 EXPECT_OUTPUT(Buf, "abc\n"
66 "def\n"
67 "ghi\n"
68 "jkl\n");
69
70 // Remove "def\n".
71 //
72 // After the removal of "def", we have:
73 //
74 // "abc\n"
75 // "\n"
76 // "ghi\n"
77 // "jkl\n"
78 //
79 // Because removeLineIfEmpty=true, RemoveText has to remove the "\n" left on
80 // the line. This happens correctly for the rewrite buffer itself, so the
81 // next check below passes.
82 //
83 // However, RemoveText's implementation incorrectly records the delta for
84 // removing the "\n" using the rewrite buffer offset, 4, where it was
85 // supposed to use the original input offset, 3. Interpreted as an original
86 // input offset, 4 points to "g" not to "\n". Thus, any future modifications
87 // at the original input's "g" will incorrectly see "g" as having become an
88 // empty string and so will map to the next character, "h", in the rewrite
89 // buffer.
90 StringRef RemoveStr0 = "def";
91 Buf.RemoveText(Input.find(RemoveStr0), RemoveStr0.size(),
92 /*removeLineIfEmpty*/ true);
93 EXPECT_OUTPUT(Buf, "abc\n"
94 "ghi\n"
95 "jkl\n");
96
97 // Try to remove "ghi\n".
98 //
99 // As discussed above, the original input offset for "ghi\n" incorrectly
100 // maps to the rewrite buffer offset for "hi\nj", so we end up with:
101 //
102 // "abc\n"
103 // "gkl\n"
104 //
105 // To show that removeLineIfEmpty=true is the culprit, change true to false
106 // and append a newline to RemoveStr0 above. The test then passes.
107 StringRef RemoveStr1 = "ghi\n";
108 Buf.RemoveText(Input.find(RemoveStr1), RemoveStr1.size());
109 EXPECT_OUTPUT(Buf, "abc\n"
110 "jkl\n");
111 }
112
113 } // anonymous namespace
114