1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
|
//===--- HeaderAnalysis.cpp -------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "clang/Tooling/Inclusions/HeaderAnalysis.h"
#include "clang/Basic/SourceLocation.h"
#include "clang/Lex/HeaderSearch.h"
namespace clang::tooling {
namespace {
// Is Line an #if or #ifdef directive?
// FIXME: This makes headers with #ifdef LINUX/WINDOWS/MACOS marked as non
// self-contained and is probably not what we want.
bool isIf(llvm::StringRef Line) {
Line = Line.ltrim();
if (!Line.consume_front("#"))
return false;
Line = Line.ltrim();
return Line.startswith("if");
}
// Is Line an #error directive mentioning includes?
bool isErrorAboutInclude(llvm::StringRef Line) {
Line = Line.ltrim();
if (!Line.consume_front("#"))
return false;
Line = Line.ltrim();
if (!Line.startswith("error"))
return false;
return Line.contains_insensitive(
"includ"); // Matches "include" or "including".
}
// Heuristically headers that only want to be included via an umbrella.
bool isDontIncludeMeHeader(StringRef Content) {
llvm::StringRef Line;
// Only sniff up to 100 lines or 10KB.
Content = Content.take_front(100 * 100);
for (unsigned I = 0; I < 100 && !Content.empty(); ++I) {
std::tie(Line, Content) = Content.split('\n');
if (isIf(Line) && isErrorAboutInclude(Content.split('\n').first))
return true;
}
return false;
}
bool isImportLine(llvm::StringRef Line) {
Line = Line.ltrim();
if (!Line.consume_front("#"))
return false;
Line = Line.ltrim();
return Line.startswith("import");
}
llvm::StringRef getFileContents(const FileEntry *FE, const SourceManager &SM) {
return const_cast<SourceManager &>(SM)
.getMemoryBufferForFileOrNone(FE)
.value_or(llvm::MemoryBufferRef())
.getBuffer();
}
} // namespace
bool isSelfContainedHeader(const FileEntry *FE, const SourceManager &SM,
HeaderSearch &HeaderInfo) {
assert(FE);
if (!HeaderInfo.isFileMultipleIncludeGuarded(FE) &&
!HeaderInfo.hasFileBeenImported(FE) &&
// Any header that contains #imports is supposed to be #import'd so no
// need to check for anything but the main-file.
(SM.getFileEntryForID(SM.getMainFileID()) != FE ||
!codeContainsImports(getFileContents(FE, SM))))
return false;
// This pattern indicates that a header can't be used without
// particular preprocessor state, usually set up by another header.
return !isDontIncludeMeHeader(getFileContents(FE, SM));
}
bool codeContainsImports(llvm::StringRef Code) {
// Only sniff up to 100 lines or 10KB.
Code = Code.take_front(100 * 100);
llvm::StringRef Line;
for (unsigned I = 0; I < 100 && !Code.empty(); ++I) {
std::tie(Line, Code) = Code.split('\n');
if (isImportLine(Line))
return true;
}
return false;
}
std::optional<StringRef> parseIWYUPragma(const char *Text) {
// Skip the comment start, // or /*.
if (Text[0] != '/' || (Text[1] != '/' && Text[1] != '*'))
return std::nullopt;
bool BlockComment = Text[1] == '*';
Text += 2;
// Per spec, direcitves are whitespace- and case-sensitive.
constexpr llvm::StringLiteral IWYUPragma = " IWYU pragma: ";
if (strncmp(Text, IWYUPragma.data(), IWYUPragma.size()))
return std::nullopt;
Text += IWYUPragma.size();
const char *End = Text;
while (*End != 0 && *End != '\n')
++End;
StringRef Rest(Text, End - Text);
// Strip off whitespace and comment markers to avoid confusion. This isn't
// fully-compatible with IWYU, which splits into whitespace-delimited tokens.
if (BlockComment)
Rest.consume_back("*/");
return Rest.trim();
}
} // namespace clang::tooling
|
