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f3dcc2351c
This patch replaces uses of StringRef::{starts,ends}with with
StringRef::{starts,ends}_with for consistency with
std::{string,string_view}::{starts,ends}_with in C++20.
I'm planning to deprecate and eventually remove
StringRef::{starts,ends}with.
119 lines
3.8 KiB
C++
119 lines
3.8 KiB
C++
//===--- HeaderAnalysis.cpp -------------------------------------*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "clang/Tooling/Inclusions/HeaderAnalysis.h"
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#include "clang/Basic/SourceLocation.h"
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#include "clang/Lex/HeaderSearch.h"
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namespace clang::tooling {
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namespace {
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// Is Line an #if or #ifdef directive?
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// FIXME: This makes headers with #ifdef LINUX/WINDOWS/MACOS marked as non
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// self-contained and is probably not what we want.
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bool isIf(llvm::StringRef Line) {
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Line = Line.ltrim();
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if (!Line.consume_front("#"))
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return false;
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Line = Line.ltrim();
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return Line.starts_with("if");
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}
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// Is Line an #error directive mentioning includes?
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bool isErrorAboutInclude(llvm::StringRef Line) {
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Line = Line.ltrim();
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if (!Line.consume_front("#"))
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return false;
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Line = Line.ltrim();
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if (!Line.starts_with("error"))
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return false;
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return Line.contains_insensitive(
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"includ"); // Matches "include" or "including".
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}
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// Heuristically headers that only want to be included via an umbrella.
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bool isDontIncludeMeHeader(StringRef Content) {
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llvm::StringRef Line;
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// Only sniff up to 100 lines or 10KB.
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Content = Content.take_front(100 * 100);
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for (unsigned I = 0; I < 100 && !Content.empty(); ++I) {
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std::tie(Line, Content) = Content.split('\n');
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if (isIf(Line) && isErrorAboutInclude(Content.split('\n').first))
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return true;
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}
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return false;
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}
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bool isImportLine(llvm::StringRef Line) {
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Line = Line.ltrim();
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if (!Line.consume_front("#"))
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return false;
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Line = Line.ltrim();
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return Line.starts_with("import");
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}
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llvm::StringRef getFileContents(FileEntryRef FE, const SourceManager &SM) {
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return const_cast<SourceManager &>(SM)
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.getMemoryBufferForFileOrNone(FE)
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.value_or(llvm::MemoryBufferRef())
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.getBuffer();
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}
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} // namespace
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bool isSelfContainedHeader(FileEntryRef FE, const SourceManager &SM,
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const HeaderSearch &HeaderInfo) {
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if (!HeaderInfo.isFileMultipleIncludeGuarded(FE) &&
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!HeaderInfo.hasFileBeenImported(FE) &&
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// Any header that contains #imports is supposed to be #import'd so no
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// need to check for anything but the main-file.
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(SM.getFileEntryForID(SM.getMainFileID()) != FE ||
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!codeContainsImports(getFileContents(FE, SM))))
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return false;
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// This pattern indicates that a header can't be used without
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// particular preprocessor state, usually set up by another header.
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return !isDontIncludeMeHeader(getFileContents(FE, SM));
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}
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bool codeContainsImports(llvm::StringRef Code) {
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// Only sniff up to 100 lines or 10KB.
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Code = Code.take_front(100 * 100);
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llvm::StringRef Line;
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for (unsigned I = 0; I < 100 && !Code.empty(); ++I) {
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std::tie(Line, Code) = Code.split('\n');
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if (isImportLine(Line))
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return true;
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}
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return false;
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}
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std::optional<StringRef> parseIWYUPragma(const char *Text) {
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// Skip the comment start, // or /*.
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if (Text[0] != '/' || (Text[1] != '/' && Text[1] != '*'))
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return std::nullopt;
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bool BlockComment = Text[1] == '*';
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Text += 2;
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// Per spec, direcitves are whitespace- and case-sensitive.
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constexpr llvm::StringLiteral IWYUPragma = " IWYU pragma: ";
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if (strncmp(Text, IWYUPragma.data(), IWYUPragma.size()))
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return std::nullopt;
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Text += IWYUPragma.size();
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const char *End = Text;
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while (*End != 0 && *End != '\n')
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++End;
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StringRef Rest(Text, End - Text);
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// Strip off whitespace and comment markers to avoid confusion. This isn't
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// fully-compatible with IWYU, which splits into whitespace-delimited tokens.
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if (BlockComment)
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Rest.consume_back("*/");
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return Rest.trim();
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}
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} // namespace clang::tooling
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