llvm-for-llvmta/tools/clang/lib/Tooling/Syntax/ComputeReplacements.cpp

128 lines
4.6 KiB
C++

//===- ComputeReplacements.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/Core/Replacement.h"
#include "clang/Tooling/Syntax/Mutations.h"
#include "clang/Tooling/Syntax/Tokens.h"
#include "llvm/Support/Error.h"
using namespace clang;
namespace {
using ProcessTokensFn = llvm::function_ref<void(llvm::ArrayRef<syntax::Token>,
bool /*IsOriginal*/)>;
/// Enumerates spans of tokens from the tree consecutively laid out in memory.
void enumerateTokenSpans(const syntax::Tree *Root, ProcessTokensFn Callback) {
struct Enumerator {
Enumerator(ProcessTokensFn Callback)
: SpanBegin(nullptr), SpanEnd(nullptr), SpanIsOriginal(false),
Callback(Callback) {}
void run(const syntax::Tree *Root) {
process(Root);
// Report the last span to the user.
if (SpanBegin)
Callback(llvm::makeArrayRef(SpanBegin, SpanEnd), SpanIsOriginal);
}
private:
void process(const syntax::Node *N) {
if (auto *T = dyn_cast<syntax::Tree>(N)) {
for (const auto *C = T->getFirstChild(); C != nullptr;
C = C->getNextSibling())
process(C);
return;
}
auto *L = cast<syntax::Leaf>(N);
if (SpanEnd == L->getToken() && SpanIsOriginal == L->isOriginal()) {
// Extend the current span.
++SpanEnd;
return;
}
// Report the current span to the user.
if (SpanBegin)
Callback(llvm::makeArrayRef(SpanBegin, SpanEnd), SpanIsOriginal);
// Start recording a new span.
SpanBegin = L->getToken();
SpanEnd = SpanBegin + 1;
SpanIsOriginal = L->isOriginal();
}
const syntax::Token *SpanBegin;
const syntax::Token *SpanEnd;
bool SpanIsOriginal;
ProcessTokensFn Callback;
};
return Enumerator(Callback).run(Root);
}
syntax::FileRange rangeOfExpanded(const syntax::Arena &A,
llvm::ArrayRef<syntax::Token> Expanded) {
const auto &Buffer = A.getTokenBuffer();
const auto &SM = A.getSourceManager();
// Check that \p Expanded actually points into expanded tokens.
assert(Buffer.expandedTokens().begin() <= Expanded.begin());
assert(Expanded.end() < Buffer.expandedTokens().end());
if (Expanded.empty())
// (!) empty tokens must always point before end().
return syntax::FileRange(
SM, SM.getExpansionLoc(Expanded.begin()->location()), /*Length=*/0);
auto Spelled = Buffer.spelledForExpanded(Expanded);
assert(Spelled && "could not find spelled tokens for expanded");
return syntax::Token::range(SM, Spelled->front(), Spelled->back());
}
} // namespace
tooling::Replacements
syntax::computeReplacements(const syntax::Arena &A,
const syntax::TranslationUnit &TU) {
const auto &Buffer = A.getTokenBuffer();
const auto &SM = A.getSourceManager();
tooling::Replacements Replacements;
// Text inserted by the replacement we are building now.
std::string Replacement;
auto emitReplacement = [&](llvm::ArrayRef<syntax::Token> ReplacedRange) {
if (ReplacedRange.empty() && Replacement.empty())
return;
llvm::cantFail(Replacements.add(tooling::Replacement(
SM, rangeOfExpanded(A, ReplacedRange).toCharRange(SM), Replacement)));
Replacement = "";
};
const syntax::Token *NextOriginal = Buffer.expandedTokens().begin();
enumerateTokenSpans(
&TU, [&](llvm::ArrayRef<syntax::Token> Tokens, bool IsOriginal) {
if (!IsOriginal) {
Replacement +=
syntax::Token::range(SM, Tokens.front(), Tokens.back()).text(SM);
return;
}
assert(NextOriginal <= Tokens.begin());
// We are looking at a span of original tokens.
if (NextOriginal != Tokens.begin()) {
// There is a gap, record a replacement or deletion.
emitReplacement(llvm::makeArrayRef(NextOriginal, Tokens.begin()));
} else {
// No gap, but we may have pending insertions. Emit them now.
emitReplacement(llvm::makeArrayRef(NextOriginal, /*Length=*/0));
}
NextOriginal = Tokens.end();
});
// We might have pending replacements at the end of file. If so, emit them.
emitReplacement(llvm::makeArrayRef(
NextOriginal, Buffer.expandedTokens().drop_back().end()));
return Replacements;
}