Coverage Report

Created: 2019-07-24 05:18

/Users/buildslave/jenkins/workspace/clang-stage2-coverage-R/llvm/include/llvm/MC/ConstantPools.h
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//===- ConstantPools.h - Keep track of assembler-generated ------*- 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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//
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// This file declares the ConstantPool and AssemblerConstantPools classes.
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_MC_CONSTANTPOOLS_H
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#define LLVM_MC_CONSTANTPOOLS_H
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#include "llvm/ADT/DenseMap.h"
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#include "llvm/ADT/MapVector.h"
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#include "llvm/ADT/SmallVector.h"
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#include "llvm/Support/SMLoc.h"
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#include <cstdint>
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#include <map>
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namespace llvm {
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class MCContext;
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class MCExpr;
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class MCSection;
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class MCStreamer;
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class MCSymbol;
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class MCSymbolRefExpr;
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struct ConstantPoolEntry {
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  ConstantPoolEntry(MCSymbol *L, const MCExpr *Val, unsigned Sz, SMLoc Loc_)
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    : Label(L), Value(Val), Size(Sz), Loc(Loc_) {}
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  MCSymbol *Label;
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  const MCExpr *Value;
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  unsigned Size;
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  SMLoc Loc;
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};
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// A class to keep track of assembler-generated constant pools that are use to
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// implement the ldr-pseudo.
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class ConstantPool {
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  using EntryVecTy = SmallVector<ConstantPoolEntry, 4>;
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  EntryVecTy Entries;
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  std::map<int64_t, const MCSymbolRefExpr *> CachedEntries;
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public:
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  // Initialize a new empty constant pool
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  ConstantPool() = default;
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  // Add a new entry to the constant pool in the next slot.
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  // \param Value is the new entry to put in the constant pool.
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  // \param Size is the size in bytes of the entry
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  //
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  // \returns a MCExpr that references the newly inserted value
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  const MCExpr *addEntry(const MCExpr *Value, MCContext &Context,
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                         unsigned Size, SMLoc Loc);
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  // Emit the contents of the constant pool using the provided streamer.
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  void emitEntries(MCStreamer &Streamer);
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  // Return true if the constant pool is empty
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  bool empty();
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  void clearCache();
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};
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class AssemblerConstantPools {
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  // Map type used to keep track of per-Section constant pools used by the
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  // ldr-pseudo opcode. The map associates a section to its constant pool. The
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  // constant pool is a vector of (label, value) pairs. When the ldr
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  // pseudo is parsed we insert a new (label, value) pair into the constant pool
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  // for the current section and add MCSymbolRefExpr to the new label as
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  // an opcode to the ldr. After we have parsed all the user input we
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  // output the (label, value) pairs in each constant pool at the end of the
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  // section.
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  //
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  // We use the MapVector for the map type to ensure stable iteration of
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  // the sections at the end of the parse. We need to iterate over the
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  // sections in a stable order to ensure that we have print the
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  // constant pools in a deterministic order when printing an assembly
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  // file.
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  using ConstantPoolMapTy = MapVector<MCSection *, ConstantPool>;
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  ConstantPoolMapTy ConstantPools;
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public:
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  void emitAll(MCStreamer &Streamer);
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  void emitForCurrentSection(MCStreamer &Streamer);
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  void clearCacheForCurrentSection(MCStreamer &Streamer);
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  const MCExpr *addEntry(MCStreamer &Streamer, const MCExpr *Expr,
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                         unsigned Size, SMLoc Loc);
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private:
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  ConstantPool *getConstantPool(MCSection *Section);
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  ConstantPool &getOrCreateConstantPool(MCSection *Section);
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};
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} // end namespace llvm
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#endif // LLVM_MC_CONSTANTPOOLS_H