1
0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-25 12:12:47 +01:00
llvm-mirror/lib/CodeGen/AsmPrinter/ByteStreamer.h
Bjorn Pettersson 7bfe1ca83a [DebugInfo] Align comments in debug_loc section
Summary:
This commit updates the BufferByteStreamer, used by DebugLocStream
to buffer bytes/comments to put in the debug_loc section, to
make sure that the Buffer and Comments vectors are synced.
Previously, when an SLEB128 or ULEB128 was emitted together with
a comment, the vectors could be out-of-sync if the LEB encoding
added several entries to the Buffer vectors, while we only added
a single entry to the Comments vector.

The goal with this is to get the comments in the debug_loc
section in the .s file correctly aligned.

Example (using ARM as target):
Instead of

  .byte 144                     @ sub-register DW_OP_regx
  .byte 128                     @ 256
  .byte 2                       @ DW_OP_piece
  .byte 147                     @ 8
  .byte 8                       @ sub-register DW_OP_regx
  .byte 144                     @ 257
  .byte 129                     @ DW_OP_piece
  .byte 2                       @ 8
  .byte 147                     @
  .byte 8                       @

we now get

  .byte 144                     @ sub-register DW_OP_regx
  .byte 128                     @ 256
  .byte 2                       @
  .byte 147                     @ DW_OP_piece
  .byte 8                       @ 8
  .byte 144                     @ sub-register DW_OP_regx
  .byte 129                     @ 257
  .byte 2                       @
  .byte 147                     @ DW_OP_piece
  .byte 8                       @ 8

Reviewers: JDevlieghere, rnk, aprantl

Reviewed By: aprantl

Subscribers: davide, Ka-Ka, uabelho, aemerson, javed.absar, kristof.beyls, llvm-commits, JDevlieghere

Differential Revision: https://reviews.llvm.org/D41763

llvm-svn: 321907
2018-01-05 22:20:30 +00:00

123 lines
3.8 KiB
C++

//===-- llvm/CodeGen/ByteStreamer.h - ByteStreamer class --------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains a class that can take bytes that would normally be
// streamed via the AsmPrinter.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIB_CODEGEN_ASMPRINTER_BYTESTREAMER_H
#define LLVM_LIB_CODEGEN_ASMPRINTER_BYTESTREAMER_H
#include "DIEHash.h"
#include "llvm/CodeGen/AsmPrinter.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/Support/LEB128.h"
#include <string>
namespace llvm {
class ByteStreamer {
protected:
~ByteStreamer() = default;
ByteStreamer(const ByteStreamer&) = default;
ByteStreamer() = default;
public:
// For now we're just handling the calls we need for dwarf emission/hashing.
virtual void EmitInt8(uint8_t Byte, const Twine &Comment = "") = 0;
virtual void EmitSLEB128(uint64_t DWord, const Twine &Comment = "") = 0;
virtual void EmitULEB128(uint64_t DWord, const Twine &Comment = "") = 0;
};
class APByteStreamer final : public ByteStreamer {
private:
AsmPrinter &AP;
public:
APByteStreamer(AsmPrinter &Asm) : AP(Asm) {}
void EmitInt8(uint8_t Byte, const Twine &Comment) override {
AP.OutStreamer->AddComment(Comment);
AP.EmitInt8(Byte);
}
void EmitSLEB128(uint64_t DWord, const Twine &Comment) override {
AP.OutStreamer->AddComment(Comment);
AP.EmitSLEB128(DWord);
}
void EmitULEB128(uint64_t DWord, const Twine &Comment) override {
AP.OutStreamer->AddComment(Comment);
AP.EmitULEB128(DWord);
}
};
class HashingByteStreamer final : public ByteStreamer {
private:
DIEHash &Hash;
public:
HashingByteStreamer(DIEHash &H) : Hash(H) {}
void EmitInt8(uint8_t Byte, const Twine &Comment) override {
Hash.update(Byte);
}
void EmitSLEB128(uint64_t DWord, const Twine &Comment) override {
Hash.addSLEB128(DWord);
}
void EmitULEB128(uint64_t DWord, const Twine &Comment) override {
Hash.addULEB128(DWord);
}
};
class BufferByteStreamer final : public ByteStreamer {
private:
SmallVectorImpl<char> &Buffer;
SmallVectorImpl<std::string> &Comments;
/// \brief Only verbose textual output needs comments. This will be set to
/// true for that case, and false otherwise. If false, comments passed in to
/// the emit methods will be ignored.
bool GenerateComments;
public:
BufferByteStreamer(SmallVectorImpl<char> &Buffer,
SmallVectorImpl<std::string> &Comments,
bool GenerateComments)
: Buffer(Buffer), Comments(Comments), GenerateComments(GenerateComments) {}
void EmitInt8(uint8_t Byte, const Twine &Comment) override {
Buffer.push_back(Byte);
if (GenerateComments)
Comments.push_back(Comment.str());
}
void EmitSLEB128(uint64_t DWord, const Twine &Comment) override {
raw_svector_ostream OSE(Buffer);
unsigned Length = encodeSLEB128(DWord, OSE);
if (GenerateComments) {
Comments.push_back(Comment.str());
// Add some empty comments to keep the Buffer and Comments vectors aligned
// with each other.
for (size_t i = 1; i < Length; ++i)
Comments.push_back("");
}
}
void EmitULEB128(uint64_t DWord, const Twine &Comment) override {
raw_svector_ostream OSE(Buffer);
unsigned Length = encodeULEB128(DWord, OSE);
if (GenerateComments) {
Comments.push_back(Comment.str());
// Add some empty comments to keep the Buffer and Comments vectors aligned
// with each other.
for (size_t i = 1; i < Length; ++i)
Comments.push_back("");
}
}
};
}
#endif