llvm-mirror/tools/llvm-readobj/StackMapPrinter.h
Sanjoy Das 58149dbd85 [Stackmap] Added callsite counts to emitted function information.
Summary:
It was previously not possible for tools to use solely the stackmap
information emitted to reconstruct the return addresses of callsites in
the map, which is necessary to use the information to walk a stack. This
patch adds per-function callsite counts when emitting the stackmap
section in order to resolve the problem. Note that this slightly alters
the stackmap format, so external tools parsing these maps will need to
be updated.

**Problem Details:**
Records only store their offset from the beginning of the function they
belong to. While these records and the functions are output in program
order, it is not possible to determine where the end of one function's
records are without the callsite count when processing the records to
compute return addresses.

Patch by Kavon Farvardin!

Reviewers: atrick, ributzka, sanjoy

Subscribers: nemanjai

Differential Revision: https://reviews.llvm.org/D23487

llvm-svn: 281532
2016-09-14 20:22:03 +00:00

82 lines
2.6 KiB
C++

//===-------- StackMapPrinter.h - Pretty-print stackmaps --------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_TOOLS_LLVM_READOBJ_STACKMAPPRINTER_H
#define LLVM_TOOLS_LLVM_READOBJ_STACKMAPPRINTER_H
#include "llvm/Object/StackMapParser.h"
namespace llvm {
// Pretty print a stackmap to the given ostream.
template <typename OStreamT, typename StackMapParserT>
void prettyPrintStackMap(OStreamT &OS, const StackMapParserT &SMP) {
OS << "LLVM StackMap Version: " << SMP.getVersion()
<< "\nNum Functions: " << SMP.getNumFunctions();
// Functions:
for (const auto &F : SMP.functions())
OS << "\n Function address: " << F.getFunctionAddress()
<< ", stack size: " << F.getStackSize()
<< ", callsite record count: " << F.getRecordCount();
// Constants:
OS << "\nNum Constants: " << SMP.getNumConstants();
unsigned ConstantIndex = 0;
for (const auto &C : SMP.constants())
OS << "\n #" << ++ConstantIndex << ": " << C.getValue();
// Records:
OS << "\nNum Records: " << SMP.getNumRecords();
for (const auto &R : SMP.records()) {
OS << "\n Record ID: " << R.getID()
<< ", instruction offset: " << R.getInstructionOffset()
<< "\n " << R.getNumLocations() << " locations:";
unsigned LocationIndex = 0;
for (const auto &Loc : R.locations()) {
OS << "\n #" << ++LocationIndex << ": ";
switch (Loc.getKind()) {
case StackMapParserT::LocationKind::Register:
OS << "Register R#" << Loc.getDwarfRegNum();
break;
case StackMapParserT::LocationKind::Direct:
OS << "Direct R#" << Loc.getDwarfRegNum() << " + "
<< Loc.getOffset();
break;
case StackMapParserT::LocationKind::Indirect:
OS << "Indirect [R#" << Loc.getDwarfRegNum() << " + "
<< Loc.getOffset() << "]";
break;
case StackMapParserT::LocationKind::Constant:
OS << "Constant " << Loc.getSmallConstant();
break;
case StackMapParserT::LocationKind::ConstantIndex:
OS << "ConstantIndex #" << Loc.getConstantIndex() << " ("
<< SMP.getConstant(Loc.getConstantIndex()).getValue() << ")";
break;
}
}
OS << "\n " << R.getNumLiveOuts() << " live-outs: [ ";
for (const auto &LO : R.liveouts())
OS << "R#" << LO.getDwarfRegNum() << " ("
<< LO.getSizeInBytes() << "-bytes) ";
OS << "]\n";
}
OS << "\n";
}
}
#endif