llvm-project/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldChecker.cpp

876 lines
32 KiB
C++

//===--- RuntimeDyldChecker.cpp - RuntimeDyld tester framework --*- 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 "llvm/ExecutionEngine/RuntimeDyldChecker.h"
#include "RuntimeDyldCheckerImpl.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCDisassembler/MCDisassembler.h"
#include "llvm/MC/MCInst.h"
#include "llvm/Support/Endian.h"
#include "llvm/Support/MSVCErrorWorkarounds.h"
#include "llvm/Support/Path.h"
#include <cctype>
#include <memory>
#include <utility>
#define DEBUG_TYPE "rtdyld"
using namespace llvm;
namespace llvm {
// Helper class that implements the language evaluated by RuntimeDyldChecker.
class RuntimeDyldCheckerExprEval {
public:
RuntimeDyldCheckerExprEval(const RuntimeDyldCheckerImpl &Checker,
raw_ostream &ErrStream)
: Checker(Checker) {}
bool evaluate(StringRef Expr) const {
// Expect equality expression of the form 'LHS = RHS'.
Expr = Expr.trim();
size_t EQIdx = Expr.find('=');
ParseContext OutsideLoad(false);
// Evaluate LHS.
StringRef LHSExpr = Expr.substr(0, EQIdx).rtrim();
StringRef RemainingExpr;
EvalResult LHSResult;
std::tie(LHSResult, RemainingExpr) =
evalComplexExpr(evalSimpleExpr(LHSExpr, OutsideLoad), OutsideLoad);
if (LHSResult.hasError())
return handleError(Expr, LHSResult);
if (RemainingExpr != "")
return handleError(Expr, unexpectedToken(RemainingExpr, LHSExpr, ""));
// Evaluate RHS.
StringRef RHSExpr = Expr.substr(EQIdx + 1).ltrim();
EvalResult RHSResult;
std::tie(RHSResult, RemainingExpr) =
evalComplexExpr(evalSimpleExpr(RHSExpr, OutsideLoad), OutsideLoad);
if (RHSResult.hasError())
return handleError(Expr, RHSResult);
if (RemainingExpr != "")
return handleError(Expr, unexpectedToken(RemainingExpr, RHSExpr, ""));
if (LHSResult.getValue() != RHSResult.getValue()) {
Checker.ErrStream << "Expression '" << Expr << "' is false: "
<< format("0x%" PRIx64, LHSResult.getValue())
<< " != " << format("0x%" PRIx64, RHSResult.getValue())
<< "\n";
return false;
}
return true;
}
private:
// RuntimeDyldCheckerExprEval requires some context when parsing exprs. In
// particular, it needs to know whether a symbol is being evaluated in the
// context of a load, in which case we want the linker's local address for
// the symbol, or outside of a load, in which case we want the symbol's
// address in the remote target.
struct ParseContext {
bool IsInsideLoad;
ParseContext(bool IsInsideLoad) : IsInsideLoad(IsInsideLoad) {}
};
const RuntimeDyldCheckerImpl &Checker;
enum class BinOpToken : unsigned {
Invalid,
Add,
Sub,
BitwiseAnd,
BitwiseOr,
ShiftLeft,
ShiftRight
};
class EvalResult {
public:
EvalResult() : Value(0), ErrorMsg("") {}
EvalResult(uint64_t Value) : Value(Value), ErrorMsg("") {}
EvalResult(std::string ErrorMsg)
: Value(0), ErrorMsg(std::move(ErrorMsg)) {}
uint64_t getValue() const { return Value; }
bool hasError() const { return ErrorMsg != ""; }
const std::string &getErrorMsg() const { return ErrorMsg; }
private:
uint64_t Value;
std::string ErrorMsg;
};
StringRef getTokenForError(StringRef Expr) const {
if (Expr.empty())
return "";
StringRef Token, Remaining;
if (isalpha(Expr[0]))
std::tie(Token, Remaining) = parseSymbol(Expr);
else if (isdigit(Expr[0]))
std::tie(Token, Remaining) = parseNumberString(Expr);
else {
unsigned TokLen = 1;
if (Expr.startswith("<<") || Expr.startswith(">>"))
TokLen = 2;
Token = Expr.substr(0, TokLen);
}
return Token;
}
EvalResult unexpectedToken(StringRef TokenStart, StringRef SubExpr,
StringRef ErrText) const {
std::string ErrorMsg("Encountered unexpected token '");
ErrorMsg += getTokenForError(TokenStart);
if (SubExpr != "") {
ErrorMsg += "' while parsing subexpression '";
ErrorMsg += SubExpr;
}
ErrorMsg += "'";
if (ErrText != "") {
ErrorMsg += " ";
ErrorMsg += ErrText;
}
return EvalResult(std::move(ErrorMsg));
}
bool handleError(StringRef Expr, const EvalResult &R) const {
assert(R.hasError() && "Not an error result.");
Checker.ErrStream << "Error evaluating expression '" << Expr
<< "': " << R.getErrorMsg() << "\n";
return false;
}
std::pair<BinOpToken, StringRef> parseBinOpToken(StringRef Expr) const {
if (Expr.empty())
return std::make_pair(BinOpToken::Invalid, "");
// Handle the two 2-character tokens.
if (Expr.startswith("<<"))
return std::make_pair(BinOpToken::ShiftLeft, Expr.substr(2).ltrim());
if (Expr.startswith(">>"))
return std::make_pair(BinOpToken::ShiftRight, Expr.substr(2).ltrim());
// Handle one-character tokens.
BinOpToken Op;
switch (Expr[0]) {
default:
return std::make_pair(BinOpToken::Invalid, Expr);
case '+':
Op = BinOpToken::Add;
break;
case '-':
Op = BinOpToken::Sub;
break;
case '&':
Op = BinOpToken::BitwiseAnd;
break;
case '|':
Op = BinOpToken::BitwiseOr;
break;
}
return std::make_pair(Op, Expr.substr(1).ltrim());
}
EvalResult computeBinOpResult(BinOpToken Op, const EvalResult &LHSResult,
const EvalResult &RHSResult) const {
switch (Op) {
default:
llvm_unreachable("Tried to evaluate unrecognized operation.");
case BinOpToken::Add:
return EvalResult(LHSResult.getValue() + RHSResult.getValue());
case BinOpToken::Sub:
return EvalResult(LHSResult.getValue() - RHSResult.getValue());
case BinOpToken::BitwiseAnd:
return EvalResult(LHSResult.getValue() & RHSResult.getValue());
case BinOpToken::BitwiseOr:
return EvalResult(LHSResult.getValue() | RHSResult.getValue());
case BinOpToken::ShiftLeft:
return EvalResult(LHSResult.getValue() << RHSResult.getValue());
case BinOpToken::ShiftRight:
return EvalResult(LHSResult.getValue() >> RHSResult.getValue());
}
}
// Parse a symbol and return a (string, string) pair representing the symbol
// name and expression remaining to be parsed.
std::pair<StringRef, StringRef> parseSymbol(StringRef Expr) const {
size_t FirstNonSymbol = Expr.find_first_not_of("0123456789"
"abcdefghijklmnopqrstuvwxyz"
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
":_.$");
return std::make_pair(Expr.substr(0, FirstNonSymbol),
Expr.substr(FirstNonSymbol).ltrim());
}
// Evaluate a call to decode_operand. Decode the instruction operand at the
// given symbol and get the value of the requested operand.
// Returns an error if the instruction cannot be decoded, or the requested
// operand is not an immediate.
// On success, returns a pair containing the value of the operand, plus
// the expression remaining to be evaluated.
std::pair<EvalResult, StringRef> evalDecodeOperand(StringRef Expr) const {
if (!Expr.startswith("("))
return std::make_pair(unexpectedToken(Expr, Expr, "expected '('"), "");
StringRef RemainingExpr = Expr.substr(1).ltrim();
StringRef Symbol;
std::tie(Symbol, RemainingExpr) = parseSymbol(RemainingExpr);
if (!Checker.isSymbolValid(Symbol))
return std::make_pair(
EvalResult(("Cannot decode unknown symbol '" + Symbol + "'").str()),
"");
if (!RemainingExpr.startswith(","))
return std::make_pair(
unexpectedToken(RemainingExpr, RemainingExpr, "expected ','"), "");
RemainingExpr = RemainingExpr.substr(1).ltrim();
EvalResult OpIdxExpr;
std::tie(OpIdxExpr, RemainingExpr) = evalNumberExpr(RemainingExpr);
if (OpIdxExpr.hasError())
return std::make_pair(OpIdxExpr, "");
if (!RemainingExpr.startswith(")"))
return std::make_pair(
unexpectedToken(RemainingExpr, RemainingExpr, "expected ')'"), "");
RemainingExpr = RemainingExpr.substr(1).ltrim();
MCInst Inst;
uint64_t Size;
if (!decodeInst(Symbol, Inst, Size))
return std::make_pair(
EvalResult(("Couldn't decode instruction at '" + Symbol + "'").str()),
"");
unsigned OpIdx = OpIdxExpr.getValue();
if (OpIdx >= Inst.getNumOperands()) {
std::string ErrMsg;
raw_string_ostream ErrMsgStream(ErrMsg);
ErrMsgStream << "Invalid operand index '" << format("%i", OpIdx)
<< "' for instruction '" << Symbol
<< "'. Instruction has only "
<< format("%i", Inst.getNumOperands())
<< " operands.\nInstruction is:\n ";
Inst.dump_pretty(ErrMsgStream, Checker.InstPrinter);
return std::make_pair(EvalResult(ErrMsgStream.str()), "");
}
const MCOperand &Op = Inst.getOperand(OpIdx);
if (!Op.isImm()) {
std::string ErrMsg;
raw_string_ostream ErrMsgStream(ErrMsg);
ErrMsgStream << "Operand '" << format("%i", OpIdx) << "' of instruction '"
<< Symbol << "' is not an immediate.\nInstruction is:\n ";
Inst.dump_pretty(ErrMsgStream, Checker.InstPrinter);
return std::make_pair(EvalResult(ErrMsgStream.str()), "");
}
return std::make_pair(EvalResult(Op.getImm()), RemainingExpr);
}
// Evaluate a call to next_pc.
// Decode the instruction at the given symbol and return the following program
// counter.
// Returns an error if the instruction cannot be decoded.
// On success, returns a pair containing the next PC, plus of the
// expression remaining to be evaluated.
std::pair<EvalResult, StringRef> evalNextPC(StringRef Expr,
ParseContext PCtx) const {
if (!Expr.startswith("("))
return std::make_pair(unexpectedToken(Expr, Expr, "expected '('"), "");
StringRef RemainingExpr = Expr.substr(1).ltrim();
StringRef Symbol;
std::tie(Symbol, RemainingExpr) = parseSymbol(RemainingExpr);
if (!Checker.isSymbolValid(Symbol))
return std::make_pair(
EvalResult(("Cannot decode unknown symbol '" + Symbol + "'").str()),
"");
if (!RemainingExpr.startswith(")"))
return std::make_pair(
unexpectedToken(RemainingExpr, RemainingExpr, "expected ')'"), "");
RemainingExpr = RemainingExpr.substr(1).ltrim();
MCInst Inst;
uint64_t InstSize;
if (!decodeInst(Symbol, Inst, InstSize))
return std::make_pair(
EvalResult(("Couldn't decode instruction at '" + Symbol + "'").str()),
"");
uint64_t SymbolAddr = PCtx.IsInsideLoad
? Checker.getSymbolLocalAddr(Symbol)
: Checker.getSymbolRemoteAddr(Symbol);
uint64_t NextPC = SymbolAddr + InstSize;
return std::make_pair(EvalResult(NextPC), RemainingExpr);
}
// Evaluate a call to stub_addr/got_addr.
// Look up and return the address of the stub for the given
// (<file name>, <section name>, <symbol name>) tuple.
// On success, returns a pair containing the stub address, plus the expression
// remaining to be evaluated.
std::pair<EvalResult, StringRef>
evalStubOrGOTAddr(StringRef Expr, ParseContext PCtx, bool IsStubAddr) const {
if (!Expr.startswith("("))
return std::make_pair(unexpectedToken(Expr, Expr, "expected '('"), "");
StringRef RemainingExpr = Expr.substr(1).ltrim();
// Handle file-name specially, as it may contain characters that aren't
// legal for symbols.
StringRef StubContainerName;
size_t ComaIdx = RemainingExpr.find(',');
StubContainerName = RemainingExpr.substr(0, ComaIdx).rtrim();
RemainingExpr = RemainingExpr.substr(ComaIdx).ltrim();
if (!RemainingExpr.startswith(","))
return std::make_pair(
unexpectedToken(RemainingExpr, Expr, "expected ','"), "");
RemainingExpr = RemainingExpr.substr(1).ltrim();
StringRef Symbol;
std::tie(Symbol, RemainingExpr) = parseSymbol(RemainingExpr);
if (!RemainingExpr.startswith(")"))
return std::make_pair(
unexpectedToken(RemainingExpr, Expr, "expected ')'"), "");
RemainingExpr = RemainingExpr.substr(1).ltrim();
uint64_t StubAddr;
std::string ErrorMsg = "";
std::tie(StubAddr, ErrorMsg) = Checker.getStubOrGOTAddrFor(
StubContainerName, Symbol, PCtx.IsInsideLoad, IsStubAddr);
if (ErrorMsg != "")
return std::make_pair(EvalResult(ErrorMsg), "");
return std::make_pair(EvalResult(StubAddr), RemainingExpr);
}
std::pair<EvalResult, StringRef> evalSectionAddr(StringRef Expr,
ParseContext PCtx) const {
if (!Expr.startswith("("))
return std::make_pair(unexpectedToken(Expr, Expr, "expected '('"), "");
StringRef RemainingExpr = Expr.substr(1).ltrim();
// Handle file-name specially, as it may contain characters that aren't
// legal for symbols.
StringRef FileName;
size_t ComaIdx = RemainingExpr.find(',');
FileName = RemainingExpr.substr(0, ComaIdx).rtrim();
RemainingExpr = RemainingExpr.substr(ComaIdx).ltrim();
if (!RemainingExpr.startswith(","))
return std::make_pair(
unexpectedToken(RemainingExpr, Expr, "expected ','"), "");
RemainingExpr = RemainingExpr.substr(1).ltrim();
StringRef SectionName;
std::tie(SectionName, RemainingExpr) = parseSymbol(RemainingExpr);
if (!RemainingExpr.startswith(")"))
return std::make_pair(
unexpectedToken(RemainingExpr, Expr, "expected ')'"), "");
RemainingExpr = RemainingExpr.substr(1).ltrim();
uint64_t StubAddr;
std::string ErrorMsg = "";
std::tie(StubAddr, ErrorMsg) = Checker.getSectionAddr(
FileName, SectionName, PCtx.IsInsideLoad);
if (ErrorMsg != "")
return std::make_pair(EvalResult(ErrorMsg), "");
return std::make_pair(EvalResult(StubAddr), RemainingExpr);
}
// Evaluate an identiefer expr, which may be a symbol, or a call to
// one of the builtin functions: get_insn_opcode or get_insn_length.
// Return the result, plus the expression remaining to be parsed.
std::pair<EvalResult, StringRef> evalIdentifierExpr(StringRef Expr,
ParseContext PCtx) const {
StringRef Symbol;
StringRef RemainingExpr;
std::tie(Symbol, RemainingExpr) = parseSymbol(Expr);
// Check for builtin function calls.
if (Symbol == "decode_operand")
return evalDecodeOperand(RemainingExpr);
else if (Symbol == "next_pc")
return evalNextPC(RemainingExpr, PCtx);
else if (Symbol == "stub_addr")
return evalStubOrGOTAddr(RemainingExpr, PCtx, true);
else if (Symbol == "got_addr")
return evalStubOrGOTAddr(RemainingExpr, PCtx, false);
else if (Symbol == "section_addr")
return evalSectionAddr(RemainingExpr, PCtx);
if (!Checker.isSymbolValid(Symbol)) {
std::string ErrMsg("No known address for symbol '");
ErrMsg += Symbol;
ErrMsg += "'";
if (Symbol.startswith("L"))
ErrMsg += " (this appears to be an assembler local label - "
" perhaps drop the 'L'?)";
return std::make_pair(EvalResult(ErrMsg), "");
}
// The value for the symbol depends on the context we're evaluating in:
// Inside a load this is the address in the linker's memory, outside a
// load it's the address in the target processes memory.
uint64_t Value = PCtx.IsInsideLoad ? Checker.getSymbolLocalAddr(Symbol)
: Checker.getSymbolRemoteAddr(Symbol);
// Looks like a plain symbol reference.
return std::make_pair(EvalResult(Value), RemainingExpr);
}
// Parse a number (hexadecimal or decimal) and return a (string, string)
// pair representing the number and the expression remaining to be parsed.
std::pair<StringRef, StringRef> parseNumberString(StringRef Expr) const {
size_t FirstNonDigit = StringRef::npos;
if (Expr.startswith("0x")) {
FirstNonDigit = Expr.find_first_not_of("0123456789abcdefABCDEF", 2);
if (FirstNonDigit == StringRef::npos)
FirstNonDigit = Expr.size();
} else {
FirstNonDigit = Expr.find_first_not_of("0123456789");
if (FirstNonDigit == StringRef::npos)
FirstNonDigit = Expr.size();
}
return std::make_pair(Expr.substr(0, FirstNonDigit),
Expr.substr(FirstNonDigit));
}
// Evaluate a constant numeric expression (hexadecimal or decimal) and
// return a pair containing the result, and the expression remaining to be
// evaluated.
std::pair<EvalResult, StringRef> evalNumberExpr(StringRef Expr) const {
StringRef ValueStr;
StringRef RemainingExpr;
std::tie(ValueStr, RemainingExpr) = parseNumberString(Expr);
if (ValueStr.empty() || !isdigit(ValueStr[0]))
return std::make_pair(
unexpectedToken(RemainingExpr, RemainingExpr, "expected number"), "");
uint64_t Value;
ValueStr.getAsInteger(0, Value);
return std::make_pair(EvalResult(Value), RemainingExpr);
}
// Evaluate an expression of the form "(<expr>)" and return a pair
// containing the result of evaluating <expr>, plus the expression
// remaining to be parsed.
std::pair<EvalResult, StringRef> evalParensExpr(StringRef Expr,
ParseContext PCtx) const {
assert(Expr.startswith("(") && "Not a parenthesized expression");
EvalResult SubExprResult;
StringRef RemainingExpr;
std::tie(SubExprResult, RemainingExpr) =
evalComplexExpr(evalSimpleExpr(Expr.substr(1).ltrim(), PCtx), PCtx);
if (SubExprResult.hasError())
return std::make_pair(SubExprResult, "");
if (!RemainingExpr.startswith(")"))
return std::make_pair(
unexpectedToken(RemainingExpr, Expr, "expected ')'"), "");
RemainingExpr = RemainingExpr.substr(1).ltrim();
return std::make_pair(SubExprResult, RemainingExpr);
}
// Evaluate an expression in one of the following forms:
// *{<number>}<expr>
// Return a pair containing the result, plus the expression remaining to be
// parsed.
std::pair<EvalResult, StringRef> evalLoadExpr(StringRef Expr) const {
assert(Expr.startswith("*") && "Not a load expression");
StringRef RemainingExpr = Expr.substr(1).ltrim();
// Parse read size.
if (!RemainingExpr.startswith("{"))
return std::make_pair(EvalResult("Expected '{' following '*'."), "");
RemainingExpr = RemainingExpr.substr(1).ltrim();
EvalResult ReadSizeExpr;
std::tie(ReadSizeExpr, RemainingExpr) = evalNumberExpr(RemainingExpr);
if (ReadSizeExpr.hasError())
return std::make_pair(ReadSizeExpr, RemainingExpr);
uint64_t ReadSize = ReadSizeExpr.getValue();
if (ReadSize < 1 || ReadSize > 8)
return std::make_pair(EvalResult("Invalid size for dereference."), "");
if (!RemainingExpr.startswith("}"))
return std::make_pair(EvalResult("Missing '}' for dereference."), "");
RemainingExpr = RemainingExpr.substr(1).ltrim();
// Evaluate the expression representing the load address.
ParseContext LoadCtx(true);
EvalResult LoadAddrExprResult;
std::tie(LoadAddrExprResult, RemainingExpr) =
evalComplexExpr(evalSimpleExpr(RemainingExpr, LoadCtx), LoadCtx);
if (LoadAddrExprResult.hasError())
return std::make_pair(LoadAddrExprResult, "");
uint64_t LoadAddr = LoadAddrExprResult.getValue();
// If there is no error but the content pointer is null then this is a
// zero-fill symbol/section.
if (LoadAddr == 0)
return std::make_pair(0, RemainingExpr);
return std::make_pair(
EvalResult(Checker.readMemoryAtAddr(LoadAddr, ReadSize)),
RemainingExpr);
}
// Evaluate a "simple" expression. This is any expression that _isn't_ an
// un-parenthesized binary expression.
//
// "Simple" expressions can be optionally bit-sliced. See evalSlicedExpr.
//
// Returns a pair containing the result of the evaluation, plus the
// expression remaining to be parsed.
std::pair<EvalResult, StringRef> evalSimpleExpr(StringRef Expr,
ParseContext PCtx) const {
EvalResult SubExprResult;
StringRef RemainingExpr;
if (Expr.empty())
return std::make_pair(EvalResult("Unexpected end of expression"), "");
if (Expr[0] == '(')
std::tie(SubExprResult, RemainingExpr) = evalParensExpr(Expr, PCtx);
else if (Expr[0] == '*')
std::tie(SubExprResult, RemainingExpr) = evalLoadExpr(Expr);
else if (isalpha(Expr[0]) || Expr[0] == '_')
std::tie(SubExprResult, RemainingExpr) = evalIdentifierExpr(Expr, PCtx);
else if (isdigit(Expr[0]))
std::tie(SubExprResult, RemainingExpr) = evalNumberExpr(Expr);
else
return std::make_pair(
unexpectedToken(Expr, Expr,
"expected '(', '*', identifier, or number"), "");
if (SubExprResult.hasError())
return std::make_pair(SubExprResult, RemainingExpr);
// Evaluate bit-slice if present.
if (RemainingExpr.startswith("["))
std::tie(SubExprResult, RemainingExpr) =
evalSliceExpr(std::make_pair(SubExprResult, RemainingExpr));
return std::make_pair(SubExprResult, RemainingExpr);
}
// Evaluate a bit-slice of an expression.
// A bit-slice has the form "<expr>[high:low]". The result of evaluating a
// slice is the bits between high and low (inclusive) in the original
// expression, right shifted so that the "low" bit is in position 0 in the
// result.
// Returns a pair containing the result of the slice operation, plus the
// expression remaining to be parsed.
std::pair<EvalResult, StringRef>
evalSliceExpr(const std::pair<EvalResult, StringRef> &Ctx) const {
EvalResult SubExprResult;
StringRef RemainingExpr;
std::tie(SubExprResult, RemainingExpr) = Ctx;
assert(RemainingExpr.startswith("[") && "Not a slice expr.");
RemainingExpr = RemainingExpr.substr(1).ltrim();
EvalResult HighBitExpr;
std::tie(HighBitExpr, RemainingExpr) = evalNumberExpr(RemainingExpr);
if (HighBitExpr.hasError())
return std::make_pair(HighBitExpr, RemainingExpr);
if (!RemainingExpr.startswith(":"))
return std::make_pair(
unexpectedToken(RemainingExpr, RemainingExpr, "expected ':'"), "");
RemainingExpr = RemainingExpr.substr(1).ltrim();
EvalResult LowBitExpr;
std::tie(LowBitExpr, RemainingExpr) = evalNumberExpr(RemainingExpr);
if (LowBitExpr.hasError())
return std::make_pair(LowBitExpr, RemainingExpr);
if (!RemainingExpr.startswith("]"))
return std::make_pair(
unexpectedToken(RemainingExpr, RemainingExpr, "expected ']'"), "");
RemainingExpr = RemainingExpr.substr(1).ltrim();
unsigned HighBit = HighBitExpr.getValue();
unsigned LowBit = LowBitExpr.getValue();
uint64_t Mask = ((uint64_t)1 << (HighBit - LowBit + 1)) - 1;
uint64_t SlicedValue = (SubExprResult.getValue() >> LowBit) & Mask;
return std::make_pair(EvalResult(SlicedValue), RemainingExpr);
}
// Evaluate a "complex" expression.
// Takes an already evaluated subexpression and checks for the presence of a
// binary operator, computing the result of the binary operation if one is
// found. Used to make arithmetic expressions left-associative.
// Returns a pair containing the ultimate result of evaluating the
// expression, plus the expression remaining to be evaluated.
std::pair<EvalResult, StringRef>
evalComplexExpr(const std::pair<EvalResult, StringRef> &LHSAndRemaining,
ParseContext PCtx) const {
EvalResult LHSResult;
StringRef RemainingExpr;
std::tie(LHSResult, RemainingExpr) = LHSAndRemaining;
// If there was an error, or there's nothing left to evaluate, return the
// result.
if (LHSResult.hasError() || RemainingExpr == "")
return std::make_pair(LHSResult, RemainingExpr);
// Otherwise check if this is a binary expressioan.
BinOpToken BinOp;
std::tie(BinOp, RemainingExpr) = parseBinOpToken(RemainingExpr);
// If this isn't a recognized expression just return.
if (BinOp == BinOpToken::Invalid)
return std::make_pair(LHSResult, RemainingExpr);
// This is a recognized bin-op. Evaluate the RHS, then evaluate the binop.
EvalResult RHSResult;
std::tie(RHSResult, RemainingExpr) = evalSimpleExpr(RemainingExpr, PCtx);
// If there was an error evaluating the RHS, return it.
if (RHSResult.hasError())
return std::make_pair(RHSResult, RemainingExpr);
// This is a binary expression - evaluate and try to continue as a
// complex expr.
EvalResult ThisResult(computeBinOpResult(BinOp, LHSResult, RHSResult));
return evalComplexExpr(std::make_pair(ThisResult, RemainingExpr), PCtx);
}
bool decodeInst(StringRef Symbol, MCInst &Inst, uint64_t &Size) const {
MCDisassembler *Dis = Checker.Disassembler;
StringRef SymbolMem = Checker.getSymbolContent(Symbol);
ArrayRef<uint8_t> SymbolBytes(SymbolMem.bytes_begin(), SymbolMem.size());
MCDisassembler::DecodeStatus S =
Dis->getInstruction(Inst, Size, SymbolBytes, 0, nulls(), nulls());
return (S == MCDisassembler::Success);
}
};
}
RuntimeDyldCheckerImpl::RuntimeDyldCheckerImpl(
IsSymbolValidFunction IsSymbolValid, GetSymbolInfoFunction GetSymbolInfo,
GetSectionInfoFunction GetSectionInfo, GetStubInfoFunction GetStubInfo,
GetGOTInfoFunction GetGOTInfo, support::endianness Endianness,
MCDisassembler *Disassembler, MCInstPrinter *InstPrinter,
raw_ostream &ErrStream)
: IsSymbolValid(std::move(IsSymbolValid)),
GetSymbolInfo(std::move(GetSymbolInfo)),
GetSectionInfo(std::move(GetSectionInfo)),
GetStubInfo(std::move(GetStubInfo)), GetGOTInfo(std::move(GetGOTInfo)),
Endianness(Endianness), Disassembler(Disassembler),
InstPrinter(InstPrinter), ErrStream(ErrStream) {}
bool RuntimeDyldCheckerImpl::check(StringRef CheckExpr) const {
CheckExpr = CheckExpr.trim();
LLVM_DEBUG(dbgs() << "RuntimeDyldChecker: Checking '" << CheckExpr
<< "'...\n");
RuntimeDyldCheckerExprEval P(*this, ErrStream);
bool Result = P.evaluate(CheckExpr);
(void)Result;
LLVM_DEBUG(dbgs() << "RuntimeDyldChecker: '" << CheckExpr << "' "
<< (Result ? "passed" : "FAILED") << ".\n");
return Result;
}
bool RuntimeDyldCheckerImpl::checkAllRulesInBuffer(StringRef RulePrefix,
MemoryBuffer *MemBuf) const {
bool DidAllTestsPass = true;
unsigned NumRules = 0;
const char *LineStart = MemBuf->getBufferStart();
// Eat whitespace.
while (LineStart != MemBuf->getBufferEnd() && std::isspace(*LineStart))
++LineStart;
while (LineStart != MemBuf->getBufferEnd() && *LineStart != '\0') {
const char *LineEnd = LineStart;
while (LineEnd != MemBuf->getBufferEnd() && *LineEnd != '\r' &&
*LineEnd != '\n')
++LineEnd;
StringRef Line(LineStart, LineEnd - LineStart);
if (Line.startswith(RulePrefix)) {
DidAllTestsPass &= check(Line.substr(RulePrefix.size()));
++NumRules;
}
// Eat whitespace.
LineStart = LineEnd;
while (LineStart != MemBuf->getBufferEnd() && std::isspace(*LineStart))
++LineStart;
}
return DidAllTestsPass && (NumRules != 0);
}
bool RuntimeDyldCheckerImpl::isSymbolValid(StringRef Symbol) const {
return IsSymbolValid(Symbol);
}
uint64_t RuntimeDyldCheckerImpl::getSymbolLocalAddr(StringRef Symbol) const {
auto SymInfo = GetSymbolInfo(Symbol);
if (!SymInfo) {
logAllUnhandledErrors(SymInfo.takeError(), errs(), "RTDyldChecker: ");
return 0;
}
if (SymInfo->isZeroFill())
return 0;
return static_cast<uint64_t>(
reinterpret_cast<uintptr_t>(SymInfo->getContent().data()));
}
uint64_t RuntimeDyldCheckerImpl::getSymbolRemoteAddr(StringRef Symbol) const {
auto SymInfo = GetSymbolInfo(Symbol);
if (!SymInfo) {
logAllUnhandledErrors(SymInfo.takeError(), errs(), "RTDyldChecker: ");
return 0;
}
return SymInfo->getTargetAddress();
}
uint64_t RuntimeDyldCheckerImpl::readMemoryAtAddr(uint64_t SrcAddr,
unsigned Size) const {
uintptr_t PtrSizedAddr = static_cast<uintptr_t>(SrcAddr);
assert(PtrSizedAddr == SrcAddr && "Linker memory pointer out-of-range.");
void *Ptr = reinterpret_cast<void*>(PtrSizedAddr);
switch (Size) {
case 1:
return support::endian::read<uint8_t>(Ptr, Endianness);
case 2:
return support::endian::read<uint16_t>(Ptr, Endianness);
case 4:
return support::endian::read<uint32_t>(Ptr, Endianness);
case 8:
return support::endian::read<uint64_t>(Ptr, Endianness);
}
llvm_unreachable("Unsupported read size");
}
StringRef RuntimeDyldCheckerImpl::getSymbolContent(StringRef Symbol) const {
auto SymInfo = GetSymbolInfo(Symbol);
if (!SymInfo) {
logAllUnhandledErrors(SymInfo.takeError(), errs(), "RTDyldChecker: ");
return StringRef();
}
return SymInfo->getContent();
}
std::pair<uint64_t, std::string> RuntimeDyldCheckerImpl::getSectionAddr(
StringRef FileName, StringRef SectionName, bool IsInsideLoad) const {
auto SecInfo = GetSectionInfo(FileName, SectionName);
if (!SecInfo) {
std::string ErrMsg;
{
raw_string_ostream ErrMsgStream(ErrMsg);
logAllUnhandledErrors(SecInfo.takeError(), ErrMsgStream,
"RTDyldChecker: ");
}
return std::make_pair(0, std::move(ErrMsg));
}
// If this address is being looked up in "load" mode, return the content
// pointer, otherwise return the target address.
uint64_t Addr = 0;
if (IsInsideLoad) {
if (SecInfo->isZeroFill())
Addr = 0;
else
Addr = pointerToJITTargetAddress(SecInfo->getContent().data());
} else
Addr = SecInfo->getTargetAddress();
return std::make_pair(Addr, "");
}
std::pair<uint64_t, std::string> RuntimeDyldCheckerImpl::getStubOrGOTAddrFor(
StringRef StubContainerName, StringRef SymbolName, bool IsInsideLoad,
bool IsStubAddr) const {
auto StubInfo = IsStubAddr ? GetStubInfo(StubContainerName, SymbolName)
: GetGOTInfo(StubContainerName, SymbolName);
if (!StubInfo) {
std::string ErrMsg;
{
raw_string_ostream ErrMsgStream(ErrMsg);
logAllUnhandledErrors(StubInfo.takeError(), ErrMsgStream,
"RTDyldChecker: ");
}
return std::make_pair((uint64_t)0, std::move(ErrMsg));
}
uint64_t Addr = 0;
if (IsInsideLoad) {
if (StubInfo->isZeroFill())
return std::make_pair((uint64_t)0, "Detected zero-filled stub/GOT entry");
Addr = pointerToJITTargetAddress(StubInfo->getContent().data());
} else
Addr = StubInfo->getTargetAddress();
return std::make_pair(Addr, "");
}
RuntimeDyldChecker::RuntimeDyldChecker(
IsSymbolValidFunction IsSymbolValid, GetSymbolInfoFunction GetSymbolInfo,
GetSectionInfoFunction GetSectionInfo, GetStubInfoFunction GetStubInfo,
GetGOTInfoFunction GetGOTInfo, support::endianness Endianness,
MCDisassembler *Disassembler, MCInstPrinter *InstPrinter,
raw_ostream &ErrStream)
: Impl(::llvm::make_unique<RuntimeDyldCheckerImpl>(
std::move(IsSymbolValid), std::move(GetSymbolInfo),
std::move(GetSectionInfo), std::move(GetStubInfo),
std::move(GetGOTInfo), Endianness, Disassembler, InstPrinter,
ErrStream)) {}
RuntimeDyldChecker::~RuntimeDyldChecker() {}
bool RuntimeDyldChecker::check(StringRef CheckExpr) const {
return Impl->check(CheckExpr);
}
bool RuntimeDyldChecker::checkAllRulesInBuffer(StringRef RulePrefix,
MemoryBuffer *MemBuf) const {
return Impl->checkAllRulesInBuffer(RulePrefix, MemBuf);
}
std::pair<uint64_t, std::string>
RuntimeDyldChecker::getSectionAddr(StringRef FileName, StringRef SectionName,
bool LocalAddress) {
return Impl->getSectionAddr(FileName, SectionName, LocalAddress);
}