+ return std::make_pair(Expr.substr(0, FirstNonDigit),
+ Expr.substr(FirstNonDigit));
+ }
+
+ // Evaluate a constant numeric expression (hexidecimal 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();
+
+ 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]))
+ std::tie(SubExprResult, RemainingExpr) = evalIdentifierExpr(Expr, PCtx);
+ else if (isdigit(Expr[0]))
+ std::tie(SubExprResult, RemainingExpr) = evalNumberExpr(Expr);
+
+ 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(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);
projects / oota-llvm.git / commitdiff