| //===-- InlineAsm.cpp - Implement the InlineAsm class ---------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file was developed by Chris Lattner and is distributed under the |
| // University of Illinois Open Source License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements the InlineAsm class. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/InlineAsm.h" |
| #include "llvm/DerivedTypes.h" |
| #include <cctype> |
| using namespace llvm; |
| |
| // NOTE: when memoizing the function type, we have to be careful to handle the |
| // case when the type gets refined. |
| |
| InlineAsm *InlineAsm::get(const FunctionType *Ty, const std::string &AsmString, |
| const std::string &Constraints, bool hasSideEffects) { |
| // FIXME: memoize! |
| return new InlineAsm(Ty, AsmString, Constraints, hasSideEffects); |
| } |
| |
| InlineAsm::InlineAsm(const FunctionType *Ty, const std::string &asmString, |
| const std::string &constraints, bool hasSideEffects) |
| : Value(PointerType::get(Ty), Value::InlineAsmVal), AsmString(asmString), |
| Constraints(constraints), HasSideEffects(hasSideEffects) { |
| |
| // Do various checks on the constraint string and type. |
| assert(Verify(Ty, constraints) && "Function type not legal for constraints!"); |
| } |
| |
| const FunctionType *InlineAsm::getFunctionType() const { |
| return cast<FunctionType>(getType()->getElementType()); |
| } |
| |
| std::vector<std::pair<InlineAsm::ConstraintPrefix, std::string> > |
| InlineAsm::ParseConstraints(const std::string &Constraints) { |
| std::vector<std::pair<InlineAsm::ConstraintPrefix, std::string> > Result; |
| |
| // Scan the constraints string. |
| for (std::string::const_iterator I = Constraints.begin(), |
| E = Constraints.end(); I != E; ) { |
| if (*I == ',') { Result.clear(); break; } // Empty constraint like ",," |
| |
| // Parse the prefix. |
| ConstraintPrefix ConstraintType = isInput; |
| |
| if (*I == '~') { |
| ConstraintType = isClobber; |
| ++I; |
| } else if (*I == '=') { |
| ++I; |
| if (I != E && *I == '=') { |
| ConstraintType = isIndirectOutput; |
| ++I; |
| } else { |
| ConstraintType = isOutput; |
| } |
| } |
| |
| if (I == E) { Result.clear(); break; } // Just a prefix, like "==" or "~". |
| |
| std::string::const_iterator IdStart = I; |
| |
| // Parse the id. We accept [a-zA-Z0-9] currently. |
| while (I != E && isalnum(*I)) ++I; |
| |
| if (IdStart == I) { // Requires more than just a prefix |
| Result.clear(); |
| break; |
| } |
| |
| // Remember this constraint. |
| Result.push_back(std::make_pair(ConstraintType, std::string(IdStart, I))); |
| |
| // If we reached the end of the ID, we must have the end of the string or a |
| // comma, which we skip now. |
| if (I != E) { |
| if (*I != ',') { Result.clear(); break; } |
| ++I; |
| if (I == E) { Result.clear(); break; } // don't allow "xyz," |
| } |
| } |
| |
| return Result; |
| } |
| |
| |
| /// Verify - Verify that the specified constraint string is reasonable for the |
| /// specified function type, and otherwise validate the constraint string. |
| bool InlineAsm::Verify(const FunctionType *Ty, const std::string &ConstStr) { |
| if (Ty->isVarArg()) return false; |
| |
| std::vector<std::pair<ConstraintPrefix, std::string> > |
| Constraints = ParseConstraints(ConstStr); |
| |
| // Error parsing constraints. |
| if (Constraints.empty() && !ConstStr.empty()) return false; |
| |
| unsigned NumOutputs = 0, NumInputs = 0, NumClobbers = 0; |
| |
| for (unsigned i = 0, e = Constraints.size(); i != e; ++i) { |
| switch (Constraints[i].first) { |
| case isOutput: |
| if (NumInputs || NumClobbers) return false; // outputs come first. |
| ++NumOutputs; |
| break; |
| case isInput: |
| case isIndirectOutput: |
| if (NumClobbers) return false; // inputs before clobbers. |
| ++NumInputs; |
| break; |
| case isClobber: |
| ++NumClobbers; |
| break; |
| } |
| } |
| |
| if (NumOutputs > 1) return false; // Only one result allowed so far. |
| |
| if ((Ty->getReturnType() != Type::VoidTy) != NumOutputs) |
| return false; // NumOutputs = 1 iff has a result type. |
| |
| if (Ty->getNumParams() != NumInputs) return false; |
| return true; |
| } |