add method for constraint parsing

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25637 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2006-01-26 02:21:59 +00:00
parent 507fdbc0e8
commit f0b415f178

View File

@ -38,25 +38,17 @@ const FunctionType *InlineAsm::getFunctionType() const {
return cast<FunctionType>(getType()->getElementType());
}
/// 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 &Constraints) {
if (Ty->isVarArg()) return false;
unsigned NumOutputs = 0, NumInputs = 0, NumClobbers = 0;
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 == ',') return false; // Empty constraint like ",,"
E = Constraints.end(); I != E; ) {
if (*I == ',') { Result.clear(); break; } // Empty constraint like ",,"
// Parse the prefix.
enum {
isInput, // 'x'
isOutput, // '=x'
isIndirectOutput, // '==x'
isClobber, // '~x'
} ConstraintType = isInput;
ConstraintPrefix ConstraintType = isInput;
if (*I == '~') {
ConstraintType = isClobber;
@ -71,9 +63,49 @@ bool InlineAsm::Verify(const FunctionType *Ty, const std::string &Constraints) {
}
}
if (I == E) return false; // Just a prefix, like "==" or "~".
if (I == E) { Result.clear(); break; } // Just a prefix, like "==" or "~".
switch (ConstraintType) {
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;
@ -87,20 +119,9 @@ bool InlineAsm::Verify(const FunctionType *Ty, const std::string &Constraints) {
++NumClobbers;
break;
}
// Parse the id. We accept [a-zA-Z0-9] currently.
while (I != E && isalnum(*I)) ++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 != ',') return false;
++I;
if (I == E) return false; // don't allow "xyz,"
}
}
if (NumOutputs > 1) return false; // Only one result allowed.
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.