/// getInfixData - If the specified expression is an infix binary
/// operator, return its infix operator attributes.
static InfixData getInfixData(TypeChecker &TC, DeclContext *DC, Expr *E) {
if (auto *ifExpr = dyn_cast<IfExpr>(E)) {
// Ternary has fixed precedence.
assert(!ifExpr->isFolded() && "already folded if expr in sequence?!");
(void)ifExpr;
return InfixData(IntrinsicPrecedences::IfExpr,
Associativity::Right,
/*assignment*/ false);
}
if (auto *assign = dyn_cast<AssignExpr>(E)) {
// Assignment has fixed precedence.
assert(!assign->isFolded() && "already folded assign expr in sequence?!");
(void)assign;
return InfixData(IntrinsicPrecedences::AssignExpr,
Associativity::Right,
/*assignment*/ true);
}
if (auto *as = dyn_cast<ExplicitCastExpr>(E)) {
// 'as' and 'is' casts have fixed precedence.
assert(!as->isFolded() && "already folded 'as' expr in sequence?!");
(void)as;
return InfixData(IntrinsicPrecedences::ExplicitCastExpr,
Associativity::None,
/*assignment*/ false);
}
if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) {
SourceFile *SF = DC->getParentSourceFile();
Identifier name = DRE->getDecl()->getName();
bool isCascading = DC->isCascadingContextForLookup(true);
if (InfixOperatorDecl *op = SF->lookupInfixOperator(name, isCascading,
E->getLoc()))
return op->getInfixData();
}
if (OverloadedDeclRefExpr *OO = dyn_cast<OverloadedDeclRefExpr>(E)) {
SourceFile *SF = DC->getParentSourceFile();
Identifier name = OO->getDecls()[0]->getName();
bool isCascading = DC->isCascadingContextForLookup(true);
if (InfixOperatorDecl *op = SF->lookupInfixOperator(name, isCascading,
E->getLoc()))
return op->getInfixData();
}
// If E is already an ErrorExpr, then we've diagnosed it as invalid already,
// otherwise emit an error.
if (!isa<ErrorExpr>(E))
TC.diagnose(E->getLoc(), diag::unknown_binop);
// Recover with an infinite-precedence left-associative operator.
return InfixData((unsigned char)~0U, Associativity::Left,
/*assignment*/ false);
}
static PrecedenceGroupDecl *
lookupPrecedenceGroupForOperator(TypeChecker &TC, DeclContext *DC,
Identifier name, SourceLoc loc) {
SourceFile *SF = DC->getParentSourceFile();
bool isCascading = DC->isCascadingContextForLookup(true);
if (auto op = SF->lookupInfixOperator(name, isCascading, loc)) {
TC.validateDecl(op);
return op->getPrecedenceGroup();
} else {
TC.diagnose(loc, diag::unknown_binop);
}
return nullptr;
}