void swift::printSILLocationDescription(llvm::raw_ostream &out,
SILLocation loc,
ASTContext &Context) {
if (loc.isNull()) {
out << "<<invalid location>>";
} else if (!loc.hasASTLocation()) {
printSourceLocDescription(out, loc.getSourceLoc(), Context);
} else if (auto decl = loc.getAsASTNode<Decl>()) {
printDeclDescription(out, decl, Context);
} else if (auto expr = loc.getAsASTNode<Expr>()) {
printExprDescription(out, expr, Context);
} else if (auto stmt = loc.getAsASTNode<Stmt>()) {
printStmtDescription(out, stmt, Context);
} else {
auto pattern = loc.castToASTNode<Pattern>();
printPatternDescription(out, pattern, Context);
}
}
static void diagnoseUnreachable(const SILInstruction *I,
ASTContext &Context) {
if (auto *UI = dyn_cast<UnreachableInst>(I)){
SILLocation L = UI->getLoc();
// Invalid location means that the instruction has been generated by SIL
// passes, such as DCE. FIXME: we might want to just introduce a separate
// instruction kind, instead of keeping this invariant.
//
// We also do not want to emit diagnostics for code that was
// transparently inlined. We should have already emitted these
// diagnostics when we process the callee function prior to
// inlining it.
if (!L.hasASTLocation() || L.is<MandatoryInlinedLocation>())
return;
// The most common case of getting an unreachable instruction is a
// missing return statement. In this case, we know that the instruction
// location will be the enclosing function.
if (L.isASTNode<AbstractFunctionDecl>() || L.isASTNode<ClosureExpr>()) {
diagnoseMissingReturn(UI, Context);
return;
}
// A non-exhaustive switch would also produce an unreachable instruction.
if (L.isASTNode<SwitchStmt>()) {
diagnose(Context, L.getEndSourceLoc(), diag::non_exhaustive_switch);
return;
}
if (auto *Guard = L.getAsASTNode<GuardStmt>()) {
diagnose(Context, Guard->getBody()->getEndLoc(),
diag::guard_body_must_not_fallthrough);
return;
}
}
}