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#include "stdafx.h"
#include "Try.h"
#include "Cast.h"
#include "Compiler/Exception.h"
#include "Compiler/Type.h"
namespace storm {
namespace bs {
/**
* Try
*/
TryBlock::TryBlock(SrcPos pos, Block *parent) : ExprBlock(pos, parent) {
toCatch = new (this) Array<CatchBlock *>();
}
void TryBlock::addCatch(CatchBlock *block) {
// Make sure no mistakes were made.
if (block->parent() == this)
throw new (this) InternalError(S("Incorrect scope of supplied catch-block."));
toCatch->push(block);
}
void TryBlock::code(CodeGen *state, CodeResult *to) {
// Create an outer block where we can store the exception temporarily while entering
// catch blocks (registers are not preserved during "begin").
CodeGen *child = state->child();
*state->l << begin(child->block);
// Tell all catch handlers about our temporary variable where we store the exception.
code::Var tempVar = child->l->createVar(child->block, Size::sPtr);
for (Nat i = 0; i < toCatch->count(); i++) {
toCatch->at(i)->exceptionVar = tempVar;
}
ExprBlock::code(child, to);
*state->l << end(child->block);
}
void TryBlock::blockCode(CodeGen *state, CodeResult *to, code::Block block) {
using namespace code;
if (toCatch->empty())
throw new (this) SyntaxError(pos, S("No catch handlers for the try-block."));
*state->l << begin(block);
CodeGen *child = state->child(block);
ExprBlock::blockCode(child, to);
*state->l << end(block);
// Skip the others if we made it this far.
Label end = state->l->label();
*state->l << jmp(end);
Value result = this->result().type();
// All catch handlers.
for (Nat i = 0; i < toCatch->count(); i++) {
CatchBlock *c = toCatch->at(i);
Label start = state->l->label();
state->l->addCatch(block, c->type, start);
*state->l << start;
// Store the exception so that the block can safely call 'enterBlock'.
*state->l << mov(c->exceptionVar, ptrA);
expectCastTo(c, result, scope)->code(state, to);
if (i != toCatch->count() - 1)
*state->l << jmp(end);
}
*state->l << end;
}
void TryBlock::blockCode(CodeGen *state, CodeResult *to) {
// Generate code for the entire block. Stop whenever we find a block that does not return.
for (Nat i = 0; i < exprs->count() - 1; i++) {
Expr *e = exprs->at(i);
*state->l << code::location(e->pos);
CodeResult *s = new (this) CodeResult();
e->code(state, s);
// Stop if this statement never returns.
if (e->result().nothing())
return;
}
*state->l << code::location(exprs->last()->pos);
Expr *last = expectCastTo(exprs->last(), result().type(), scope);
last->code(state, to);
// Generate a last location.
*state->l << code::location(pos.lastCh());
}
ExprResult TryBlock::result() {
// We're using a fairly simple version of 'common' here.
ExprResult r = ExprBlock::result();
for (Nat i = 0; i < toCatch->count(); i++)
r = common(r, toCatch->at(i)->result());
return r;
}
void TryBlock::toS(StrBuf *to) const {
*to << S("try ");
ExprBlock::toS(to);
for (Nat i = 0; i < toCatch->count(); i++)
*to << S(" ") << toCatch->at(i)->toS();
}
/**
* Catch
*/
CatchBlock::CatchBlock(SrcPos pos, Block *parent, SrcName *t, MAYBE(syntax::SStr *) name) : Block(pos, parent) {
type = as<Type>(parent->scope.find(t));
if (!type)
throw new (this) SyntaxError(t->pos, TO_S(this, S("Unable to find the type ") << t << S(".")));
if (!type->isA(StormInfo<Exception>::type(engine())))
throw new (this) SyntaxError(t->pos, S("Can only catch classes that inherit from Exception!"));
if (name) {
var = new (this) LocalVar(name->v, Value(type), name->pos, false);
add(var);
}
}
CatchBlock::CatchBlock(SrcPos pos, Block *parent, Type *t, MAYBE(syntax::SStr *) name) : Block(pos, parent), type(t) {
if (!type->isA(StormInfo<Exception>::type(engine())))
throw new (this) SyntaxError(t->pos, S("Can only catch classes that inherit from Exception!"));
if (name) {
var = new (this) LocalVar(name->v, Value(type), name->pos, false);
add(var);
}
}
void CatchBlock::expr(Expr *e) {
run = e;
}
void CatchBlock::blockCode(CodeGen *state, CodeResult *to) {
using namespace code;
if (var) {
*state->l << mov(var->var.v, exceptionVar);
}
if (run) {
run->code(state, to);
}
}
ExprResult CatchBlock::result() {
if (run)
return run->result();
else
return ExprResult();
}
void CatchBlock::toS(StrBuf *to) const {
*to << S("catch (") << type->identifier();
if (var)
*to << S(" ") << var->name;
*to << S(") ");
if (run)
run->toS(to);
else
*to << S(";\n");
}
}
}
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