Method make_random

src/Block.cpp:123–200

* */

 *
 */
Block *
Block::make_random(CGContext &cg_context, bool looping)
{
	//static int bid = 0;
	DEPTH_GUARD_BY_TYPE_RETURN(dtBlock, NULL);

	Function *curr_func = cg_context.get_current_func();
	assert(curr_func);

	Block *b = new Block(cg_context.get_current_block(), CGOptions::max_block_size());
	b->func = curr_func;
	b->looping = looping;
	// if there are induction variables, we are in a loop that traverses array(s)
	b->in_array_loop = !(cg_context.iv_bounds.empty());
	//b->stm_id = bid++;

	// Push this block onto the variable scope stack.
	curr_func->stack.push_back(b);
	curr_func->blocks.push_back(b);

	// record global facts at this moment so that subsequent statement
	// inside the block doesn't ruin it
	FactMgr* fm = get_fact_mgr_for_func(curr_func);
	fm->set_fact_in(b, fm->global_facts);
	Effect pre_effect = cg_context.get_accum_effect();

	unsigned int max = BlockProbability(*b);
	if (Error::get_error() != SUCCESS) {
		curr_func->stack.pop_back();
		delete b;
		return NULL;
	}
	unsigned int i;
	if (b->stm_id == 1)
		BREAK_NOP;			// for debugging
	for (i = 0; i <= max; ++i) {
		Statement *s = Statement::make_random(cg_context);
		// In the exhaustive mode, Statement::make_random could return NULL;
		if (!s)
			break;
		b->stms.push_back(s);
		if (s->must_return()) {
			break;
		}
	}

	if (Error::get_error() != SUCCESS) {
		curr_func->stack.pop_back();
		delete b;
		return NULL;
	}

	// append nested loop if some must-read/write variables hasn't been accessed
	if (b->need_nested_loop(cg_context) && cg_context.blk_depth < CGOptions::max_blk_depth()) {
		b->append_nested_loop(cg_context);
	}

	// perform DFA analysis after creation