int parser_t::eval_block_node(node_offset_t node_idx, const io_chain_t &io,
enum block_type_t block_type) {
// Paranoia. It's a little frightening that we're given only a node_idx and we interpret this in
// the topmost execution context's tree. What happens if two trees were to be interleaved?
// Fortunately that cannot happen (yet); in the future we probably want some sort of reference
// counted trees.
parse_execution_context_t *ctx = execution_contexts.back();
assert(ctx != NULL);
CHECK_BLOCK(1);
// Handle cancellation requests. If our block stack is currently empty, then we already did
// successfully cancel (or there was nothing to cancel); clear the flag. If our block stack is
// not empty, we are still in the process of cancelling; refuse to evaluate anything.
if (this->cancellation_requested) {
if (!block_stack.empty()) {
return 1;
}
this->cancellation_requested = false;
}
// Only certain blocks are allowed.
if ((block_type != TOP) && (block_type != SUBST)) {
debug(1, INVALID_SCOPE_ERR_MSG, parser_t::get_block_desc(block_type));
bugreport();
return 1;
}
job_reap(0); // not sure why we reap jobs here
/* Start it up */
const block_t *const start_current_block = current_block();
block_t *scope_block = new scope_block_t(block_type);
this->push_block(scope_block);
int result = ctx->eval_node_at_offset(node_idx, scope_block, io);
// Clean up the block stack.
this->pop_block();
while (start_current_block != current_block()) {
if (current_block() == NULL) {
debug(0, _(L"End of block mismatch. Program terminating."));
bugreport();
FATAL_EXIT();
break;
}
this->pop_block();
}
job_reap(0); // reap again
return result;
}
void parser_t::pop_block()
{
if (block_stack.empty())
{
debug(1,
L"function %s called on empty block stack.",
__func__);
bugreport();
return;
}
block_t *old = block_stack.back();
block_stack.pop_back();
if (old->wants_pop_env)
env_pop();
delete old;
// Figure out if `status -b` should consider us to be in a block now
int new_is_block=0;
for (std::vector<block_t*>::const_iterator it = block_stack.begin(), end = block_stack.end(); it != end; ++it)
{
const enum block_type_t type = (*it)->type();
if (type != TOP && type != SUBST)
{
new_is_block = 1;
break;
}
}
is_block = new_is_block;
}
int parser_t::eval(const wcstring &cmd, const io_chain_t &io, enum block_type_t block_type)
{
CHECK_BLOCK(1);
if (block_type != TOP && block_type != SUBST)
{
debug(1, INVALID_SCOPE_ERR_MSG, parser_t::get_block_desc(block_type));
bugreport();
return 1;
}
/* Parse the source into a tree, if we can */
parse_node_tree_t tree;
parse_error_list_t error_list;
if (! parse_tree_from_string(cmd, parse_flag_none, &tree, this->show_errors ? &error_list : NULL))
{
if (this->show_errors)
{
/* Get a backtrace */
wcstring backtrace_and_desc;
this->get_backtrace(cmd, error_list, &backtrace_and_desc);
/* Print it */
fprintf(stderr, "%ls", backtrace_and_desc.c_str());
}
return 1;
}
//print_stderr(block_stack_description());
/* Determine the initial eval level. If this is the first context, it's -1; otherwise it's the eval level of the top context. This is sort of wonky because we're stitching together a global notion of eval level from these separate objects. A better approach would be some profile object that all contexts share, and that tracks the eval levels on its own. */
int exec_eval_level = (execution_contexts.empty() ? -1 : execution_contexts.back()->current_eval_level());
/* Append to the execution context stack */
parse_execution_context_t *ctx = new parse_execution_context_t(tree, cmd, this, exec_eval_level);
execution_contexts.push_back(ctx);
/* Execute the first node */
if (! tree.empty())
{
this->eval_block_node(0, io, block_type);
}
/* Clean up the execution context stack */
assert(! execution_contexts.empty() && execution_contexts.back() == ctx);
execution_contexts.pop_back();
delete ctx;
return 0;
}
void signal_unblock() {
ASSERT_IS_MAIN_THREAD();
sigset_t chldset;
block_count--;
if (block_count < 0) {
debug(0, _(L"Signal block mismatch"));
bugreport();
FATAL_EXIT();
}
if (!block_count) {
sigfillset(&chldset);
VOMIT_ON_FAILURE(pthread_sigmask(SIG_UNBLOCK, &chldset, 0));
}
// debug( 0, L"signal block level decreased to %d", block_count );
}
void parser_t::pop_block()
{
if (block_stack.empty())
{
debug(1,
L"function %s called on empty block stack.",
__func__);
bugreport();
return;
}
block_t *old = block_stack.back();
block_stack.pop_back();
if (old->wants_pop_env)
env_pop();
delete old;
}
int parser_t::eval_node(parsed_source_ref_t ps, tnode_t<T> node, const io_chain_t &io,
enum block_type_t block_type) {
static_assert(
std::is_same<T, grammar::statement>::value || std::is_same<T, grammar::job_list>::value,
"Unexpected node type");
CHECK_BLOCK(1);
// Handle cancellation requests. If our block stack is currently empty, then we already did
// successfully cancel (or there was nothing to cancel); clear the flag. If our block stack is
// not empty, we are still in the process of cancelling; refuse to evaluate anything.
if (this->cancellation_requested) {
if (!block_stack.empty()) {
return 1;
}
this->cancellation_requested = false;
}
// Only certain blocks are allowed.
if ((block_type != TOP) && (block_type != SUBST)) {
debug(1, INVALID_SCOPE_ERR_MSG, parser_t::get_block_desc(block_type));
bugreport();
return 1;
}
job_reap(0); // not sure why we reap jobs here
// Start it up
scope_block_t *scope_block = this->push_block<scope_block_t>(block_type);
// Create and set a new execution context.
using exc_ctx_ref_t = std::unique_ptr<parse_execution_context_t>;
scoped_push<exc_ctx_ref_t> exc(&execution_context,
make_unique<parse_execution_context_t>(ps, this));
int result = execution_context->eval_node(node, scope_block, io);
exc.restore();
this->pop_block(scope_block);
job_reap(0); // reap again
return result;
}
void parser_t::pop_block(const block_t *expected) {
assert(expected == this->current_block());
if (block_stack.empty()) {
debug(1, L"function %s called on empty block stack.", __func__);
bugreport();
return;
}
// acquire ownership out of the block stack
// this will trigger deletion when it goes out of scope
std::unique_ptr<block_t> old = std::move(block_stack.back());
block_stack.pop_back();
if (old->wants_pop_env) env_pop();
// Figure out if `status is-block` should consider us to be in a block now.
bool new_is_block = false;
for (const auto &b : block_stack) {
const enum block_type_t type = b->type();
if (type != TOP && type != SUBST) {
new_is_block = true;
break;
}
}
is_block = new_is_block;
// Are we still in a breakpoint?
bool new_is_breakpoint = false;
for (const auto &b : block_stack) {
const enum block_type_t type = b->type();
if (type == BREAKPOINT) {
new_is_breakpoint = true;
break;
}
}
is_breakpoint = new_is_breakpoint;
}