/**\file parse_execution.cpp
Provides the "linkage" between a parse_node_tree_t and actual execution structures (job_t, etc.)
A note on error handling: fish has two kind of errors, fatal parse errors non-fatal runtime errors. A fatal error prevents execution of the entire file, while a non-fatal error skips that job.
Non-fatal errors are printed as soon as they are encountered; otherwise you would have to wait for the execution to finish to see them.
*/
#include "parse_execution.h"
#include "parse_util.h"
#include "complete.h"
#include "wildcard.h"
#include "builtin.h"
#include "parser.h"
#include "expand.h"
#include "reader.h"
#include "wutil.h"
#include "exec.h"
#include "path.h"
#include <algorithm>
/* These are the specific statement types that support redirections */
static bool specific_statement_type_is_redirectable_block(const parse_node_t &node)
{
return node.type == symbol_block_statement || node.type == symbol_if_statement || node.type == symbol_switch_statement;
}
/* Get the name of a redirectable block, for profiling purposes */
static wcstring profiling_cmd_name_for_redirectable_block(const parse_node_t &node, const parse_node_tree_t &tree, const wcstring &src)
{
assert(specific_statement_type_is_redirectable_block(node));
assert(node.has_source());
/* Get the source for the block, and cut it at the next statement terminator. */
const size_t src_start = node.source_start;
size_t src_len = node.source_length;
const parse_node_tree_t::parse_node_list_t statement_terminator_nodes = tree.find_nodes(node, parse_token_type_end, 1);
if (! statement_terminator_nodes.empty())
{
const parse_node_t *term = statement_terminator_nodes.at(0);
assert(term->source_start >= src_start);
src_len = term->source_start - src_start;
}
wcstring result = wcstring(src, src_start, src_len);
result.append(L"...");
return result;
}
parse_execution_context_t::parse_execution_context_t(const parse_node_tree_t &t, const wcstring &s, parser_t *p, int initial_eval_level) : tree(t), src(s), parser(p), eval_level(initial_eval_level), executing_node_idx(NODE_OFFSET_INVALID), cached_lineno_offset(0), cached_lineno_count(0)
{
}
/* Utilities */
wcstring parse_execution_context_t::get_source(const parse_node_t &node) const
{
return node.get_source(this->src);
}
const parse_node_t *parse_execution_context_t::get_child(const parse_node_t &parent, node_offset_t which, parse_token_type_t expected_type) const
{
return this->tree.get_child(parent, which, expected_type);
}
node_offset_t parse_execution_context_t::get_offset(const parse_node_t &node) const
{
/* Get the offset of a node via pointer arithmetic, very hackish */
const parse_node_t *addr = &node;
const parse_node_t *base = &this->tree.at(0);
assert(addr >= base);
assert(addr - base < SOURCE_OFFSET_INVALID);
node_offset_t offset = static_cast<node_offset_t>(addr - base);
assert(offset < this->tree.size());
assert(&tree.at(offset) == &node);
return offset;
}
const parse_node_t *parse_execution_context_t::infinite_recursive_statement_in_job_list(const parse_node_t &job_list, wcstring *out_func_name) const
{
assert(job_list.type == symbol_job_list);
/*
This is a bit fragile. It is a test to see if we are
inside of function call, but not inside a block in that
function call. If, in the future, the rules for what
block scopes are pushed on function invocation changes,
then this check will break.
*/
const block_t *current = parser->block_at_index(0), *parent = parser->block_at_index(1);
bool is_within_function_call = (current && parent && current->type() == TOP && parent->type() == FUNCTION_CALL);
if (! is_within_function_call)
{
return NULL;
}
/* Check to see which function call is forbidden */
if (parser->forbidden_function.empty())
{
return NULL;
}
const wcstring &forbidden_function_name = parser->forbidden_function.back();
/* Get the first job in the job list. */
const parse_node_t *first_job = tree.next_node_in_node_list(job_list, symbol_job, NULL);
if (first_job == NULL)
{
return NULL;
}
/* Here's the statement node we find that's infinite recursive */
const parse_node_t *infinite_recursive_statement = NULL;
/* Get the list of statements */
const parse_node_tree_t::parse_node_list_t statements = tree.specific_statements_for_job(*first_job);
/* Find all the decorated statements. We are interested in statements with no decoration (i.e. not command, not builtin) whose command expands to the forbidden function */
for (size_t i=0; i < statements.size(); i++)
{
/* We only care about decorated statements, not while statements, etc. */
const parse_node_t &statement = *statements.at(i);
if (statement.type != symbol_decorated_statement)
{
continue;
}
const parse_node_t &plain_statement = tree.find_child(statement, symbol_plain_statement);
if (tree.decoration_for_plain_statement(plain_statement) != parse_statement_decoration_none)
{
/* This statement has a decoration like 'builtin' or 'command', and therefore is not infinite recursion. In particular this is what enables 'wrapper functions' */
continue;
}
/* Ok, this is an undecorated plain statement. Get and expand its command */
wcstring cmd;
tree.command_for_plain_statement(plain_statement, src, &cmd);
expand_one(cmd, EXPAND_SKIP_CMDSUBST | EXPAND_SKIP_VARIABLES, NULL);
if (cmd == forbidden_function_name)
{
/* This is it */
infinite_recursive_statement = &statement;
if (out_func_name != NULL)
{
*out_func_name = forbidden_function_name;
}
break;
}
}
assert(infinite_recursive_statement == NULL || infinite_recursive_statement->type == symbol_decorated_statement);
return infinite_recursive_statement;
}
enum process_type_t parse_execution_context_t::process_type_for_command(const parse_node_t &plain_statement, const wcstring &cmd) const
{
assert(plain_statement.type == symbol_plain_statement);
enum process_type_t process_type = EXTERNAL;
/* Determine the process type, which depends on the statement decoration (command, builtin, etc) */
enum parse_statement_decoration_t decoration = tree.decoration_for_plain_statement(plain_statement);
if (decoration == parse_statement_decoration_exec)
{
/* Always exec */
process_type = INTERNAL_EXEC;
}
else if (decoration == parse_statement_decoration_command)
{
/* Always a command */
process_type = EXTERNAL;
}
else if (decoration == parse_statement_decoration_builtin)
{
/* What happens if this builtin is not valid? */
process_type = INTERNAL_BUILTIN;
}
else if (function_exists(cmd))
{
process_type = INTERNAL_FUNCTION;
}
else if (builtin_exists(cmd))
{
process_type = INTERNAL_BUILTIN;
}
else
{
process_type = EXTERNAL;
}
return process_type;
}
bool parse_execution_context_t::should_cancel_execution(const block_t *block) const
{
return cancellation_reason(block) != execution_cancellation_none;
}
parse_execution_context_t::execution_cancellation_reason_t parse_execution_context_t::cancellation_reason(const block_t *block) const
{
if (shell_is_exiting())
{
return execution_cancellation_exit;
}
else if (parser && parser->cancellation_requested)
{
return execution_cancellation_skip;
}
else if (block && block->loop_status != LOOP_NORMAL)
{
/* Nasty hack - break and continue set the 'skip' flag as well as the loop status flag. */
return execution_cancellation_loop_control;
}
else if (block && block->skip)
{
return execution_cancellation_skip;
}
else
{
return execution_cancellation_none;
}
}
/* Return whether the job contains a single statement, of block type, with no redirections */
bool parse_execution_context_t::job_is_simple_block(const parse_node_t &job_node) const
{
assert(job_node.type == symbol_job);
/* Must have one statement */
const parse_node_t &statement = *get_child(job_node, 0, symbol_statement);
const parse_node_t &specific_statement = *get_child(statement, 0);
if (! specific_statement_type_is_redirectable_block(specific_statement))
{
/* Not an appropriate block type */
return false;
}
/* Must be no pipes */
const parse_node_t &continuation = *get_child(job_node, 1, symbol_job_continuation);
if (continuation.child_count > 0)
{
/* Multiple statements in this job, so there's pipes involved */
return false;
}
/* Check for arguments and redirections. All of the above types have an arguments / redirections list. It must be empty. */
const parse_node_t &args_and_redirections = tree.find_child(specific_statement, symbol_arguments_or_redirections_list);
if (args_and_redirections.child_count > 0)
{
/* Non-empty, we have an argument or redirection */
return false;
}
/* Ok, we are a simple block! */
return true;
}
parse_execution_result_t parse_execution_context_t::run_if_statement(const parse_node_t &statement)
{
assert(statement.type == symbol_if_statement);
/* Push an if block */
if_block_t *ib = new if_block_t();
ib->node_offset = this->get_offset(statement);
parser->push_block(ib);
parse_execution_result_t result = parse_execution_success;
/* We have a sequence of if clauses, with a final else, resulting in a single job list that we execute */
const parse_node_t *job_list_to_execute = NULL;
const parse_node_t *if_clause = get_child(statement, 0, symbol_if_clause);
const parse_node_t *else_clause = get_child(statement, 1, symbol_else_clause);
for (;;)
{
if (should_cancel_execution(ib))
{
result = parse_execution_cancelled;
break;
}
assert(if_clause != NULL && else_clause != NULL);
const parse_node_t &condition = *get_child(*if_clause, 1, symbol_job);
/* Check the condition. We treat parse_execution_errored here as failure, in accordance with historic behavior */
parse_execution_result_t cond_ret = run_1_job(condition, ib);
bool take_branch = (cond_ret == parse_execution_success) && proc_get_last_status() == EXIT_SUCCESS;
if (take_branch)
{
/* condition succeeded */
job_list_to_execute = get_child(*if_clause, 3, symbol_job_list);
break;
}
else if (else_clause->child_count == 0)
{
/* 'if' condition failed, no else clause, we're done */
job_list_to_execute = NULL;
break;
}
else
{
/* We have an 'else continuation' (either else-if or else) */
const parse_node_t &else_cont = *get_child(*else_clause, 1, symbol_else_continuation);
assert(else_cont.production_idx < 2);
if (else_cont.production_idx == 0)
{
/* it's an 'else if', go to the next one */
if_clause = get_child(else_cont, 0, symbol_if_clause);
else_clause = get_child(else_cont, 1, symbol_else_clause);
}
else
{
/* it's the final 'else', we're done */
assert(else_cont.production_idx == 1);
job_list_to_execute = get_child(else_cont, 1, symbol_job_list);
break;
}
}
}
/* Execute any job list we got */
if (job_list_to_execute != NULL)
{
run_job_list(*job_list_to_execute, ib);
}
/* It's possible there's a last-minute cancellation, in which case we should not stomp the exit status (#1297) */
if (should_cancel_execution(ib))
{
result = parse_execution_cancelled;
}
/* Done */
parser->pop_block(ib);
/* Issue 1061: If we executed, then always report success, instead of letting the exit status of the last command linger */
if (result == parse_execution_success)
{
proc_set_last_status(STATUS_BUILTIN_OK);
}
return result;
}
parse_execution_result_t parse_execution_context_t::run_begin_statement(const parse_node_t &header, const parse_node_t &contents)
{
assert(header.type == symbol_begin_header);
assert(contents.type == symbol_job_list);
/* Basic begin/end block. Push a scope block. */
scope_block_t *sb = new scope_block_t(BEGIN);
parser->push_block(sb);
/* Run the job list */
parse_execution_result_t ret = run_job_list(contents, sb);
/* Pop the block */
parser->pop_block(sb);
return ret;
}
/* Define a function */
parse_execution_result_t parse_execution_context_t::run_function_statement(const parse_node_t &header, const parse_node_t &contents)
{
assert(header.type == symbol_function_header);
assert(contents.type == symbol_job_list);
/* Get arguments */
const parse_node_t *unmatched_wildcard = NULL;
wcstring_list_t argument_list;
parse_execution_result_t result = this->determine_arguments(header, &argument_list, &unmatched_wildcard);
/* Handle unmatched wildcards */
if (result == parse_execution_success && unmatched_wildcard != NULL)
{
report_unmatched_wildcard_error(*unmatched_wildcard);
result = parse_execution_errored;
}
if (result == parse_execution_success)
{
const wcstring contents_str = get_source(contents);
int definition_line_offset = this->line_offset_of_node_at_offset(this->get_offset(contents));
wcstring error_str;
int err = define_function(*parser, argument_list, contents_str, definition_line_offset, &error_str);
proc_set_last_status(err);
if (! error_str.empty())
{
this->report_error(header, L"%ls", error_str.c_str());
result = parse_execution_errored;
}
}
return result;
}
parse_execution_result_t parse_execution_context_t::run_block_statement(const parse_node_t &statement)
{
assert(statement.type == symbol_block_statement);
const parse_node_t &block_header = *get_child(statement, 0, symbol_block_header); //block header
const parse_node_t &header = *get_child(block_header, 0); //specific header type (e.g. for loop)
const parse_node_t &contents = *get_child(statement, 2, symbol_job_list); //block contents
parse_execution_result_t ret = parse_execution_success;
switch (header.type)
{
case symbol_for_header:
ret = run_for_statement(header, contents);
break;
case symbol_while_header:
ret = run_while_statement(header, contents);
break;
case symbol_function_header:
ret = run_function_statement(header, contents);
break;
case symbol_begin_header:
ret = run_begin_statement(header, contents);
break;
default:
fprintf(stderr, "Unexpected block header: %ls\n", header.describe().c_str());
PARSER_DIE();
break;
}
return ret;
}
parse_execution_result_t parse_execution_context_t::run_for_statement(const parse_node_t &header, const parse_node_t &block_contents)
{
assert(header.type == symbol_for_header);
assert(block_contents.type == symbol_job_list);
/* Get the variable name: `for var_name in ...`. We expand the variable name. It better result in just one. */
const parse_node_t &var_name_node = *get_child(header, 1, parse_token_type_string);
wcstring for_var_name = get_source(var_name_node);
if (! expand_one(for_var_name, 0, NULL))
{
report_error(var_name_node, FAILED_EXPANSION_VARIABLE_NAME_ERR_MSG, for_var_name.c_str());
return parse_execution_errored;
}
/* Get the contents to iterate over. */
const parse_node_t *unmatched_wildcard = NULL;
wcstring_list_t argument_sequence;
parse_execution_result_t ret = this->determine_arguments(header, &argument_sequence, &unmatched_wildcard);
if (ret != parse_execution_success)
{
return ret;
}
if (unmatched_wildcard != NULL)
{
return report_unmatched_wildcard_error(*unmatched_wildcard);
}
for_block_t *fb = new for_block_t();
parser->push_block(fb);
/* Now drive the for loop. */
const size_t arg_count = argument_sequence.size();
for (size_t i=0; i < arg_count; i++)
{
if (should_cancel_execution(fb))
{
ret = parse_execution_cancelled;
break;
}
const wcstring &val = argument_sequence.at(i);
env_set(for_var_name, val.c_str(), ENV_LOCAL);
fb->loop_status = LOOP_NORMAL;
fb->skip = 0;
this->run_job_list(block_contents, fb);
if (this->cancellation_reason(fb) == execution_cancellation_loop_control)
{
/* Handle break or continue */
if (fb->loop_status == LOOP_CONTINUE)
{
/* Reset the loop state */
fb->loop_status = LOOP_NORMAL;
fb->skip = false;
continue;
}
else if (fb->loop_status == LOOP_BREAK)
{
break;
}
}
}
parser->pop_block(fb);
return ret;
}
parse_execution_result_t parse_execution_context_t::run_switch_statement(const parse_node_t &statement)
{
assert(statement.type == symbol_switch_statement);
const parse_node_t *matching_case_item = NULL;
parse_execution_result_t result = parse_execution_success;
/* Get the switch variable */
const parse_node_t &switch_value_node = *get_child(statement, 1, symbol_argument);
const wcstring switch_value = get_source(switch_value_node);
/* Expand it. We need to offset any errors by the position of the string */
std::vector<completion_t> switch_values_expanded;
parse_error_list_t errors;
int expand_ret = expand_string(switch_value, switch_values_expanded, EXPAND_NO_DESCRIPTIONS, &errors);
parse_error_offset_source_start(&errors, switch_value_node.source_start);
switch (expand_ret)
{
case EXPAND_ERROR:
{
result = report_errors(errors);
break;
}
case EXPAND_WILDCARD_NO_MATCH:
{
/* Store the node that failed to expand */
report_error(switch_value_node, WILDCARD_ERR_MSG, switch_value.c_str());
result = parse_execution_errored;
break;
}
case EXPAND_WILDCARD_MATCH:
case EXPAND_OK:
{
break;
}
}
if (result == parse_execution_success && switch_values_expanded.size() != 1)
{
result = report_error(switch_value_node,
_(L"switch: Expected exactly one argument, got %lu\n"),
switch_values_expanded.size());
}
if (result == parse_execution_success)
{
const wcstring &switch_value_expanded = switch_values_expanded.at(0).completion;
switch_block_t *sb = new switch_block_t();
parser->push_block(sb);
/* Expand case statements */
const parse_node_t *case_item_list = get_child(statement, 3, symbol_case_item_list);
/* Loop while we don't have a match but do have more of the list */
while (matching_case_item == NULL && case_item_list != NULL)
{
if (should_cancel_execution(sb))
{
result = parse_execution_cancelled;
break;
}
/* Get the next item and the remainder of the list */
const parse_node_t *case_item = tree.next_node_in_node_list(*case_item_list, symbol_case_item, &case_item_list);
if (case_item == NULL)
{
/* No more items */
break;
}
/* Pull out the argument list */
const parse_node_t &arg_list = *get_child(*case_item, 1, symbol_argument_list);
/* Expand arguments. We explicitly ignore unmatched_wildcard. That is, a case item list may have a wildcard that fails to expand to anything. We also report case errors, but don't stop execution; i.e. a case item that contains an unexpandable process will report and then fail to match. */
wcstring_list_t case_args;
parse_execution_result_t case_result = this->determine_arguments(arg_list, &case_args, NULL);
if (case_result == parse_execution_success)
{
for (size_t i=0; i < case_args.size(); i++)
{
const wcstring &arg = case_args.at(i);
/* Unescape wildcards so they can be expanded again */
wchar_t *unescaped_arg = parse_util_unescape_wildcards(arg.c_str());
bool match = wildcard_match(switch_value_expanded, unescaped_arg);
free(unescaped_arg);
/* If this matched, we're done */
if (match)
{
matching_case_item = case_item;
break;
}
}
}
}
if (result == parse_execution_success && matching_case_item != NULL)
{
/* Success, evaluate the job list */
const parse_node_t *job_list = get_child(*matching_case_item, 3, symbol_job_list);
result = this->run_job_list(*job_list, sb);
}
parser->pop_block(sb);
}
return result;
}
parse_execution_result_t parse_execution_context_t::run_while_statement(const parse_node_t &header, const parse_node_t &block_contents)
{
assert(header.type == symbol_while_header);
assert(block_contents.type == symbol_job_list);
/* Push a while block */
while_block_t *wb = new while_block_t();
wb->node_offset = this->get_offset(header);
parser->push_block(wb);
parse_execution_result_t ret = parse_execution_success;
/* The condition and contents of the while loop, as a job and job list respectively */
const parse_node_t &while_condition = *get_child(header, 1, symbol_job);
/* Run while the condition is true */
for (;;)
{
/* Check the condition */
parse_execution_result_t cond_result = this->run_1_job(while_condition, wb);
/* We only continue on successful execution and EXIT_SUCCESS */
if (cond_result != parse_execution_success || proc_get_last_status() != EXIT_SUCCESS)
{
break;
}
/* Check cancellation */
if (this->should_cancel_execution(wb))
{
ret = parse_execution_cancelled;
break;
}
/* The block ought to go inside the loop (see #1212) */
this->run_job_list(block_contents, wb);
if (this->cancellation_reason(wb) == execution_cancellation_loop_control)
{
/* Handle break or continue */
if (wb->loop_status == LOOP_CONTINUE)
{
/* Reset the loop state */
wb->loop_status = LOOP_NORMAL;
wb->skip = false;
continue;
}
else if (wb->loop_status == LOOP_BREAK)
{
break;
}
}
/* no_exec means that fish was invoked with -n or --no-execute. If set, we allow the loop to not-execute once so its contents can be checked, and then break */
if (no_exec)
{
break;
}
}
/* Done */
parser->pop_block(wb);
return ret;
}
/* Reports an error. Always returns parse_execution_errored, so you can assign the result to an 'errored' variable */
parse_execution_result_t parse_execution_context_t::report_error(const parse_node_t &node, const wchar_t *fmt, ...) const
{
if (parser->show_errors)
{
/* Create an error */
parse_error_list_t error_list = parse_error_list_t(1);
parse_error_t *error = &error_list.at(0);
error->source_start = node.source_start;
error->source_length = node.source_length;
error->code = parse_error_syntax; //hackish
va_list va;
va_start(va, fmt);
error->text = vformat_string(fmt, va);
va_end(va);
this->report_errors(error_list);
}
return parse_execution_errored;
}
parse_execution_result_t parse_execution_context_t::report_errors(const parse_error_list_t &error_list) const
{
if (parser->show_errors)
{
if (error_list.empty())
{
fprintf(stderr, "Bug: Error reported but no error text found.");
}
/* Get a backtrace */
wcstring backtrace_and_desc;
parser->get_backtrace(src, error_list, &backtrace_and_desc);
/* Print it */
fprintf(stderr, "%ls", backtrace_and_desc.c_str());
}
return parse_execution_errored;
}
/* Reoports an unmatched wildcard error and returns parse_execution_errored */
parse_execution_result_t parse_execution_context_t::report_unmatched_wildcard_error(const parse_node_t &unmatched_wildcard)
{
proc_set_last_status(STATUS_UNMATCHED_WILDCARD);
/* For reasons I cannot explain, unmatched wildcards are only reported in interactive use. */
if (get_is_interactive())
{
report_error(unmatched_wildcard, WILDCARD_ERR_MSG, get_source(unmatched_wildcard).c_str());
}
return parse_execution_errored;
}
/* Handle the case of command not found */
void parse_execution_context_t::handle_command_not_found(const wcstring &cmd_str, const parse_node_t &statement_node, int err_code)
{
assert(statement_node.type == symbol_plain_statement);
/* We couldn't find the specified command. This is a non-fatal error. We want to set the exit status to 127, which is the standard number used by other shells like bash and zsh. */
const wchar_t * const cmd = cmd_str.c_str();
const wchar_t * const equals_ptr = wcschr(cmd, L'=');
if (equals_ptr != NULL)
{
/* Try to figure out if this is a pure variable assignment (foo=bar), or if this appears to be running a command (foo=bar ruby...) */
const wcstring name_str = wcstring(cmd, equals_ptr - cmd); //variable name, up to the =
const wcstring val_str = wcstring(equals_ptr + 1); //variable value, past the =
const parse_node_tree_t::parse_node_list_t args = tree.find_nodes(statement_node, symbol_argument, 1);
if (! args.empty())
{
const wcstring argument = get_source(*args.at(0));
wcstring ellipsis_str = wcstring(1, ellipsis_char);
if (ellipsis_str == L"$")
ellipsis_str = L"...";
/* Looks like a command */
this->report_error(statement_node,
_(L"Unknown command '%ls'. Did you mean to run %ls with a modified environment? Try 'env %ls=%ls %ls%ls'. See the help section on the set command by typing 'help set'."),
cmd,
argument.c_str(),
name_str.c_str(),
val_str.c_str(),
argument.c_str(),
ellipsis_str.c_str());
}
else
{
this->report_error(statement_node,
COMMAND_ASSIGN_ERR_MSG,
cmd,
name_str.c_str(),
val_str.c_str());
}
}
else if (cmd[0]==L'$' || cmd[0] == VARIABLE_EXPAND || cmd[0] == VARIABLE_EXPAND_SINGLE)
{
const env_var_t val_wstr = env_get_string(cmd+1);
const wchar_t *val = val_wstr.missing() ? NULL : val_wstr.c_str();
if (val)
{
this->report_error(statement_node,
_(L"Variables may not be used as commands. Instead, define a function like 'function %ls; %ls $argv; end' or use the eval builtin instead, like 'eval %ls'. See the help section for the function command by typing 'help function'."),
cmd+1,
val,
cmd,
cmd);
}
else
{
this->report_error(statement_node,
_(L"Variables may not be used as commands. Instead, define a function or use the eval builtin instead, like 'eval %ls'. See the help section for the function command by typing 'help function'."),
cmd,
cmd);
}
}
else if (wcschr(cmd, L'$'))
{
this->report_error(statement_node,
_(L"Commands may not contain variables. Use the eval builtin instead, like 'eval %ls'. See the help section for the eval command by typing 'help eval'."),
cmd,
cmd);
}
else if (err_code!=ENOENT)
{
this->report_error(statement_node,
_(L"The file '%ls' is not executable by this user"),
cmd?cmd:L"UNKNOWN");
}
else
{
/*
Handle unrecognized commands with standard
command not found handler that can make better
error messages
*/
wcstring_list_t event_args;
event_args.push_back(cmd_str);
event_fire_generic(L"fish_command_not_found", &event_args);
/* Here we want to report an error (so it shows a backtrace), but with no text */
this->report_error(statement_node, L"");
}
/* Set the last proc status appropriately */
proc_set_last_status(err_code==ENOENT?STATUS_UNKNOWN_COMMAND:STATUS_NOT_EXECUTABLE);
}
/* Creates a 'normal' (non-block) process */
parse_execution_result_t parse_execution_context_t::populate_plain_process(job_t *job, process_t *proc, const parse_node_t &statement)
{
assert(job != NULL);
assert(proc != NULL);
assert(statement.type == symbol_plain_statement);
/* We may decide that a command should be an implicit cd */
bool use_implicit_cd = false;
/* Get the command. We expect to always get it here. */
wcstring cmd;
bool got_cmd = tree.command_for_plain_statement(statement, src, &cmd);
assert(got_cmd);
/* Expand it as a command. Return an error on failure. */
bool expanded = expand_one(cmd, EXPAND_SKIP_CMDSUBST | EXPAND_SKIP_VARIABLES, NULL);
if (! expanded)
{
report_error(statement, ILLEGAL_CMD_ERR_MSG, cmd.c_str());
return parse_execution_errored;
}
/* Determine the process type */
enum process_type_t process_type = process_type_for_command(statement, cmd);
/* Check for stack overflow */
if (process_type == INTERNAL_FUNCTION && parser->forbidden_function.size() > FISH_MAX_STACK_DEPTH)
{
this->report_error(statement, CALL_STACK_LIMIT_EXCEEDED_ERR_MSG);
return parse_execution_errored;
}
wcstring path_to_external_command;
if (process_type == EXTERNAL || process_type == INTERNAL_EXEC)
{
/* Determine the actual command. This may be an implicit cd. */
bool has_command = path_get_path(cmd, &path_to_external_command);
/* If there was no command, then we care about the value of errno after checking for it, to distinguish between e.g. no file vs permissions problem */
const int no_cmd_err_code = errno;
/* If the specified command does not exist, and is undecorated, try using an implicit cd. */
if (! has_command && tree.decoration_for_plain_statement(statement) == parse_statement_decoration_none)
{
/* Implicit cd requires an empty argument and redirection list */
const parse_node_t *args = get_child(statement, 1, symbol_arguments_or_redirections_list);
if (args->child_count == 0)
{
/* Ok, no arguments or redirections; check to see if the first argument is a directory */
wcstring implicit_cd_path;
use_implicit_cd = path_can_be_implicit_cd(cmd, &implicit_cd_path);
}
}
if (! has_command && ! use_implicit_cd)
{
/* No command */
this->handle_command_not_found(cmd, statement, no_cmd_err_code);
return parse_execution_errored;
}
}
/* The argument list and set of IO redirections that we will construct for the process */
wcstring_list_t argument_list;
io_chain_t process_io_chain;
if (use_implicit_cd)
{
/* Implicit cd is simple */
argument_list.push_back(L"cd");
argument_list.push_back(cmd);
path_to_external_command.clear();
/* If we have defined a wrapper around cd, use it, otherwise use the cd builtin */
process_type = function_exists(L"cd") ? INTERNAL_FUNCTION : INTERNAL_BUILTIN;
}
else
{
/* Form the list of arguments. The command is the first argument. TODO: count hack, where we treat 'count --help' as different from 'count $foo' that expands to 'count --help'. fish 1.x never successfully did this, but it tried to! */
const parse_node_t *unmatched_wildcard = NULL;
parse_execution_result_t arg_result = this->determine_arguments(statement, &argument_list, &unmatched_wildcard);
if (arg_result != parse_execution_success)
{
return arg_result;
}
argument_list.insert(argument_list.begin(), cmd);
/* If we were not able to expand any wildcards, here is the first one that failed */
if (unmatched_wildcard != NULL)
{
job_set_flag(job, JOB_WILDCARD_ERROR, 1);
return report_unmatched_wildcard_error(*unmatched_wildcard);
}
/* The set of IO redirections that we construct for the process */
if (! this->determine_io_chain(statement, &process_io_chain))
{
return parse_execution_errored;
}
/* Determine the process type */
process_type = process_type_for_command(statement, cmd);
}
/* Populate the process */
proc->type = process_type;
proc->set_argv(argument_list);
proc->set_io_chain(process_io_chain);
proc->actual_cmd = path_to_external_command;
return parse_execution_success;
}
/* Determine the list of arguments, expanding stuff. Reports any errors caused by expansion. If we have a wildcard and none could be expanded, return the unexpandable wildcard node by reference. */
parse_execution_result_t parse_execution_context_t::determine_arguments(const parse_node_t &parent, wcstring_list_t *out_arguments, const parse_node_t **out_unmatched_wildcard_node)
{
/* Whether we failed to match any wildcards, and succeeded in matching any wildcards */
bool unmatched_wildcard = false, matched_wildcard = false;
/* The ultimate result */
enum parse_execution_result_t result = parse_execution_success;
/* First node that failed to expand as a wildcard (if any) */
const parse_node_t *unmatched_wildcard_node = NULL;
/* Get all argument nodes underneath the statement. We guess we'll have that many arguments (but may have more or fewer, if there are wildcards involved) */
const parse_node_tree_t::parse_node_list_t argument_nodes = tree.find_nodes(parent, symbol_argument);
out_arguments->reserve(out_arguments->size() + argument_nodes.size());
for (size_t i=0; i < argument_nodes.size(); i++)
{
const parse_node_t &arg_node = *argument_nodes.at(i);
/* Expect all arguments to have source */
assert(arg_node.has_source());
const wcstring arg_str = arg_node.get_source(src);
/* Expand this string */
std::vector<completion_t> arg_expanded;
parse_error_list_t errors;
int expand_ret = expand_string(arg_str, arg_expanded, EXPAND_NO_DESCRIPTIONS, &errors);
parse_error_offset_source_start(&errors, arg_node.source_start);
switch (expand_ret)
{
case EXPAND_ERROR:
{
this->report_errors(errors);
result = parse_execution_errored;
break;
}
case EXPAND_WILDCARD_NO_MATCH:
{
/* Store the node that failed to expand */
unmatched_wildcard = true;
if (! unmatched_wildcard_node)
{
unmatched_wildcard_node = &arg_node;
}
break;
}
case EXPAND_WILDCARD_MATCH:
{
matched_wildcard = true;
break;
}
case EXPAND_OK:
{
break;
}
}
/* Now copy over any expanded arguments */
for (size_t i=0; i < arg_expanded.size(); i++)
{
out_arguments->push_back(arg_expanded.at(i).completion);
}
}
/* Return if we had a wildcard problem */
if (out_unmatched_wildcard_node != NULL && unmatched_wildcard && ! matched_wildcard)
{
*out_unmatched_wildcard_node = unmatched_wildcard_node;
}
return result;
}
bool parse_execution_context_t::determine_io_chain(const parse_node_t &statement_node, io_chain_t *out_chain)
{
io_chain_t result;
bool errored = false;
/* We are called with a statement of varying types. We require that the statement have an arguments_or_redirections_list child. */
const parse_node_t &args_and_redirections_list = tree.find_child(statement_node, symbol_arguments_or_redirections_list);
/* Get all redirection nodes underneath the statement */
const parse_node_tree_t::parse_node_list_t redirect_nodes = tree.find_nodes(args_and_redirections_list, symbol_redirection);
for (size_t i=0; i < redirect_nodes.size(); i++)
{
const parse_node_t &redirect_node = *redirect_nodes.at(i);
int source_fd = -1; /* source fd */
wcstring target; /* file path or target fd */
enum token_type redirect_type = tree.type_for_redirection(redirect_node, src, &source_fd, &target);
/* PCA: I can't justify this EXPAND_SKIP_VARIABLES flag. It was like this when I got here. */
bool target_expanded = expand_one(target, no_exec ? EXPAND_SKIP_VARIABLES : 0, NULL);
if (! target_expanded || target.empty())
{
/* Should improve this error message */
errored = report_error(redirect_node,
_(L"Invalid redirection target: %ls"),
target.c_str());
}
/* Generate the actual IO redirection */
shared_ptr<io_data_t> new_io;
assert(redirect_type != TOK_NONE);
switch (redirect_type)
{
case TOK_REDIRECT_FD:
{
if (target == L"-")
{
new_io.reset(new io_close_t(source_fd));
}
else
{
wchar_t *end = NULL;
errno = 0;
int old_fd = fish_wcstoi(target.c_str(), &end, 10);
if (old_fd < 0 || errno || *end)
{
errored = report_error(redirect_node,
_(L"Requested redirection to '%ls', which is not a valid file descriptor"),
target.c_str());
}
else
{
new_io.reset(new io_fd_t(source_fd, old_fd));
}
}
break;
}
case TOK_REDIRECT_OUT:
case TOK_REDIRECT_APPEND:
case TOK_REDIRECT_IN:
case TOK_REDIRECT_NOCLOB:
{
int oflags = oflags_for_redirection_type(redirect_type);
io_file_t *new_io_file = new io_file_t(source_fd, target, oflags);
new_io.reset(new_io_file);
break;
}
default:
{
// Should be unreachable
fprintf(stderr, "Unexpected redirection type %ld. aborting.\n", (long)redirect_type);
PARSER_DIE();
break;
}
}
/* Append the new_io if we got one */
if (new_io.get() != NULL)
{
result.push_back(new_io);
}
}
if (out_chain && ! errored)
{
out_chain->swap(result);
}
return ! errored;
}
parse_execution_result_t parse_execution_context_t::populate_boolean_process(job_t *job, process_t *proc, const parse_node_t &bool_statement)
{
// Handle a boolean statement
bool skip_job = false;
assert(bool_statement.type == symbol_boolean_statement);
switch (bool_statement.production_idx)
{
// These magic numbers correspond to productions for boolean_statement
case 0:
// AND. Skip if the last job failed.
skip_job = (proc_get_last_status() != 0);
break;
case 1:
// OR. Skip if the last job succeeded.
skip_job = (proc_get_last_status() == 0);
break;
case 2:
// NOT. Negate it.
job_set_flag(job, JOB_NEGATE, !job_get_flag(job, JOB_NEGATE));
break;
default:
{
fprintf(stderr, "Unexpected production in boolean statement\n");
PARSER_DIE();
break;
}
}
if (skip_job)
{
return parse_execution_skipped;
}
else
{
const parse_node_t &subject = *tree.get_child(bool_statement, 1, symbol_statement);
return this->populate_job_process(job, proc, subject);
}
}
parse_execution_result_t parse_execution_context_t::populate_block_process(job_t *job, process_t *proc, const parse_node_t &statement_node)
{
/* We handle block statements by creating INTERNAL_BLOCK_NODE, that will bounce back to us when it's time to execute them */
assert(statement_node.type == symbol_block_statement || statement_node.type == symbol_if_statement || statement_node.type == symbol_switch_statement);
/* The set of IO redirections that we construct for the process */
io_chain_t process_io_chain;
bool errored = ! this->determine_io_chain(statement_node, &process_io_chain);
if (errored)
return parse_execution_errored;
proc->type = INTERNAL_BLOCK_NODE;
proc->internal_block_node = this->get_offset(statement_node);
proc->set_io_chain(process_io_chain);
return parse_execution_success;
}
/* Returns a process_t allocated with new. It's the caller's responsibility to delete it (!) */
parse_execution_result_t parse_execution_context_t::populate_job_process(job_t *job, process_t *proc, const parse_node_t &statement_node)
{
assert(statement_node.type == symbol_statement);
assert(statement_node.child_count == 1);
// Get the "specific statement" which is boolean / block / if / switch / decorated
const parse_node_t &specific_statement = *get_child(statement_node, 0);
parse_execution_result_t result = parse_execution_success;
switch (specific_statement.type)
{
case symbol_boolean_statement:
{
result = this->populate_boolean_process(job, proc, specific_statement);
break;
}
case symbol_block_statement:
case symbol_if_statement:
case symbol_switch_statement:
{
result = this->populate_block_process(job, proc, specific_statement);
break;
}
case symbol_decorated_statement:
{
/* Get the plain statement. It will pull out the decoration itself */
const parse_node_t &plain_statement = tree.find_child(specific_statement, symbol_plain_statement);
result = this->populate_plain_process(job, proc, plain_statement);
break;
}
default:
fprintf(stderr, "'%ls' not handled by new parser yet\n", specific_statement.describe().c_str());
PARSER_DIE();
break;
}
return result;
}
parse_execution_result_t parse_execution_context_t::populate_job_from_job_node(job_t *j, const parse_node_t &job_node, const block_t *associated_block)
{
assert(job_node.type == symbol_job);
/* Tell the job what its command is */
j->set_command(get_source(job_node));
/* We are going to construct process_t structures for every statement in the job. Get the first statement. */
const parse_node_t *statement_node = get_child(job_node, 0, symbol_statement);
assert(statement_node != NULL);
parse_execution_result_t result = parse_execution_success;
/* Create processes. Each one may fail. */
std::vector<process_t *> processes;
processes.push_back(new process_t());
result = this->populate_job_process(j, processes.back(), *statement_node);
/* Construct process_ts for job continuations (pipelines), by walking the list until we hit the terminal (empty) job continuation */
const parse_node_t *job_cont = get_child(job_node, 1, symbol_job_continuation);
assert(job_cont != NULL);
while (result == parse_execution_success && job_cont->child_count > 0)
{
assert(job_cont->type == symbol_job_continuation);
/* Handle the pipe, whose fd may not be the obvious stdout */
const parse_node_t &pipe_node = *get_child(*job_cont, 0, parse_token_type_pipe);
int pipe_write_fd = fd_redirected_by_pipe(get_source(pipe_node));
if (pipe_write_fd == -1)
{
result = report_error(pipe_node, ILLEGAL_FD_ERR_MSG, get_source(pipe_node).c_str());
break;
}
processes.back()->pipe_write_fd = pipe_write_fd;
/* Get the statement node and make a process from it */
const parse_node_t *statement_node = get_child(*job_cont, 1, symbol_statement);
assert(statement_node != NULL);
/* Store the new process (and maybe with an error) */
processes.push_back(new process_t());
result = this->populate_job_process(j, processes.back(), *statement_node);
/* Get the next continuation */
job_cont = get_child(*job_cont, 2, symbol_job_continuation);
assert(job_cont != NULL);
}
/* Return what happened */
if (result == parse_execution_success)
{
/* Link up the processes */
assert(! processes.empty());
j->first_process = processes.at(0);
for (size_t i=1 ; i < processes.size(); i++)
{
processes.at(i-1)->next = processes.at(i);
}
}
else
{
/* Clean up processes */
for (size_t i=0; i < processes.size(); i++)
{
const process_t *proc = processes.at(i);
processes.at(i) = NULL;
delete proc;
}
}
return result;
}
parse_execution_result_t parse_execution_context_t::run_1_job(const parse_node_t &job_node, const block_t *associated_block)
{
parse_execution_result_t result = parse_execution_success;
bool log_it = false;
if (log_it)
{
fprintf(stderr, "%s: %ls\n", __FUNCTION__, get_source(job_node).c_str());
}
if (should_cancel_execution(associated_block))
{
return parse_execution_cancelled;
}
// Get terminal modes
struct termios tmodes = {};
if (get_is_interactive())
{
if (tcgetattr(STDIN_FILENO, &tmodes))
{
// need real error handling here
wperror(L"tcgetattr");
return parse_execution_errored;
}
}
/* Increment the eval_level for the duration of this command */
scoped_push<int> saved_eval_level(&eval_level, eval_level + 1);
/* Save the node index */
scoped_push<node_offset_t> saved_node_offset(&executing_node_idx, this->get_offset(job_node));
/* Profiling support */
long long start_time = 0, parse_time = 0, exec_time = 0;
profile_item_t *profile_item = this->parser->create_profile_item();
if (profile_item != NULL)
{
start_time = get_time();
}
/* When we encounter a block construct (e.g. while loop) in the general case, we create a "block process" that has a pointer to its source. This allows us to handle block-level redirections. However, if there are no redirections, then we can just jump into the block directly, which is significantly faster. */
if (job_is_simple_block(job_node))
{
const parse_node_t &statement = *get_child(job_node, 0, symbol_statement);
const parse_node_t &specific_statement = *get_child(statement, 0);
assert(specific_statement_type_is_redirectable_block(specific_statement));
switch (specific_statement.type)
{
case symbol_block_statement:
result = this->run_block_statement(specific_statement);
break;
case symbol_if_statement:
result = this->run_if_statement(specific_statement);
break;
case symbol_switch_statement:
result = this->run_switch_statement(specific_statement);
break;
default:
/* Other types should be impossible due to the specific_statement_type_is_redirectable_block check */
PARSER_DIE();
break;
}
if (profile_item != NULL)
{
/* Block-types profile a little weird. They have no 'parse' time, and their command is just the block type */
exec_time = get_time();
profile_item->level=eval_level;
profile_item->parse = 0;
profile_item->exec=(int)(exec_time-start_time);
profile_item->cmd = profiling_cmd_name_for_redirectable_block(specific_statement, this->tree, this->src);
profile_item->skipped = result != parse_execution_success;
}
return result;
}
job_t *j = new job_t(acquire_job_id(), block_io);
j->tmodes = tmodes;
job_set_flag(j, JOB_CONTROL,
(job_control_mode==JOB_CONTROL_ALL) ||
((job_control_mode == JOB_CONTROL_INTERACTIVE) && (get_is_interactive())));
job_set_flag(j, JOB_FOREGROUND, ! tree.job_should_be_backgrounded(job_node));
job_set_flag(j, JOB_TERMINAL, job_get_flag(j, JOB_CONTROL) \
&& (!is_subshell && !is_event));
job_set_flag(j, JOB_SKIP_NOTIFICATION, is_subshell \
|| is_block \
|| is_event \
|| (!get_is_interactive()));
/* Tell the current block what its job is. This has to happen before we populate it (#1394) */
parser->current_block()->job = j;
/* Populate the job. This may fail for reasons like command_not_found. If this fails, an error will have been printed */
parse_execution_result_t pop_result = this->populate_job_from_job_node(j, job_node, associated_block);
/* Clean up the job on failure or cancellation */
bool populated_job = (pop_result == parse_execution_success);
if (! populated_job || this->should_cancel_execution(associated_block))
{
assert(parser->current_block()->job == j);
parser->current_block()->job = NULL;
delete j;
j = NULL;
populated_job = false;
}
/* Store time it took to 'parse' the command */
if (profile_item != NULL)
{
parse_time = get_time();
}
if (populated_job)
{
/* Success. Give the job to the parser - it will clean it up. */
parser->job_add(j);
/* Check to see if this contained any external commands */
bool job_contained_external_command = false;
for (const process_t *proc = j->first_process; proc != NULL; proc = proc->next)
{
if (proc->type == EXTERNAL)
{
job_contained_external_command = true;
break;
}
}
/* Actually execute the job */
exec_job(*this->parser, j);
/* Only external commands require a new fishd barrier */
if (job_contained_external_command)
{
set_proc_had_barrier(false);
}
}
if (profile_item != NULL)
{
exec_time = get_time();
profile_item->level=eval_level;
profile_item->parse = (int)(parse_time-start_time);
profile_item->exec=(int)(exec_time-parse_time);
profile_item->cmd = j ? j->command() : wcstring();
profile_item->skipped = ! populated_job || result != parse_execution_success;
}
/* If the job was skipped, we pretend it ran anyways */
if (result == parse_execution_skipped)
{
result = parse_execution_success;
}
/* Clean up jobs. */
job_reap(0);
/* All done */
return result;
}
parse_execution_result_t parse_execution_context_t::run_job_list(const parse_node_t &job_list_node, const block_t *associated_block)
{
assert(job_list_node.type == symbol_job_list);
parse_execution_result_t result = parse_execution_success;
const parse_node_t *job_list = &job_list_node;
while (job_list != NULL && ! should_cancel_execution(associated_block))
{
assert(job_list->type == symbol_job_list);
// Try pulling out a job
const parse_node_t *job = tree.next_node_in_node_list(*job_list, symbol_job, &job_list);
if (job != NULL)
{
result = this->run_1_job(*job, associated_block);
}
}
/* Returns the last job executed */
return result;
}
parse_execution_result_t parse_execution_context_t::eval_node_at_offset(node_offset_t offset, const block_t *associated_block, const io_chain_t &io)
{
bool log_it = false;
/* Don't ever expect to have an empty tree if this is called */
assert(! tree.empty());
assert(offset < tree.size());
/* Apply this block IO for the duration of this function */
scoped_push<io_chain_t> block_io_push(&block_io, io);
const parse_node_t &node = tree.at(offset);
if (log_it)
{
fprintf(stderr, "eval node: %ls\n", get_source(node).c_str());
}
/* Currently, we only expect to execute the top level job list, or a block node. Assert that. */
assert(node.type == symbol_job_list || specific_statement_type_is_redirectable_block(node));
enum parse_execution_result_t status = parse_execution_success;
switch (node.type)
{
case symbol_job_list:
{
/* We should only get a job list if it's the very first node. This is because this is the entry point for both top-level execution (the first node) and INTERNAL_BLOCK_NODE execution (which does block statements, but never job lists) */
assert(offset == 0);
wcstring func_name;
const parse_node_t *infinite_recursive_node = this->infinite_recursive_statement_in_job_list(node, &func_name);
if (infinite_recursive_node != NULL)
{
/* We have an infinite recursion */
this->report_error(*infinite_recursive_node, INFINITE_FUNC_RECURSION_ERR_MSG, func_name.c_str());
status = parse_execution_errored;
}
else
{
/* No infinite recursion */
status = this->run_job_list(node, associated_block);
}
break;
}
case symbol_block_statement:
status = this->run_block_statement(node);
break;
case symbol_if_statement:
status = this->run_if_statement(node);
break;
case symbol_switch_statement:
status = this->run_switch_statement(node);
break;
default:
/* In principle, we could support other node types. However we never expect to be passed them - see above. */
fprintf(stderr, "Unexpected node %ls found in %s\n", node.describe().c_str(), __FUNCTION__);
PARSER_DIE();
break;
}
return status;
}
int parse_execution_context_t::line_offset_of_node_at_offset(node_offset_t requested_index)
{
/* If we're not executing anything, return -1 */
if (requested_index == NODE_OFFSET_INVALID)
{
return -1;
}
/* If for some reason we're executing a node without source, return -1 */
const parse_node_t &node = tree.at(requested_index);
if (! node.has_source())
{
return -1;
}
/* Count the number of newlines, leveraging our cache */
const size_t offset = tree.at(requested_index).source_start;
assert(offset <= src.size());
/* Easy hack to handle 0 */
if (offset == 0)
{
return 0;
}
/* We want to return (one plus) the number of newlines at offsets less than the given offset. cached_lineno_count is the number of newlines at indexes less than cached_lineno_offset. */
const wchar_t *str = src.c_str();
if (offset > cached_lineno_offset)
{
size_t i;
for (i = cached_lineno_offset; str[i] != L'\0' && i < offset; i++)
{
/* Add one for every newline we find in the range [cached_lineno_offset, offset) */
if (str[i] == L'\n')
{
cached_lineno_count++;
}
}
cached_lineno_offset = i; //note: i, not offset, in case offset is beyond the length of the string
}
else if (offset < cached_lineno_offset)
{
/* Subtract one for every newline we find in the range [offset, cached_lineno_offset) */
for (size_t i = offset; i < cached_lineno_offset; i++)
{
if (str[i] == L'\n')
{
cached_lineno_count--;
}
}
cached_lineno_offset = offset;
}
return cached_lineno_count;
}
int parse_execution_context_t::get_current_line_number()
{
int line_number = -1;
int line_offset = this->line_offset_of_node_at_offset(this->executing_node_idx);
if (line_offset >= 0)
{
/* The offset is 0 based; the number is 1 based */
line_number = line_offset + 1;
}
return line_number;
}
int parse_execution_context_t::get_current_source_offset() const
{
int result = -1;
if (executing_node_idx != NODE_OFFSET_INVALID)
{
const parse_node_t &node = tree.at(executing_node_idx);
if (node.has_source())
{
result = static_cast<int>(node.source_start);
}
}
return result;
}