github-mirror/fish-shell
2
0
Fork 0
mirror of https://github.com/fish-shell/fish-shell.git synced 2024-11-30 14:24:35 +08:00
Code Issues Actions 2 Packages Projects Releases Wiki Activity
6bed255a52
fish-shell/src/parse_util.cpp
ridiculousfish b405b979ec Eliminate the CHECK() macro 
This thing was pretty useless.
2019-05-27 17:24:19 -07:00

1336 lines
52 KiB
C++
Raw Blame History

// Various mostly unrelated utility functions related to parsing, loading and evaluating fish code.
//
// This library can be seen as a 'toolbox' for functions that are used in many places in fish and
// that are somehow related to parsing the code.
#include "config.h" // IWYU pragma: keep
#include <stdarg.h>
#include <stdlib.h>
#include <cwchar>
#include <memory>
#include <string>
#include <type_traits>
#include "builtin.h"
#include "common.h"
#include "expand.h"
#include "fallback.h" // IWYU pragma: keep
#include "future_feature_flags.h"
#include "parse_constants.h"
#include "parse_util.h"
#include "parser.h"
#include "tnode.h"
#include "tokenizer.h"
#include "wildcard.h"
#include "wutil.h" // IWYU pragma: keep
/// Error message for improper use of the exec builtin.
#define EXEC_ERR_MSG _(L"The '%ls' command can not be used in a pipeline")
/// Error message for use of backgrounded commands before and/or.
#define BOOL_AFTER_BACKGROUND_ERROR_MSG \
_(L"The '%ls' command can not be used immediately after a backgrounded job")
/// Error message for backgrounded commands as conditionals.
#define BACKGROUND_IN_CONDITIONAL_ERROR_MSG \
_(L"Backgrounded commands can not be used as conditionals")
/// Error message for arguments to 'end'
#define END_ARG_ERR_MSG _(L"'end' does not take arguments. Did you forget a ';'?")
int parse_util_lineno(const wchar_t *str, size_t offset) {
if (!str) return 0;
int res = 1;
for (size_t i = 0; i < offset && str[i] != L'\0'; i++) {
if (str[i] == L'\n') {
res++;
}
}
return res;
}
int parse_util_get_line_from_offset(const wcstring &str, size_t pos) {
const wchar_t *buff = str.c_str();
int count = 0;
for (size_t i = 0; i < pos; i++) {
if (!buff[i]) {
return -1;
}
if (buff[i] == L'\n') {
count++;
}
}
return count;
}
size_t parse_util_get_offset_from_line(const wcstring &str, int line) {
const wchar_t *buff = str.c_str();
size_t i;
int count = 0;
if (line < 0) return (size_t)-1;
if (line == 0) return 0;
for (i = 0;; i++) {
if (!buff[i]) return (size_t)-1;
if (buff[i] == L'\n') {
count++;
if (count == line) {
return (i + 1) < str.size() ? i + 1 : i;
}
}
}
}
size_t parse_util_get_offset(const wcstring &str, int line, long line_offset) {
size_t off = parse_util_get_offset_from_line(str, line);
size_t off2 = parse_util_get_offset_from_line(str, line + 1);
if (off == (size_t)-1) return (size_t)-1;
if (off2 == (size_t)-1) off2 = str.length() + 1;
if (line_offset < 0) line_offset = 0; //!OCLINT(parameter reassignment)
if ((size_t)line_offset >= off2 - off - 1) {
line_offset = off2 - off - 1; //!OCLINT(parameter reassignment)
}
return off + line_offset;
}
static int parse_util_locate_brackets_of_type(const wchar_t *in, wchar_t **begin, wchar_t **end,
bool allow_incomplete, wchar_t open_type,
wchar_t close_type) {
// open_type is typically ( or [, and close type is the corresponding value.
wchar_t *pos;
wchar_t prev = 0;
int syntax_error = 0;
int paran_count = 0;
wchar_t *paran_begin = 0, *paran_end = 0;
assert(in && "null parameter");
for (pos = const_cast<wchar_t *>(in); *pos; pos++) {
if (prev != '\\') {
if (std::wcschr(L"\'\"", *pos)) {
wchar_t *q_end = quote_end(pos);
if (q_end && *q_end) {
pos = q_end;
} else {
break;
}
} else {
if (*pos == open_type) {
if ((paran_count == 0) && (paran_begin == 0)) {
paran_begin = pos;
}
paran_count++;
} else if (*pos == close_type) {
paran_count--;
if ((paran_count == 0) && (paran_end == 0)) {
paran_end = pos;
break;
}
if (paran_count < 0) {
syntax_error = 1;
break;
}
}
}
}
prev = *pos;
}
syntax_error |= (paran_count < 0);
syntax_error |= ((paran_count > 0) && (!allow_incomplete));
if (syntax_error) {
return -1;
}
if (paran_begin == 0) {
return 0;
}
if (begin) {
*begin = paran_begin;
}
if (end) {
*end = paran_count ? (wchar_t *)in + std::wcslen(in) : paran_end;
}
return 1;
}
int parse_util_locate_cmdsubst(const wchar_t *in, wchar_t **begin, wchar_t **end,
bool accept_incomplete) {
return parse_util_locate_brackets_of_type(in, begin, end, accept_incomplete, L'(', L')');
}
int parse_util_locate_slice(const wchar_t *in, wchar_t **begin, wchar_t **end,
bool accept_incomplete) {
return parse_util_locate_brackets_of_type(in, begin, end, accept_incomplete, L'[', L']');
}
static int parse_util_locate_brackets_range(const wcstring &str, size_t *inout_cursor_offset,
wcstring *out_contents, size_t *out_start,
size_t *out_end, bool accept_incomplete,
wchar_t open_type, wchar_t close_type) {
// Clear the return values.
if (out_contents != nullptr) out_contents->clear();
*out_start = 0;
*out_end = str.size();
// Nothing to do if the offset is at or past the end of the string.
if (*inout_cursor_offset >= str.size()) return 0;
// Defer to the wonky version.
const wchar_t *const buff = str.c_str();
const wchar_t *const valid_range_start = buff + *inout_cursor_offset,
*valid_range_end = buff + str.size();
wchar_t *bracket_range_begin = NULL, *bracket_range_end = NULL;
int ret = parse_util_locate_brackets_of_type(valid_range_start, &bracket_range_begin,
&bracket_range_end, accept_incomplete, open_type,
close_type);
if (ret <= 0) {
return ret;
}
// The command substitutions must not be NULL and must be in the valid pointer range, and
// the end must be bigger than the beginning.
assert(bracket_range_begin != NULL && bracket_range_begin >= valid_range_start &&
bracket_range_begin <= valid_range_end);
assert(bracket_range_end != NULL && bracket_range_end > bracket_range_begin &&
bracket_range_end >= valid_range_start && bracket_range_end <= valid_range_end);
// Assign the substring to the out_contents.
const wchar_t *interior_begin = bracket_range_begin + 1;
if (out_contents != nullptr) {
out_contents->assign(interior_begin, bracket_range_end - interior_begin);
}
// Return the start and end.
*out_start = bracket_range_begin - buff;
*out_end = bracket_range_end - buff;
// Update the inout_cursor_offset. Note this may cause it to exceed str.size(), though
// overflow is not likely.
*inout_cursor_offset = 1 + *out_end;
return ret;
}
int parse_util_locate_cmdsubst_range(const wcstring &str, size_t *inout_cursor_offset,
wcstring *out_contents, size_t *out_start, size_t *out_end,
bool accept_incomplete) {
return parse_util_locate_brackets_range(str, inout_cursor_offset, out_contents, out_start,
out_end, accept_incomplete, L'(', L')');
}
void parse_util_cmdsubst_extent(const wchar_t *buff, size_t cursor_pos, const wchar_t **a,
const wchar_t **b) {
assert(buff && "Null buffer");
const wchar_t *const cursor = buff + cursor_pos;
const size_t bufflen = std::wcslen(buff);
assert(cursor_pos <= bufflen);
// ap and bp are the beginning and end of the tightest command substitition found so far.
const wchar_t *ap = buff, *bp = buff + bufflen;
const wchar_t *pos = buff;
for (;;) {
wchar_t *begin = NULL, *end = NULL;
if (parse_util_locate_cmdsubst(pos, &begin, &end, true) <= 0) {
// No subshell found, all done.
break;
}
// Interpret NULL to mean the end.
if (end == NULL) {
end = const_cast<wchar_t *>(buff) + bufflen;
}
if (begin < cursor && end >= cursor) {
// This command substitution surrounds the cursor, so it's a tighter fit.
begin++;
ap = begin;
bp = end;
// pos is where to begin looking for the next one. But if we reached the end there's no
// next one.
if (begin >= end) break;
pos = begin + 1;
} else if (begin >= cursor) {
// This command substitution starts at or after the cursor. Since it was the first
// command substitution in the string, we're done.
break;
} else {
// This command substitution ends before the cursor. Skip it.
assert(end < cursor);
pos = end + 1;
assert(pos <= buff + bufflen);
}
}
if (a != NULL) *a = ap;
if (b != NULL) *b = bp;
}
/// Get the beginning and end of the job or process definition under the cursor.
static void job_or_process_extent(const wchar_t *buff, size_t cursor_pos, const wchar_t **a,
const wchar_t **b, int process) {
assert(buff && "Null buffer");
const wchar_t *begin, *end;
wchar_t *buffcpy;
int finished = 0;
if (a) *a = 0;
if (b) *b = 0;
parse_util_cmdsubst_extent(buff, cursor_pos, &begin, &end);
if (!end || !begin) {
return;
}
assert(cursor_pos >= (size_t)(begin - buff));
const size_t pos = cursor_pos - (begin - buff);
if (a) *a = begin;
if (b) *b = end;
buffcpy = wcsndup(begin, end - begin);
assert(buffcpy != NULL);
tokenizer_t tok(buffcpy, TOK_ACCEPT_UNFINISHED);
tok_t token;
while (tok.next(&token) && !finished) {
size_t tok_begin = token.offset;
switch (token.type) {
case TOK_PIPE: {
if (!process) {
break;
}
}
/* FALLTHROUGH */
case TOK_END:
case TOK_BACKGROUND: {
if (tok_begin >= pos) {
finished = 1;
if (b) *b = (wchar_t *)begin + tok_begin;
} else {
if (a) *a = (wchar_t *)begin + tok_begin + 1;
}
break;
}
default: {
break;
}
}
}
free(buffcpy);
}
void parse_util_process_extent(const wchar_t *buff, size_t pos, const wchar_t **a,
const wchar_t **b) {
job_or_process_extent(buff, pos, a, b, 1);
}
void parse_util_job_extent(const wchar_t *buff, size_t pos, const wchar_t **a, const wchar_t **b) {
job_or_process_extent(buff, pos, a, b, 0);
}
void parse_util_token_extent(const wchar_t *buff, size_t cursor_pos, const wchar_t **tok_begin,
const wchar_t **tok_end, const wchar_t **prev_begin,
const wchar_t **prev_end) {
assert(buff && "Null buffer");
const wchar_t *a = NULL, *b = NULL, *pa = NULL, *pb = NULL;
const wchar_t *cmdsubst_begin, *cmdsubst_end;
parse_util_cmdsubst_extent(buff, cursor_pos, &cmdsubst_begin, &cmdsubst_end);
if (!cmdsubst_end || !cmdsubst_begin) {
return;
}
// pos is equivalent to cursor_pos within the range of the command substitution {begin, end}.
size_t offset_within_cmdsubst = cursor_pos - (cmdsubst_begin - buff);
size_t bufflen = std::wcslen(buff);
a = cmdsubst_begin + offset_within_cmdsubst;
b = a;
pa = cmdsubst_begin + offset_within_cmdsubst;
pb = pa;
assert(cmdsubst_begin >= buff);
assert(cmdsubst_begin <= (buff + bufflen));
assert(cmdsubst_end >= cmdsubst_begin);
assert(cmdsubst_end <= (buff + bufflen));
const wcstring buffcpy = wcstring(cmdsubst_begin, cmdsubst_end - cmdsubst_begin);
tokenizer_t tok(buffcpy.c_str(), TOK_ACCEPT_UNFINISHED);
tok_t token;
while (tok.next(&token)) {
size_t tok_begin = token.offset;
size_t tok_end = tok_begin;
// Calculate end of token.
if (token.type == TOK_STRING) {
tok_end += token.length;
}
// Cursor was before beginning of this token, means that the cursor is between two tokens,
// so we set it to a zero element string and break.
if (tok_begin > offset_within_cmdsubst) {
a = b = cmdsubst_begin + offset_within_cmdsubst;
break;
}
// If cursor is inside the token, this is the token we are looking for. If so, set a and b
// and break.
if (token.type == TOK_STRING && tok_end >= offset_within_cmdsubst) {
a = cmdsubst_begin + token.offset;
b = a + token.length;
break;
}
// Remember previous string token.
if (token.type == TOK_STRING) {
pa = cmdsubst_begin + token.offset;
pb = pa + token.length;
}
}
if (tok_begin) *tok_begin = a;
if (tok_end) *tok_end = b;
if (prev_begin) *prev_begin = pa;
if (prev_end) *prev_end = pb;
assert(pa >= buff);
assert(pa <= (buff + bufflen));
assert(pb >= pa);
assert(pb <= (buff + bufflen));
}
wcstring parse_util_unescape_wildcards(const wcstring &str) {
wcstring result;
result.reserve(str.size());
bool unesc_qmark = !feature_test(features_t::qmark_noglob);
const wchar_t *const cs = str.c_str();
for (size_t i = 0; cs[i] != L'\0'; i++) {
if (cs[i] == L'*') {
result.push_back(ANY_STRING);
} else if (cs[i] == L'?' && unesc_qmark) {
result.push_back(ANY_CHAR);
} else if (cs[i] == L'\\' && cs[i + 1] == L'*') {
result.push_back(cs[i + 1]);
i += 1;
} else if (cs[i] == L'\\' && cs[i + 1] == L'?' && unesc_qmark) {
result.push_back(cs[i + 1]);
i += 1;
} else if (cs[i] == L'\\' && cs[i + 1] == L'\\') {
// Not a wildcard, but ensure the next iteration doesn't see this escaped backslash.
result.append(L"\\\\");
i += 1;
} else {
result.push_back(cs[i]);
}
}
return result;
}
/// Find the outermost quoting style of current token. Returns 0 if token is not quoted.
static wchar_t get_quote(const wcstring &cmd_str, size_t len) {
size_t i = 0;
wchar_t res = 0;
const wchar_t *const cmd = cmd_str.c_str();
while (1) {
if (!cmd[i]) break;
if (cmd[i] == L'\\') {
i++;
if (!cmd[i]) break;
i++;
} else {
if (cmd[i] == L'\'' || cmd[i] == L'\"') {
const wchar_t *end = quote_end(&cmd[i]);
// std::fwprintf( stderr, L"Jump %d\n", end-cmd );
if ((end == 0) || (!*end) || (end > cmd + len)) {
res = cmd[i];
break;
}
i = end - cmd + 1;
} else
i++;
}
}
return res;
}
void parse_util_get_parameter_info(const wcstring &cmd, const size_t pos, wchar_t *quote,
size_t *offset, enum token_type *out_type) {
size_t prev_pos = 0;
wchar_t last_quote = L'\0';
tokenizer_t tok(cmd.c_str(), TOK_ACCEPT_UNFINISHED);
tok_t token;
while (tok.next(&token)) {
if (token.offset > pos) break;
if (token.type == TOK_STRING)
last_quote = get_quote(tok.text_of(token), pos - token.offset);
if (out_type != NULL) *out_type = token.type;
prev_pos = token.offset;
}
wchar_t *cmd_tmp = wcsdup(cmd.c_str());
cmd_tmp[pos] = 0;
size_t cmdlen = pos;
bool finished = cmdlen != 0;
if (finished) {
finished = (quote == NULL);
if (finished && std::wcschr(L" \t\n\r", cmd_tmp[cmdlen - 1])) {
finished = cmdlen > 1 && cmd_tmp[cmdlen - 2] == L'\\';
}
}
if (quote) *quote = last_quote;
if (offset != 0) {
if (finished) {
while ((cmd_tmp[prev_pos] != 0) && (std::wcschr(L";|", cmd_tmp[prev_pos]) != 0))
prev_pos++;
*offset = prev_pos;
} else {
*offset = pos;
}
}
free(cmd_tmp);
}
wcstring parse_util_escape_string_with_quote(const wcstring &cmd, wchar_t quote, bool no_tilde) {
wcstring result;
if (quote == L'\0') {
escape_flags_t flags = ESCAPE_ALL | ESCAPE_NO_QUOTED | (no_tilde ? ESCAPE_NO_TILDE : 0);
result = escape_string(cmd, flags);
} else {
// Here we are going to escape a string with quotes.
// A few characters cannot be represented inside quotes, e.g. newlines. In that case,
// terminate the quote and then re-enter it.
result.reserve(cmd.size());
for (wchar_t c : cmd) {
switch (c) {
case L'\n':
result.append({quote, L'\\', L'n', quote});
break;
case L'\t':
result.append({quote, L'\\', L't', quote});
break;
case L'\b':
result.append({quote, L'\\', L'b', quote});
break;
case L'\r':
result.append({quote, L'\\', L'r', quote});
break;
case L'\\':
result.append({L'\\', L'\\'});
break;
default:
if (c == quote) result.push_back(L'\\');
result.push_back(c);
break;
}
}
}
return result;
}
/// We are given a parse tree, the index of a node within the tree, its indent, and a vector of
/// indents the same size as the original source string. Set the indent correspdonding to the node's
/// source range, if appropriate.
///
/// trailing_indent is the indent for nodes with unrealized source, i.e. if I type 'if false <ret>'
/// then we have an if node with an empty job list (without source) but we want the last line to be
/// indented anyways.
///
/// switch statements also indent.
///
/// max_visited_node_idx is the largest index we visited.
static void compute_indents_recursive(const parse_node_tree_t &tree, node_offset_t node_idx,
int node_indent, parse_token_type_t parent_type,
std::vector<int> *indents, int *trailing_indent,
node_offset_t *max_visited_node_idx) {
// Guard against incomplete trees.
if (node_idx > tree.size()) return;
// Update max_visited_node_idx.
if (node_idx > *max_visited_node_idx) *max_visited_node_idx = node_idx;
// We could implement this by utilizing the fish grammar. But there's an easy trick instead:
// almost everything that wraps a job list should be indented by 1. So just find all of the job
// lists. One exception is switch, which wraps a case_item_list instead of a job_list. The other
// exception is job_list itself: a job_list is a job and a job_list, and we want that child list
// to be indented the same as the parent. So just find all job_lists whose parent is not a
// job_list, and increment their indent by 1. We also want to treat andor_job_list like
// job_lists.
const parse_node_t &node = tree.at(node_idx);
const parse_token_type_t node_type = node.type;
// Increment the indent if we are either a root job_list, or root case_item_list.
const bool is_root_job_list = node_type != parent_type && (node_type == symbol_job_list ||
node_type == symbol_andor_job_list);
const bool is_root_case_item_list =
node_type == symbol_case_item_list && parent_type != symbol_case_item_list;
if (is_root_job_list || is_root_case_item_list) {
node_indent += 1;
}
// If we have source, store the trailing indent unconditionally. If we do not have source, store
// the trailing indent only if ours is bigger; this prevents the trailing "run" of terminal job
// lists from affecting the trailing indent. For example, code like this:
//
// if foo
//
// will be parsed as this:
//
// job_list
// job
// if_statement
// job [if]
// job_list [empty]
// job_list [empty]
//
// There's two "terminal" job lists, and we want the innermost one.
//
// Note we are relying on the fact that nodes are in the same order as the source, i.e. an
// in-order traversal of the node tree also traverses the source from beginning to end.
if (node.has_source() || node_indent > *trailing_indent) {
*trailing_indent = node_indent;
}
// Store the indent into the indent array.
if (node.source_start != SOURCE_OFFSET_INVALID && node.source_start < indents->size()) {
if (node.has_source()) {
// A normal non-empty node. Store the indent unconditionally.
indents->at(node.source_start) = node_indent;
} else {
// An empty node. We have a source offset but no source length. This can come about when
// a node legitimately empty:
//
// while true; end
//
// The job_list inside the while loop is empty. It still has a source offset (at the end
// of the while statement) but no source extent. We still need to capture that indent,
// because there may be comments inside:
//
// while true
// # loop forever
// end
//
// The 'loop forever' comment must be indented, by virtue of storing the indent.
//
// Now consider what happens if we remove the end:
//
// while true
// # loop forever
//
// Now both the job_list and end_command are unmaterialized. However, we want the indent
// to be of the job_list and not the end_command. Therefore, we only store the indent
// if it's bigger.
if (node_indent > indents->at(node.source_start)) {
indents->at(node.source_start) = node_indent;
}
}
}
// Recursive to all our children.
for (node_offset_t idx = 0; idx < node.child_count; idx++) {
// Note we pass our type to our child, which becomes its parent node type.
compute_indents_recursive(tree, node.child_start + idx, node_indent, node_type, indents,
trailing_indent, max_visited_node_idx);
}
}
std::vector<int> parse_util_compute_indents(const wcstring &src) {
// Make a vector the same size as the input string, which contains the indents. Initialize them
// to -1.
const size_t src_size = src.size();
std::vector<int> indents(src_size, -1);
// Parse the string. We pass continue_after_error to produce a forest; the trailing indent of
// the last node we visited becomes the input indent of the next. I.e. in the case of 'switch
// foo ; cas', we get an invalid parse tree (since 'cas' is not valid) but we indent it as if it
// were a case item list.
parse_node_tree_t tree;
parse_tree_from_string(src,
parse_flag_continue_after_error | parse_flag_include_comments |
parse_flag_accept_incomplete_tokens,
&tree, NULL /* errors */);
// Start indenting at the first node. If we have a parse error, we'll have to start indenting
// from the top again.
node_offset_t start_node_idx = 0;
int last_trailing_indent = 0;
while (start_node_idx < tree.size()) {
// The indent that we'll get for the last line.
int trailing_indent = 0;
// Biggest offset we visited.
node_offset_t max_visited_node_idx = 0;
// Invoke the recursive version. As a hack, pass job_list for the 'parent' token type, which
// will prevent the really-root job list from indenting.
compute_indents_recursive(tree, start_node_idx, last_trailing_indent, symbol_job_list,
&indents, &trailing_indent, &max_visited_node_idx);
// We may have more to indent. The trailing indent becomes our current indent. Start at the
// node after the last we visited.
last_trailing_indent = trailing_indent;
start_node_idx = max_visited_node_idx + 1;
}
// Handle comments. Each comment node has a parent (which is whatever the top of the symbol
// stack was when the comment was encountered). So the source range of the comment has the same
// indent as its parent.
const size_t tree_size = tree.size();
for (node_offset_t i = 0; i < tree_size; i++) {
const parse_node_t &node = tree.at(i);
if (node.type == parse_special_type_comment && node.has_source() &&
node.parent < tree_size) {
const parse_node_t &parent = tree.at(node.parent);
if (parent.source_start != SOURCE_OFFSET_INVALID) {
indents.at(node.source_start) = indents.at(parent.source_start);
}
}
}
// Now apply the indents. The indents array has -1 for places where the indent does not change,
// so start at each value and extend it along the run of -1s.
int last_indent = 0;
for (size_t i = 0; i < src_size; i++) {
int this_indent = indents.at(i);
if (this_indent < 0) {
indents.at(i) = last_indent;
} else {
// New indent level.
last_indent = this_indent;
// Make all whitespace before a token have the new level. This avoid using the wrong
// indentation level if a new line starts with whitespace.
size_t prev_char_idx = i;
while (prev_char_idx--) {
if (!std::wcschr(L" \n\t\r", src.at(prev_char_idx))) break;
indents.at(prev_char_idx) = last_indent;
}
}
}
// Ensure trailing whitespace has the trailing indent. This makes sure a new line is correctly
// indented even if it is empty.
size_t suffix_idx = src_size;
while (suffix_idx--) {
if (!std::wcschr(L" \n\t\r", src.at(suffix_idx))) break;
indents.at(suffix_idx) = last_trailing_indent;
}
return indents;
}
/// Append a syntax error to the given error list.
static bool append_syntax_error(parse_error_list_t *errors, size_t source_location,
const wchar_t *fmt, ...) {
parse_error_t error;
error.source_start = source_location;
error.source_length = 0;
error.code = parse_error_syntax;
va_list va;
va_start(va, fmt);
error.text = vformat_string(fmt, va);
va_end(va);
errors->push_back(error);
return true;
}
/// Returns 1 if the specified command is a builtin that may not be used in a pipeline.
static const wchar_t *const forbidden_pipe_commands[] = {L"exec", L"case", L"break", L"return",
L"continue"};
static int parser_is_pipe_forbidden(const wcstring &word) {
return contains(forbidden_pipe_commands, word);
}
bool parse_util_argument_is_help(const wchar_t *s) {
return std::wcscmp(L"-h", s) == 0 || std::wcscmp(L"--help", s) == 0;
}
/// Check if the first argument under the given node is --help.
static bool first_argument_is_help(tnode_t<grammar::plain_statement> statement,
const wcstring &src) {
bool is_help = false;
auto arg_nodes = get_argument_nodes(statement.child<1>());
if (!arg_nodes.empty()) {
// Check the first argument only.
wcstring first_arg_src = arg_nodes.front().get_source(src);
is_help = parse_util_argument_is_help(first_arg_src.c_str());
}
return is_help;
}
/// If a var name or command is too long for error reporting, make it shorter.
static wcstring truncate_string(const wcstring &str) {
const size_t max_len = 16;
wcstring result(str, 0, max_len);
if (str.size() > max_len) {
// Truncate!
wchar_t ellipsis_char = get_ellipsis_char();
if (ellipsis_char == L'\x2026') {
result.at(max_len - 1) = ellipsis_char;
} else {
result.replace(max_len - 3, 3, L"...");
}
}
return result;
}
/// Given a wide character immediately after a dollar sign, return the appropriate error message.
/// For example, if wc is @, then the variable name was $@ and we suggest $argv.
static const wchar_t *error_format_for_character(wchar_t wc) {
switch (wc) {
case L'?': {
return ERROR_NOT_STATUS;
}
case L'#': {
return ERROR_NOT_ARGV_COUNT;
}
case L'@': {
return ERROR_NOT_ARGV_AT;
}
case L'*': {
return ERROR_NOT_ARGV_STAR;
}
case L'$':
case VARIABLE_EXPAND:
case VARIABLE_EXPAND_SINGLE:
case VARIABLE_EXPAND_EMPTY: {
return ERROR_NOT_PID;
}
default: {
return ERROR_BAD_VAR_CHAR1;
}
}
}
void parse_util_expand_variable_error(const wcstring &token, size_t global_token_pos,
size_t dollar_pos, parse_error_list_t *errors) {
// Note that dollar_pos is probably VARIABLE_EXPAND or VARIABLE_EXPAND_SINGLE, not a literal
// dollar sign.
assert(errors != NULL);
assert(dollar_pos < token.size());
const bool double_quotes = token.at(dollar_pos) == VARIABLE_EXPAND_SINGLE;
const size_t start_error_count = errors->size();
const size_t global_dollar_pos = global_token_pos + dollar_pos;
const size_t global_after_dollar_pos = global_dollar_pos + 1;
wchar_t char_after_dollar = dollar_pos + 1 >= token.size() ? 0 : token.at(dollar_pos + 1);
switch (char_after_dollar) {
case BRACE_BEGIN:
case L'{': {
// The BRACE_BEGIN is for unquoted, the { is for quoted. Anyways we have (possible
// quoted) ${. See if we have a }, and the stuff in between is variable material. If so,
// report a bracket error. Otherwise just complain about the ${.
bool looks_like_variable = false;
size_t closing_bracket =
token.find(char_after_dollar == L'{' ? L'}' : wchar_t(BRACE_END), dollar_pos + 2);
wcstring var_name;
if (closing_bracket != wcstring::npos) {
size_t var_start = dollar_pos + 2, var_end = closing_bracket;
var_name = wcstring(token, var_start, var_end - var_start);
looks_like_variable = valid_var_name(var_name);
}
if (looks_like_variable) {
append_syntax_error(
errors, global_after_dollar_pos,
double_quotes ? ERROR_BRACKETED_VARIABLE_QUOTED1 : ERROR_BRACKETED_VARIABLE1,
truncate_string(var_name).c_str());
} else {
append_syntax_error(errors, global_after_dollar_pos, ERROR_BAD_VAR_CHAR1, L'{');
}
break;
}
case INTERNAL_SEPARATOR: {
// e.g.: echo foo"$"baz
// These are only ever quotes, not command substitutions. Command substitutions are
// handled earlier.
append_syntax_error(errors, global_dollar_pos, ERROR_NO_VAR_NAME);
break;
}
case '(': {
// e.g.: 'echo "foo$(bar)baz"
// Try to determine what's in the parens.
wcstring token_after_parens;
wcstring paren_text;
size_t open_parens = dollar_pos + 1, cmdsub_start = 0, cmdsub_end = 0;
if (parse_util_locate_cmdsubst_range(token, &open_parens, &paren_text, &cmdsub_start,
&cmdsub_end, true) > 0) {
token_after_parens = tok_first(paren_text);
}
// Make sure we always show something.
if (token_after_parens.empty()) {
token_after_parens = L"...";
}
append_syntax_error(errors, global_dollar_pos, ERROR_BAD_VAR_SUBCOMMAND1,
truncate_string(token_after_parens).c_str());
break;
}
case L'\0': {
append_syntax_error(errors, global_dollar_pos, ERROR_NO_VAR_NAME);
break;
}
default: {
wchar_t token_stop_char = char_after_dollar;
// Unescape (see issue #50).
if (token_stop_char == ANY_CHAR)
token_stop_char = L'?';
else if (token_stop_char == ANY_STRING || token_stop_char == ANY_STRING_RECURSIVE)
token_stop_char = L'*';
// Determine which error message to use. The format string may not consume all the
// arguments we pass but that's harmless.
const wchar_t *error_fmt = error_format_for_character(token_stop_char);
append_syntax_error(errors, global_after_dollar_pos, error_fmt, token_stop_char);
break;
}
}
// We should have appended exactly one error.
assert(errors->size() == start_error_count + 1);
}
/// Detect cases like $(abc). Given an arg like foo(bar), let arg_src be foo and cmdsubst_src be
/// bar. If arg ends with VARIABLE_EXPAND, then report an error.
static parser_test_error_bits_t detect_dollar_cmdsub_errors(size_t arg_src_offset,
const wcstring &arg_src,
const wcstring &cmdsubst_src,
parse_error_list_t *out_errors) {
parser_test_error_bits_t result_bits = 0;
wcstring unescaped_arg_src;
if (!unescape_string(arg_src, &unescaped_arg_src, UNESCAPE_SPECIAL) ||
unescaped_arg_src.empty()) {
return result_bits;
}
wchar_t last = unescaped_arg_src.at(unescaped_arg_src.size() - 1);
if (last == VARIABLE_EXPAND) {
result_bits |= PARSER_TEST_ERROR;
if (out_errors != NULL) {
wcstring subcommand_first_token = tok_first(cmdsubst_src);
if (subcommand_first_token.empty()) {
// e.g. $(). Report somthing.
subcommand_first_token = L"...";
}
append_syntax_error(
out_errors,
arg_src_offset + arg_src.size() - 1, // global position of the dollar
ERROR_BAD_VAR_SUBCOMMAND1, truncate_string(subcommand_first_token).c_str());
}
}
return result_bits;
}
/// Test if this argument contains any errors. Detected errors include syntax errors in command
/// substitutions, improperly escaped characters and improper use of the variable expansion
/// operator.
parser_test_error_bits_t parse_util_detect_errors_in_argument(tnode_t<grammar::argument> node,
const wcstring &arg_src,
parse_error_list_t *out_errors) {
assert(node.has_source() && "argument has no source");
auto source_start = node.source_range()->start;
int err = 0;
wchar_t *paran_begin, *paran_end;
int do_loop = 1;
wcstring working_copy = arg_src;
while (do_loop) {
const wchar_t *working_copy_cstr = working_copy.c_str();
switch (parse_util_locate_cmdsubst(working_copy_cstr, &paran_begin, &paran_end, false)) {
case -1: {
err = 1;
if (out_errors) {
append_syntax_error(out_errors, source_start, L"Mismatched parenthesis");
}
return err;
}
case 0: {
do_loop = 0;
break;
}
case 1: {
const wcstring subst(paran_begin + 1, paran_end);
// Replace the command substitution with just INTERNAL_SEPARATOR.
size_t cmd_sub_start = paran_begin - working_copy_cstr;
size_t cmd_sub_len = paran_end + 1 - paran_begin;
working_copy.replace(cmd_sub_start, cmd_sub_len, wcstring(1, INTERNAL_SEPARATOR));
parse_error_list_t subst_errors;
err |= parse_util_detect_errors(subst, &subst_errors,
false /* do not accept incomplete */);
// Our command substitution produced error offsets relative to its source. Tweak the
// offsets of the errors in the command substitution to account for both its offset
// within the string, and the offset of the node.
size_t error_offset = cmd_sub_start + 1 + source_start;
parse_error_offset_source_start(&subst_errors, error_offset);
if (out_errors != NULL) {
out_errors->insert(out_errors->end(), subst_errors.begin(), subst_errors.end());
// Hackish. Take this opportunity to report $(...) errors. We do this because
// after we've replaced with internal separators, we can't distinguish between
// "" and (), and also we no longer have the source of the command substitution.
// As an optimization, this is only necessary if the last character is a $.
if (cmd_sub_start > 0 && working_copy.at(cmd_sub_start - 1) == L'$') {
err |= detect_dollar_cmdsub_errors(
source_start, working_copy.substr(0, cmd_sub_start), subst, out_errors);
}
}
break;
}
default: {
DIE("unexpected parse_util_locate_cmdsubst() return value");
break;
}
}
}
wcstring unesc;
if (!unescape_string(working_copy, &unesc, UNESCAPE_SPECIAL)) {
if (out_errors) {
append_syntax_error(out_errors, source_start, L"Invalid token '%ls'",
working_copy.c_str());
}
return 1;
}
// Check for invalid variable expansions.
const size_t unesc_size = unesc.size();
for (size_t idx = 0; idx < unesc_size; idx++) {
if (unesc.at(idx) != VARIABLE_EXPAND && unesc.at(idx) != VARIABLE_EXPAND_SINGLE) {
continue;
}
wchar_t next_char = idx + 1 < unesc_size ? unesc.at(idx + 1) : L'\0';
if (next_char != VARIABLE_EXPAND && next_char != VARIABLE_EXPAND_SINGLE &&
!valid_var_name_char(next_char)) {
err = 1;
if (out_errors) {
// We have something like $$$^.... Back up until we reach the first $.
size_t first_dollar = idx;
while (first_dollar > 0 && (unesc.at(first_dollar - 1) == VARIABLE_EXPAND ||
unesc.at(first_dollar - 1) == VARIABLE_EXPAND_SINGLE)) {
first_dollar--;
}
parse_util_expand_variable_error(unesc, source_start, first_dollar, out_errors);
}
}
}
return err;
}
/// Given that the job given by node should be backgrounded, return true if we detect any errors.
static bool detect_errors_in_backgrounded_job(tnode_t<grammar::job> job,
parse_error_list_t *parse_errors) {
namespace g = grammar;
auto source_range = job.source_range();
if (!source_range) return false;
bool errored = false;
// Disallow background in the following cases:
// foo & ; and bar
// foo & ; or bar
// if foo & ; end
// while foo & ; end
auto job_conj = job.try_get_parent<g::job_conjunction>();
if (job_conj.try_get_parent<g::if_clause>()) {
errored = append_syntax_error(parse_errors, source_range->start,
BACKGROUND_IN_CONDITIONAL_ERROR_MSG);
} else if (job_conj.try_get_parent<g::while_header>()) {
errored = append_syntax_error(parse_errors, source_range->start,
BACKGROUND_IN_CONDITIONAL_ERROR_MSG);
} else if (auto jlist = job_conj.try_get_parent<g::job_list>()) {
// This isn't very complete, e.g. we don't catch 'foo & ; not and bar'.
// Fetch the job list and then advance it by one.
auto first_jconj = jlist.next_in_list<g::job_conjunction>();
assert(first_jconj == job.try_get_parent<g::job_conjunction>() &&
"Expected first job to be the node we found");
(void)first_jconj;
// Try getting the next job's decorator.
if (auto next_job_dec = jlist.next_in_list<g::job_decorator>()) {
// The next job is indeed a boolean statement.
parse_bool_statement_type_t bool_type = bool_statement_type(next_job_dec);
if (bool_type == parse_bool_and) {
errored = append_syntax_error(parse_errors, next_job_dec.source_range()->start,
BOOL_AFTER_BACKGROUND_ERROR_MSG, L"and");
} else if (bool_type == parse_bool_or) {
errored = append_syntax_error(parse_errors, next_job_dec.source_range()->start,
BOOL_AFTER_BACKGROUND_ERROR_MSG, L"or");
}
}
}
return errored;
}
static bool detect_errors_in_plain_statement(const wcstring &buff_src,
const parse_node_tree_t &node_tree,
tnode_t<grammar::plain_statement> pst,
parse_error_list_t *parse_errors) {
using namespace grammar;
bool errored = false;
auto source_start = pst.source_range()->start;
// In a few places below, we want to know if we are in a pipeline.
tnode_t<statement> st = pst.try_get_parent<decorated_statement>().try_get_parent<statement>();
pipeline_position_t pipe_pos = get_pipeline_position(st);
bool is_in_pipeline = (pipe_pos != pipeline_position_t::none);
// We need to know the decoration.
const enum parse_statement_decoration_t decoration = get_decoration(pst);
// Check that we don't try to pipe through exec.
if (is_in_pipeline && decoration == parse_statement_decoration_exec) {
errored = append_syntax_error(parse_errors, source_start, EXEC_ERR_MSG, L"exec");
}
// This is a somewhat stale check that 'and' and 'or' are not in pipelines, except at the
// beginning. We can't disallow them as commands entirely because we need to support 'and
// --help', etc.
if (pipe_pos == pipeline_position_t::subsequent) {
// check if our command is 'and' or 'or'. This is very clumsy; we don't catch e.g. quoted
// commands.
wcstring command = pst.child<0>().get_source(buff_src);
if (command == L"and" || command == L"or") {
errored =
append_syntax_error(parse_errors, source_start, EXEC_ERR_MSG, command.c_str());
}
}
if (maybe_t<wcstring> unexp_command = command_for_plain_statement(pst, buff_src)) {
wcstring command;
// Check that we can expand the command.
if (expand_to_command_and_args(*unexp_command, null_environment_t{}, &command, nullptr,
parse_errors) == expand_result_t::error) {
errored = true;
parse_error_offset_source_start(parse_errors, source_start);
}
// Check that pipes are sound.
if (!errored && parser_is_pipe_forbidden(command) && is_in_pipeline) {
errored =
append_syntax_error(parse_errors, source_start, EXEC_ERR_MSG, command.c_str());
}
// Check that we don't return from outside a function. But we allow it if it's
// 'return --help'.
if (!errored && command == L"return") {
bool found_function = false;
for (const parse_node_t *ancestor = pst.node(); ancestor != nullptr;
ancestor = node_tree.get_parent(*ancestor)) {
auto fh = tnode_t<block_statement>::try_create(&node_tree, ancestor)
.child<0>()
.try_get_child<function_header, 0>();
if (fh) {
found_function = true;
break;
}
}
if (!found_function && !first_argument_is_help(pst, buff_src)) {
errored = append_syntax_error(parse_errors, source_start, INVALID_RETURN_ERR_MSG);
}
}
// Check that we don't break or continue from outside a loop.
if (!errored && (command == L"break" || command == L"continue")) {
// Walk up until we hit a 'for' or 'while' loop. If we hit a function first,
// stop the search; we can't break an outer loop from inside a function.
// This is a little funny because we can't tell if it's a 'for' or 'while'
// loop from the ancestor alone; we need the header. That is, we hit a
// block_statement, and have to check its header.
bool found_loop = false;
for (const parse_node_t *ancestor = pst.node(); ancestor != nullptr;
ancestor = node_tree.get_parent(*ancestor)) {
tnode_t<block_header> bh =
tnode_t<block_statement>::try_create(&node_tree, ancestor).child<0>();
if (bh.try_get_child<while_header, 0>() || bh.try_get_child<for_header, 0>()) {
// This is a loop header, so we can break or continue.
found_loop = true;
break;
} else if (bh.try_get_child<function_header, 0>()) {
// This is a function header, so we cannot break or
// continue. We stop our search here.
found_loop = false;
break;
}
}
if (!found_loop && !first_argument_is_help(pst, buff_src)) {
errored = append_syntax_error(
parse_errors, source_start,
(command == L"break" ? INVALID_BREAK_ERR_MSG : INVALID_CONTINUE_ERR_MSG));
}
}
// Check that we don't do an invalid builtin (issue #1252).
if (!errored && decoration == parse_statement_decoration_builtin &&
expand_one(*unexp_command, expand_flag::skip_cmdsubst, null_environment_t{}, nullptr,
parse_errors) &&
!builtin_exists(*unexp_command)) {
errored = append_syntax_error(parse_errors, source_start, UNKNOWN_BUILTIN_ERR_MSG,
unexp_command->c_str());
}
}
return errored;
}
parser_test_error_bits_t parse_util_detect_errors(const wcstring &buff_src,
parse_error_list_t *out_errors,
bool allow_incomplete,
parsed_source_ref_t *out_pstree) {
namespace g = grammar;
parse_node_tree_t node_tree;
parse_error_list_t parse_errors;
parser_test_error_bits_t res = 0;
// Whether we encountered a parse error.
bool errored = false;
// Whether we encountered an unclosed block. We detect this via an 'end_command' block without
// source.
bool has_unclosed_block = false;
// Whether we encounter a missing statement, i.e. a newline after a pipe. This is found by
// detecting job_continuations that have source for pipes but not the statement.
bool has_unclosed_pipe = false;
// Whether there's an unclosed quote, and therefore unfinished. This is only set if
// allow_incomplete is set.
bool has_unclosed_quote = false;
// Parse the input string into a parse tree. Some errors are detected here.
bool parsed = parse_tree_from_string(
buff_src, allow_incomplete ? parse_flag_leave_unterminated : parse_flag_none, &node_tree,
&parse_errors);
if (allow_incomplete) {
size_t idx = parse_errors.size();
while (idx--) {
if (parse_errors.at(idx).code == parse_error_tokenizer_unterminated_quote) {
// Remove this error, since we don't consider it a real error.
has_unclosed_quote = true;
parse_errors.erase(parse_errors.begin() + idx);
}
}
}
// Issue #1238: If the only error was unterminated quote, then consider this to have parsed
// successfully. A better fix would be to have parse_tree_from_string return this information
// directly (but it would be a shame to munge up its nice bool return).
if (parse_errors.empty() && has_unclosed_quote) {
parsed = true;
}
if (!parsed) {
errored = true;
}
// has_unclosed_quote may only be set if allow_incomplete is true.
assert(!has_unclosed_quote || allow_incomplete);
// Expand all commands.
// Verify 'or' and 'and' not used inside pipelines.
// Verify pipes via parser_is_pipe_forbidden.
// Verify return only within a function.
// Verify no variable expansions.
if (!errored) {
for (const parse_node_t &node : node_tree) {
if (node.type == symbol_end_command && !node.has_source()) {
// An 'end' without source is an unclosed block.
has_unclosed_block = true;
} else if (node.type == symbol_statement && !node.has_source()) {
// Check for a statement without source in a pipeline, i.e. unterminated pipeline.
auto pipe_pos = get_pipeline_position({&node_tree, &node});
if (pipe_pos != pipeline_position_t::none) {
has_unclosed_pipe = true;
}
} else if (node.type == symbol_argument) {
tnode_t<g::argument> arg{&node_tree, &node};
const wcstring arg_src = node.get_source(buff_src);
res |= parse_util_detect_errors_in_argument(arg, arg_src, &parse_errors);
} else if (node.type == symbol_job) {
// Disallow background in the following cases:
//
// foo & ; and bar
// foo & ; or bar
// if foo & ; end
// while foo & ; end
// If it's not a background job, nothing to do.
auto job = tnode_t<g::job>{&node_tree, &node};
if (job_node_is_background(job)) {
errored |= detect_errors_in_backgrounded_job(job, &parse_errors);
}
} else if (node.type == symbol_arguments_or_redirections_list) {
// verify no arguments to the end command of if, switch, begin (#986).
auto list = tnode_t<g::arguments_or_redirections_list>{&node_tree, &node};
if (list.try_get_parent<g::if_statement>() ||
list.try_get_parent<g::switch_statement>() ||
list.try_get_parent<g::block_statement>()) {
if (auto arg = list.next_in_list<g::argument>()) {
errored = append_syntax_error(&parse_errors, arg.source_range()->start,
END_ARG_ERR_MSG);
}
}
} else if (node.type == symbol_plain_statement) {
tnode_t<grammar::plain_statement> pst{&node_tree, &node};
errored |=
detect_errors_in_plain_statement(buff_src, node_tree, pst, &parse_errors);
}
}
}
if (errored) res |= PARSER_TEST_ERROR;
if (has_unclosed_block || has_unclosed_quote || has_unclosed_pipe)
res |= PARSER_TEST_INCOMPLETE;
if (out_errors != NULL) {
*out_errors = std::move(parse_errors);
}
if (out_pstree != NULL) {
*out_pstree = std::make_shared<parsed_source_t>(buff_src, std::move(node_tree));
}
return res;
}
Reference in New Issue View Git Blame Copy Permalink