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authorBoris Kolpackov <boris@codesynthesis.com>2020-04-28 08:48:53 +0200
committerBoris Kolpackov <boris@codesynthesis.com>2020-05-27 15:47:28 +0200
commitb808c255b6a9ddba085bf5646e7d20ec344f2e2d (patch)
tree32730291f7e6de8ef0a227905520dd66fb4ec0f3 /libbuild2/script/parser.cxx
parent3552356a87402727e663131994fa87f48b3cd4fb (diff)
Initial support for ad hoc recipes (still work in progress)
Diffstat (limited to 'libbuild2/script/parser.cxx')
-rw-r--r--libbuild2/script/parser.cxx2015
1 files changed, 2015 insertions, 0 deletions
diff --git a/libbuild2/script/parser.cxx b/libbuild2/script/parser.cxx
new file mode 100644
index 0000000..aa60111
--- /dev/null
+++ b/libbuild2/script/parser.cxx
@@ -0,0 +1,2015 @@
+// file : libbuild2/script/parser.cxx -*- C++ -*-
+// license : MIT; see accompanying LICENSE file
+
+#include <libbuild2/script/parser.hxx>
+
+#include <libbuild2/variable.hxx>
+#include <libbuild2/script/run.hxx> // exit
+#include <libbuild2/script/lexer.hxx>
+
+using namespace std;
+
+namespace build2
+{
+ namespace script
+ {
+ using type = token_type;
+
+ value parser::
+ parse_variable_line (token& t, type& tt)
+ {
+ // enter: assignment
+ // leave: newline or unknown token
+
+ next_with_attributes (t, tt);
+
+ // Parse value attributes if any. Note that it's ok not to have
+ // anything after the attributes (e.g., foo=[null]).
+ //
+ attributes_push (t, tt, true);
+
+ // @@ PAT: Should we expand patterns? Note that it will only be
+ // simple ones since we have disabled {}. Also, what would be the
+ // pattern base directory?
+ //
+ return tt != type::newline && start_names (tt)
+ ? parse_value (t, tt,
+ pattern_mode::ignore,
+ "variable value",
+ nullptr)
+ : value (names ());
+ }
+
+ // Parse the regular expression representation (non-empty string value
+ // framed with introducer characters and optionally followed by flag
+ // characters from the {di} set, for example '/foo/id') into
+ // components. Also return end-of-parsing position if requested,
+ // otherwise treat any unparsed characters left as an error.
+ //
+ struct regex_parts
+ {
+ string value;
+ char intro;
+ string flags; // Combination of characters from {di} set.
+
+ // Create a special empty object.
+ //
+ regex_parts (): intro ('\0') {}
+
+ regex_parts (string v, char i, string f)
+ : value (move (v)), intro (i), flags (move (f)) {}
+ };
+
+ static regex_parts
+ parse_regex (const string& s,
+ const location& l,
+ const char* what,
+ size_t* end = nullptr)
+ {
+ if (s.empty ())
+ fail (l) << "no introducer character in " << what;
+
+ size_t p (s.find (s[0], 1)); // Find terminating introducer.
+
+ if (p == string::npos)
+ fail (l) << "no closing introducer character in " << what;
+
+ size_t rn (p - 1); // Regex length.
+ if (rn == 0)
+ fail (l) << what << " is empty";
+
+ // Find end-of-flags position.
+ //
+ size_t fp (++p); // Save flags starting position.
+ for (char c; (c = s[p]) == 'd' || c == 'i'; ++p) ;
+
+ // If string end is not reached then report invalid flags, unless
+ // end-of-parsing position is requested (which means regex is just a
+ // prefix).
+ //
+ if (s[p] != '\0' && end == nullptr)
+ fail (l) << "junk at the end of " << what;
+
+ if (end != nullptr)
+ *end = p;
+
+ return regex_parts (string (s, 1, rn), s[0], string (s, fp, p - fp));
+ }
+
+ pair<command_expr, parser::here_docs> parser::
+ parse_command_expr (token& t, type& tt,
+ const redirect_aliases& ra)
+ {
+ // enter: first token of the command line
+ // leave: <newline> or unknown token
+
+ command_expr expr;
+
+ // OR-ed to an implied false for the first term.
+ //
+ expr.push_back ({expr_operator::log_or, command_pipe ()});
+
+ command c; // Command being assembled.
+
+ // Make sure the command makes sense.
+ //
+ auto check_command = [&c, this] (const location& l, bool last)
+ {
+ if (c.out && c.out->type == redirect_type::merge &&
+ c.err && c.err->type == redirect_type::merge)
+ fail (l) << "stdout and stderr redirected to each other";
+
+ if (!last && c.out)
+ fail (l) << "stdout is both redirected and piped";
+ };
+
+ // Check that the introducer character differs from '/' if the
+ // portable path modifier is specified. Must be called before
+ // parse_regex() (see below) to make sure its diagnostics is
+ // meaningful.
+ //
+ // Note that the portable path modifier assumes '/' to be a valid
+ // regex character and so makes it indistinguishable from the
+ // terminating introducer.
+ //
+ auto check_regex_mod = [this] (const string& mod,
+ const string& re,
+ const location& l,
+ const char* what)
+ {
+ // Handles empty regex properly.
+ //
+ if (mod.find ('/') != string::npos && re[0] == '/')
+ fail (l) << "portable path modifier and '/' introducer in "
+ << what;
+ };
+
+ // Pending positions where the next word should go.
+ //
+ enum class pending
+ {
+ none,
+ program,
+ in_string,
+ in_document,
+ in_file,
+ out_merge,
+ out_string,
+ out_str_regex,
+ out_document,
+ out_doc_regex,
+ out_file,
+ err_merge,
+ err_string,
+ err_str_regex,
+ err_document,
+ err_doc_regex,
+ err_file,
+ clean
+ };
+ pending p (pending::program);
+ string mod; // Modifiers for pending in_* and out_* positions.
+ here_docs hd; // Expected here-documents.
+
+ // Add the next word to either one of the pending positions or to
+ // program arguments by default.
+ //
+ auto add_word = [&c, &p, &mod, &check_regex_mod, this] (
+ string&& w, const location& l)
+ {
+ auto add_merge = [&l, this] (optional<redirect>& r,
+ const string& w,
+ int fd)
+ {
+ assert (r); // Must already be present.
+
+ try
+ {
+ size_t n;
+ if (stoi (w, &n) == fd && n == w.size ())
+ {
+ r->fd = fd;
+ return;
+ }
+ }
+ catch (const exception&) {} // Fall through.
+
+ fail (l) << (fd == 1 ? "stderr" : "stdout") << " merge redirect "
+ << "file descriptor must be " << fd;
+ };
+
+ auto add_here_str = [] (optional<redirect>& r, string&& w)
+ {
+ assert (r); // Must already be present.
+
+ if (r->modifiers ().find (':') == string::npos)
+ w += '\n';
+ r->str = move (w);
+ };
+
+ auto add_here_str_regex = [&l, &check_regex_mod] (
+ optional<redirect>& r, int fd, string&& w)
+ {
+ assert (r); // Must already be present.
+
+ const char* what (nullptr);
+ switch (fd)
+ {
+ case 1: what = "stdout regex redirect"; break;
+ case 2: what = "stderr regex redirect"; break;
+ }
+
+ check_regex_mod (r->modifiers (), w, l, what);
+
+ regex_parts rp (parse_regex (w, l, what));
+
+ regex_lines& re (r->regex);
+ re.intro = rp.intro;
+
+ re.lines.emplace_back (
+ l.line, l.column, move (rp.value), move (rp.flags));
+
+ // Add final blank line unless suppressed.
+ //
+ // Note that the position is synthetic, but that's ok as we don't
+ // expect any diagnostics to refer this line.
+ //
+ if (r->modifiers ().find (':') == string::npos)
+ re.lines.emplace_back (l.line, l.column, string (), false);
+ };
+
+ auto parse_path = [&l, this] (string&& w, const char* what) -> path
+ {
+ try
+ {
+ path p (move (w));
+
+ if (!p.empty ())
+ {
+ p.normalize ();
+ return p;
+ }
+
+ fail (l) << "empty " << what << endf;
+ }
+ catch (const invalid_path& e)
+ {
+ fail (l) << "invalid " << what << " '" << e.path << "'" << endf;
+ }
+ };
+
+ auto add_file = [&parse_path] (optional<redirect>& r,
+ int fd,
+ string&& w)
+ {
+ assert (r); // Must already be present.
+
+ const char* what (nullptr);
+ switch (fd)
+ {
+ case 0: what = "stdin redirect path"; break;
+ case 1: what = "stdout redirect path"; break;
+ case 2: what = "stderr redirect path"; break;
+ }
+
+ r->file.path = parse_path (move (w), what);
+ };
+
+ switch (p)
+ {
+ case pending::none: c.arguments.push_back (move (w)); break;
+ case pending::program:
+ c.program = parse_path (move (w), "program path");
+ break;
+
+ case pending::out_merge: add_merge (c.out, w, 2); break;
+ case pending::err_merge: add_merge (c.err, w, 1); break;
+
+ case pending::in_string: add_here_str (c.in, move (w)); break;
+ case pending::out_string: add_here_str (c.out, move (w)); break;
+ case pending::err_string: add_here_str (c.err, move (w)); break;
+
+ case pending::out_str_regex:
+ {
+ add_here_str_regex (c.out, 1, move (w));
+ break;
+ }
+ case pending::err_str_regex:
+ {
+ add_here_str_regex (c.err, 2, move (w));
+ break;
+ }
+
+ // These are handled specially below.
+ //
+ case pending::in_document:
+ case pending::out_document:
+ case pending::err_document:
+ case pending::out_doc_regex:
+ case pending::err_doc_regex: assert (false); break;
+
+ case pending::in_file: add_file (c.in, 0, move (w)); break;
+ case pending::out_file: add_file (c.out, 1, move (w)); break;
+ case pending::err_file: add_file (c.err, 2, move (w)); break;
+
+ case pending::clean:
+ {
+ cleanup_type t;
+ switch (mod[0]) // Ok, if empty
+ {
+ case '!': t = cleanup_type::never; break;
+ case '?': t = cleanup_type::maybe; break;
+ default: t = cleanup_type::always; break;
+ }
+
+ c.cleanups.push_back (
+ {t, parse_path (move (w), "cleanup path")});
+ break;
+ }
+ }
+
+ p = pending::none;
+ mod.clear ();
+ };
+
+ // Make sure we don't have any pending positions to fill.
+ //
+ auto check_pending = [&p, this] (const location& l)
+ {
+ const char* what (nullptr);
+
+ switch (p)
+ {
+ case pending::none: break;
+ case pending::program: what = "program"; break;
+ case pending::in_string: what = "stdin here-string"; break;
+ case pending::in_document: what = "stdin here-document end"; break;
+ case pending::in_file: what = "stdin file"; break;
+ case pending::out_merge: what = "stdout file descriptor"; break;
+ case pending::out_string: what = "stdout here-string"; break;
+ case pending::out_document: what = "stdout here-document end"; break;
+ case pending::out_file: what = "stdout file"; break;
+ case pending::err_merge: what = "stderr file descriptor"; break;
+ case pending::err_string: what = "stderr here-string"; break;
+ case pending::err_document: what = "stderr here-document end"; break;
+ case pending::err_file: what = "stderr file"; break;
+ case pending::clean: what = "cleanup path"; break;
+
+ case pending::out_str_regex:
+ {
+ what = "stdout here-string regex";
+ break;
+ }
+ case pending::err_str_regex:
+ {
+ what = "stderr here-string regex";
+ break;
+ }
+ case pending::out_doc_regex:
+ {
+ what = "stdout here-document regex end";
+ break;
+ }
+ case pending::err_doc_regex:
+ {
+ what = "stderr here-document regex end";
+ break;
+ }
+ }
+
+ if (what != nullptr)
+ fail (l) << "missing " << what;
+ };
+
+ // Parse the redirect operator.
+ //
+ // If the token type is the redirect alias then tt must contain the type
+ // the alias resolves to and the token type otherwise. Note that this
+ // argument defines the redirect semantics. Also note that the token is
+ // saved into the redirect to keep the modifiers and the original
+ // representation.
+ //
+ auto parse_redirect = [&c, &expr, &p, &mod, &hd, this]
+ (token&& t, type tt, const location& l)
+ {
+ // The redirect alias token type must be resolved.
+ //
+ assert (tt != type::in_l &&
+ tt != type::in_ll &&
+ tt != type::in_lll &&
+ tt != type::out_g &&
+ tt != type::out_gg &&
+ tt != type::out_ggg);
+
+ // Our semantics is the last redirect seen takes effect.
+ //
+ assert (p == pending::none && mod.empty ());
+
+ // See if we have the file descriptor.
+ //
+ unsigned long fd (3);
+ if (!t.separated)
+ {
+ if (c.arguments.empty ())
+ fail (l) << "missing redirect file descriptor";
+
+ const string& s (c.arguments.back ());
+
+ try
+ {
+ size_t n;
+ fd = stoul (s, &n);
+
+ if (n != s.size () || fd > 2)
+ throw invalid_argument (string ());
+ }
+ catch (const exception&)
+ {
+ fail (l) << "invalid redirect file descriptor '" << s << "'";
+ }
+
+ c.arguments.pop_back ();
+ }
+
+ // Validate/set default file descriptor.
+ //
+ switch (tt)
+ {
+ case type::in_pass:
+ case type::in_null:
+ case type::in_str:
+ case type::in_doc:
+ case type::in_file:
+ {
+ if ((fd = fd == 3 ? 0 : fd) != 0)
+ fail (l) << "invalid in redirect file descriptor " << fd;
+
+ if (!expr.back ().pipe.empty ())
+ fail (l) << "stdin is both piped and redirected";
+
+ break;
+ }
+ case type::out_pass:
+ case type::out_null:
+ case type::out_trace:
+ case type::out_merge:
+ case type::out_str:
+ case type::out_doc:
+ case type::out_file_cmp:
+ case type::out_file_ovr:
+ case type::out_file_app:
+ {
+ if ((fd = fd == 3 ? 1 : fd) == 0)
+ fail (l) << "invalid out redirect file descriptor " << fd;
+
+ break;
+ }
+ }
+
+ // Don't move as we will save the token into the redirect object.
+ //
+ mod = t.value;
+
+ // Handle the none redirect (no data allowed) in the switch construct
+ // if/when the respective syntax is invented.
+ //
+ redirect_type rt (redirect_type::none);
+ switch (tt)
+ {
+ case type::in_pass:
+ case type::out_pass: rt = redirect_type::pass; break;
+
+ case type::in_null:
+ case type::out_null: rt = redirect_type::null; break;
+
+ case type::out_trace: rt = redirect_type::trace; break;
+
+ case type::out_merge: rt = redirect_type::merge; break;
+
+ case type::in_str:
+ case type::out_str:
+ {
+ bool re (mod.find ('~') != string::npos);
+ assert (tt == type::out_str || !re);
+
+ rt = re
+ ? redirect_type::here_str_regex
+ : redirect_type::here_str_literal;
+
+ break;
+ }
+
+ case type::in_doc:
+ case type::out_doc:
+ {
+ bool re (mod.find ('~') != string::npos);
+ assert (tt == type::out_doc || !re);
+
+ rt = re
+ ? redirect_type::here_doc_regex
+ : redirect_type::here_doc_literal;
+
+ break;
+ }
+
+ case type::in_file:
+ case type::out_file_cmp:
+ case type::out_file_ovr:
+ case type::out_file_app: rt = redirect_type::file; break;
+ }
+
+ optional<redirect>& r (fd == 0 ? c.in :
+ fd == 1 ? c.out :
+ c.err);
+
+ optional<redirect_type> overriden;
+
+ if (r)
+ overriden = r->type;
+
+ r = redirect (rt);
+
+ // Don't move as still may be used for pending here-document end
+ // marker processing.
+ //
+ r->token = move (t);
+
+ switch (rt)
+ {
+ case redirect_type::none:
+ // Remove the assertion if/when the none redirect syntax is
+ // invented.
+ //
+ assert (false);
+ // Fall through.
+ case redirect_type::pass:
+ case redirect_type::null:
+ case redirect_type::trace:
+ break;
+ case redirect_type::merge:
+ switch (fd)
+ {
+ case 0: assert (false); break;
+ case 1: p = pending::out_merge; break;
+ case 2: p = pending::err_merge; break;
+ }
+ break;
+ case redirect_type::here_str_literal:
+ switch (fd)
+ {
+ case 0: p = pending::in_string; break;
+ case 1: p = pending::out_string; break;
+ case 2: p = pending::err_string; break;
+ }
+ break;
+ case redirect_type::here_str_regex:
+ switch (fd)
+ {
+ case 0: assert (false); break;
+ case 1: p = pending::out_str_regex; break;
+ case 2: p = pending::err_str_regex; break;
+ }
+ break;
+ case redirect_type::here_doc_literal:
+ switch (fd)
+ {
+ case 0: p = pending::in_document; break;
+ case 1: p = pending::out_document; break;
+ case 2: p = pending::err_document; break;
+ }
+ break;
+ case redirect_type::here_doc_regex:
+ switch (fd)
+ {
+ case 0: assert (false); break;
+ case 1: p = pending::out_doc_regex; break;
+ case 2: p = pending::err_doc_regex; break;
+ }
+ break;
+ case redirect_type::file:
+ switch (fd)
+ {
+ case 0: p = pending::in_file; break;
+ case 1: p = pending::out_file; break;
+ case 2: p = pending::err_file; break;
+ }
+
+ // Also sets for stdin, but this is harmless.
+ //
+ r->file.mode = tt == type::out_file_ovr ? redirect_fmode::overwrite :
+ tt == type::out_file_app ? redirect_fmode::append :
+ redirect_fmode::compare;
+
+ break;
+
+ case redirect_type::here_doc_ref: assert (false); break;
+ }
+
+ // If we are overriding a here-document, then remove the reference
+ // to this command redirect from the corresponding here_doc object.
+ //
+ if (!pre_parse_ &&
+ overriden &&
+ (*overriden == redirect_type::here_doc_literal ||
+ *overriden == redirect_type::here_doc_regex))
+ {
+ size_t e (expr.size () - 1);
+ size_t p (expr.back ().pipe.size ());
+ int f (static_cast<int> (fd));
+
+ for (here_doc& d: hd)
+ {
+ small_vector<here_redirect, 2>& rs (d.redirects);
+
+ auto i (find_if (rs.begin (), rs.end (),
+ [e, p, f] (const here_redirect& r)
+ {
+ return r.expr == e &&
+ r.pipe == p &&
+ r.fd == f;
+ }));
+
+ if (i != rs.end ())
+ {
+ rs.erase (i);
+ break;
+ }
+ }
+ }
+ };
+
+ // Set pending cleanup type.
+ //
+ auto parse_clean = [&p, &mod] (token& t)
+ {
+ p = pending::clean;
+ mod = move (t.value);
+ };
+
+ const location ll (get_location (t)); // Line location.
+
+ // Keep parsing chunks of the command line until we see one of the
+ // "terminators" (newline, exit status comparison, etc).
+ //
+ location l (ll);
+ names ns; // Reuse to reduce allocations.
+
+ for (bool done (false); !done; l = get_location (t))
+ {
+ tt = ra.resolve (tt);
+
+ switch (tt)
+ {
+ case type::newline:
+ {
+ done = true;
+ break;
+ }
+
+ case type::equal:
+ case type::not_equal:
+ {
+ if (!pre_parse_)
+ check_pending (l);
+
+ c.exit = parse_command_exit (t, tt);
+
+ // Only a limited set of things can appear after the exit status
+ // so we check this here.
+ //
+ switch (tt)
+ {
+ case type::newline:
+
+ case type::pipe:
+ case type::log_or:
+ case type::log_and:
+ break;
+
+ default:
+ {
+ // Bail out if this is one of the unknown/unexpected tokens.
+ //
+ done = true;
+ break;
+ }
+ }
+
+ break;
+ }
+
+ case type::pipe:
+ case type::log_or:
+ case type::log_and:
+
+ case type::in_pass:
+ case type::out_pass:
+
+ case type::in_null:
+ case type::out_null:
+
+ case type::out_trace:
+
+ case type::out_merge:
+
+ case type::in_str:
+ case type::in_doc:
+ case type::out_str:
+ case type::out_doc:
+
+ case type::in_file:
+ case type::out_file_cmp:
+ case type::out_file_ovr:
+ case type::out_file_app:
+
+ case type::clean:
+ {
+ if (pre_parse_)
+ {
+ // The only things we need to handle here are the here-document
+ // and here-document regex end markers since we need to know
+ // how many of them to pre-parse after the command.
+ //
+ switch (tt)
+ {
+ case type::in_doc:
+ case type::out_doc:
+ mod = move (t.value);
+
+ bool re (mod.find ('~') != string::npos);
+ const char* what (re
+ ? "here-document regex end marker"
+ : "here-document end marker");
+
+ // We require the end marker to be a literal, unquoted word.
+ // In particularm, we don't allow quoted because of cases
+ // like foo"$bar" (where we will see word 'foo').
+ //
+ next (t, tt);
+
+ // We require the end marker to be an unquoted or completely
+ // quoted word. The complete quoting becomes important for
+ // cases like foo"$bar" (where we will see word 'foo').
+ //
+ // For good measure we could have also required it to be
+ // separated from the following token, but out grammar
+ // allows one to write >>EOO;. The problematic sequence
+ // would be >>FOO$bar -- on reparse it will be expanded
+ // as a single word.
+ //
+ if (tt != type::word || t.value.empty ())
+ fail (t) << "expected " << what;
+
+ peek ();
+ const token& p (peeked ());
+ if (!p.separated)
+ {
+ switch (p.type)
+ {
+ case type::dollar:
+ case type::lparen:
+ fail (p) << what << " must be literal";
+ }
+ }
+
+ quote_type qt (t.qtype);
+ switch (qt)
+ {
+ case quote_type::unquoted:
+ qt = quote_type::single; // Treat as single-quoted.
+ break;
+ case quote_type::single:
+ case quote_type::double_:
+ if (t.qcomp)
+ break;
+ // Fall through.
+ case quote_type::mixed:
+ fail (t) << "partially-quoted " << what;
+ }
+
+ regex_parts r;
+ string end (move (t.value));
+
+ if (re)
+ {
+ check_regex_mod (mod, end, l, what);
+
+ r = parse_regex (end, l, what);
+ end = move (r.value); // The "cleared" end marker.
+ }
+
+ bool literal (qt == quote_type::single);
+ bool shared (false);
+
+ for (const auto& d: hd)
+ {
+ if (d.end == end)
+ {
+ auto check = [&t, &end, &re, this] (bool c,
+ const char* what)
+ {
+ if (!c)
+ fail (t) << "different " << what
+ << " for shared here-document "
+ << (re ? "regex '" : "'") << end << "'";
+ };
+
+ check (d.modifiers == mod, "modifiers");
+ check (d.literal == literal, "quoting");
+
+ if (re)
+ {
+ check (d.regex == r.intro, "introducers");
+ check (d.regex_flags == r.flags, "global flags");
+ }
+
+ shared = true;
+ break;
+ }
+ }
+
+ if (!shared)
+ hd.push_back (
+ here_doc {
+ {},
+ move (end),
+ literal,
+ move (mod),
+ r.intro, move (r.flags)});
+
+ break;
+ }
+
+ next (t, tt);
+ break;
+ }
+
+ // If this is one of the operators/separators, check that we
+ // don't have any pending locations to be filled.
+ //
+ check_pending (l);
+
+ // Note: there is another one in the inner loop below.
+ //
+ switch (tt)
+ {
+ case type::pipe:
+ case type::log_or:
+ case type::log_and:
+ {
+ // Check that the previous command makes sense.
+ //
+ check_command (l, tt != type::pipe);
+ expr.back ().pipe.push_back (move (c));
+
+ c = command ();
+ p = pending::program;
+
+ if (tt != type::pipe)
+ {
+ expr_operator o (tt == type::log_or
+ ? expr_operator::log_or
+ : expr_operator::log_and);
+ expr.push_back ({o, command_pipe ()});
+ }
+
+ break;
+ }
+
+ case type::in_pass:
+ case type::out_pass:
+
+ case type::in_null:
+ case type::out_null:
+
+ case type::out_trace:
+
+ case type::out_merge:
+
+ case type::in_str:
+ case type::in_doc:
+ case type::out_str:
+ case type::out_doc:
+
+ case type::in_file:
+ case type::out_file_cmp:
+ case type::out_file_ovr:
+ case type::out_file_app:
+ {
+ parse_redirect (move (t), tt, l);
+ break;
+ }
+
+ case type::clean:
+ {
+ parse_clean (t);
+ break;
+ }
+
+ default: assert (false); break;
+ }
+
+ next (t, tt);
+ break;
+ }
+ default:
+ {
+ // Bail out if this is one of the unknown tokens.
+ //
+ if (!start_names (tt))
+ {
+ done = true;
+ break;
+ }
+
+ // Here-document end markers are literal (we verified that above
+ // during pre-parsing) and we need to know whether they were
+ // quoted. So handle this case specially.
+ //
+ {
+ int fd;
+ switch (p)
+ {
+ case pending::in_document: fd = 0; break;
+ case pending::out_document:
+ case pending::out_doc_regex: fd = 1; break;
+ case pending::err_document:
+ case pending::err_doc_regex: fd = 2; break;
+ default: fd = -1; break;
+ }
+
+ if (fd != -1)
+ {
+ if (tt != type::word || t.value.empty ())
+ fail (t) << "expected here-document end marker";
+
+ here_redirect rd {
+ expr.size () - 1, expr.back ().pipe.size (), fd};
+
+ string end (move (t.value));
+
+ regex_parts r;
+
+ if (p == pending::out_doc_regex ||
+ p == pending::err_doc_regex)
+ {
+ // We can't fail here as we already parsed all the end
+ // markers during pre-parsing stage, and so no need in the
+ // description.
+ //
+ r = parse_regex (end, l, "");
+ end = move (r.value); // The "cleared" end marker.
+ }
+
+ bool shared (false);
+ for (auto& d: hd)
+ {
+ // No need to check that redirects that share here-document
+ // have the same modifiers, etc. That have been done during
+ // pre-parsing.
+ //
+ if (d.end == end)
+ {
+ d.redirects.emplace_back (rd);
+ shared = true;
+ break;
+ }
+ }
+
+ if (!shared)
+ hd.push_back (
+ here_doc {
+ {rd},
+ move (end),
+ (t.qtype == quote_type::unquoted ||
+ t.qtype == quote_type::single),
+ move (mod),
+ r.intro, move (r.flags)});
+
+ p = pending::none;
+ mod.clear ();
+
+ next (t, tt);
+ break;
+ }
+ }
+
+ // Parse the next chunk as simple names to get expansion, etc.
+ // Note that we do it in the chunking mode to detect whether
+ // anything in each chunk is quoted.
+ //
+ // @@ PAT: should we support pattern expansion? This is even
+ // fuzzier than the variable case above. Though this is the
+ // shell semantics. Think what happens when we do rm *.txt?
+ //
+ reset_quoted (t);
+ parse_names (t, tt,
+ ns,
+ pattern_mode::ignore,
+ true,
+ "command line",
+ nullptr);
+
+ if (pre_parse_) // Nothing else to do if we are pre-parsing.
+ break;
+
+ // Process what we got. Determine whether anything inside was
+ // quoted (note that the current token is "next" and is not part
+ // of this).
+ //
+ bool q ((quoted () -
+ (t.qtype != quote_type::unquoted ? 1 : 0)) != 0);
+
+ for (name& n: ns)
+ {
+ string s;
+
+ try
+ {
+ s = value_traits<string>::convert (move (n), nullptr);
+ }
+ catch (const invalid_argument&)
+ {
+ diag_record dr (fail (l));
+ dr << "invalid string value ";
+ to_stream (dr.os, n, true); // Quote.
+ }
+
+ // If it is a quoted chunk, then we add the word as is.
+ // Otherwise we re-lex it. But if the word doesn't contain any
+ // interesting characters (operators plus quotes/escapes),
+ // then no need to re-lex.
+ //
+ // NOTE: update quoting (script.cxx:to_stream_q()) if adding
+ // any new characters.
+ //
+ if (q || s.find_first_of ("|&<>\'\"\\") == string::npos)
+ add_word (move (s), l);
+ else
+ {
+ // If the chunk re-parsing results in error, our diagnostics
+ // will look like this:
+ //
+ // <string>:1:4: error: stdout merge redirect file descriptor must be 2
+ // script:2:5: info: while parsing string '1>&a'
+ //
+ auto df = make_diag_frame (
+ [this, s, &l](const diag_record& dr)
+ {
+ dr << info (l) << "while parsing string '" << s << "'";
+ });
+
+ // When re-lexing we do "effective escaping" and only for
+ // ['"\] (quotes plus the backslash itself). In particular,
+ // there is no way to escape redirects, operators, etc. The
+ // idea is to prefer quoting except for passing literal
+ // quotes, for example:
+ //
+ // args = \"&foo\"
+ // cmd $args # cmd &foo
+ //
+ // args = 'x=\"foo bar\"'
+ // cmd $args # cmd x="foo bar"
+ //
+ istringstream is (s);
+ path_name in ("<string>");
+ lexer lex (is, in,
+ lexer_mode::command_expansion,
+ ra,
+ "\'\"\\");
+
+ // Treat the first "sub-token" as always separated from what
+ // we saw earlier.
+ //
+ // Note that this is not "our" token so we cannot do
+ // fail(t). Rather we should do fail(l).
+ //
+ token t (lex.next ());
+ location l (build2::get_location (t, in));
+ t.separated = true;
+
+ string w;
+ bool f (t.type == type::eos); // If the whole thing is empty.
+
+ for (; t.type != type::eos; t = lex.next ())
+ {
+ type tt (ra.resolve (t.type));
+ l = build2::get_location (t, in);
+
+ // Re-lexing double-quotes will recognize $, ( inside as
+ // tokens so we have to reverse them back. Since we don't
+ // treat spaces as separators we can be sure we will get
+ // it right.
+ //
+ switch (tt)
+ {
+ case type::dollar: w += '$'; continue;
+ case type::lparen: w += '('; continue;
+ }
+
+ // Retire the current word. We need to distinguish between
+ // empty and non-existent (e.g., > vs >"").
+ //
+ if (!w.empty () || f)
+ {
+ add_word (move (w), l);
+ f = false;
+ }
+
+ if (tt == type::word)
+ {
+ w = move (t.value);
+ f = true;
+ continue;
+ }
+
+ // If this is one of the operators/separators, check that
+ // we don't have any pending locations to be filled.
+ //
+ check_pending (l);
+
+ // Note: there is another one in the outer loop above.
+ //
+ switch (tt)
+ {
+ case type::pipe:
+ case type::log_or:
+ case type::log_and:
+ {
+ // Check that the previous command makes sense.
+ //
+ check_command (l, tt != type::pipe);
+ expr.back ().pipe.push_back (move (c));
+
+ c = command ();
+ p = pending::program;
+
+ if (tt != type::pipe)
+ {
+ expr_operator o (tt == type::log_or
+ ? expr_operator::log_or
+ : expr_operator::log_and);
+ expr.push_back ({o, command_pipe ()});
+ }
+
+ break;
+ }
+
+ case type::in_pass:
+ case type::out_pass:
+
+ case type::in_null:
+ case type::out_null:
+
+ case type::out_trace:
+
+ case type::out_merge:
+
+ case type::in_str:
+ case type::out_str:
+
+ case type::in_file:
+ case type::out_file_cmp:
+ case type::out_file_ovr:
+ case type::out_file_app:
+ {
+ parse_redirect (move (t), tt, l);
+ break;
+ }
+
+ case type::clean:
+ {
+ parse_clean (t);
+ break;
+ }
+
+ case type::in_doc:
+ case type::out_doc:
+ {
+ fail (l) << "here-document redirect in expansion";
+ break;
+ }
+ }
+ }
+
+ // Don't forget the last word.
+ //
+ if (!w.empty () || f)
+ add_word (move (w), l);
+ }
+ }
+
+ ns.clear ();
+ break;
+ }
+ }
+ }
+
+ if (!pre_parse_)
+ {
+ // Verify we don't have anything pending to be filled and the
+ // command makes sense.
+ //
+ check_pending (l);
+ check_command (l, true);
+
+ expr.back ().pipe.push_back (move (c));
+ }
+
+ return make_pair (move (expr), move (hd));
+ }
+
+ command_exit parser::
+ parse_command_exit (token& t, type& tt)
+ {
+ // enter: equal/not_equal
+ // leave: token after exit status (one parse_names() chunk)
+
+ exit_comparison comp (tt == type::equal
+ ? exit_comparison::eq
+ : exit_comparison::ne);
+
+ // The next chunk should be the exit status.
+ //
+ next (t, tt);
+ location l (get_location (t));
+ names ns (parse_names (t, tt,
+ pattern_mode::ignore,
+ true,
+ "exit status",
+ nullptr));
+ unsigned long es (256);
+
+ if (!pre_parse_)
+ {
+ try
+ {
+ if (ns.size () == 1 && ns[0].simple () && !ns[0].empty ())
+ es = stoul (ns[0].value);
+ }
+ catch (const exception&) {} // Fall through.
+
+ if (es > 255)
+ {
+ diag_record dr;
+
+ dr << fail (l) << "expected exit status instead of ";
+ to_stream (dr.os, ns, true); // Quote.
+
+ dr << info << "exit status is an unsigned integer less than 256";
+ }
+ }
+
+ return command_exit {comp, static_cast<uint8_t> (es)};
+ }
+
+ void parser::
+ parse_here_documents (token& t, type& tt,
+ pair<command_expr, here_docs>& p)
+ {
+ // enter: newline
+ // leave: newline
+
+ // Parse here-document fragments in the order they were mentioned on
+ // the command line.
+ //
+ for (here_doc& h: p.second)
+ {
+ // Switch to the here-line mode which is like single/double-quoted
+ // string but recognized the newline as a separator.
+ //
+ mode (h.literal
+ ? lexer_mode::here_line_single
+ : lexer_mode::here_line_double);
+ next (t, tt);
+
+ parsed_doc v (
+ parse_here_document (t, tt, h.end, h.modifiers, h.regex));
+
+ // If all the here-document redirects are overridden, then we just
+ // drop the fragment.
+ //
+ if (!pre_parse_ && !h.redirects.empty ())
+ {
+ auto i (h.redirects.cbegin ());
+
+ command& c (p.first[i->expr].pipe[i->pipe]);
+
+ optional<redirect>& r (i->fd == 0 ? c.in :
+ i->fd == 1 ? c.out :
+ c.err);
+
+ assert (r); // Must be present since it is referred.
+
+ if (v.re)
+ {
+ assert (r->type == redirect_type::here_doc_regex);
+
+ r->regex = move (v.regex);
+ r->regex.flags = move (h.regex_flags);
+ }
+ else
+ {
+ assert (r->type == redirect_type::here_doc_literal);
+
+ r->str = move (v.str);
+ }
+
+ r->end = move (h.end);
+ r->end_line = v.end_line;
+ r->end_column = v.end_column;
+
+ // Note that our references cannot be invalidated because the
+ // command_expr/command-pipe vectors already contain all their
+ // elements.
+ //
+ for (++i; i != h.redirects.cend (); ++i)
+ {
+ command& c (p.first[i->expr].pipe[i->pipe]);
+
+ optional<redirect>& ir (i->fd == 0 ? c.in :
+ i->fd == 1 ? c.out :
+ c.err);
+
+ // Must be present since it is referenced by here-doc.
+ //
+ assert (ir);
+
+ // Note: preserve the original representation.
+ //
+ ir = redirect (redirect_type::here_doc_ref, *r, move (ir->token));
+ }
+ }
+
+ expire_mode ();
+ }
+ }
+
+ parser::parsed_doc parser::
+ parse_here_document (token& t, type& tt,
+ const string& em,
+ const string& mod,
+ char re)
+ {
+ // enter: first token on first line
+ // leave: newline (after end marker)
+
+ // String literal. Note that when decide if to terminate the previously
+ // added line with a newline, we need to distinguish a yet empty result
+ // and the one that has a single blank line added.
+ //
+ optional<string> rs;
+
+ regex_lines rre;
+
+ // Here-documents can be indented. The leading whitespaces of the end
+ // marker line (called strip prefix) determine the indentation. Every
+ // other line in the here-document should start with this prefix which
+ // is automatically stripped. The only exception is a blank line.
+ //
+ // The fact that the strip prefix is only known at the end, after
+ // seeing all the lines, is rather inconvenient. As a result, the way
+ // we implement this is a bit hackish (though there is also something
+ // elegant about it): at the end of the pre-parse stage we are going
+ // re-examine the sequence of tokens that comprise this here-document
+ // and "fix up" the first token of each line by stripping the prefix.
+ //
+ string sp;
+
+ // Remember the position of the first token in this here-document.
+ //
+ size_t ri (pre_parse_ ? replay_data_.size () - 1 : 0);
+
+ // We will use the location of the first token on the line for the
+ // regex diagnostics. At the end of the loop it will point to the
+ // beginning of the end marker.
+ //
+ location l;
+
+ while (tt != type::eos)
+ {
+ l = get_location (t);
+
+ // Check if this is the end marker. For starters, it should be a
+ // single, unquoted word followed by a newline.
+ //
+ if (tt == type::word &&
+ t.qtype == quote_type::unquoted &&
+ peek () == type::newline)
+ {
+ const string& v (t.value);
+
+ size_t vn (v.size ());
+ size_t en (em.size ());
+
+ // Then check that it ends with the end marker.
+ //
+ if (vn >= en && v.compare (vn - en, en, em) == 0)
+ {
+ // Now check that the prefix only contains whitespaces.
+ //
+ size_t n (vn - en);
+
+ if (v.find_first_not_of (" \t") >= n)
+ {
+ assert (pre_parse_ || n == 0); // Should have been stripped.
+
+ if (n != 0)
+ sp.assign (v, 0, n); // Save the strip prefix.
+
+ next (t, tt); // Get the newline.
+ break;
+ }
+ }
+ }
+
+ // Expand the line (can be blank).
+ //
+ // @@ PAT: one could argue that if we do it in variables, then we
+ // should do it here as well. Though feels bizarre.
+ //
+ names ns (tt != type::newline
+ ? parse_names (t, tt,
+ pattern_mode::ignore,
+ false,
+ "here-document line",
+ nullptr)
+ : names ());
+
+ if (!pre_parse_)
+ {
+ // What shall we do if the expansion results in multiple names?
+ // For, example if the line contains just the variable expansion
+ // and it is of type strings. Adding all the elements space-
+ // separated seems like the natural thing to do.
+ //
+ string s;
+ for (auto b (ns.begin ()), i (b); i != ns.end (); ++i)
+ {
+ string n;
+
+ try
+ {
+ n = value_traits<string>::convert (move (*i), nullptr);
+ }
+ catch (const invalid_argument&)
+ {
+ fail (l) << "invalid string value '" << *i << "'";
+ }
+
+ if (i == b)
+ s = move (n);
+ else
+ {
+ s += ' ';
+ s += n;
+ }
+ }
+
+ if (!re)
+ {
+ // Add newline after previous line.
+ //
+ if (rs)
+ {
+ *rs += '\n';
+ *rs += s;
+ }
+ else
+ rs = move (s);
+ }
+ else
+ {
+ // Due to expansion we can end up with multiple lines. If empty
+ // then will add a blank textual literal.
+ //
+ for (size_t p (0); p != string::npos; )
+ {
+ string ln;
+ size_t np (s.find ('\n', p));
+
+ if (np != string::npos)
+ {
+ ln = string (s, p, np - p);
+ p = np + 1;
+ }
+ else
+ {
+ ln = string (s, p);
+ p = np;
+ }
+
+ if (ln[0] != re) // Line doesn't start with regex introducer.
+ {
+ // This is a line-char literal (covers blank lines as well).
+ //
+ // Append textual literal.
+ //
+ rre.lines.emplace_back (l.line, l.column, move (ln), false);
+ }
+ else // Line starts with the regex introducer.
+ {
+ // This is a char-regex, or a sequence of line-regex syntax
+ // characters or both (in this specific order). So we will
+ // add regex (with optional special characters) or special
+ // literal.
+ //
+ size_t p (ln.find (re, 1));
+ if (p == string::npos)
+ {
+ // No regex, just a sequence of syntax characters.
+ //
+ string spec (ln, 1);
+ if (spec.empty ())
+ fail (l) << "no syntax line characters";
+
+ // Append special literal.
+ //
+ rre.lines.emplace_back (
+ l.line, l.column, move (spec), true);
+ }
+ else
+ {
+ // Regex (probably with syntax characters).
+ //
+ regex_parts re;
+
+ // Empty regex is a special case repesenting a blank line.
+ //
+ if (p == 1)
+ // Position to optional specal characters of an empty
+ // regex.
+ //
+ ++p;
+ else
+ // Can't fail as all the pre-conditions verified
+ // (non-empty with both introducers in place), so no
+ // description required.
+ //
+ re = parse_regex (ln, l, "", &p);
+
+ // Append regex with optional special characters.
+ //
+ rre.lines.emplace_back (l.line, l.column,
+ move (re.value), move (re.flags),
+ string (ln, p));
+ }
+ }
+ }
+ }
+ }
+
+ // We should expand the whole line at once so this would normally be
+ // a newline but can also be an end-of-stream.
+ //
+ if (tt == type::newline)
+ next (t, tt);
+ else
+ assert (tt == type::eos);
+ }
+
+ if (tt == type::eos)
+ fail (t) << "missing here-document end marker '" << em << "'";
+
+ if (pre_parse_)
+ {
+ // Strip the indentation prefix if there is one.
+ //
+ assert (replay_ == replay::save);
+
+ if (!sp.empty ())
+ {
+ size_t sn (sp.size ());
+
+ for (; ri != replay_data_.size (); ++ri)
+ {
+ token& rt (replay_data_[ri].token);
+
+ if (rt.type == type::newline) // Blank
+ continue;
+
+ if (rt.type != type::word || rt.value.compare (0, sn, sp) != 0)
+ fail (rt) << "unindented here-document line";
+
+ // If the word is equal to the strip prefix then we have to drop
+ // the token. Note that simply making it an empty word won't
+ // have the same semantics. For instance, it would trigger
+ // concatenated expansion.
+ //
+ if (rt.value.size () == sn)
+ replay_data_.erase (replay_data_.begin () + ri);
+ else
+ {
+ rt.value.erase (0, sn);
+ rt.column += sn;
+ ++ri;
+ }
+
+ // Skip until next newline.
+ //
+ for (; replay_data_[ri].token.type != type::newline; ++ri) ;
+ }
+ }
+ }
+ else
+ {
+ // Add final newline unless suppressed.
+ //
+ if (mod.find (':') == string::npos)
+ {
+ if (re)
+ // Note that the position is synthetic, but that's ok as we don't
+ // expect any diagnostics to refer this line.
+ //
+ rre.lines.emplace_back (l.line, l.column, string (), false);
+ else if (rs)
+ *rs += '\n';
+ else
+ rs = "\n";
+ }
+
+ // Finalize regex lines.
+ //
+ if (re)
+ {
+ // Empty regex matches nothing, so not of much use.
+ //
+ if (rre.lines.empty ())
+ fail (l) << "empty here-document regex";
+
+ rre.intro = re;
+ }
+ }
+
+ return re
+ ? parsed_doc (move (rre), l.line, l.column)
+ : parsed_doc (rs ? move (*rs) : string (), l.line, l.column);
+ }
+
+ size_t parser::
+ quoted () const
+ {
+ size_t r (0);
+
+ if (replay_ != replay::play)
+ r = lexer_->quoted ();
+ else
+ {
+ // Examine tokens we have replayed since last reset.
+ //
+ for (size_t i (replay_quoted_); i != replay_i_; ++i)
+ if (replay_data_[i].token.qtype != quote_type::unquoted)
+ ++r;
+ }
+
+ return r;
+ }
+
+ void parser::
+ reset_quoted (token& cur)
+ {
+ if (replay_ != replay::play)
+ lexer_->reset_quoted (cur.qtype != quote_type::unquoted ? 1 : 0);
+ else
+ {
+ replay_quoted_ = replay_i_ - 1;
+
+ // Must be the same token.
+ //
+ assert (replay_data_[replay_quoted_].token.qtype == cur.qtype);
+ }
+ }
+
+ void parser::
+ set_lexer (lexer* l)
+ {
+ lexer_ = l;
+ build2::parser::lexer_ = l;
+ }
+
+ static redirect_aliases no_redirect_aliases;
+
+ void parser::
+ apply_value_attributes (const variable* var,
+ value& lhs,
+ value&& rhs,
+ const string& attributes,
+ token_type kind,
+ const path_name& name)
+ {
+ path_ = &name;
+
+ istringstream is (attributes);
+
+ // Note that the redirect alias information is not used in the
+ // attributes lexer mode.
+ //
+ lexer l (is, name, lexer_mode::attributes, no_redirect_aliases);
+
+ set_lexer (&l);
+
+ token t;
+ type tt;
+
+ next_with_attributes (t, tt); // Enable `[` recognition.
+
+ if (tt != type::lsbrace && tt != type::eos)
+ fail (t) << "expected '[' instead of " << t;
+
+ attributes_push (t, tt, true);
+
+ if (tt != type::eos)
+ fail (t) << "trailing junk after ']'";
+
+ build2::parser::apply_value_attributes (var, lhs, move (rhs), kind);
+ }
+
+ line_type parser::
+ pre_parse_line_start (token& t, token_type& tt, lexer_mode stm)
+ {
+ replay_save (); // Start saving tokens from the current one.
+ next (t, tt);
+
+ // Decide whether this is a variable assignment or a command.
+ //
+ // It is an assignment if the first token is an unquoted name and
+ // the next token is an assign/append/prepend operator. Assignment
+ // to a computed variable name must use the set builtin.
+ //
+ // Note also that special commands take precedence over variable
+ // assignments.
+ //
+ line_type r (line_type::cmd); // Default.
+
+ if (tt == type::word && t.qtype == quote_type::unquoted)
+ {
+ const string& n (t.value);
+
+ if (n == "if") r = line_type::cmd_if;
+ else if (n == "if!") r = line_type::cmd_ifn;
+ else if (n == "elif") r = line_type::cmd_elif;
+ else if (n == "elif!") r = line_type::cmd_elifn;
+ else if (n == "else") r = line_type::cmd_else;
+ else if (n == "end") r = line_type::cmd_end;
+ else
+ {
+ // Switch the recognition of leading variable assignments for
+ // the next token. This is safe to do because we know we
+ // cannot be in the quoted mode (since the current token is
+ // not quoted).
+ //
+ type p (peek (stm));
+
+ if (p == type::assign || p == type::prepend || p == type::append)
+ {
+ r = line_type::var;
+
+ // Note that the missing command program is detected later, by
+ // parse_command_expr().
+ //
+ if (n.empty ())
+ fail (t) << "missing variable name";
+ }
+ }
+ }
+
+ return r;
+ }
+
+ bool parser::
+ exec_lines (lines::const_iterator i, lines::const_iterator e,
+ const function<exec_set_function>& exec_set,
+ const function<exec_cmd_function>& exec_cmd,
+ const function<exec_if_function>& exec_if,
+ size_t& li,
+ variable_pool* var_pool)
+ {
+ try
+ {
+ token t;
+ type tt;
+ for (; i != e; ++i)
+ {
+ const line& ln (*i);
+ line_type lt (ln.type);
+
+ assert (path_ == nullptr);
+
+ // Copy the tokens and start playing.
+ //
+ replay_data (replay_tokens (ln.tokens));
+
+ // We don't really need to change the mode since we already know
+ // the line type.
+ //
+ next (t, tt);
+ const location ll (get_location (t));
+
+ switch (lt)
+ {
+ case line_type::var:
+ {
+ // Enter the variable into the pool if this is not done during
+ // the script parsing. Note that in this case the pool is
+ // expected to be provided.
+ //
+ const variable* var (ln.var);
+
+ if (var == nullptr)
+ {
+ assert (var_pool != nullptr);
+
+ var = &var_pool->insert (t.value);
+ }
+
+ exec_set (*var, t, tt, ll);
+
+ replay_stop ();
+ break;
+ }
+ case line_type::cmd:
+ {
+ bool single (false);
+
+ if (li == 1)
+ {
+ lines::const_iterator j (i);
+ for (++j; j != e && j->type == line_type::var; ++j) ;
+
+ if (j == e) // We have no another command.
+ single = true;
+ }
+
+ exec_cmd (t, tt, li++, single, ll);
+
+ replay_stop ();
+ break;
+ }
+ case line_type::cmd_if:
+ case line_type::cmd_ifn:
+ case line_type::cmd_elif:
+ case line_type::cmd_elifn:
+ case line_type::cmd_else:
+ {
+ next (t, tt); // Skip to start of command.
+
+ bool take;
+ if (lt != line_type::cmd_else)
+ {
+ take = exec_if (t, tt, li++, ll);
+
+ if (lt == line_type::cmd_ifn || lt == line_type::cmd_elifn)
+ take = !take;
+ }
+ else
+ {
+ assert (tt == type::newline);
+ take = true;
+ }
+
+ replay_stop ();
+
+ // If end is true, then find the 'end' line. Otherwise, find
+ // the next if-else line. If skip is true then increment the
+ // command line index.
+ //
+ auto next = [e, &li] (lines::const_iterator j,
+ bool end,
+ bool skip) -> lines::const_iterator
+ {
+ // We need to be aware of nested if-else chains.
+ //
+ size_t n (0);
+
+ for (++j; j != e; ++j)
+ {
+ line_type lt (j->type);
+
+ if (lt == line_type::cmd_if || lt == line_type::cmd_ifn)
+ ++n;
+
+ // If we are nested then we just wait until we get back
+ // to the surface.
+ //
+ if (n == 0)
+ {
+ switch (lt)
+ {
+ case line_type::cmd_elif:
+ case line_type::cmd_elifn:
+ case line_type::cmd_else:
+ if (end) break;
+ // Fall through.
+ case line_type::cmd_end: return j;
+ default: break;
+ }
+ }
+
+ if (lt == line_type::cmd_end)
+ --n;
+
+ if (skip)
+ {
+ // Note that we don't count else and end as commands.
+ //
+ switch (lt)
+ {
+ case line_type::cmd:
+ case line_type::cmd_if:
+ case line_type::cmd_ifn:
+ case line_type::cmd_elif:
+ case line_type::cmd_elifn: ++li; break;
+ default: break;
+ }
+ }
+ }
+
+ assert (false); // Missing end.
+ return e;
+ };
+
+ // If we are taking this branch then we need to parse all the
+ // lines until the next if-else line and then skip all the
+ // lines until the end (unless next is already end).
+ //
+ // Otherwise, we need to skip all the lines until the next
+ // if-else line and then continue parsing.
+ //
+ if (take)
+ {
+ // Next if-else.
+ //
+ lines::const_iterator j (next (i, false, false));
+ if (!exec_lines (i + 1, j,
+ exec_set, exec_cmd, exec_if,
+ li,
+ var_pool))
+ return false;
+
+ i = j->type == line_type::cmd_end ? j : next (j, true, true);
+ }
+ else
+ {
+ i = next (i, false, true);
+ if (i->type != line_type::cmd_end)
+ --i; // Continue with this line (e.g., elif or else).
+ }
+
+ break;
+ }
+ case line_type::cmd_end:
+ {
+ assert (false);
+ }
+ }
+ }
+
+ return true;
+ }
+ catch (const exit& e)
+ {
+ // Bail out if the script is exited with the failure status. Otherwise
+ // exit the lines execution normally.
+ //
+ if (!e.status)
+ throw failed ();
+
+ replay_stop ();
+ return false;
+ }
+ }
+
+ // parser::parsed_doc
+ //
+ parser::parsed_doc::
+ parsed_doc (string s, uint64_t l, uint64_t c)
+ : str (move (s)), re (false), end_line (l), end_column (c)
+ {
+ }
+
+ parser::parsed_doc::
+ parsed_doc (regex_lines&& r, uint64_t l, uint64_t c)
+ : regex (move (r)), re (true), end_line (l), end_column (c)
+ {
+ }
+
+ parser::parsed_doc::
+ parsed_doc (parsed_doc&& d)
+ : re (d.re), end_line (d.end_line), end_column (d.end_column)
+ {
+ if (re)
+ new (&regex) regex_lines (move (d.regex));
+ else
+ new (&str) string (move (d.str));
+ }
+
+ parser::parsed_doc::
+ ~parsed_doc ()
+ {
+ if (re)
+ regex.~regex_lines ();
+ else
+ str.~string ();
+ }
+ }
+}