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/* This file is part of GCC.
GCC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.
GCC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
#include "rust-parse.h"
#include "rust-linemap.h"
#include "rust-diagnostics.h"
namespace Rust {
std::string
extract_module_path (const AST::AttrVec &inner_attrs,
const AST::AttrVec &outer_attrs, const std::string &name)
{
AST::Attribute path_attr = AST::Attribute::create_empty ();
for (const auto &attr : inner_attrs)
{
if (attr.get_path ().as_string () == "path")
{
path_attr = attr;
break;
}
}
// Here, we found a path attribute, but it has no associated string. This is
// invalid
if (!path_attr.is_empty () && !path_attr.has_attr_input ())
{
rust_error_at (
path_attr.get_locus (),
// Split the format string so that -Wformat-diag does not complain...
"path attributes must contain a filename: '%s'", "#![path = \"file\"]");
return name;
}
for (const auto &attr : outer_attrs)
{
if (attr.get_path ().as_string () == "path")
{
path_attr = attr;
break;
}
}
// We didn't find a path attribute. This is not an error, there simply isn't
// one present
if (path_attr.is_empty ())
return name;
// Here, we found a path attribute, but it has no associated string. This is
// invalid
if (!path_attr.has_attr_input ())
{
rust_error_at (
path_attr.get_locus (),
// Split the format string so that -Wformat-diag does not complain...
"path attributes must contain a filename: '%s'", "#[path = \"file\"]");
return name;
}
auto path_value = path_attr.get_attr_input ().as_string ();
// At this point, the 'path' is of the following format: '= "<file.rs>"'
// We need to remove the equal sign and only keep the actual filename.
// In order to do this, we can simply go through the string until we find
// a character that is not an equal sign or whitespace
auto filename_begin = path_value.find_first_not_of ("=\t ");
auto path = path_value.substr (filename_begin);
// On windows, the path might mix '/' and '\' separators. Replace the
// UNIX-like separators by MSDOS separators to make sure the path will resolve
// properly.
//
// Source: rustc compiler
// (https://github.com/rust-lang/rust/blob/9863bf51a52b8e61bcad312f81b5193d53099f9f/compiler/rustc_expand/src/module.rs#L174)
#if defined(HAVE_DOS_BASED_FILE_SYSTEM)
path.replace ('/', '\\');
#endif /* HAVE_DOS_BASED_FILE_SYSTEM */
return path;
}
static bool
peculiar_fragment_match_compatible (AST::MacroMatchFragment &last_match,
AST::MacroMatch &match)
{
static std::unordered_map<AST::MacroFragSpec::Kind, std::vector<TokenId>>
follow_set = {
{AST::MacroFragSpec::EXPR, {MATCH_ARROW, COMMA, SEMICOLON}},
{AST::MacroFragSpec::STMT, {MATCH_ARROW, COMMA, SEMICOLON}},
};
Location error_locus = match.get_match_locus ();
// There are two behaviors to handle here: If the follow-up match is a token,
// we want to check if it is allowed.
// If it is a fragment, repetition or matcher then we know that it will be
// an error.
// For repetitions and matchers we want to extract a proper location to report
// the error.
switch (match.get_macro_match_type ())
{
case AST::MacroMatch::Tok: {
auto tok = static_cast<AST::Token *> (&match);
auto &allowed_toks
= follow_set[last_match.get_frag_spec ().get_kind ()];
auto is_valid = std::find (allowed_toks.begin (), allowed_toks.end (),
tok->get_id ())
!= allowed_toks.end ();
if (!is_valid)
// FIXME: Add hint about allowed fragments
rust_error_at (tok->get_match_locus (),
"token %<%s%> is not allowed after %<%s%> fragment",
tok->get_str ().c_str (),
last_match.get_frag_spec ().as_string ().c_str ());
return is_valid;
}
break;
case AST::MacroMatch::Repetition: {
auto repetition = static_cast<AST::MacroMatchRepetition *> (&match);
auto &matches = repetition->get_matches ();
if (!matches.empty ())
error_locus = matches.front ()->get_match_locus ();
break;
}
case AST::MacroMatch::Matcher: {
auto matcher = static_cast<AST::MacroMatcher *> (&match);
auto &matches = matcher->get_matches ();
if (!matches.empty ())
error_locus = matches.front ()->get_match_locus ();
break;
}
default:
break;
}
rust_error_at (error_locus, "fragment not allowed after %<%s%> fragment",
last_match.get_frag_spec ().as_string ().c_str ());
return false;
}
/**
* Avoid UB by calling .front() and .back() on empty containers...
*/
template <typename T>
static T *
get_back_ptr (std::vector<std::unique_ptr<T>> &values)
{
if (values.empty ())
return nullptr;
return values.back ().get ();
}
template <typename T>
static T *
get_front_ptr (std::vector<std::unique_ptr<T>> &values)
{
if (values.empty ())
return nullptr;
return values.front ().get ();
}
bool
is_match_compatible (AST::MacroMatch &last_match, AST::MacroMatch &match)
{
AST::MacroMatch *new_last = nullptr;
// We want to "extract" the concerning matches. In cases such as matchers and
// repetitions, we actually store multiple matchers, but are only concerned
// about the follow-set ambiguities of certain elements.
// There are some cases where we can short-circuit the algorithm: There will
// never be restrictions on token literals, or on certain fragments which do
// not have a set of follow-restrictions.
switch (last_match.get_macro_match_type ())
{
// This is our main stop condition: When we are finally looking at the
// last match (or its actual last component), and it is a fragment, it
// may contain some follow up restrictions.
case AST::MacroMatch::Fragment: {
auto fragment = static_cast<AST::MacroMatchFragment *> (&last_match);
if (fragment->get_frag_spec ().has_follow_set_restrictions ())
return peculiar_fragment_match_compatible (*fragment, match);
else
return true;
}
case AST::MacroMatch::Repetition: {
// A repetition on the left hand side means we want to make sure the
// last match of the repetition is compatible with the new match
auto repetition
= static_cast<AST::MacroMatchRepetition *> (&last_match);
new_last = get_back_ptr (repetition->get_matches ());
// If there are no matches in the matcher, then it can be followed by
// anything
if (!new_last)
return true;
break;
}
case AST::MacroMatch::Matcher: {
// Likewise for another matcher
auto matcher = static_cast<AST::MacroMatcher *> (&last_match);
new_last = get_back_ptr (matcher->get_matches ());
// If there are no matches in the matcher, then it can be followed by
// anything
if (!new_last)
return true;
break;
}
case AST::MacroMatch::Tok:
return true;
}
rust_assert (new_last);
// We check recursively until we find a terminating condition
// FIXME: Does expansion depth/limit matter here?
return is_match_compatible (*new_last, match);
}
} // namespace Rust
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