match line endings used by parser and error reports

the parser treats a plain \r as a newline, error reports do not. this
can lead to interesting divergences if anything makes use of this
feature, with error reports pointing to wrong locations in the input (or
even outside the input altogether).
This commit is contained in:
pennae 2024-01-29 06:19:23 +01:00
parent f7e3a0b19f
commit 72396e0038
8 changed files with 98 additions and 24 deletions

View file

@ -29,32 +29,17 @@ std::optional<LinesOfCode> Pos::getCodeLines() const
return std::nullopt;
if (auto source = getSource()) {
std::istringstream iss(*source);
// count the newlines.
int count = 0;
std::string curLine;
int pl = line - 1;
LinesIterator lines(*source), end;
LinesOfCode loc;
do {
std::getline(iss, curLine);
++count;
if (count < pl)
;
else if (count == pl) {
loc.prevLineOfCode = curLine;
} else if (count == pl + 1) {
loc.errLineOfCode = curLine;
} else if (count == pl + 2) {
loc.nextLineOfCode = curLine;
break;
}
if (!iss.good())
break;
} while (true);
if (line > 1)
std::advance(lines, line - 2);
if (lines != end && line > 1)
loc.prevLineOfCode = *lines++;
if (lines != end)
loc.errLineOfCode = *lines++;
if (lines != end)
loc.nextLineOfCode = *lines++;
return loc;
}
@ -109,4 +94,26 @@ std::ostream & operator<<(std::ostream & str, const Pos & pos)
return str;
}
void Pos::LinesIterator::bump(bool atFirst)
{
if (!atFirst) {
pastEnd = input.empty();
if (!input.empty() && input[0] == '\r')
input.remove_prefix(1);
if (!input.empty() && input[0] == '\n')
input.remove_prefix(1);
}
// nix line endings are not only \n as eg std::getline assumes, but also
// \r\n **and \r alone**. not treating them all the same causes error
// reports to not match with line numbers as the parser expects them.
auto eol = input.find_first_of("\r\n");
if (eol > input.size())
eol = input.size();
curLine = input.substr(0, eol);
input.remove_prefix(eol);
}
}

View file

@ -67,6 +67,47 @@ struct Pos
bool operator==(const Pos & rhs) const = default;
bool operator!=(const Pos & rhs) const = default;
bool operator<(const Pos & rhs) const;
struct LinesIterator {
using difference_type = size_t;
using value_type = std::string_view;
using reference = const std::string_view &;
using pointer = const std::string_view *;
using iterator_category = std::input_iterator_tag;
LinesIterator(): pastEnd(true) {}
explicit LinesIterator(std::string_view input): input(input) {
bump(true);
}
LinesIterator & operator++() {
bump(false);
return *this;
}
LinesIterator operator++(int) {
auto result = *this;
++*this;
return result;
}
reference operator*() const { return curLine; }
pointer operator->() const { return &curLine; }
bool operator!=(const LinesIterator & other) const {
return !(*this == other);
}
bool operator==(const LinesIterator & other) const {
return (pastEnd && other.pastEnd)
|| (std::forward_as_tuple(input.size(), input.data())
== std::forward_as_tuple(other.input.size(), other.input.data()));
}
private:
std::string_view input, curLine;
bool pastEnd = false;
void bump(bool atFirst);
};
};
std::ostream & operator<<(std::ostream & str, const Pos & pos);

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@ -0,0 +1,6 @@
error: undefined variable 'invalid'
at /pwd/lang/eval-fail-eol-1.nix:2:1:
1| # foo
2| invalid
| ^
3| # bar

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@ -0,0 +1,3 @@
# foo
invalid
# bar

View file

@ -0,0 +1,6 @@
error: undefined variable 'invalid'
at /pwd/lang/eval-fail-eol-2.nix:2:1:
1| # foo
2| invalid
| ^
3| # bar

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@ -0,0 +1,2 @@
# foo invalid
# bar

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@ -0,0 +1,6 @@
error: undefined variable 'invalid'
at /pwd/lang/eval-fail-eol-3.nix:2:1:
1| # foo
2| invalid
| ^
3| # bar

View file

@ -0,0 +1,3 @@
# foo
invalid
# bar