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).

(cherry picked from commit 2be6b143289e5479cc4a2667bb84e879116c2447)
Change-Id: Ieb7f7655bac8cb0cf5734c60bd41723388f2973c
This commit is contained in:
eldritch horrors 2024-01-29 06:19:23 +01:00
parent 9cf92c012d
commit 4c072c7c5f
8 changed files with 99 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 +67,48 @@ 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), pastEnd(input.empty()) {
if (!pastEnd)
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

View file

@ -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