kakoune/src/face_registry.cc
Qeole 3abf2b8260 Faces: Check that underline colour comes before base/attributes markers
Parsing a (non-valid) font with a comma in the name of the base colour
makes Kakoune crash. It is not a valid face, but Kakoune should just
return an error message instead.

Reproducer:

    :set-face global foo ,red@,blue

Note the comma "," after the "@". This is not a valid base name, and it
leads to a crash. Let's see what happens.

At the beginning of parse_face(), we have the following code:

    auto bg_it = find(facedesc, ',');
    auto underline_it = bg_it == facedesc.end() ? bg_it : std::find(bg_it+1, facedesc.end(), ',');
    auto attr_it = find(facedesc, '+');
    auto base_it = find(facedesc, '@');
    [...]
    auto colors_end = std::min(attr_it, base_it);

After this:

- bg_it points to ",red@,blue"
- bg_it != facedesc.end(), so we have underline_it pointing to the first
  comma after bg_it. This means that underline_it points to ",blue"
- base_it points to "@,blue"
- attr_it points to the end of facedesc (no "+" marker), so colors_end
  points to base_it, "@,blue"

Later in the code, just after parsing the foreground and background
colours, we have:

    if (underline_it != facedesc.end())
        face.underline = parse_color({underline_it+1, colors_end});

When passing {underline_it+1, colors_end} to parse_color(), we pass in
fact iterators pointing to {",blue", "@,blue"}. Because the second one
starts _before_ the first one in the string, this means that the
resulting string is considered to have a _negative_ length.
parse_color() passes the string to str_to_color(), who fails to turn up
the colour, and attempts to throw:

    throw runtime_error(format("unable to parse color: '{}'", color));

The variable "color" still has this negative length, and this goes all
the way down to an assert in src/units.hh where we expect that string to
be >= 0, and we crash on the assertion failure.

For similar reasons, we also get a crash if the comma comes after the
marker for the face attributes:

    :set-face global foo ,red+,a

To fix both cases, let's add a check to make sure that the underline_it,
marked with a comma, never gets detected as present and pointing after
colors_end, be it "@" or "+".
2022-02-11 09:35:49 +00:00

205 lines
7.7 KiB
C++

#include "face_registry.hh"
#include "exception.hh"
#include "ranges.hh"
#include "string_utils.hh"
namespace Kakoune
{
static FaceRegistry::FaceSpec parse_face(StringView facedesc)
{
constexpr StringView invalid_face_error = "invalid face description, expected [<fg>][,<bg>[,<underline>]][+<attr>][@base] or just [base]";
if (all_of(facedesc, [](char c){ return is_word(c); }) and not is_color_name(facedesc))
return {Face{}, facedesc.str()};
auto bg_it = find(facedesc, ',');
auto underline_it = bg_it == facedesc.end() ? bg_it : std::find(bg_it+1, facedesc.end(), ',');
auto attr_it = find(facedesc, '+');
auto base_it = find(facedesc, '@');
if (bg_it != facedesc.end()
and (attr_it < bg_it or (bg_it + 1) == facedesc.end()))
throw runtime_error(invalid_face_error.str());
if (attr_it != facedesc.end()
and (attr_it + 1) == facedesc.end())
throw runtime_error(invalid_face_error.str());
auto colors_end = std::min(attr_it, base_it);
if (underline_it != facedesc.end()
and underline_it > colors_end)
throw runtime_error(invalid_face_error.str());
auto parse_color = [](StringView spec) {
return spec.empty() ? Color::Default : str_to_color(spec);
};
FaceRegistry::FaceSpec spec;
auto& face = spec.face;
face.fg = parse_color({facedesc.begin(), std::min(bg_it, colors_end)});
if (bg_it != facedesc.end())
{
face.bg = parse_color({bg_it+1, std::min(underline_it, colors_end)});
if (underline_it != facedesc.end())
face.underline = parse_color({underline_it+1, colors_end});
}
if (attr_it != facedesc.end())
{
for (++attr_it; attr_it != base_it; ++attr_it)
{
switch (*attr_it)
{
case 'u': face.attributes |= Attribute::Underline; break;
case 'c': face.attributes |= Attribute::CurlyUnderline; break;
case 'r': face.attributes |= Attribute::Reverse; break;
case 'b': face.attributes |= Attribute::Bold; break;
case 'B': face.attributes |= Attribute::Blink; break;
case 'd': face.attributes |= Attribute::Dim; break;
case 'i': face.attributes |= Attribute::Italic; break;
case 's': face.attributes |= Attribute::Strikethrough; break;
case 'f': face.attributes |= Attribute::FinalFg; break;
case 'g': face.attributes |= Attribute::FinalBg; break;
case 'a': face.attributes |= Attribute::FinalAttr; break;
case 'F': face.attributes |= Attribute::Final; break;
default: throw runtime_error(format("no such face attribute: '{}'", StringView{*attr_it}));
}
}
}
if (base_it != facedesc.end())
spec.base = String{base_it+1, facedesc.end()};
return spec;
}
String to_string(Attribute attributes)
{
if (attributes == Attribute::Normal)
return "";
struct Attr { Attribute attr; StringView name; }
attrs[] {
{ Attribute::Underline, "u" },
{ Attribute::CurlyUnderline, "c" },
{ Attribute::Reverse, "r" },
{ Attribute::Blink, "B" },
{ Attribute::Bold, "b" },
{ Attribute::Dim, "d" },
{ Attribute::Italic, "i" },
{ Attribute::Strikethrough, "s" },
{ Attribute::Final, "F" },
{ Attribute::FinalFg, "f" },
{ Attribute::FinalBg, "g" },
{ Attribute::FinalAttr, "a" },
};
auto filteredAttrs = attrs |
filter([&](const Attr& a) {
if ((attributes & a.attr) != a.attr)
return false;
attributes &= ~a.attr;
return true;
}) | transform([](const Attr& a) { return a.name; });
return accumulate(filteredAttrs, "+"_str, std::plus<>{});
}
String to_string(Face face)
{
return format("{},{},{}{}", face.fg, face.bg, face.underline, face.attributes);
}
Face FaceRegistry::operator[](StringView facedesc) const
{
return resolve_spec(parse_face(facedesc));
}
Face FaceRegistry::resolve_spec(const FaceSpec& spec) const
{
if (spec.base.empty())
return spec.face;
StringView base = spec.base;
Face face = spec.face;
for (auto* reg = this; reg != nullptr; reg = reg->m_parent.get())
{
auto it = reg->m_faces.find(base);
if (it == reg->m_faces.end())
continue;
if (it->value.base.empty())
return merge_faces(it->value.face, face);
if (it->value.base != it->key)
return merge_faces(reg->resolve_spec(it->value), face);
else
{
face = merge_faces(it->value.face, face);
base = it->value.base;
}
}
return face;
}
void FaceRegistry::add_face(StringView name, StringView facedesc, bool override)
{
if (not override and m_faces.find(name) != m_faces.end())
throw runtime_error(format("face '{}' already defined", name));
if (name.empty() or is_color_name(name) or
any_of(name, [](char c){ return not is_word(c); }))
throw runtime_error(format("invalid face name: '{}'", name));
FaceSpec spec = parse_face(facedesc);
auto it = m_faces.find(spec.base);
if (spec.base == name and it != m_faces.end())
{
it->value.face = merge_faces(it->value.face, spec.face);
it->value.base = spec.base;
return;
}
while (it != m_faces.end() and not it->value.base.empty())
{
if (it->value.base == name)
throw runtime_error("face cycle detected");
it = m_faces.find(it->value.base);
}
m_faces[name] = std::move(spec);
}
void FaceRegistry::remove_face(StringView name)
{
m_faces.remove(name);
}
FaceRegistry::FaceRegistry()
: m_faces{
{ "Default", {Face{ Color::Default, Color::Default }} },
{ "PrimarySelection", {Face{ Color::White, Color::Blue }} },
{ "SecondarySelection", {Face{ Color::Black, Color::Blue }} },
{ "PrimaryCursor", {Face{ Color::Black, Color::White }} },
{ "SecondaryCursor", {Face{ Color::Black, Color::White }} },
{ "PrimaryCursorEol", {Face{ Color::Black, Color::Cyan }} },
{ "SecondaryCursorEol", {Face{ Color::Black, Color::Cyan }} },
{ "LineNumbers", {Face{ Color::Default, Color::Default }} },
{ "LineNumberCursor", {Face{ Color::Default, Color::Default, Attribute::Reverse }} },
{ "LineNumbersWrapped", {Face{ Color::Default, Color::Default, Attribute::Italic }} },
{ "WrapMarker", {Face{ Color::Blue, Color::Default }} },
{ "MenuForeground", {Face{ Color::White, Color::Blue }} },
{ "MenuBackground", {Face{ Color::Blue, Color::White }} },
{ "MenuInfo", {Face{ Color::Cyan, Color::Default }} },
{ "Information", {Face{ Color::Black, Color::Yellow }} },
{ "Error", {Face{ Color::Black, Color::Red }} },
{ "DiagnosticError", {Face{ Color::Red, Color::Default }} },
{ "DiagnosticWarning", {Face{ Color::Yellow, Color::Default }} },
{ "StatusLine", {Face{ Color::Cyan, Color::Default }} },
{ "StatusLineMode", {Face{ Color::Yellow, Color::Default }} },
{ "StatusLineInfo", {Face{ Color::Blue, Color::Default }} },
{ "StatusLineValue", {Face{ Color::Green, Color::Default }} },
{ "StatusCursor", {Face{ Color::Black, Color::Cyan }} },
{ "Prompt", {Face{ Color::Yellow, Color::Default }} },
{ "MatchingChar", {Face{ Color::Default, Color::Default, Attribute::Bold }} },
{ "BufferPadding", {Face{ Color::Blue, Color::Default }} },
{ "Whitespace", {Face{ Color::Default, Color::Default, Attribute::FinalFg }} },
}
{}
}