lix/src/libexpr/eval-error.hh
jade 0cc285f87b
treewide: fix a bunch of lints
Fixes:
- Identifiers starting with _ are prohibited
- Some driveby header dependency cleaning which wound up with doing some
  extra fixups.
- Fucking C style casts, man. C++ made these 1000% worse by letting you
  also do memory corruption with them with references.
  - Remove casts to Expr * where ExprBlackHole is an incomplete type by
    introducing an explicitly-cast eBlackHoleAddr as Expr *.
  - An incredibly illegal cast of the text bytes of the StorePath hash
    into a size_t directly. You can't DO THAT.

    Replaced with actually parsing the hash so we get 100% of the bits
    being entropy, then memcpying the start of the hash. If this shows
    up in a profile we should just make the hash parser faster with a
    lookup table or something sensible like that.
  - This horrendous bit of UB which I thankfully slapped a deprecation
    warning on, built, and it didn't trigger anywhere so it was dead
    code and I just deleted it. But holy crap you *cannot* do that.

    inline void mkString(const Symbol & s)
    {
        mkString(((const std::string &) s).c_str());
    }
- Some wrong lints. Lots of wrong macro lints, one wrong
  suspicious-sizeof lint triggered by the template being instantiated
  with only pointers, but the calculation being correct for both
  pointers and not-pointers.
- Exceptions in destructors strike again. I tried to catch the
  exceptions that might actually happen rather than all the exceptions
  imaginable. We can let the runtime hard-kill it on other exceptions
  imo.

Change-Id: I71761620846cba64d66ee7ca231b20c061e69710
2024-08-26 16:13:03 -07:00

109 lines
2.9 KiB
C++

#pragma once
///@file
#include "error.hh"
#include "types.hh"
#include "pos-idx.hh"
namespace nix {
struct Env;
struct Expr;
struct Value;
class EvalState;
template<class T>
class EvalErrorBuilder;
class EvalError : public Error
{
template<class T>
friend class EvalErrorBuilder;
public:
EvalState & state;
EvalError(EvalState & state, ErrorInfo && errorInfo)
: Error(errorInfo)
, state(state)
{
}
template<typename... Args>
explicit EvalError(EvalState & state, const std::string & formatString, const Args &... formatArgs)
: Error(formatString, formatArgs...)
, state(state)
{
}
};
MakeError(ParseError, Error);
MakeError(AssertionError, EvalError);
MakeError(ThrownError, AssertionError);
MakeError(Abort, EvalError);
MakeError(TypeError, EvalError);
MakeError(UndefinedVarError, EvalError);
MakeError(MissingArgumentError, EvalError);
MakeError(RestrictedPathError, Error);
MakeError(InfiniteRecursionError, EvalError);
/**
* Represents an exception due to an invalid path; that is, it does not exist.
* It corresponds to `!Store::validPath()`.
*/
struct InvalidPathError : public EvalError
{
public:
Path path;
InvalidPathError(EvalState & state, const Path & path)
: EvalError(state, "path '%s' did not exist in the store during evaluation", path)
{
}
};
/**
* `EvalErrorBuilder`s may only be constructed by `EvalState`. The `debugThrow`
* method must be the final method in any such `EvalErrorBuilder` usage, and it
* handles deleting the object.
*/
template<class T>
class EvalErrorBuilder final
{
friend class EvalState;
template<typename... Args>
explicit EvalErrorBuilder(EvalState & state, const Args &... args)
: error(T(state, args...))
{
}
public:
T error;
[[nodiscard, gnu::noinline]] EvalErrorBuilder<T> & withExitStatus(unsigned int exitStatus);
[[nodiscard, gnu::noinline]] EvalErrorBuilder<T> & atPos(PosIdx pos);
[[nodiscard, gnu::noinline]] EvalErrorBuilder<T> & atPos(Value & value, PosIdx fallback = noPos);
[[nodiscard, gnu::noinline]] EvalErrorBuilder<T> & withTrace(PosIdx pos, const std::string_view text);
[[nodiscard, gnu::noinline]] EvalErrorBuilder<T> & withFrameTrace(PosIdx pos, const std::string_view text);
[[nodiscard, gnu::noinline]] EvalErrorBuilder<T> & withSuggestions(Suggestions & s);
[[nodiscard, gnu::noinline]] EvalErrorBuilder<T> & withFrame(const Env & e, const Expr & ex);
[[nodiscard, gnu::noinline]] EvalErrorBuilder<T> & addTrace(PosIdx pos, HintFmt hint);
template<typename... Args>
[[nodiscard, gnu::noinline]] EvalErrorBuilder<T> &
addTrace(PosIdx pos, std::string_view formatString, const Args &... formatArgs);
/**
* Delete the `EvalErrorBuilder` and throw the underlying exception.
*/
[[gnu::noinline, gnu::noreturn]] void debugThrow();
};
}