Merge pull request #9917 from 9999years/enter-debugger-more-reliably

Enter debugger more reliably in `let` expressions and function calls
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Théophane Hufschmitt 2024-02-08 10:09:54 +01:00 committed by GitHub
commit c4ed92fa6f
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2 changed files with 53 additions and 3 deletions

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@ -0,0 +1,25 @@
---
synopsis: The `--debugger` will start more reliably in `let` expressions and function calls
prs: 9917
issues: 6649
---
Previously, if you attempted to evaluate this file with the debugger:
```nix
let
a = builtins.trace "before inner break" (
builtins.break "hello"
);
b = builtins.trace "before outer break" (
builtins.break a
);
in
b
```
Nix would correctly enter the debugger at `builtins.break a`, but if you asked
it to `:continue`, it would skip over the `builtins.break "hello"` expression
entirely.
Now, Nix will correctly enter the debugger at both breakpoints.

View file

@ -844,20 +844,20 @@ void EvalState::addErrorTrace(Error & e, const PosIdx pos, const char * s, const
e.addTrace(positions[pos], hintfmt(s, s2), frame);
}
template<typename... Args>
static std::unique_ptr<DebugTraceStacker> makeDebugTraceStacker(
EvalState & state,
Expr & expr,
Env & env,
std::shared_ptr<Pos> && pos,
const char * s,
const std::string & s2)
const Args & ... formatArgs)
{
return std::make_unique<DebugTraceStacker>(state,
DebugTrace {
.pos = std::move(pos),
.expr = expr,
.env = env,
.hint = hintfmt(s, s2),
.hint = hintfmt(formatArgs...),
.isError = false
});
}
@ -1320,6 +1320,19 @@ void ExprLet::eval(EvalState & state, Env & env, Value & v)
for (auto & i : attrs->attrs)
env2.values[displ++] = i.second.e->maybeThunk(state, i.second.inherited ? env : env2);
auto dts = state.debugRepl
? makeDebugTraceStacker(
state,
*this,
env2,
getPos()
? std::make_shared<Pos>(state.positions[getPos()])
: nullptr,
"while evaluating a '%1%' expression",
"let"
)
: nullptr;
body->eval(state, env2, v);
}
@ -1716,6 +1729,18 @@ void EvalState::callFunction(Value & fun, size_t nrArgs, Value * * args, Value &
void ExprCall::eval(EvalState & state, Env & env, Value & v)
{
auto dts = state.debugRepl
? makeDebugTraceStacker(
state,
*this,
env,
getPos()
? std::make_shared<Pos>(state.positions[getPos()])
: nullptr,
"while calling a function"
)
: nullptr;
Value vFun;
fun->eval(state, env, vFun);