Merge pull request #9914 from 9999years/debugger-on-trace

Enter debugger on `builtins.trace` with an option

(cherry picked from commit 774e7ca5847ebc392eac2a124a8f12b24da4f65a)
Change-Id: If01e2110b3a128e639b05143227e365227d149f1
This commit is contained in:
eldritch horrors 2024-03-08 09:30:33 +01:00
parent 030c8aa833
commit f2e11ddce1
3 changed files with 29 additions and 0 deletions

View file

@ -0,0 +1,9 @@
---
synopsis: Enter the `--debugger` when `builtins.trace` is called if `debugger-on-trace` is set
prs: 9914
---
If the `debugger-on-trace` option is set and `--debugger` is given,
`builtins.trace` calls will behave similarly to `builtins.break` and will enter
the debug REPL. This is useful for determining where warnings are being emitted
from.

View file

@ -114,6 +114,16 @@ struct EvalSettings : Config
Setting<unsigned int> maxCallDepth{this, 10000, "max-call-depth", Setting<unsigned int> maxCallDepth{this, 10000, "max-call-depth",
"The maximum function call depth to allow before erroring."}; "The maximum function call depth to allow before erroring."};
Setting<bool> builtinsTraceDebugger{this, false, "debugger-on-trace",
R"(
If set to true and the `--debugger` flag is given,
[`builtins.trace`](@docroot@/language/builtins.md#builtins-trace) will
enter the debugger like
[`builtins.break`](@docroot@/language/builtins.md#builtins-break).
This is useful for debugging warnings in third-party Nix code.
)"};
}; };
extern EvalSettings evalSettings; extern EvalSettings evalSettings;

View file

@ -980,6 +980,10 @@ static void prim_trace(EvalState & state, const PosIdx pos, Value * * args, Valu
printError("trace: %1%", args[0]->string.s); printError("trace: %1%", args[0]->string.s);
else else
printError("trace: %1%", ValuePrinter(state, *args[0])); printError("trace: %1%", ValuePrinter(state, *args[0]));
if (evalSettings.builtinsTraceDebugger && state.debugRepl && !state.debugTraces.empty()) {
const DebugTrace & last = state.debugTraces.front();
state.runDebugRepl(nullptr, last.env, last.expr);
}
state.forceValue(*args[1], pos); state.forceValue(*args[1], pos);
v = *args[1]; v = *args[1];
} }
@ -991,6 +995,12 @@ static RegisterPrimOp primop_trace({
Evaluate *e1* and print its abstract syntax representation on Evaluate *e1* and print its abstract syntax representation on
standard error. Then return *e2*. This function is useful for standard error. Then return *e2*. This function is useful for
debugging. debugging.
If the
[`debugger-on-trace`](@docroot@/command-ref/conf-file.md#conf-debugger-on-trace)
option is set to `true` and the `--debugger` flag is given, the
interactive debugger will be started when `trace` is called (like
[`break`](@docroot@/language/builtins.md#builtins-break)).
)", )",
.fun = prim_trace, .fun = prim_trace,
}); });