From f5b023bd9cf43803a6d39b101c54a98cb7e7da7c Mon Sep 17 00:00:00 2001 From: Kyle Huey Date: Mon, 18 Nov 2024 18:48:10 -0800 Subject: When the required discriminator value exceeds LLVM's limits, drop the debug info for the function instead of panicking. The maximum discriminator value LLVM can currently encode is 2^12. If macro use results in more than 2^12 calls to the same function attributed to the same callsite, and those calls are MIR-inlined, we will require more than the maximum discriminator value to completely represent the debug information. Once we reach that point drop the debug info instead. --- compiler/rustc_codegen_ssa/src/mir/debuginfo.rs | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'compiler/rustc_codegen_ssa/src') diff --git a/compiler/rustc_codegen_ssa/src/mir/debuginfo.rs b/compiler/rustc_codegen_ssa/src/mir/debuginfo.rs index 21d20475408..d4d7f16db55 100644 --- a/compiler/rustc_codegen_ssa/src/mir/debuginfo.rs +++ b/compiler/rustc_codegen_ssa/src/mir/debuginfo.rs @@ -20,7 +20,9 @@ use crate::traits::*; pub struct FunctionDebugContext<'tcx, S, L> { /// Maps from source code to the corresponding debug info scope. - pub scopes: IndexVec>, + /// May be None if the backend is not capable of representing the scope for + /// some reason. + pub scopes: IndexVec>>, /// Maps from an inlined function to its debug info declaration. pub inlined_function_scopes: FxHashMap, S>, @@ -231,7 +233,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { &self, source_info: mir::SourceInfo, ) -> Option<(Bx::DIScope, Option, Span)> { - let scope = &self.debug_context.as_ref()?.scopes[source_info.scope]; + let scope = &self.debug_context.as_ref()?.scopes[source_info.scope]?; let span = hygiene::walk_chain_collapsed(source_info.span, self.mir.span); Some((scope.adjust_dbg_scope_for_span(self.cx, span), scope.inlined_at, span)) } -- cgit 1.4.1-3-g733a5