diff options
5 files changed, 133 insertions, 3 deletions
diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/create_scope_map.rs b/compiler/rustc_codegen_llvm/src/debuginfo/create_scope_map.rs index ac6c2fb1b83..0f1909486ec 100644 --- a/compiler/rustc_codegen_llvm/src/debuginfo/create_scope_map.rs +++ b/compiler/rustc_codegen_llvm/src/debuginfo/create_scope_map.rs @@ -1,11 +1,15 @@ +use std::collections::hash_map::Entry; + use rustc_codegen_ssa::mir::debuginfo::{DebugScope, FunctionDebugContext}; use rustc_codegen_ssa::traits::*; +use rustc_data_structures::fx::FxHashMap; use rustc_index::Idx; use rustc_index::bit_set::BitSet; use rustc_middle::mir::{Body, SourceScope}; use rustc_middle::ty::layout::FnAbiOf; use rustc_middle::ty::{self, Instance}; use rustc_session::config::DebugInfo; +use rustc_span::BytePos; use super::metadata::file_metadata; use super::utils::DIB; @@ -37,10 +41,20 @@ pub(crate) fn compute_mir_scopes<'ll, 'tcx>( None }; let mut instantiated = BitSet::new_empty(mir.source_scopes.len()); + let mut discriminators = FxHashMap::default(); // Instantiate all scopes. for idx in 0..mir.source_scopes.len() { let scope = SourceScope::new(idx); - make_mir_scope(cx, instance, mir, &variables, debug_context, &mut instantiated, scope); + make_mir_scope( + cx, + instance, + mir, + &variables, + debug_context, + &mut instantiated, + &mut discriminators, + scope, + ); } assert!(instantiated.count() == mir.source_scopes.len()); } @@ -52,6 +66,7 @@ fn make_mir_scope<'ll, 'tcx>( variables: &Option<BitSet<SourceScope>>, debug_context: &mut FunctionDebugContext<'tcx, &'ll DIScope, &'ll DILocation>, instantiated: &mut BitSet<SourceScope>, + discriminators: &mut FxHashMap<BytePos, u32>, scope: SourceScope, ) { if instantiated.contains(scope) { @@ -60,7 +75,16 @@ fn make_mir_scope<'ll, 'tcx>( let scope_data = &mir.source_scopes[scope]; let parent_scope = if let Some(parent) = scope_data.parent_scope { - make_mir_scope(cx, instance, mir, variables, debug_context, instantiated, parent); + make_mir_scope( + cx, + instance, + mir, + variables, + debug_context, + instantiated, + discriminators, + parent, + ); debug_context.scopes[parent] } else { // The root is the function itself. @@ -117,7 +141,37 @@ fn make_mir_scope<'ll, 'tcx>( // FIXME(eddyb) this doesn't account for the macro-related // `Span` fixups that `rustc_codegen_ssa::mir::debuginfo` does. let callsite_scope = parent_scope.adjust_dbg_scope_for_span(cx, callsite_span); - cx.dbg_loc(callsite_scope, parent_scope.inlined_at, callsite_span) + let loc = cx.dbg_loc(callsite_scope, parent_scope.inlined_at, callsite_span); + + // NB: In order to produce proper debug info for variables (particularly + // arguments) in multiply-inline functions, LLVM expects to see a single + // DILocalVariable with multiple different DILocations in the IR. While + // the source information for each DILocation would be identical, their + // inlinedAt attributes will be unique to the particular callsite. + // + // We generate DILocations here based on the callsite's location in the + // source code. A single location in the source code usually can't + // produce multiple distinct calls so this mostly works, until + // proc-macros get involved. A proc-macro can generate multiple calls + // at the same span, which breaks the assumption that we're going to + // produce a unique DILocation for every scope we process here. We + // have to explicitly add discriminators if we see inlines into the + // same source code location. + // + // Note further that we can't key this hashtable on the span itself, + // because these spans could have distinct SyntaxContexts. We have + // to key on exactly what we're giving to LLVM. + match discriminators.entry(callsite_span.lo()) { + Entry::Occupied(mut o) => { + *o.get_mut() += 1; + unsafe { llvm::LLVMRustDILocationCloneWithBaseDiscriminator(loc, *o.get()) } + .expect("Failed to encode discriminator in DILocation") + } + Entry::Vacant(v) => { + v.insert(0); + loc + } + } }); debug_context.scopes[scope] = DebugScope { diff --git a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs index 3d2e270a386..75a5ec44c22 100644 --- a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs +++ b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs @@ -2174,6 +2174,10 @@ unsafe extern "C" { Scope: &'a DIScope, InlinedAt: Option<&'a DILocation>, ) -> &'a DILocation; + pub fn LLVMRustDILocationCloneWithBaseDiscriminator<'a>( + Location: &'a DILocation, + BD: c_uint, + ) -> Option<&'a DILocation>; pub fn LLVMRustDIBuilderCreateOpDeref() -> u64; pub fn LLVMRustDIBuilderCreateOpPlusUconst() -> u64; pub fn LLVMRustDIBuilderCreateOpLLVMFragment() -> u64; diff --git a/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp index 9330c83b7f2..cd70c3f2669 100644 --- a/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp +++ b/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp @@ -1305,6 +1305,14 @@ LLVMRustDIBuilderCreateDebugLocation(unsigned Line, unsigned Column, return wrap(Loc); } +extern "C" LLVMMetadataRef +LLVMRustDILocationCloneWithBaseDiscriminator(LLVMMetadataRef Location, + unsigned BD) { + DILocation *Loc = unwrapDIPtr<DILocation>(Location); + auto NewLoc = Loc->cloneWithBaseDiscriminator(BD); + return wrap(NewLoc.has_value() ? NewLoc.value() : nullptr); +} + extern "C" uint64_t LLVMRustDIBuilderCreateOpDeref() { return dwarf::DW_OP_deref; } diff --git a/tests/codegen/debuginfo-proc-macro/auxiliary/macro_def.rs b/tests/codegen/debuginfo-proc-macro/auxiliary/macro_def.rs new file mode 100644 index 00000000000..159ecfd0974 --- /dev/null +++ b/tests/codegen/debuginfo-proc-macro/auxiliary/macro_def.rs @@ -0,0 +1,11 @@ +//@ force-host +//@ no-prefer-dynamic +#![crate_type = "proc-macro"] + +extern crate proc_macro; +use proc_macro::*; + +#[proc_macro] +pub fn square_twice(_item: TokenStream) -> TokenStream { + "(square(env::vars().count() as i32), square(env::vars().count() as i32))".parse().unwrap() +} diff --git a/tests/codegen/debuginfo-proc-macro/mir_inlined_twice_var_locs.rs b/tests/codegen/debuginfo-proc-macro/mir_inlined_twice_var_locs.rs new file mode 100644 index 00000000000..c3858044c0c --- /dev/null +++ b/tests/codegen/debuginfo-proc-macro/mir_inlined_twice_var_locs.rs @@ -0,0 +1,53 @@ +//@ min-llvm-version: 19 +//@ compile-flags: -Cdebuginfo=2 -Copt-level=0 -Zmir-enable-passes=+Inline +// MSVC is different because of the individual allocas. +//@ ignore-msvc + +//@ aux-build:macro_def.rs + +// Find the variable. +// CHECK-DAG: ![[#var_dbg:]] = !DILocalVariable(name: "n",{{( arg: 1,)?}} scope: ![[#var_scope:]] + +// Find both dbg_declares. These will proceed the variable metadata, of course, so we're looking +// backwards. +// CHECK-DAG: dbg_declare(ptr %n.dbg.spill{{[0-9]}}, ![[#var_dbg]], !DIExpression(), ![[#var_loc2:]]) +// CHECK-DAG: dbg_declare(ptr %n.dbg.spill, ![[#var_dbg]], !DIExpression(), ![[#var_loc1:]]) + +// Find the first location definition, looking forwards again. +// CHECK: ![[#var_loc1]] = !DILocation +// CHECK-SAME: scope: ![[#var_scope:]], inlinedAt: ![[#var_inlinedAt1:]] + +// Find the first location's inlinedAt +// NB: If we fail here it's *probably* because we failed to produce two +// different locations and ended up reusing an earlier one. +// CHECK: ![[#var_inlinedAt1]] = !DILocation +// CHECK-SAME: scope: ![[var_inlinedAt1_scope:]] + +// Find the second location definition, still looking forwards. +// NB: If we failed to produce two different locations, the test will +// definitely fail by this point (if it hasn't already) because we won't +// be able to find the same line again. +// CHECK: ![[#var_loc2]] = !DILocation +// CHECK-SAME: scope: ![[#var_scope]], inlinedAt: ![[#var_inlinedAt2:]] + +// Find the second location's inlinedAt. +// CHECK: ![[#var_inlinedAt2]] = !DILocation +// CHECK-SAME: scope: ![[#var_inlinedAt2_scope:]] + +// Finally, check that a discriminator was emitted for the second scope. +// FIXMEkhuey ideally we would check that *either* scope has a discriminator +// but I don't know that it's possible to check that with FileCheck. +// CHECK: ![[#var_inlinedAt2_scope]] = !DILexicalBlockFile +// CHECK-SAME: discriminator: [[#]] +extern crate macro_def; + +use std::env; + +fn square(n: i32) -> i32 { + n * n +} + +fn main() { + let (z1, z2) = macro_def::square_twice!(); + println!("{z1} == {z2}"); +} |