diff --git a/compiler/rustc_codegen_ssa/src/mir/debuginfo.rs b/compiler/rustc_codegen_ssa/src/mir/debuginfo.rs index 7df830692d3e7..4d3f1fbc91e77 100644 --- a/compiler/rustc_codegen_ssa/src/mir/debuginfo.rs +++ b/compiler/rustc_codegen_ssa/src/mir/debuginfo.rs @@ -445,9 +445,23 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { bx.store(place.llval, alloca.llval, alloca.align); // Point the debug info to `*alloca` for the current variable - bx.dbg_var_addr(dbg_var, dbg_loc, alloca.llval, Size::ZERO, &[Size::ZERO], None); + bx.dbg_var_addr( + dbg_var, + dbg_loc, + alloca.llval, + Size::ZERO, + &[Size::ZERO], + var.fragment, + ); } else { - bx.dbg_var_addr(dbg_var, dbg_loc, base.llval, direct_offset, &indirect_offsets, None); + bx.dbg_var_addr( + dbg_var, + dbg_loc, + base.llval, + direct_offset, + &indirect_offsets, + var.fragment, + ); } } @@ -570,17 +584,22 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> { } let place = fragment.contents; + let fragment = if fragment_layout.size == Size::ZERO { + // Fragment is a ZST, so does not represent anything. + continue; + } else if fragment_layout.size == var_layout.size { + // Fragment covers entire variable, so as far as + // DWARF is concerned, it's not really a fragment. + None + } else { + Some(fragment_start..fragment_start + fragment_layout.size) + }; + per_local[place.local].push(PerLocalVarDebugInfo { name: var.name, source_info: var.source_info, dbg_var, - fragment: if fragment_layout.size == var_layout.size { - // Fragment covers entire variable, so as far as - // DWARF is concerned, it's not really a fragment. - None - } else { - Some(fragment_start..fragment_start + fragment_layout.size) - }, + fragment, projection: place.projection, }); } diff --git a/tests/codegen/sroa-fragment-debuginfo.rs b/tests/codegen/sroa-fragment-debuginfo.rs new file mode 100644 index 0000000000000..fb10f63beaf45 --- /dev/null +++ b/tests/codegen/sroa-fragment-debuginfo.rs @@ -0,0 +1,46 @@ +// compile-flags: -g -Zmir-opt-level=0 -Zmir-enable-passes=+ScalarReplacementOfAggregates +// compile-flags: -Cno-prepopulate-passes +// +// Tested offsets are only correct for x86_64. +// only-x86_64 + +#![crate_type = "lib"] + +pub struct ExtraSlice<'input> { + slice: &'input [u8], + extra: u32, +} + +#[no_mangle] +pub fn extra(s: &[u8]) { +// CHECK: void @extra( +// CHECK: %slice.dbg.spill1 = alloca i32, +// CHECK: %slice.dbg.spill = alloca { ptr, i64 }, +// CHECK: %s.dbg.spill = alloca { ptr, i64 }, +// CHECK: call void @llvm.dbg.declare(metadata ptr %s.dbg.spill, metadata ![[S_EXTRA:.*]], metadata !DIExpression()), +// CHECK: call void @llvm.dbg.declare(metadata ptr %slice.dbg.spill, metadata ![[SLICE_EXTRA:.*]], metadata !DIExpression(DW_OP_LLVM_fragment, 0, 128)), +// CHECK: call void @llvm.dbg.declare(metadata ptr %slice.dbg.spill1, metadata ![[SLICE_EXTRA]], metadata !DIExpression(DW_OP_LLVM_fragment, 128, 32)), + let slice = ExtraSlice { slice: s, extra: s.len() as u32 }; +} + +struct Zst; + +pub struct ZstSlice<'input> { + slice: &'input [u8], + extra: Zst, +} + +#[no_mangle] +pub fn zst(s: &[u8]) { + // The field `extra` is a ZST. The fragment for the field `slice` encompasses the whole + // variable, so is not a fragment. In that case, the variable must have no fragment. + +// CHECK: void @zst( +// CHECK-NOT: call void @llvm.dbg.declare(metadata ptr %slice.dbg.spill, metadata !{}, metadata !DIExpression(DW_OP_LLVM_fragment, +// CHECK: call void @llvm.dbg.declare(metadata ptr %{{.*}}, metadata ![[SLICE_ZST:.*]], metadata !DIExpression()), +// CHECK-NOT: call void @llvm.dbg.declare(metadata ptr %{{.*}}, metadata ![[SLICE_ZST]], + let slice = ZstSlice { slice: s, extra: Zst }; +} + +// CHECK: ![[S_EXTRA]] = !DILocalVariable(name: "s", +// CHECK: ![[SLICE_EXTRA]] = !DILocalVariable(name: "slice", diff --git a/tests/ui/debuginfo/sroa-fragment-debuginfo.rs b/tests/ui/debuginfo/sroa-fragment-debuginfo.rs new file mode 100644 index 0000000000000..9c3c359e395d5 --- /dev/null +++ b/tests/ui/debuginfo/sroa-fragment-debuginfo.rs @@ -0,0 +1,31 @@ +// Verify that we do not trigger a LLVM assertion by creating zero-sized DWARF fragments. +// +// build-pass +// compile-flags: -g -Zmir-opt-level=0 -Zmir-enable-passes=+ScalarReplacementOfAggregates +// compile-flags: -Cno-prepopulate-passes + +#![crate_type = "lib"] + +pub struct ExtraSlice<'input> { + slice: &'input [u8], + extra: u32, +} + +#[no_mangle] +pub fn extra(s: &[u8]) { + let slice = ExtraSlice { slice: s, extra: s.len() as u32 }; +} + +struct Zst; + +pub struct ZstSlice<'input> { + slice: &'input [u8], + extra: Zst, +} + +#[no_mangle] +pub fn zst(s: &[u8]) { + // The field `extra` is a ZST. The fragment for the field `slice` encompasses the whole + // variable, so is not a fragment. In that case, the variable must have no fragment. + let slice = ZstSlice { slice: s, extra: Zst }; +}