When emitting DW_AT_discr_value, discriminants that don't fit in a 64-bit integer are truncated or cause LLVM assertions
#119655
Labels
Comments
EugeneZelenko
added
debuginfo
crash
|
@llvm/issue-subscribers-debuginfo Author: None (beetrees)
When compiling the following IR ([compiler explorer](https://godbolt.org/z/PxhfM1KP4); the IR is [compiled from this Rust code](https://godbolt.org/z/8doGjqq36)):
<details><summary>LLVM IR</summary>
; ModuleID = 'example.bbc0a90001a6c25f-cgu.0'
source_filename = "example.bbc0a90001a6c25f-cgu.0"
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
; Function Attrs: nonlazybind uwtable
define void @<!-- -->f(ptr align 16 %arg) unnamed_addr #<!-- -->0 !dbg !7 {
start:
%arg.dbg.spill = alloca [8 x i8], align 8
store ptr %arg, ptr %arg.dbg.spill, align 8
#dbg_declare(ptr %arg.dbg.spill, !29, !DIExpression(), !30)
ret void, !dbg !31
}
attributes #<!-- -->0 = { nonlazybind uwtable "probe-stack"="inline-asm" "target-cpu"="x86-64" }
!llvm.module.flags = !{!0, !1, !2, !3}
!llvm.ident = !{!4}
!llvm.dbg.cu = !{!5}
!0 = !{i32 8, !"PIC Level", i32 2}
!1 = !{i32 2, !"RtLibUseGOT", i32 1}
!2 = !{i32 2, !"Dwarf Version", i32 4}
!3 = !{i32 2, !"Debug Info Version", i32 3}
!4 = !{!"rustc version 1.85.0-nightly (33c245b9e 2024-12-10)"}
!5 = distinct !DICompileUnit(language: DW_LANG_Rust, file: !6, producer: "clang LLVM (rustc version 1.85.0-nightly (33c245b9e 2024-12-10))", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, splitDebugInlining: false, nameTableKind: None)
!6 = !DIFile(filename: "/app/example.rs/@/example.bbc0a90001a6c25f-cgu.0", directory: "/app")
!7 = distinct !DISubprogram(name: "f", scope: !9, file: !8, line: 10, type: !10, scopeLine: 10, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !5, templateParams: !23, retainedNodes: !28)
!8 = !DIFile(filename: "example.rs", directory: "/app", checksumkind: CSK_MD5, checksum: "a5e69d61728bea50929f951cefeb214d")
!9 = !DINamespace(name: "example", scope: null)
!10 = !DISubroutineType(types: !11)
!11 = !{null, !12}
!12 = !DIDerivedType(tag: DW_TAG_pointer_type, name: "&example::Enum", baseType: !13, size: 64, align: 64, dwarfAddressSpace: 0)
!13 = !DICompositeType(tag: DW_TAG_structure_type, name: "Enum", scope: !9, file: !14, size: 256, align: 128, flags: DIFlagPrivate, elements: !15, templateParams: !23, identifier: "469ee2dc29a0e6d2c8e5f6f5942b091")
!14 = !DIFile(filename: "<unknown>", directory: "")
!15 = !{!16}
!16 = !DICompositeType(tag: DW_TAG_variant_part, scope: !13, file: !14, size: 256, align: 128, elements: !17, templateParams: !23, identifier: "190ce2747378be38ac7362eb40a80906", discriminator: !26)
!17 = !{!18, !24}
!18 = !DIDerivedType(tag: DW_TAG_member, name: "VariantA", scope: !16, file: !14, baseType: !19, size: 256, align: 128, extraData: i128 0)
!19 = !DICompositeType(tag: DW_TAG_structure_type, name: "VariantA", scope: !13, file: !14, size: 256, align: 128, flags: DIFlagPrivate, elements: !20, templateParams: !23, identifier: "588fffa66c9ca296e16b6bf021973a50")
!20 = !{!21}
!21 = !DIDerivedType(tag: DW_TAG_member, name: "__0", scope: !19, file: !14, baseType: !22, size: 8, align: 8, offset: 128, flags: DIFlagPrivate)
!22 = !DIBasicType(name: "u8", size: 8, encoding: DW_ATE_unsigned)
!23 = !{}
!24 = !DIDerivedType(tag: DW_TAG_member, name: "VariantB", scope: !16, file: !14, baseType: !25, size: 256, align: 128, extraData: i128 18446744073709551616)
!25 = !DICompositeType(tag: DW_TAG_structure_type, name: "VariantB", scope: !13, file: !14, size: 256, align: 128, flags: DIFlagPrivate, elements: !23, identifier: "ace4dd05425154b121f11815fa7d85bc")
!26 = !DIDerivedType(tag: DW_TAG_member, scope: !13, file: !14, baseType: !27, size: 128, align: 128, flags: DIFlagArtificial)
!27 = !DIBasicType(name: "u128", size: 128, encoding: DW_ATE_unsigned)
!28 = !{!29}
!29 = !DILocalVariable(name: "arg", arg: 1, scope: !7, file: !8, line: 10, type: !12)
!30 = !DILocation(line: 10, column: 6, scope: !7)
!31 = !DILocation(line: 12, column: 2, scope: !32)
!32 = !DILexicalBlockFile(scope: !7, file: !8, discriminator: 0)</details> An LLVM assertion is triggered by the <details><summary>Assertion backtrace</summary> </details> |
tromey
added a commit
to tromey/llvm-project
that referenced
this issue
Feb 3, 2025
If a variant part has a 128-bit discriminator, then DwarfUnit::constructTypeDIE will assert. This patch fixes the problem by allowing any size of integer to be used here. This is mostly implemented by copying DwarfUnit::addConstantValue. However, I did not reimplement that method in terms of the new addInt because that would introduce the need for unrelated test case changes. Fixes llvm#119655
tromey
added a commit
to tromey/llvm-project
that referenced
this issue
Feb 4, 2025
If a variant part has a 128-bit discriminator, then DwarfUnit::constructTypeDIE will assert. This patch fixes the problem by allowing any size of integer to be used here. This is largely accomplished by moving part of DwarfUnit::addConstantValue to a new method. Fixes llvm#119655
dwblaikie
pushed a commit
that referenced
this issue
Feb 4, 2025
If a variant part has a 128-bit discriminator, then DwarfUnit::constructTypeDIE will assert. This patch fixes the problem by allowing any size of integer to be used here. This is largely accomplished by moving part of DwarfUnit::addConstantValue to a new method. Fixes #119655
swift-ci
pushed a commit
to swiftlang/llvm-project
that referenced
this issue
Feb 8, 2025
If a variant part has a 128-bit discriminator, then DwarfUnit::constructTypeDIE will assert. This patch fixes the problem by allowing any size of integer to be used here. This is largely accomplished by moving part of DwarfUnit::addConstantValue to a new method. Fixes llvm#119655 (cherry picked from commit 3c28076)
Icohedron
pushed a commit
to Icohedron/llvm-project
that referenced
this issue
Feb 11, 2025
If a variant part has a 128-bit discriminator, then DwarfUnit::constructTypeDIE will assert. This patch fixes the problem by allowing any size of integer to be used here. This is largely accomplished by moving part of DwarfUnit::addConstantValue to a new method. Fixes llvm#119655
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
When compiling the following IR (compiler explorer; the IR is compiled from this Rust code):
LLVM IR
An LLVM assertion is triggered by the
getZExtValue/getSExtValuecall inDwarfUnit::constructTypeDIE(if assertions are disabled, the discriminant value is instead truncated to a 64-bit integer), as the discriminant value ofVariantBdoes not fit in a 64-bit integer.Assertion backtrace
The text was updated successfully, but these errors were encountered: