7b410ac352
This patch implements BTF (BPF Type Format).
The BTF is the debug info format for BPF, introduced
in the below linux patch:
69b693f0ae (diff-06fb1c8825f653d7e539058b72c83332)
and further extended several times, e.g.,
https://www.spinics.net/lists/netdev/msg534640.html
https://www.spinics.net/lists/netdev/msg538464.html
https://www.spinics.net/lists/netdev/msg540246.html
The main advantage of implementing in LLVM is:
. better integration/deployment as no extra tools are needed.
. bpf JIT based compilation (like bcc, bpftrace, etc.) can get
BTF without much extra effort.
. BTF line_info needs selective source codes, which can be
easily retrieved when inside the compiler.
This patch implemented BTF generation by registering a BPF
specific DebugHandler in BPFAsmPrinter.
Signed-off-by: Yonghong Song <yhs@fb.com>
Differential Revision: https://reviews.llvm.org/D55752
llvm-svn: 349640
71 lines
3.1 KiB
LLVM
71 lines
3.1 KiB
LLVM
; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
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; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
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; Source code:
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; struct t {};
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; struct t a[10];
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; Compilation flag:
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; clang -target bpf -O2 -g -S -emit-llvm t.c
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%struct.t = type {}
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@a = common dso_local local_unnamed_addr global [10 x %struct.t] zeroinitializer, align 1, !dbg !0
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!llvm.dbg.cu = !{!2}
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!llvm.module.flags = !{!10, !11, !12}
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!llvm.ident = !{!13}
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; CHECK: .section .BTF,"",@progbits
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; CHECK-NEXT: .short 60319 # 0xeb9f
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; CHECK-NEXT: .byte 1
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; CHECK-NEXT: .byte 0
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; CHECK-NEXT: .long 24
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; CHECK-NEXT: .long 0
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; CHECK-NEXT: .long 52
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; CHECK-NEXT: .long 52
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; CHECK-NEXT: .long 23
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; CHECK-NEXT: .long 0 # BTF_KIND_ARRAY(id = 1)
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; CHECK-NEXT: .long 50331648 # 0x3000000
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; CHECK-NEXT: .long 0
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; CHECK-NEXT: .long 3
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; CHECK-NEXT: .long 2
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; CHECK-NEXT: .long 0
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; CHECK-NEXT: .long 1 # BTF_KIND_INT(id = 2)
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; CHECK-NEXT: .long 16777216 # 0x1000000
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; CHECK-NEXT: .long 4
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; CHECK-NEXT: .long 32 # 0x20
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; CHECK-NEXT: .long 21 # BTF_KIND_STRUCT(id = 3)
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; CHECK-NEXT: .long 67108864 # 0x4000000
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; CHECK-NEXT: .long 0
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; CHECK-NEXT: .byte 0 # string offset=0
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; CHECK-NEXT: .ascii "__ARRAY_SIZE_TYPE__" # string offset=1
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; CHECK-NEXT: .byte 0
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; CHECK-NEXT: .byte 116 # string offset=21
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; CHECK-NEXT: .byte 0
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; CHECK-NEXT: .section .BTF.ext,"",@progbits
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; CHECK-NEXT: .short 60319 # 0xeb9f
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; CHECK-NEXT: .byte 1
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; CHECK-NEXT: .byte 0
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; CHECK-NEXT: .long 24
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; CHECK-NEXT: .long 0
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; CHECK-NEXT: .long 4
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; CHECK-NEXT: .long 4
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; CHECK-NEXT: .long 4
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; CHECK-NEXT: .long 8 # FuncInfo
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; CHECK-NEXT: .long 16 # LineInfo
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!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
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!1 = distinct !DIGlobalVariable(name: "a", scope: !2, file: !3, line: 2, type: !6, isLocal: false, isDefinition: true)
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!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 8.0.0 (trunk 345296) (llvm/trunk 345297)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
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!3 = !DIFile(filename: "t.c", directory: "/home/yhs/tmp")
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!4 = !{}
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!5 = !{!0}
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!6 = !DICompositeType(tag: DW_TAG_array_type, baseType: !7, elements: !8)
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!7 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "t", file: !3, line: 1, elements: !4)
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!8 = !{!9}
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!9 = !DISubrange(count: 10)
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!10 = !{i32 2, !"Dwarf Version", i32 4}
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!11 = !{i32 2, !"Debug Info Version", i32 3}
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!12 = !{i32 1, !"wchar_size", i32 4}
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!13 = !{!"clang version 8.0.0 (trunk 345296) (llvm/trunk 345297)"}
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