[llvm] [BPF] Handle nested wrapper structs in BPF map definition traversal (PR #144097)
Tamir Duberstein via llvm-commits
llvm-commits at lists.llvm.org
Fri Jun 20 06:33:26 PDT 2025
================
@@ -0,0 +1,117 @@
+; RUN: llc -mtriple=bpfel -mcpu=v3 -filetype=obj -o %t1 %s
+; RUN: llvm-objcopy --dump-section='.BTF'=%t2 %t1
+; RUN: %python %p/print_btf.py %t2 | FileCheck -check-prefixes=CHECK-BTF-SHORT %s
+; RUN: %python %p/print_btf.py %t2 | FileCheck -check-prefixes=CHECK-BTF %s
+
+; Source code:
+; struct key { int i; };
+; struct val { int j; };
+;
+; #define __uint(name, val) int (*name)[val]
+; #define __type(name, val) typeof(val) *name
+;
+; struct {
+; struct {
+; __uint(type, 1);
+; __uint(max_entries, 1337);
+; __type(key, struct key);
+; __type(value, struct val);
+; } map_def;
+; } map __attribute__((section(".maps")));
+; Compilation flag:
+; clang -target bpf -O2 -g -S -emit-llvm t.c
+
+; ModuleID = 'bpf.c'
+source_filename = "bpf.c"
+target datalayout = "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128"
+target triple = "bpf"
+
+%struct.anon = type { %struct.anon.0 }
+%struct.anon.0 = type { ptr, ptr, ptr, ptr }
+
+ at map = dso_local local_unnamed_addr global %struct.anon zeroinitializer, section ".maps", align 8, !dbg !0
+
+; We expect exactly 4 structs:
+; * key
+; * val
+; * inner map type (the actual definition)
+; * outer map type (the wrapper)
+;
+; CHECK-BTF-SHORT-COUNT-4: STRUCT
+; CHECK-BTF-SHORT-NOT: STRUCT
+
+; We expect no forward declarations.
+;
+; CHECK-BTF-SHORT-NOT: FWD
+
+; Assert the whole BTF.
+;
+; CHECK-BTF: [1] PTR '(anon)' type_id=3
+; CHECK-BTF-NEXT: [2] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED
+; CHECK-BTF-NEXT: [3] ARRAY '(anon)' type_id=2 index_type_id=4 nr_elems=1
+; CHECK-BTF-NEXT: [4] INT '__ARRAY_SIZE_TYPE__' size=4 bits_offset=0 nr_bits=32 encoding=(none)
+; CHECK-BTF-NEXT: [5] PTR '(anon)' type_id=6
+; CHECK-BTF-NEXT: [6] ARRAY '(anon)' type_id=2 index_type_id=4 nr_elems=1337
+; CHECK-BTF-NEXT: [7] PTR '(anon)' type_id=8
+;
+; Before bug https://github.com/llvm/llvm-project/issues/143361 was fixed, the
+; BTF kind of MyKey (#6) and MyValue (#9) would be FWD instead of STRUCT. The
+; main goal of this test is making sure that the full STRUCT BTF is generated
+; for these types.
+;
+; CHECK-BTF-NEXT: [8] STRUCT 'key' size=4 vlen=1
+; CHECK-BTF-NEXT: 'i' type_id=2 bits_offset=0
+; CHECK-BTF-NEXT: [9] PTR '(anon)' type_id=10
+; CHECK-BTF-NEXT: [10] STRUCT 'val' size=4 vlen=1
+; CHECK-BTF-NEXT: 'j' type_id=2 bits_offset=0
+; CHECK-BTF-NEXT: [11] STRUCT '(anon)' size=32 vlen=4
+; CHECK-BTF-NEXT: 'type' type_id=1 bits_offset=0
+; CHECK-BTF-NEXT: 'max_entries' type_id=5 bits_offset=64
+; CHECK-BTF-NEXT: 'key' type_id=7 bits_offset=128
+; CHECK-BTF-NEXT: 'value' type_id=9 bits_offset=192
+; CHECK-BTF-NEXT: [12] STRUCT '(anon)' size=32 vlen=1
+; CHECK-BTF-NEXT: 'map_def' type_id=11 bits_offset=0
+; CHECK-BTF-NEXT: [13] VAR 'map' type_id=12, linkage=global
+; CHECK-BTF-NEXT: [14] DATASEC '.maps' size=0 vlen=1
+; CHECK-BTF-NEXT: type_id=13 offset=0 size=32
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!31, !32, !33, !34}
+!llvm.ident = !{!35}
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "map", scope: !2, file: !3, line: 14, type: !5, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C11, file: !3, producer: "clang version 21.0.0git (git at github.com:vadorovsky/llvm-project.git c935bd3798b39330aab2c9ca29a519457d5e5245)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, globals: !4, splitDebugInlining: false, nameTableKind: None)
+!3 = !DIFile(filename: "bpf.c", directory: "/home/vadorovsky/playground/btf", checksumkind: CSK_MD5, checksum: "2330cce6d83c72ef5335abc3016de28e")
+!4 = !{!0}
+!5 = distinct !DICompositeType(tag: DW_TAG_structure_type, file: !3, line: 7, size: 256, elements: !6)
+!6 = !{!7}
+!7 = !DIDerivedType(tag: DW_TAG_member, name: "map_def", scope: !5, file: !3, line: 13, baseType: !8, size: 256)
+!8 = distinct !DICompositeType(tag: DW_TAG_structure_type, scope: !5, file: !3, line: 8, size: 256, elements: !9)
+!9 = !{!10, !16, !21, !26}
+!10 = !DIDerivedType(tag: DW_TAG_member, name: "type", scope: !8, file: !3, line: 9, baseType: !11, size: 64)
+!11 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !12, size: 64)
+!12 = !DICompositeType(tag: DW_TAG_array_type, baseType: !13, size: 32, elements: !14)
+!13 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!14 = !{!15}
+!15 = !DISubrange(count: 1)
+!16 = !DIDerivedType(tag: DW_TAG_member, name: "max_entries", scope: !8, file: !3, line: 10, baseType: !17, size: 64, offset: 64)
+!17 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !18, size: 64)
+!18 = !DICompositeType(tag: DW_TAG_array_type, baseType: !13, size: 42784, elements: !19)
+!19 = !{!20}
+!20 = !DISubrange(count: 1337)
+!21 = !DIDerivedType(tag: DW_TAG_member, name: "key", scope: !8, file: !3, line: 11, baseType: !22, size: 64, offset: 128)
+!22 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !23, size: 64)
+!23 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "key", file: !3, line: 1, size: 32, elements: !24)
+!24 = !{!25}
+!25 = !DIDerivedType(tag: DW_TAG_member, name: "i", scope: !23, file: !3, line: 1, baseType: !13, size: 32)
+!26 = !DIDerivedType(tag: DW_TAG_member, name: "value", scope: !8, file: !3, line: 12, baseType: !27, size: 64, offset: 192)
+!27 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !28, size: 64)
+!28 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "val", file: !3, line: 2, size: 32, elements: !29)
+!29 = !{!30}
+!30 = !DIDerivedType(tag: DW_TAG_member, name: "j", scope: !28, file: !3, line: 2, baseType: !13, size: 32)
+!31 = !{i32 7, !"Dwarf Version", i32 5}
+!32 = !{i32 2, !"Debug Info Version", i32 3}
+!33 = !{i32 1, !"wchar_size", i32 4}
+!34 = !{i32 7, !"frame-pointer", i32 2}
+!35 = !{!"clang version 21.0.0git (git at github.com:vadorovsky/llvm-project.git c935bd3798b39330aab2c9ca29a519457d5e5245)"}
----------------
tamird wrote:
https://github.com/llvm/llvm-project/blob/c3929fbf0ef2d0fac05c54237bd9eac4fd57b1d8/llvm/test/CodeGen/BPF/BTF/annot-dup-ptr-struct.ll#L57
looks like that's more common.
not also the occurrences on line 84 and 85.
https://github.com/llvm/llvm-project/pull/144097
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