[llvm-branch-commits] [llvm] 5b149c4 - BPF: generate proper BTF for globals with WeakODRLinkage
Tom Stellard via llvm-branch-commits
llvm-branch-commits at lists.llvm.org
Thu Jun 10 16:16:10 PDT 2021
Author: Yonghong Song
Date: 2021-06-10T16:15:21-07:00
New Revision: 5b149c437194d10877e9e45b3d8cc9252af1944b
URL: https://github.com/llvm/llvm-project/commit/5b149c437194d10877e9e45b3d8cc9252af1944b
DIFF: https://github.com/llvm/llvm-project/commit/5b149c437194d10877e9e45b3d8cc9252af1944b.diff
LOG: BPF: generate proper BTF for globals with WeakODRLinkage
For a global weak symbol defined as below:
char g __attribute__((weak)) = 2;
LLVM generates an allocated global with WeakAnyLinkage,
for which BPF backend generates proper BTF info.
For the above example, if a modifier "const" is added like
const char g __attribute__((weak)) = 2;
LLVM generates an allocated global with WeakODRLinkage,
for which BPF backend didn't generate any BTF as it
didn't handle WeakODRLinkage.
This patch addes support for WeakODRLinkage and proper
BTF info can be generated for weak symbol defined with
"const" modifier.
Differential Revision: https://reviews.llvm.org/D100362
(cherry picked from commit 968292cb93198442138128d850fd54dc7edc0035)
Added:
llvm/test/CodeGen/BPF/BTF/weak-global-3.ll
Modified:
llvm/lib/Target/BPF/BTFDebug.cpp
Removed:
################################################################################
diff --git a/llvm/lib/Target/BPF/BTFDebug.cpp b/llvm/lib/Target/BPF/BTFDebug.cpp
index bedf159430dc..9249d679c7bd 100644
--- a/llvm/lib/Target/BPF/BTFDebug.cpp
+++ b/llvm/lib/Target/BPF/BTFDebug.cpp
@@ -1196,6 +1196,7 @@ void BTFDebug::processGlobals(bool ProcessingMapDef) {
if (Linkage != GlobalValue::InternalLinkage &&
Linkage != GlobalValue::ExternalLinkage &&
Linkage != GlobalValue::WeakAnyLinkage &&
+ Linkage != GlobalValue::WeakODRLinkage &&
Linkage != GlobalValue::ExternalWeakLinkage)
continue;
diff --git a/llvm/test/CodeGen/BPF/BTF/weak-global-3.ll b/llvm/test/CodeGen/BPF/BTF/weak-global-3.ll
new file mode 100644
index 000000000000..dbd6380a9f1a
--- /dev/null
+++ b/llvm/test/CodeGen/BPF/BTF/weak-global-3.ll
@@ -0,0 +1,86 @@
+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+;
+; Source code:
+; const volatile char g __attribute__((weak)) = 2;
+; int test() {
+; return g;
+; }
+; Compilation flag:
+; clang -target bpf -O2 -g -S -emit-llvm test.c
+
+ at g = weak_odr dso_local constant i8 2, align 1, !dbg !0
+
+; Function Attrs: nofree norecurse nounwind willreturn
+define dso_local i32 @test() local_unnamed_addr #0 !dbg !13 {
+entry:
+ %0 = load volatile i8, i8* @g, align 1, !dbg !17, !tbaa !18
+ %conv = sext i8 %0 to i32, !dbg !17
+ ret i32 %conv, !dbg !21
+}
+
+; CHECK: .long 0 # BTF_KIND_FUNC_PROTO(id = 1)
+; CHECK-NEXT: .long 218103808 # 0xd000000
+; CHECK-NEXT: .long 2
+; CHECK-NEXT: .long 1 # BTF_KIND_INT(id = 2)
+; CHECK-NEXT: .long 16777216 # 0x1000000
+; CHECK-NEXT: .long 4
+; CHECK-NEXT: .long 16777248 # 0x1000020
+; CHECK-NEXT: .long 5 # BTF_KIND_FUNC(id = 3)
+; CHECK-NEXT: .long 201326593 # 0xc000001
+; CHECK-NEXT: .long 1
+; CHECK-NEXT: .long 0 # BTF_KIND_CONST(id = 4)
+; CHECK-NEXT: .long 167772160 # 0xa000000
+; CHECK-NEXT: .long 5
+; CHECK-NEXT: .long 0 # BTF_KIND_VOLATILE(id = 5)
+; CHECK-NEXT: .long 150994944 # 0x9000000
+; CHECK-NEXT: .long 6
+; CHECK-NEXT: .long 47 # BTF_KIND_INT(id = 6)
+; CHECK-NEXT: .long 16777216 # 0x1000000
+; CHECK-NEXT: .long 1
+; CHECK-NEXT: .long 16777224 # 0x1000008
+; CHECK-NEXT: .long 52 # BTF_KIND_VAR(id = 7)
+; CHECK-NEXT: .long 234881024 # 0xe000000
+; CHECK-NEXT: .long 4
+; CHECK-NEXT: .long 1
+; CHECK-NEXT: .long 54 # BTF_KIND_DATASEC(id = 8)
+; CHECK-NEXT: .long 251658241 # 0xf000001
+; CHECK-NEXT: .long 0
+; CHECK-NEXT: .long 7
+; CHECK-NEXT: .long g
+; CHECK-NEXT: .long 1
+
+; CHECK: .ascii "int" # string offset=1
+; CHECK: .ascii "test" # string offset=5
+; CHECK: .ascii "char" # string offset=47
+; CHECK: .byte 103 # string offset=52
+; CHECK: .ascii ".rodata" # string offset=54
+
+attributes #0 = { nofree norecurse nounwind willreturn "frame-pointer"="all" "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" }
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!9, !10, !11}
+!llvm.ident = !{!12}
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "g", scope: !2, file: !3, line: 1, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 13.0.0 (https://github.com/llvm/llvm-project.git 9cc417cbca1cece0d55fa3d1e15682943a06139e)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, splitDebugInlining: false, nameTableKind: None)
+!3 = !DIFile(filename: "test.c", directory: "/tmp/home/yhs/btf/tests")
+!4 = !{}
+!5 = !{!0}
+!6 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !7)
+!7 = !DIDerivedType(tag: DW_TAG_volatile_type, baseType: !8)
+!8 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_signed_char)
+!9 = !{i32 7, !"Dwarf Version", i32 4}
+!10 = !{i32 2, !"Debug Info Version", i32 3}
+!11 = !{i32 1, !"wchar_size", i32 4}
+!12 = !{!"clang version 13.0.0 (https://github.com/llvm/llvm-project.git 9cc417cbca1cece0d55fa3d1e15682943a06139e)"}
+!13 = distinct !DISubprogram(name: "test", scope: !3, file: !3, line: 2, type: !14, scopeLine: 2, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !2, retainedNodes: !4)
+!14 = !DISubroutineType(types: !15)
+!15 = !{!16}
+!16 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!17 = !DILocation(line: 3, column: 10, scope: !13)
+!18 = !{!19, !19, i64 0}
+!19 = !{!"omnipotent char", !20, i64 0}
+!20 = !{!"Simple C/C++ TBAA"}
+!21 = !DILocation(line: 3, column: 3, scope: !13)
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