[PATCH] D43860: [AArch64] DWARF: do not generate AT_location for thread local

[Lei Liu via Phabricator via llvm-commits]

lliu0 updated this revision to Diff 158188.
lliu0 added a comment.

Update test case to pass -mtriple=aarch64--linux-gnu to llc.

Rebase to LLVM trunk.


https://reviews.llvm.org/D43860

Files:
  include/llvm/Target/TargetLoweringObjectFile.h
  lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
  lib/Target/AArch64/AArch64TargetObjectFile.cpp
  test/DebugInfo/AArch64/tls-at-location.ll


Index: test/DebugInfo/AArch64/tls-at-location.ll
===================================================================
--- /dev/null
+++ test/DebugInfo/AArch64/tls-at-location.ll
@@ -0,0 +1,37 @@
+; RUN: llc -filetype=obj -mtriple=aarch64--linux-gnu -o - %s | llvm-dwarfdump -v - | FileCheck %s
+;
+; CHECK: .debug_info contents:
+; CHECK: DW_TAG_variable
+; CHECK-NOT: DW_AT_location
+
+ at var = thread_local global i32 0, align 4, !dbg !0
+
+; Function Attrs: noinline nounwind optnone
+define i32 @foo() #0 !dbg !11 {
+entry:
+  %0 = load i32, i32* @var, align 4, !dbg !14
+  ret i32 %0, !dbg !15
+}
+
+attributes #0 = { noinline nounwind optnone }
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!7, !8, !9}
+!llvm.ident = !{!10}
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "var", scope: !2, file: !3, line: 1, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 7.0.0 (https://github.com/llvm-mirror/clang.git 43eac1f9d7d2c985831b485d9ccc807416d1cf29) (https://github.com/llvm-mirror/llvm.git d53cdbf4cc5414ea540174a036202c555ce8fc4b)", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5)
+!3 = !DIFile(filename: "tls-at-location.c", directory: "/home/lliu0/llvm/tls-at-location/DebugInfo/AArch64")
+!4 = !{}
+!5 = !{!0}
+!6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!7 = !{i32 2, !"Dwarf Version", i32 4}
+!8 = !{i32 2, !"Debug Info Version", i32 3}
+!9 = !{i32 1, !"wchar_size", i32 4}
+!10 = !{!"clang version 7.0.0 (https://github.com/llvm-mirror/clang.git 43eac1f9d7d2c985831b485d9ccc807416d1cf29) (https://github.com/llvm-mirror/llvm.git d53cdbf4cc5414ea540174a036202c555ce8fc4b)"}
+!11 = distinct !DISubprogram(name: "foo", scope: !3, file: !3, line: 3, type: !12, isLocal: false, isDefinition: true, scopeLine: 3, isOptimized: false, unit: !2)
+!12 = !DISubroutineType(types: !13)
+!13 = !{!6}
+!14 = !DILocation(line: 4, column: 10, scope: !11)
+!15 = !DILocation(line: 4, column: 3, scope: !11)
Index: lib/Target/AArch64/AArch64TargetObjectFile.cpp
===================================================================
--- lib/Target/AArch64/AArch64TargetObjectFile.cpp
+++ lib/Target/AArch64/AArch64TargetObjectFile.cpp
@@ -22,6 +22,9 @@
                                              const TargetMachine &TM) {
   TargetLoweringObjectFileELF::Initialize(Ctx, TM);
   InitializeELF(TM.Options.UseInitArray);
+  // AARCH64 ELF ABI does not define static relocation type for TLS offset
+  // within a module.  Do not generate AT_location for TLS variables.
+  SupportDebugThreadLocalLocation = false;
 }
 
 AArch64_MachoTargetObjectFile::AArch64_MachoTargetObjectFile()
Index: lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
===================================================================
--- lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
+++ lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
@@ -186,6 +186,10 @@
     if (!Global && (!Expr || !Expr->isConstant()))
       continue;
 
+    if (Global && Global->isThreadLocal() &&
+        !Asm->getObjFileLowering().supportDebugThreadLocalLocation())
+      continue;
+
     if (!Loc) {
       addToAccelTable = true;
       Loc = new (DIEValueAllocator) DIELoc;
Index: include/llvm/Target/TargetLoweringObjectFile.h
===================================================================
--- include/llvm/Target/TargetLoweringObjectFile.h
+++ include/llvm/Target/TargetLoweringObjectFile.h
@@ -45,6 +45,7 @@
 protected:
   bool SupportIndirectSymViaGOTPCRel = false;
   bool SupportGOTPCRelWithOffset = true;
+  bool SupportDebugThreadLocalLocation = true;
 
   /// This section contains the static constructor pointer list.
   MCSection *StaticCtorSection = nullptr;
@@ -170,6 +171,11 @@
     return SupportGOTPCRelWithOffset;
   }
 
+  /// Target supports TLS offset relocation in debug section?
+  bool supportDebugThreadLocalLocation() const {
+    return SupportDebugThreadLocalLocation;
+  }
+
   /// Get the target specific PC relative GOT entry relocation
   virtual const MCExpr *getIndirectSymViaGOTPCRel(const MCSymbol *Sym,
                                                   const MCValue &MV,


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