[dsymutil] Emit valid debug locations when no symbol flags are set

Summary:
swiftc emits symbols without flags set, which led dsymutil to ignore
them when searching for global symbols, causing dwarf location data
to be omitted. Xcode's dsymutil handles this case correctly, and emits
valid location data. Add this functionality to llvm-dsymutil by
allowing parsing of symbols with no flags set.

Reviewers: aprantl, friss, JDevlieghere

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D38587

llvm-svn: 315218

3 files changed, 37 insertions, 0 deletions

diff --git a/llvm/test/tools/dsymutil/Inputs/swift-dwarf-loc.macho.x86_64 b/llvm/test/tools/dsymutil/Inputs/swift-dwarf-loc.macho.x86_64
new file mode 100755
index 00000000000..b232e509442
--- /dev/null
+++ b/llvm/test/tools/dsymutil/Inputs/swift-dwarf-loc.macho.x86_64
diff --git a/llvm/test/tools/dsymutil/Inputs/swift-dwarf-loc.macho.x86_64.o b/llvm/test/tools/dsymutil/Inputs/swift-dwarf-loc.macho.x86_64.o
new file mode 100644
index 00000000000..2e34ce3de5b
--- /dev/null
+++ b/llvm/test/tools/dsymutil/Inputs/swift-dwarf-loc.macho.x86_64.o
diff --git a/llvm/test/tools/dsymutil/X86/swift-dwarf-loc.test b/llvm/test/tools/dsymutil/X86/swift-dwarf-loc.test
new file mode 100644
index 00000000000..29310cae6a4
--- /dev/null
+++ b/llvm/test/tools/dsymutil/X86/swift-dwarf-loc.test
@@ -0,0 +1,37 @@
+RUN: llvm-dsymutil -oso-prepend-path %p/../Inputs %p/../Inputs/swift-dwarf-loc.macho.x86_64 -no-output -verbose | FileCheck %s
+
+This test checks that dsymutil generates a valid dwarf location for a symbol with no flags set.
+
+The following IR was compiled for x86_64-apple:
+; ModuleID = '-'
+source_filename = "-"
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.12"
+
+%TSi = type <{ i64 }>
+
+@_var = hidden global %TSi zeroinitializer, align 8, !dbg !0
+
+!llvm.dbg.cu = !{!8}
+!llvm.module.flags = !{!11, !12}
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "x", linkageName: "_var", scope: !2, file: !3, line: 1, type: !4, isLocal: false, isDefinition: true)
+!2 = !DIModule(scope: null, name: "main")
+!3 = !DIFile(filename: "<stdin>", directory: "")
+!4 = !DICompositeType(tag: DW_TAG_structure_type, name: "Int", scope: !6, file: !5, size: 64, elements: !7, runtimeLang: DW_LANG_Swift, identifier: "_T0SiD")
+!5 = !DIFile(filename: "foo", directory: "/tmp")
+!6 = !DIModule(scope: null, name: "foo", includePath: "")
+!7 = !{}
+!8 = distinct !DICompileUnit(language: DW_LANG_Swift, file: !9, producer: "swiftc", isOptimized: false, flags: "", runtimeVersion: 4, emissionKind: FullDebug, enums: !7, globals: !10, imports: null)
+!9 = !DIFile(filename: "/tmp", directory: "")
+!10 = !{!0}
+!11 = !{i32 2, !"Dwarf Version", i32 4}
+!12 = !{i32 2, !"Debug Info Version", i32 3}
+
+Compiled with: llc -filetype=obj %p/../Inputs/swift-dwarf-loc.ll -mtriple x86_64-apple-darwin
+Linked with: ld -dylib %T/swift-dwarf-loc.o -arch x86_64 -lSystem -macosx_version_min 10.9.0
+
+CHECK: __var,
+CHECK-NOT: __var,{{.*}}binAddr: 0x0000000000000000
+CHECK-NOT: __var{{.*}} => 0000000000000000