[llvm] r315082 - [dsymutil] Emit valid debug locations when no symbol flags are set

[Francis Ricci via llvm-commits]

Author: fjricci
Date: Fri Oct  6 10:43:37 2017
New Revision: 315082

URL: http://llvm.org/viewvc/llvm-project?rev=315082&view=rev
Log:
[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

Added:
    llvm/trunk/test/tools/dsymutil/Inputs/swift-dwarf-loc.ll
    llvm/trunk/test/tools/dsymutil/X86/swift-dwarf-loc.test
Modified:
    llvm/trunk/tools/dsymutil/MachODebugMapParser.cpp

Added: llvm/trunk/test/tools/dsymutil/Inputs/swift-dwarf-loc.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/dsymutil/Inputs/swift-dwarf-loc.ll?rev=315082&view=auto
==============================================================================
--- llvm/trunk/test/tools/dsymutil/Inputs/swift-dwarf-loc.ll (added)
+++ llvm/trunk/test/tools/dsymutil/Inputs/swift-dwarf-loc.ll Fri Oct  6 10:43:37 2017
@@ -0,0 +1,25 @@
+; 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 }>
+
+ at _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}

Added: llvm/trunk/test/tools/dsymutil/X86/swift-dwarf-loc.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/dsymutil/X86/swift-dwarf-loc.test?rev=315082&view=auto
==============================================================================
--- llvm/trunk/test/tools/dsymutil/X86/swift-dwarf-loc.test (added)
+++ llvm/trunk/test/tools/dsymutil/X86/swift-dwarf-loc.test Fri Oct  6 10:43:37 2017
@@ -0,0 +1,9 @@
+RUN: llc -filetype=obj %p/../Inputs/swift-dwarf-loc.ll -mtriple x86_64-apple-darwin -o %T/swift-dwarf-loc.o
+RUN: ld -dylib %T/swift-dwarf-loc.o -arch x86_64 -lSystem -macosx_version_min 10.9.0 -o %T/swift-dwarf-loc
+RUN: llvm-dsymutil %T/swift-dwarf-loc -no-output -verbose | FileCheck %s
+
+This test checks that dsymutil generates a valid dwarf location for a symbol with no flags set.
+
+CHECK: __var,
+CHECK-NOT: __var,{{.*}}binAddr: 0x0000000000000000
+CHECK-NOT: __var{{.*}} => 0000000000000000

Modified: llvm/trunk/tools/dsymutil/MachODebugMapParser.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/dsymutil/MachODebugMapParser.cpp?rev=315082&r1=315081&r2=315082&view=diff
==============================================================================
--- llvm/trunk/tools/dsymutil/MachODebugMapParser.cpp (original)
+++ llvm/trunk/tools/dsymutil/MachODebugMapParser.cpp Fri Oct  6 10:43:37 2017
@@ -482,7 +482,9 @@ void MachODebugMapParser::loadMainBinary
     // are the only ones that need to be queried because the address
     // of common data won't be described in the debug map. All other
     // addresses should be fetched for the debug map.
-    if (!(Sym.getFlags() & SymbolRef::SF_Global))
+    uint8_t SymType =
+        MainBinary.getSymbolTableEntry(Sym.getRawDataRefImpl()).n_type;
+    if (!(SymType & (MachO::N_EXT | MachO::N_PEXT)))
       continue;
     Expected<section_iterator> SectionOrErr = Sym.getSection();
     if (!SectionOrErr) {