7 files changed, 39 insertions, 0 deletions
diff --git a/llvm/include/llvm/Object/MachO.h b/llvm/include/llvm/Object/MachO.h
index a4ecc51a6fa..03fd52fb482 100644
--- a/llvm/include/llvm/Object/MachO.h
+++ b/llvm/include/llvm/Object/MachO.h
@@ -310,6 +310,16 @@ public:
   bool isSectionBSS(DataRefImpl Sec) const override;
   bool isSectionVirtual(DataRefImpl Sec) const override;
   bool isSectionBitcode(DataRefImpl Sec) const override;
+
+  /// When dsymutil generates the companion file, it strips all unnecessary
+  /// sections (e.g. everything in the _TEXT segment) by omitting their body
+  /// and setting the offset in their corresponding load command to zero.
+  ///
+  /// While the load command itself is valid, reading the section corresponds
+  /// to reading the number of bytes specified in the load command, starting
+  /// from offset 0 (i.e. the Mach-O header at the beginning of the file).
+  bool isSectionStripped(DataRefImpl Sec) const override;
+
   relocation_iterator section_rel_begin(DataRefImpl Sec) const override;
   relocation_iterator section_rel_end(DataRefImpl Sec) const override;
 
diff --git a/llvm/include/llvm/Object/ObjectFile.h b/llvm/include/llvm/Object/ObjectFile.h
index 867c218c2a9..57496373973 100644
--- a/llvm/include/llvm/Object/ObjectFile.h
+++ b/llvm/include/llvm/Object/ObjectFile.h
@@ -109,6 +109,7 @@ public:
   bool isBSS() const;
   bool isVirtual() const;
   bool isBitcode() const;
+  bool isStripped() const;
 
   bool containsSymbol(SymbolRef S) const;
 
@@ -236,6 +237,7 @@ protected:
   // A section is 'virtual' if its contents aren't present in the object image.
   virtual bool isSectionVirtual(DataRefImpl Sec) const = 0;
   virtual bool isSectionBitcode(DataRefImpl Sec) const;
+  virtual bool isSectionStripped(DataRefImpl Sec) const;
   virtual relocation_iterator section_rel_begin(DataRefImpl Sec) const = 0;
   virtual relocation_iterator section_rel_end(DataRefImpl Sec) const = 0;
   virtual section_iterator getRelocatedSection(DataRefImpl Sec) const;
@@ -442,6 +444,10 @@ inline bool SectionRef::isBitcode() const {
   return OwningObject->isSectionBitcode(SectionPimpl);
 }
 
+inline bool SectionRef::isStripped() const {
+  return OwningObject->isSectionStripped(SectionPimpl);
+}
+
 inline relocation_iterator SectionRef::relocation_begin() const {
   return OwningObject->section_rel_begin(SectionPimpl);
 }
diff --git a/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp b/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
index 59cf636e604..156c65ad92a 100644
--- a/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
@@ -1135,6 +1135,10 @@ public:
       if (Section.isBSS() || Section.isVirtual())
         continue;
 
+      // Skip sections stripped by dsymutil.
+      if (Section.isStripped())
+        continue;
+
       StringRef Data;
       section_iterator RelocatedSection = Section.getRelocatedSection();
       // Try to obtain an already relocated version of this section.
diff --git a/llvm/lib/Object/MachOObjectFile.cpp b/llvm/lib/Object/MachOObjectFile.cpp
index b943c4063d6..7b4be973a09 100644
--- a/llvm/lib/Object/MachOObjectFile.cpp
+++ b/llvm/lib/Object/MachOObjectFile.cpp
@@ -1928,6 +1928,12 @@ bool MachOObjectFile::isSectionBitcode(DataRefImpl Sec) const {
   return false;
 }
 
+bool MachOObjectFile::isSectionStripped(DataRefImpl Sec) const {
+  if (is64Bit())
+    return getSection64(Sec).offset == 0;
+  return getSection(Sec).offset == 0;
+}
+
 relocation_iterator MachOObjectFile::section_rel_begin(DataRefImpl Sec) const {
   DataRefImpl Ret;
   Ret.d.a = Sec.d.a;
diff --git a/llvm/lib/Object/ObjectFile.cpp b/llvm/lib/Object/ObjectFile.cpp
index 67818409986..2b80d0bf538 100644
--- a/llvm/lib/Object/ObjectFile.cpp
+++ b/llvm/lib/Object/ObjectFile.cpp
@@ -75,6 +75,8 @@ bool ObjectFile::isSectionBitcode(DataRefImpl Sec) const {
   return false;
 }
 
+bool ObjectFile::isSectionStripped(DataRefImpl Sec) const { return false; }
+
 section_iterator ObjectFile::getRelocatedSection(DataRefImpl Sec) const {
   return section_iterator(SectionRef(Sec, this));
 }
diff --git a/llvm/test/tools/llvm-dwarfdump/X86/Inputs/empty.dSYM b/llvm/test/tools/llvm-dwarfdump/X86/Inputs/empty.dSYM
new file mode 100644
index 00000000000..5f7962d2e4f
--- /dev/null
+++ b/llvm/test/tools/llvm-dwarfdump/X86/Inputs/empty.dSYM
diff --git a/llvm/test/tools/llvm-dwarfdump/X86/stripped.test b/llvm/test/tools/llvm-dwarfdump/X86/stripped.test
new file mode 100644
index 00000000000..1eaf1925105
--- /dev/null
+++ b/llvm/test/tools/llvm-dwarfdump/X86/stripped.test
@@ -0,0 +1,11 @@
+RUN: llvm-dwarfdump -debug-frame %S/Inputs/empty.dSYM | FileCheck %s
+
+You can generate an empty dSYM companion file by invoking dsymutil on any
+object file.
+
+CHECK: .debug_frame contents:
+CHECK-NOT: CIE
+CHECK-NOT: FDE
+CHECK: .eh_frame contents:
+CHECK-NOT: CIE
+CHECK-NOT: FDE