COFF: Implement Safe SEH support for x86.

An object file compatible with Safe SEH contains a .sxdata section.
The section contains a list of symbol table indices, each of which
is an exception handler function. A safe SEH-enabled executable
contains a list of exception handler RVAs. So, what the linker has
to do to support Safe SEH is basically to read the .sxdata section,
interpret the contents as a list of symbol indices, unique-fy and
sort their RVAs, and then emit that list to .rdata. This patch
implements that feature.

llvm-svn: 243182

14 files changed, 545 insertions, 9 deletions

diff --git a/lld/COFF/Chunks.cpp b/lld/COFF/Chunks.cpp
index 4f1ac166847..30e52963da0 100644
--- a/lld/COFF/Chunks.cpp
+++ b/lld/COFF/Chunks.cpp
@@ -23,6 +23,7 @@ using namespace llvm;
 using namespace llvm::object;
 using namespace llvm::support::endian;
 using namespace llvm::COFF;
+using llvm::support::ulittle32_t;
 
 namespace lld {
 namespace coff {
@@ -280,6 +281,14 @@ void LocalImportChunk::writeTo(uint8_t *Buf) {
   }
 }
 
+void SEHTableChunk::writeTo(uint8_t *Buf) {
+  ulittle32_t *Begin = reinterpret_cast<ulittle32_t *>(Buf + FileOff);
+  size_t Cnt = 0;
+  for (Defined *D : Syms)
+    Begin[Cnt++] = D->getRVA();
+  std::sort(Begin, Begin + Cnt);
+}
+
 // Windows-specific.
 // This class represents a block in .reloc section.
 BaserelChunk::BaserelChunk(uint32_t Page, uint32_t *Begin, uint32_t *End) {
diff --git a/lld/COFF/Chunks.h b/lld/COFF/Chunks.h
index a069f31e945..e84c11e50e7 100644
--- a/lld/COFF/Chunks.h
+++ b/lld/COFF/Chunks.h
@@ -255,6 +255,19 @@ private:
 };
 
 // Windows-specific.
+// A chunk for SEH table which contains RVAs of safe exception handler
+// functions. x86-only.
+class SEHTableChunk : public Chunk {
+public:
+  explicit SEHTableChunk(std::set<Defined *> S) : Syms(S) {}
+  size_t getSize() const override { return Syms.size() * 4; }
+  void writeTo(uint8_t *Buf) override;
+
+private:
+  std::set<Defined *> Syms;
+};
+
+// Windows-specific.
 // This class represents a block in .reloc section.
 // See the PE/COFF spec 5.6 for details.
 class BaserelChunk : public Chunk {
diff --git a/lld/COFF/Config.h b/lld/COFF/Config.h
index 8fe537a9abd..d0ddc194e60 100644
--- a/lld/COFF/Config.h
+++ b/lld/COFF/Config.h
@@ -24,6 +24,8 @@ using llvm::COFF::IMAGE_FILE_MACHINE_AMD64;
 using llvm::COFF::IMAGE_FILE_MACHINE_UNKNOWN;
 using llvm::COFF::WindowsSubsystem;
 using llvm::StringRef;
+class DefinedAbsolute;
+class DefinedRelative;
 class Undefined;
 
 // Represents an /export option.
@@ -72,6 +74,10 @@ struct Configuration {
   std::set<std::string> DelayLoads;
   Undefined *DelayLoadHelper = nullptr;
 
+  // Used for SafeSEH.
+  DefinedRelative *SEHTable = nullptr;
+  DefinedAbsolute *SEHCount = nullptr;
+
   // Used for /opt:icf
   bool ICF = false;
 
diff --git a/lld/COFF/Driver.cpp b/lld/COFF/Driver.cpp
index 689892be489..7156b359e20 100644
--- a/lld/COFF/Driver.cpp
+++ b/lld/COFF/Driver.cpp
@@ -603,6 +603,10 @@ bool LinkerDriver::link(llvm::ArrayRef<const char *> ArgsArr) {
   }
 
   Symtab.addRelative(mangle("__ImageBase"), 0);
+  if (Config->MachineType == IMAGE_FILE_MACHINE_I386) {
+    Config->SEHTable = Symtab.addRelative("___safe_se_handler_table", 0);
+    Config->SEHCount = Symtab.addAbsolute("___safe_se_handler_count", 0);
+  }
 
   // Read as much files as we can from directives sections.
   if (auto EC = Symtab.run()) {
@@ -639,6 +643,12 @@ bool LinkerDriver::link(llvm::ArrayRef<const char *> ArgsArr) {
           U->WeakAlias = Symtab.addUndefined(To);
     }
 
+    // Windows specific -- if __load_config_used can be resolved, resolve it.
+    if (Config->MachineType == IMAGE_FILE_MACHINE_I386)
+      if (Symbol *Sym = Symtab.find("__load_config_used"))
+        if (isa<Lazy>(Sym->Body))
+          Symtab.addUndefined("__load_config_used");
+
     if (Symtab.queueEmpty())
       break;
     if (auto EC = Symtab.run()) {
diff --git a/lld/COFF/InputFiles.cpp b/lld/COFF/InputFiles.cpp
index d9312f633f3..4e5e34c3405 100644
--- a/lld/COFF/InputFiles.cpp
+++ b/lld/COFF/InputFiles.cpp
@@ -25,6 +25,7 @@ using namespace llvm::object;
 using namespace llvm::support::endian;
 using llvm::RoundUpToAlignment;
 using llvm::Triple;
+using llvm::support::ulittle32_t;
 using llvm::sys::fs::file_magic;
 using llvm::sys::fs::identify_magic;
 
@@ -112,7 +113,9 @@ std::error_code ObjectFile::parse() {
   // Read section and symbol tables.
   if (auto EC = initializeChunks())
     return EC;
-  return initializeSymbols();
+  if (auto EC = initializeSymbols())
+    return EC;
+  return initializeSEH();
 }
 
 std::error_code ObjectFile::initializeChunks() {
@@ -132,6 +135,10 @@ std::error_code ObjectFile::initializeChunks() {
                    << EC.message() << "\n";
       return make_error_code(LLDError::BrokenFile);
     }
+    if (Name == ".sxdata") {
+      SXData = Sec;
+      continue;
+    }
     if (Name == ".drectve") {
       ArrayRef<uint8_t> Data;
       COFFObj->getSectionContents(Sec, Data);
@@ -214,8 +221,14 @@ Defined *ObjectFile::createDefined(COFFSymbolRef Sym, const void *AuxP,
   if (Sym.isAbsolute()) {
     COFFObj->getSymbolName(Sym, Name);
     // Skip special symbols.
-    if (Name == "@comp.id" || Name == "@feat.00")
+    if (Name == "@comp.id")
       return nullptr;
+    // COFF spec 5.10.1. The .sxdata section.
+    if (Name == "@feat.00") {
+      if (Sym.getValue() & 1)
+        SEHCompat = true;
+      return nullptr;
+    }
     return new (Alloc) DefinedAbsolute(Name, Sym);
   }
   if (Sym.getSectionNumber() == llvm::COFF::IMAGE_SYM_DEBUG)
@@ -242,6 +255,22 @@ Defined *ObjectFile::createDefined(COFFSymbolRef Sym, const void *AuxP,
   return B;
 }
 
+std::error_code ObjectFile::initializeSEH() {
+  if (!SEHCompat || !SXData)
+    return std::error_code();
+  ArrayRef<uint8_t> A;
+  COFFObj->getSectionContents(SXData, A);
+  if (A.size() % 4 != 0) {
+    llvm::errs() << ".sxdata must be an array of symbol table indices\n";
+    return make_error_code(LLDError::BrokenFile);
+  }
+  auto *I = reinterpret_cast<const ulittle32_t *>(A.data());
+  auto *E = reinterpret_cast<const ulittle32_t *>(A.data() + A.size());
+  for (; I != E; ++I)
+    SEHandlers.insert(SparseSymbolBodies[*I]);
+  return std::error_code();
+}
+
 MachineTypes ObjectFile::getMachineType() {
   if (COFFObj)
     return static_cast<MachineTypes>(COFFObj->getMachine());
diff --git a/lld/COFF/InputFiles.h b/lld/COFF/InputFiles.h
index 361d97d8af1..6f201d66892 100644
--- a/lld/COFF/InputFiles.h
+++ b/lld/COFF/InputFiles.h
@@ -29,6 +29,7 @@ using llvm::COFF::MachineTypes;
 using llvm::object::Archive;
 using llvm::object::COFFObjectFile;
 using llvm::object::COFFSymbolRef;
+using llvm::object::coff_section;
 
 class Chunk;
 class Defined;
@@ -130,9 +131,18 @@ public:
   // Returns the underying COFF file.
   COFFObjectFile *getCOFFObj() { return COFFObj.get(); }
 
+  // True if this object file is compatible with SEH.
+  // COFF-specific and x86-only.
+  bool SEHCompat = false;
+
+  // The list of safe exception handlers listed in .sxdata section.
+  // COFF-specific and x86-only.
+  std::set<SymbolBody *> SEHandlers;
+
 private:
   std::error_code initializeChunks();
   std::error_code initializeSymbols();
+  std::error_code initializeSEH();
 
   Defined *createDefined(COFFSymbolRef Sym, const void *Aux, bool IsFirst);
   Undefined *createUndefined(COFFSymbolRef Sym);
@@ -140,6 +150,7 @@ private:
 
   std::unique_ptr<COFFObjectFile> COFFObj;
   llvm::BumpPtrAllocator Alloc;
+  const coff_section *SXData = nullptr;
 
   // List of all chunks defined by this file. This includes both section
   // chunks and non-section chunks for common symbols.
diff --git a/lld/COFF/SymbolTable.cpp b/lld/COFF/SymbolTable.cpp
index 14fb72480d9..d3f8b038460 100644
--- a/lld/COFF/SymbolTable.cpp
+++ b/lld/COFF/SymbolTable.cpp
@@ -317,8 +317,16 @@ Undefined *SymbolTable::addUndefined(StringRef Name) {
   return New;
 }
 
-void SymbolTable::addRelative(StringRef Name, uint64_t VA) {
-  addSymbol(new (Alloc) DefinedRelative(Name, VA));
+DefinedRelative *SymbolTable::addRelative(StringRef Name, uint64_t VA) {
+  auto *New = new (Alloc) DefinedRelative(Name, VA);
+  addSymbol(New);
+  return New;
+}
+
+DefinedAbsolute *SymbolTable::addAbsolute(StringRef Name, uint64_t VA) {
+  auto *New = new (Alloc) DefinedAbsolute(Name, VA);
+  addSymbol(New);
+  return New;
 }
 
 void SymbolTable::printMap(llvm::raw_ostream &OS) {
diff --git a/lld/COFF/SymbolTable.h b/lld/COFF/SymbolTable.h
index a8d12b876ae..479dce6fbcb 100644
--- a/lld/COFF/SymbolTable.h
+++ b/lld/COFF/SymbolTable.h
@@ -81,7 +81,8 @@ public:
 
   // Creates an Undefined symbol for a given name.
   Undefined *addUndefined(StringRef Name);
-  void addRelative(StringRef Name, uint64_t VA);
+  DefinedRelative *addRelative(StringRef Name, uint64_t VA);
+  DefinedAbsolute *addAbsolute(StringRef Name, uint64_t VA);
 
   // A list of chunks which to be added to .rdata.
   std::vector<Chunk *> LocalImportChunks;
diff --git a/lld/COFF/Symbols.h b/lld/COFF/Symbols.h
index 2730f9bc044..bb199a99be5 100644
--- a/lld/COFF/Symbols.h
+++ b/lld/COFF/Symbols.h
@@ -218,6 +218,7 @@ public:
   }
 
   uint64_t getRVA() { return VA - Config->ImageBase; }
+  void setVA(uint64_t V) { VA = V; }
 
 private:
   uint64_t VA;
diff --git a/lld/COFF/Writer.cpp b/lld/COFF/Writer.cpp
index 8825f664f90..1245a21da37 100644
--- a/lld/COFF/Writer.cpp
+++ b/lld/COFF/Writer.cpp
@@ -58,6 +58,7 @@ std::error_code Writer::write(StringRef OutputPath) {
   } else {
     writeHeader<pe32_header>();
   }
+  fixSafeSEHSymbols();
   writeSections();
   sortExceptionTable();
   return Buffer->commit();
@@ -211,11 +212,25 @@ void Writer::createSections() {
 }
 
 void Writer::createMiscChunks() {
-  if (Symtab->LocalImportChunks.empty())
+  // Create thunks for locally-dllimported symbols.
+  if (!Symtab->LocalImportChunks.empty()) {
+    OutputSection *Sec = createSection(".rdata");
+    for (Chunk *C : Symtab->LocalImportChunks)
+      Sec->addChunk(C);
+  }
+
+  // Create SEH table. x86-only.
+  if (Config->MachineType != IMAGE_FILE_MACHINE_I386)
     return;
-  OutputSection *Sec = createSection(".rdata");
-  for (Chunk *C : Symtab->LocalImportChunks)
-    Sec->addChunk(C);
+  std::set<Defined *> Handlers;
+  for (ObjectFile *File : Symtab->ObjectFiles) {
+    if (!File->SEHCompat)
+      return;
+    for (SymbolBody *B : File->SEHandlers)
+      Handlers.insert(cast<Defined>(B->repl()));
+  }
+  SEHTable.reset(new SEHTableChunk(Handlers));
+  createSection(".rdata")->addChunk(SEHTable.get());
 }
 
 // Create .idata section for the DLL-imported symbol table.
@@ -524,6 +539,13 @@ std::error_code Writer::openFile(StringRef Path) {
   return std::error_code();
 }
 
+void Writer::fixSafeSEHSymbols() {
+  if (!SEHTable)
+    return;
+  Config->SEHTable->setRVA(SEHTable->getRVA());
+  Config->SEHCount->setVA(SEHTable->getSize() / 4);
+}
+
 // Write section contents to a mmap'ed file.
 void Writer::writeSections() {
   uint8_t *Buf = Buffer->getBufferStart();
diff --git a/lld/COFF/Writer.h b/lld/COFF/Writer.h
index fdeb28a5941..5af6b3d0660 100644
--- a/lld/COFF/Writer.h
+++ b/lld/COFF/Writer.h
@@ -89,6 +89,7 @@ private:
   void createSymbolAndStringTable();
   std::error_code openFile(StringRef OutputPath);
   template <typename PEHeaderTy> void writeHeader();
+  void fixSafeSEHSymbols();
   void writeSections();
   void sortExceptionTable();
   void applyRelocations();
@@ -114,6 +115,7 @@ private:
   IdataContents Idata;
   DelayLoadContents DelayIdata;
   EdataContents Edata;
+  std::unique_ptr<SEHTableChunk> SEHTable;
 
   bool Is64;
   uint64_t FileSize;
diff --git a/lld/test/COFF/Inputs/seh.c b/lld/test/COFF/Inputs/seh.c
new file mode 100644
index 00000000000..b1c139a58f2
--- /dev/null
+++ b/lld/test/COFF/Inputs/seh.c
@@ -0,0 +1,13 @@
+__declspec(noinline) void triggerSEH() {
+  volatile int *p = 0;
+  *p = 1;
+}
+
+int main() {
+  __try {
+    triggerSEH();
+  } __except(1) {
+    return 42;
+  }
+  return 0;
+}
diff --git a/lld/test/COFF/Inputs/seh.obj.yaml b/lld/test/COFF/Inputs/seh.obj.yaml
new file mode 100644
index 00000000000..6767671cdaf
--- /dev/null
+++ b/lld/test/COFF/Inputs/seh.obj.yaml
@@ -0,0 +1,387 @@
+---
+header:
+  Machine:         IMAGE_FILE_MACHINE_I386
+  Characteristics: [  ]
+sections:
+  - Name:            .drectve
+    Characteristics: [ IMAGE_SCN_LNK_INFO, IMAGE_SCN_LNK_REMOVE ]
+    Alignment:       1
+    SectionData:     2020202F44454641554C544C49423A22757569642E6C696222202F44454641554C544C49423A22757569642E6C696222202F4641494C49464D49534D415443483A225F4D53435F5645523D3138303022202F4641494C49464D49534D415443483A225F4954455241544F525F44454255475F4C4556454C3D3022202F4641494C49464D49534D415443483A2252756E74696D654C6962726172793D4D445F44796E616D696352656C6561736522202F44454641554C544C49423A226D73766370727422202F44454641554C544C49423A224D535643525422202F44454641554C544C49423A224F4C444E414D45532220
+  - Name:            '.debug$S'
+    Characteristics: [ IMAGE_SCN_CNT_INITIALIZED_DATA, IMAGE_SCN_MEM_DISCARDABLE, IMAGE_SCN_MEM_READ ]
+    Alignment:       1
+    SectionData:     04000000F1000000600000002200011100000000433A5C63796777696E5C686F6D655C727569755C7365682E6F626A003A003C11012200000700120000000D520100120000000D5201004D6963726F736F667420285229204F7074696D697A696E6720436F6D70696C657200
+  - Name:            .rdata
+    Characteristics: [ IMAGE_SCN_CNT_INITIALIZED_DATA, IMAGE_SCN_LNK_COMDAT, IMAGE_SCN_MEM_READ ]
+    Alignment:       1
+    SectionData:     00
+  - Name:            .rdata
+    Characteristics: [ IMAGE_SCN_CNT_INITIALIZED_DATA, IMAGE_SCN_LNK_COMDAT, IMAGE_SCN_MEM_READ ]
+    Alignment:       1
+    SectionData:     01
+  - Name:            .rdata
+    Characteristics: [ IMAGE_SCN_CNT_INITIALIZED_DATA, IMAGE_SCN_MEM_READ ]
+    Alignment:       4
+    SectionData:     54726967676572696E672053454820657863657074696F6E0D0A0000457865637574696E6720534548205F5F65786365707420626C6F636B20696E20666F6F0D0A000000457865637574696E6720534548205F5F65786365707420626C6F636B0D0A00
+  - Name:            '.text$mn'
+    Characteristics: [ IMAGE_SCN_CNT_CODE, IMAGE_SCN_MEM_EXECUTE, IMAGE_SCN_MEM_READ ]
+    Alignment:       16
+    SectionData:     558BEC516800000000FF150000000083C404C745FC000000008B45FCC700140000008BE55DC3CCCCCCCCCCCCCCCCCCCC558BEC51E8000000008D4DFFE8000000008BE55DC3CCCCCCCCCCCCCCCCCCCCCC558BEC6AFE6800000000680000000064A1000000005083EC08535657A1000000003145F833C5508D45F064A3000000008965E8C745FC00000000E800000000C745FCFEFFFFFFEB1EB801000000C38B65E86800000000FF150000000083C404C745FCFEFFFFFF8B4DF064890D00000000595F5E5B8BE55DC3CCCCCCCCCCCCCCCC558BEC6AFE6800000000680000000064A1000000005083EC08535657A1000000003145F833C5508D45F064A3000000008965E8C745FC00000000E800000000E800000000C745FCFEFFFFFFEB1EB801000000C38B65E86800000000FF150000000083C404C745FCFEFFFFFF33C08B4DF064890D00000000595F5E5B8BE55DC3
+    Relocations:
+      - VirtualAddress:  5
+        SymbolName:      '$SG73531'
+        Type:            IMAGE_REL_I386_DIR32
+      - VirtualAddress:  11
+        SymbolName:      __imp__printf
+        Type:            IMAGE_REL_I386_DIR32
+      - VirtualAddress:  53
+        SymbolName:      '?TestCPPEX@@YAXXZ'
+        Type:            IMAGE_REL_I386_REL32
+      - VirtualAddress:  61
+        SymbolName:      '??1TestClass@@QAE@XZ'
+        Type:            IMAGE_REL_I386_REL32
+      - VirtualAddress:  86
+        SymbolName:      '__sehtable$?foo@@YAXXZ'
+        Type:            IMAGE_REL_I386_DIR32
+      - VirtualAddress:  91
+        SymbolName:      __except_handler4
+        Type:            IMAGE_REL_I386_DIR32
+      - VirtualAddress:  109
+        SymbolName:      ___security_cookie
+        Type:            IMAGE_REL_I386_DIR32
+      - VirtualAddress:  139
+        SymbolName:      '?TestExceptions@@YAXXZ'
+        Type:            IMAGE_REL_I386_REL32
+      - VirtualAddress:  162
+        SymbolName:      '$SG73539'
+        Type:            IMAGE_REL_I386_DIR32
+      - VirtualAddress:  168
+        SymbolName:      __imp__printf
+        Type:            IMAGE_REL_I386_DIR32
+      - VirtualAddress:  214
+        SymbolName:      '__sehtable$_main'
+        Type:            IMAGE_REL_I386_DIR32
+      - VirtualAddress:  219
+        SymbolName:      __except_handler4
+        Type:            IMAGE_REL_I386_DIR32
+      - VirtualAddress:  237
+        SymbolName:      ___security_cookie
+        Type:            IMAGE_REL_I386_DIR32
+      - VirtualAddress:  267
+        SymbolName:      '?foo@@YAXXZ'
+        Type:            IMAGE_REL_I386_REL32
+      - VirtualAddress:  272
+        SymbolName:      '?TestExceptions@@YAXXZ'
+        Type:            IMAGE_REL_I386_REL32
+      - VirtualAddress:  295
+        SymbolName:      '$SG73543'
+        Type:            IMAGE_REL_I386_DIR32
+      - VirtualAddress:  301
+        SymbolName:      __imp__printf
+        Type:            IMAGE_REL_I386_DIR32
+  - Name:            '.text$mn'
+    Characteristics: [ IMAGE_SCN_CNT_CODE, IMAGE_SCN_LNK_COMDAT, IMAGE_SCN_MEM_EXECUTE, IMAGE_SCN_MEM_READ ]
+    Alignment:       16
+    SectionData:     558BEC51894DFC6800000000FF150000000083C4048BE55DC3
+    Relocations:
+      - VirtualAddress:  8
+        SymbolName:      '??_C@_0BI@BBHGNMOG@Destroying?5TestClass?$CB?$AN?6?$AA@'
+        Type:            IMAGE_REL_I386_DIR32
+      - VirtualAddress:  14
+        SymbolName:      __imp__printf
+        Type:            IMAGE_REL_I386_DIR32
+  - Name:            '.xdata$x'
+    Characteristics: [ IMAGE_SCN_CNT_INITIALIZED_DATA, IMAGE_SCN_MEM_READ ]
+    Alignment:       8
+    SectionData:     FEFFFFFF00000000D8FFFFFF00000000FEFFFFFF000000000000000000000000FEFFFFFF00000000D8FFFFFF00000000FEFFFFFF0000000000000000
+    Relocations:
+      - VirtualAddress:  20
+        SymbolName:      '$LN5'
+        Type:            IMAGE_REL_I386_DIR32
+      - VirtualAddress:  24
+        SymbolName:      '$LN6'
+        Type:            IMAGE_REL_I386_DIR32
+      - VirtualAddress:  52
+        SymbolName:      '$LN5'
+        Type:            IMAGE_REL_I386_DIR32
+      - VirtualAddress:  56
+        SymbolName:      '$LN6'
+        Type:            IMAGE_REL_I386_DIR32
+  - Name:            .rdata
+    Characteristics: [ IMAGE_SCN_CNT_INITIALIZED_DATA, IMAGE_SCN_LNK_COMDAT, IMAGE_SCN_MEM_READ ]
+    Alignment:       4
+    SectionData:     44657374726F79696E672054657374436C617373210D0A00
+  - Name:            .sxdata
+    Characteristics: [ IMAGE_SCN_LNK_INFO ]
+    Alignment:       4
+    SectionData:     1B0000001A000000
+symbols:
+  - Name:            '@comp.id'
+    Value:           14766605
+    SectionNumber:   65535
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+  - Name:            '@feat.00'
+    Value:           2147484049
+    SectionNumber:   65535
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+  - Name:            .drectve
+    Value:           0
+    SectionNumber:   1
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+    SectionDefinition:
+      Length:          240
+      NumberOfRelocations: 0
+      NumberOfLinenumbers: 0
+      CheckSum:        0
+      Number:          0
+  - Name:            '.debug$S'
+    Value:           0
+    SectionNumber:   2
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+    SectionDefinition:
+      Length:          108
+      NumberOfRelocations: 0
+      NumberOfLinenumbers: 0
+      CheckSum:        0
+      Number:          0
+  - Name:            .rdata
+    Value:           0
+    SectionNumber:   3
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+    SectionDefinition:
+      Length:          1
+      NumberOfRelocations: 0
+      NumberOfLinenumbers: 0
+      CheckSum:        0
+      Number:          0
+      Selection:       IMAGE_COMDAT_SELECT_ANY
+  - Name:            '?value@?$integral_constant@_N$0A@@std@@2_NB'
+    Value:           0
+    SectionNumber:   3
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
+  - Name:            .rdata
+    Value:           0
+    SectionNumber:   4
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+    SectionDefinition:
+      Length:          1
+      NumberOfRelocations: 0
+      NumberOfLinenumbers: 0
+      CheckSum:        1996959894
+      Number:          0
+      Selection:       IMAGE_COMDAT_SELECT_ANY
+  - Name:            '?value@?$integral_constant@_N$00@std@@2_NB'
+    Value:           0
+    SectionNumber:   4
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
+  - Name:            .rdata
+    Value:           0
+    SectionNumber:   5
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+    SectionDefinition:
+      Length:          99
+      NumberOfRelocations: 0
+      NumberOfLinenumbers: 0
+      CheckSum:        2801625422
+      Number:          0
+  - Name:            '$SG73531'
+    Value:           0
+    SectionNumber:   5
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+  - Name:            '$SG73539'
+    Value:           28
+    SectionNumber:   5
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+  - Name:            '$SG73543'
+    Value:           68
+    SectionNumber:   5
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+  - Name:            '.text$mn'
+    Value:           0
+    SectionNumber:   6
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+    SectionDefinition:
+      Length:          335
+      NumberOfRelocations: 17
+      NumberOfLinenumbers: 0
+      CheckSum:        2488225337
+      Number:          0
+  - Name:            '.text$mn'
+    Value:           0
+    SectionNumber:   7
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+    SectionDefinition:
+      Length:          25
+      NumberOfRelocations: 2
+      NumberOfLinenumbers: 0
+      CheckSum:        210566957
+      Number:          0
+      Selection:       IMAGE_COMDAT_SELECT_ANY
+  - Name:            __imp__printf
+    Value:           0
+    SectionNumber:   0
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
+  - Name:            '??1TestClass@@QAE@XZ'
+    Value:           0
+    SectionNumber:   7
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_FUNCTION
+    StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
+  - Name:            '?TestCPPEX@@YAXXZ'
+    Value:           0
+    SectionNumber:   6
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_FUNCTION
+    StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
+  - Name:            '?TestExceptions@@YAXXZ'
+    Value:           48
+    SectionNumber:   6
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_FUNCTION
+    StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
+  - Name:            '?foo@@YAXXZ'
+    Value:           80
+    SectionNumber:   6
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_FUNCTION
+    StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
+  - Name:            _main
+    Value:           208
+    SectionNumber:   6
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_FUNCTION
+    StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
+  - Name:            __except_handler4
+    Value:           0
+    SectionNumber:   0
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_FUNCTION
+    StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
+  - Name:            '$LN5'
+    Value:           152
+    SectionNumber:   6
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_LABEL
+  - Name:            '$LN7'
+    Value:           157
+    SectionNumber:   6
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_LABEL
+  - Name:            '$LN6'
+    Value:           158
+    SectionNumber:   6
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_LABEL
+  - Name:            '$LN5'
+    Value:           285
+    SectionNumber:   6
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_LABEL
+  - Name:            '$LN7'
+    Value:           290
+    SectionNumber:   6
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_LABEL
+  - Name:            '$LN6'
+    Value:           291
+    SectionNumber:   6
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_LABEL
+  - Name:            '.xdata$x'
+    Value:           0
+    SectionNumber:   8
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+    SectionDefinition:
+      Length:          60
+      NumberOfRelocations: 4
+      NumberOfLinenumbers: 0
+      CheckSum:        2900129504
+      Number:          0
+  - Name:            '__sehtable$?foo@@YAXXZ'
+    Value:           32
+    SectionNumber:   8
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+  - Name:            '__sehtable$_main'
+    Value:           0
+    SectionNumber:   8
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+  - Name:            .rdata
+    Value:           0
+    SectionNumber:   9
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+    SectionDefinition:
+      Length:          24
+      NumberOfRelocations: 0
+      NumberOfLinenumbers: 0
+      CheckSum:        1296623929
+      Number:          0
+      Selection:       IMAGE_COMDAT_SELECT_ANY
+  - Name:            '??_C@_0BI@BBHGNMOG@Destroying?5TestClass?$CB?$AN?6?$AA@'
+    Value:           0
+    SectionNumber:   9
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
+  - Name:            ___security_cookie
+    Value:           0
+    SectionNumber:   0
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
+  - Name:            .sxdata
+    Value:           0
+    SectionNumber:   10
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+    SectionDefinition:
+      Length:          4
+      NumberOfRelocations: 0
+      NumberOfLinenumbers: 0
+      CheckSum:        0
+      Number:          0
+...
diff --git a/lld/test/COFF/seh.test b/lld/test/COFF/seh.test
new file mode 100644
index 00000000000..2082aad1e35
--- /dev/null
+++ b/lld/test/COFF/seh.test
@@ -0,0 +1,24 @@
+# RUN: yaml2obj %p/Inputs/seh.obj.yaml > %t.obj
+#
+# RUN: lld -flavor link /out:%t.exe /subsystem:console /force /nodefaultlib %t.obj
+# RUN: llvm-objdump -private-headers %t.exe | FileCheck %s
+
+CHECK: Load configuration:
+CHECK:   Timestamp: 0
+CHECK:   Major Version: 0
+CHECK:   Minor Version: 0
+CHECK:   GlobalFlags Clear: 0
+CHECK:   GlobalFlags Set: 0
+CHECK:   Critical Section Default Timeout: 0
+CHECK:   Decommit Free Block Threshold: 0
+CHECK:   Decommit Total Free Threshold: 0
+CHECK:   Lock Prefix Table: 0
+CHECK:   Maximum Allocation Size: 0
+CHECK:   Virtual Memory Threshold: 0
+CHECK:   Process Affinity Mask: 0
+CHECK:   Process Heap Flags: 0
+CHECK:   CSD Version: 0
+CHECK:   Security Cookie: 0
+CHECK:   SEH Table: 4206592
+CHECK:   SEH Count: 2
+CHECK: SEH Table: 0x80001b 0x8040ea