[COFF] Implement /safeseh:no and check @feat.00 flags by default

[rnk]

Summary

Fixes PR41828. Before this, LLD always emitted SafeSEH chunks and
defined __safe_se_handler_table & size. Now, /safeseh:no leaves those
undefined.

Additionally, we were checking for the safeseh @feat.00 flag in two
places: once to emit errors, and once during safeseh table construction.
The error was set up to be off by default, but safeseh is supposed to be
on by default. I combined the two checks, so now LLD emits an error if
an input object lacks @feat.00 and safeseh is enabled. This caused the
majority of 32-bit LLD tests to fail, since many test input object files
lack @feat.00 symbols. I explicitly added -safeseh:no to those tests to
preserve behavior.

Finally, LLD no longer sets IMAGE_DLL_CHARACTERISTICS_NO_SEH if any
input file wasn't compiled for safeseh.

[mstorsjo]

lld/COFF/Driver.cpp

1537 ↗

(On Diff #205661)

Should the default be off in the mingw case, if linking objects from gcc?

lld/COFF/Writer.cpp

1431 ↗

(On Diff #205661)

Changing this flag for writing different output, right after flagging an error (which will, eventually, abort the writing?) feels a bit weird, but I guess it's good for completeness.

[thakis]

Thanks for doing this1

lld/COFF/Driver.cpp

1765 ↗

(On Diff #205661)

Huh, why was the default here false?

lld/COFF/Writer.cpp

1431 ↗

(On Diff #205661)

I agree, I would've expected an early return instead. (e.g. the if (ErrorCount) return after the loop that the lhs has)

[ruiu]

LGTM

Sorry, I thought that I reviewed this alreayd.

[mstorsjo]

lld/COFF/Driver.cpp

1537 ↗

(On Diff #205661)

I tested this patch now, and indeed, either the default needs to be different if Config->MinGW is true, or the MinGW driver needs to pass -safeseh:no by default.

[rnk]

lld/COFF/Driver.cpp

1537 ↗

(On Diff #205661)

I figured as much. :) Glad I waited. I think today for mingw we silently don't emit a safeseh table, because we stop as soon as we find an object file without the @feat.00 bit set. So, I think if we change this default to !Config->Mingw, that will be the smallest change in behavior.

I think it might be useful to expose a mode for mingw that assumes that object files that lack the @feat.00 bit have no SEH, but that would be a new feature.

1765 ↗

(On Diff #205661)

Unclear, but it probably had to be since it wouldn't have worked at all for mingw.

lld/COFF/Writer.cpp

1431 ↗

(On Diff #205661)

I guess I was anticipating having to downgrade this to a warning. I'll remove it.

[rnk]

• change default
• simplify

[mstorsjo]

LGTM, although you still have to rebase it past the change to camelBack casing of variables :-)

lld/test/COFF/dllexport-mingw.s

5 ↗

(On Diff #209990)

Aren't many of the test changes redundant, in the places where we have -lldmingw? Although it might be good for consistency...

[rnk]

• rebase

lld/trunk/COFF/Config.h

struct Configuration {
   Symbol *delayLoadHelper = nullptr;
 
   bool saveTemps = false;
 
   // /guard:cf
   GuardCFLevel guardCF = GuardCFLevel::Off;
 
   // Used for SafeSEH.
+  bool safeSEH = false;
   Symbol *sehTable = nullptr;
   Symbol *sehCount = nullptr;
 
   // Used for /opt:lldlto=N
   unsigned ltoo = 2;
 
   // Used for /opt:lldltojobs=N
   unsigned thinLTOJobs = 0;

lld/trunk/COFF/Driver.cpp

void LinkerDriver::link(ArrayRef<const char *> argsArr) {
   // We should have inferred a machine type by now from the input files, but if
   // not we assume x64.
   if (config->machine == IMAGE_FILE_MACHINE_UNKNOWN) {
     warn("/machine is not specified. x64 is assumed");
     config->machine = AMD64;
   }
   config->wordsize = config->is64() ? 8 : 4;
 
+  // Handle /safeseh, x86 only, on by default, except for mingw.
+  if (config->machine == I386 &&
+      args.hasFlag(OPT_safeseh, OPT_safeseh_no, !config->mingw))
+    config->safeSEH = true;
+
   // Handle /functionpadmin
   for (auto *arg : args.filtered(OPT_functionpadmin, OPT_functionpadmin_opt))
     parseFunctionPadMin(arg, config->machine);
 
   // Input files can be Windows resource files (.res files). We use
   // WindowsResource to convert resource files to a regular COFF file,
   // then link the resulting file normally.
   if (!resources.empty())
if (config->mingw) {
     run();
   }
 
   // Make sure we have resolved all symbols.
   symtab->reportRemainingUndefines();
   if (errorCount())
     return;
 
-  // Handle /safeseh.
-  if (args.hasFlag(OPT_safeseh, OPT_safeseh_no, false)) {
-    for (ObjFile *file : ObjFile::instances)
-      if (!file->hasSafeSEH())
-        error("/safeseh: " + file->getName() + " is not compatible with SEH");
-    if (errorCount())
-      return;
-  }
-
   if (config->mingw) {
     // In MinGW, all symbols are automatically exported if no symbols
     // are chosen to be exported.
     maybeExportMinGWSymbols(args);
 
     // Make sure the crtend.o object is the last object file. This object
     // file can contain terminating section chunks that need to be placed
     // last. GNU ld processes files and static libraries explicitly in the

lld/trunk/COFF/Writer.cpp

if (config->debug) {
     buildId = make<CVDebugRecordChunk>();
     debugRecords.push_back(buildId);
 
     for (Chunk *c : debugRecords)
       debugInfoSec->addChunk(c);
   }
 
   // Create SEH table. x86-only.
-  if (config->machine == I386)
+  if (config->safeSEH)
     createSEHTable();
 
   // Create /guard:cf tables if requested.
   if (config->guardCF != GuardCFLevel::Off)
     createGuardCFTables();
 
   if (config->mingw) {
     createRuntimePseudoRelocs();

 
 void Writer::openFile(StringRef path) {
   buffer = CHECK(
       FileOutputBuffer::create(path, fileSize, FileOutputBuffer::F_executable),
       "failed to open " + path);
 }
 
 void Writer::createSEHTable() {
-  // Set the no SEH characteristic on x86 binaries unless we find exception
-  // handlers.
-  setNoSEHCharacteristic = true;
-
   SymbolRVASet handlers;
   for (ObjFile *file : ObjFile::instances) {
-    // FIXME: We should error here instead of earlier unless /safeseh:no was
-    // passed.
     if (!file->hasSafeSEH())
-      return;
-
+      error("/safeseh: " + file->getName() + " is not compatible with SEH");
     markSymbolsForRVATable(file, file->getSXDataChunks(), handlers);
   }
 
-  // Remove the "no SEH" characteristic if all object files were built with
-  // safeseh, we found some exception handlers, and there is a load config in
-  // the object.
+  // Set the "no SEH" characteristic if there really were no handlers, or if
+  // there is no load config object to point to the table of handlers.
   setNoSEHCharacteristic =
       handlers.empty() || !symtab->findUnderscore("_load_config_used");
 
   maybeAddRVATable(std::move(handlers), "__safe_se_handler_table",
                    "__safe_se_handler_count");
 }
 
 // Add a symbol to an RVA set. Two symbols may have the same RVA, but an RVA set

lld/trunk/test/COFF/allow-unknown-debug-info.test

 # RUN: yaml2obj %s > %t.obj
-# RUN: lld-link /dll /noentry /debug %t.obj 2>&1 | FileCheck %s
+# RUN: lld-link -safeseh:no /dll /noentry /debug %t.obj 2>&1 | FileCheck %s
 
 # CHECK: ignoring section .debug$S with unrecognized magic 0x1
 
 --- !COFF
 header:
   Machine:         IMAGE_FILE_MACHINE_I386
   Characteristics: []
 sections:

lld/trunk/test/COFF/constant.test

 REQUIRES: x86
 RUN: mkdir -p %t
 RUN: llvm-mc -triple i686-unknown-windows-msvc -filetype obj -o %t/import.o %S/Inputs/constant-import.s
 RUN: llc -mtriple i686-unknown-windows-msvc -filetype obj -o %t/export.o %S/Inputs/constant-export.ll
-RUN: lld-link -machine:x86 -dll -out:%t/export.dll %t/export.o -entry:__CFConstantStringClassReference
-RUN: lld-link -machine:x86 -dll -out:%t/import.dll %t/import.o %t/export.lib
+RUN: lld-link -safeseh:no -machine:x86 -dll -out:%t/export.dll %t/export.o -entry:__CFConstantStringClassReference
+RUN: lld-link -safeseh:no -machine:x86 -dll -out:%t/import.dll %t/import.o %t/export.lib

lld/trunk/test/COFF/def-export-stdcall.s

 # REQUIRES: x86
 # RUN: llvm-mc -filetype=obj -triple=i686-windows-msvc %s -o %t.obj
 # RUN: echo -e "LIBRARY foo\nEXPORTS\n  stdcall\n  fastcall\n  vectorcall\n  _underscored" > %t.def
-# RUN: lld-link -entry:dllmain -dll -def:%t.def %t.obj -out:%t.dll -implib:%t.lib
+# RUN: lld-link -safeseh:no -entry:dllmain -dll -def:%t.def %t.obj -out:%t.dll -implib:%t.lib
 # RUN: llvm-readobj %t.lib | FileCheck -check-prefix UNDECORATED-IMPLIB %s
 # RUN: llvm-readobj --coff-exports %t.dll | FileCheck -check-prefix UNDECORATED-EXPORTS %s
 
 # UNDECORATED-IMPLIB: Name type: noprefix
 # UNDECORATED-IMPLIB-NEXT: __imp___underscored
 # UNDECORATED-IMPLIB-NEXT: __underscored
 # UNDECORATED-IMPLIB: Name type: undecorate
 # UNDECORATED-IMPLIB-NEXT: __imp_@fastcall@8
 # UNDECORATED-IMPLIB-NEXT: fastcall@8
 # UNDECORATED-IMPLIB: Name type: undecorate
 # UNDECORATED-IMPLIB-NEXT: __imp__stdcall@8
 # UNDECORATED-IMPLIB-NEXT: _stdcall@8
 # UNDECORATED-IMPLIB: Name type: undecorate
 # UNDECORATED-IMPLIB-NEXT: __imp_vectorcall@@8
 # UNDECORATED-IMPLIB-NEXT: vectorcall@@8
 
 # UNDECORATED-EXPORTS: Name: _underscored
 # UNDECORATED-EXPORTS: Name: fastcall
 # UNDECORATED-EXPORTS: Name: stdcall
 # UNDECORATED-EXPORTS: Name: vectorcall
 
 
 # RUN: echo -e "LIBRARY foo\nEXPORTS\n  _stdcall@8\n  @fastcall@8\n  vectorcall@@8" > %t.def
-# RUN: lld-link -entry:dllmain -dll -def:%t.def %t.obj -out:%t.dll -implib:%t.lib
+# RUN: lld-link -safeseh:no -entry:dllmain -dll -def:%t.def %t.obj -out:%t.dll -implib:%t.lib
 # RUN: llvm-readobj %t.lib | FileCheck -check-prefix DECORATED-IMPLIB %s
 # RUN: llvm-readobj --coff-exports %t.dll | FileCheck -check-prefix DECORATED-EXPORTS %s
 
 # DECORATED-IMPLIB: Name type: name
 # DECORATED-IMPLIB-NEXT: __imp_@fastcall@8
 # DECORATED-IMPLIB-NEXT: @fastcall@8
 # DECORATED-IMPLIB: Name type: name
 # DECORATED-IMPLIB-NEXT: __imp__stdcall@8

lld/trunk/test/COFF/delayimports32.test

 # REQUIRES: x86
 # RUN: yaml2obj < %p/Inputs/hello32.yaml > %t.obj
-# RUN: lld-link %t.obj %p/Inputs/std32.lib /subsystem:console \
+# RUN: lld-link -safeseh:no %t.obj %p/Inputs/std32.lib /subsystem:console \
 # RUN:   /entry:main@0 /alternatename:___delayLoadHelper2@8=_main@0 \
 # RUN:   /delayload:std32.dll /out:%t.exe
 # RUN: llvm-readobj --coff-imports %t.exe | FileCheck -check-prefix=IMPORT %s
 # RUN: llvm-readobj --coff-basereloc %t.exe | FileCheck -check-prefix=BASEREL %s
 # RUN: llvm-objdump -d %t.exe | FileCheck -check-prefix=DISASM %s
 
 IMPORT:      Format: COFF-i386
 IMPORT-NEXT: Arch: i386

lld/trunk/test/COFF/dllexport.s

 # REQUIRES: x86
 # RUN: llvm-mc -filetype=obj -triple=i686-windows-msvc %s -o %t.obj
 
-# RUN: lld-link -entry:dllmain -dll %t.obj -out:%t.dll -implib:%t.lib
+# RUN: lld-link -safeseh:no -entry:dllmain -dll %t.obj -out:%t.dll -implib:%t.lib
 # RUN: llvm-readobj %t.lib | FileCheck -check-prefix DECORATED-IMPLIB %s
 # RUN: llvm-readobj --coff-exports %t.dll | FileCheck -check-prefix DECORATED-EXPORTS %s
 
 # DECORATED-IMPLIB: Name type: name
 # DECORATED-IMPLIB-NEXT: __imp_@fastcall@8
 # DECORATED-IMPLIB-NEXT: @fastcall@8
 # DECORATED-IMPLIB: Name type: name
 # DECORATED-IMPLIB-NEXT: __imp__stdcall@8

lld/trunk/test/COFF/entry-drectve.test

 # RUN: yaml2obj < %s > %t.obj
-# RUN: lld-link /subsystem:console /out:%t.exe %t.obj
+# RUN: lld-link -safeseh:no /subsystem:console /out:%t.exe %t.obj
 
 --- !COFF
 header:
   Machine:         IMAGE_FILE_MACHINE_I386
   Characteristics: []
 sections:
   - Name:            .text
     Characteristics: [ IMAGE_SCN_CNT_CODE, IMAGE_SCN_MEM_EXECUTE, IMAGE_SCN_MEM_READ ]

lld/trunk/test/COFF/entry-inference332.test

 # RUN: sed -e s/ENTRYNAME/_mainCRTStartup/ %s | yaml2obj > %t.obj
-# RUN: lld-link /subsystem:console /out:%t.exe %t.obj /verbose /nodefaultlib > %t.log 2>&1
+# RUN: lld-link -safeseh:no /subsystem:console /out:%t.exe %t.obj /verbose /nodefaultlib > %t.log 2>&1
 # RUN: FileCheck %s < %t.log
 
 # RUN: sed -e s/ENTRYNAME/?mainCRTStartup@@YAHXZ/ %s | yaml2obj > %t.obj
-# RUN: lld-link /subsystem:console /out:%t.exe %t.obj /verbose /nodefaultlib > %t.log 2>&1
+# RUN: lld-link -safeseh:no /subsystem:console /out:%t.exe %t.obj /verbose /nodefaultlib > %t.log 2>&1
 # RUN: FileCheck %s < %t.log
 
 # CHECK: Entry name inferred: _mainCRTStartup
 
 --- !COFF
 header:
   Machine:         IMAGE_FILE_MACHINE_I386
   Characteristics: []

lld/trunk/test/COFF/exclude-all.s

_dataSym:
   .int 4
 
 # Test specifying -exclude-all-symbols, on an object file that contains
 # dllexport directive for some of the symbols. In this case, the dllexported
 # symbols are still exported.
 
 # RUN: yaml2obj < %p/Inputs/export.yaml > %t.obj
 #
-# RUN: lld-link -out:%t.dll -dll %t.obj -lldmingw -exclude-all-symbols -output-def:%t.def
+# RUN: lld-link -safeseh:no -out:%t.dll -dll %t.obj -lldmingw -exclude-all-symbols -output-def:%t.def
 # RUN: llvm-readobj --coff-exports %t.dll | FileCheck -check-prefix=DLLEXPORT %s
 
 # DLLEXPORT: Name: exportfn3

lld/trunk/test/COFF/export-all.s

 .refptr._foobar:
   .int _foobar
 
 # Test specifying -export-all-symbols, on an object file that contains
 # dllexport directive for some of the symbols.
 
 # RUN: yaml2obj < %p/Inputs/export.yaml > %t.obj
 #
-# RUN: lld-link -out:%t.dll -dll %t.obj -lldmingw -export-all-symbols -output-def:%t.def
+# RUN: lld-link -safeseh:no -out:%t.dll -dll %t.obj -lldmingw -export-all-symbols -output-def:%t.def
 # RUN: llvm-readobj --coff-exports %t.dll | FileCheck -check-prefix=CHECK2 %s
 # RUN: cat %t.def | FileCheck -check-prefix=CHECK2-DEF %s
 
 # Note, this will actually export _DllMainCRTStartup as well, since
 # it uses the standard spelling in this object file, not the MinGW one.
 
 # CHECK2: Name: exportfn1
 # CHECK2: Name: exportfn2

 # RUN: llvm-mc -triple=x86_64-windows-gnu %t.main.s -filetype=obj -o %t.main.obj
 # RUN: mkdir -p %T/libs
 # RUN: echo -e ".global mingwfunc\n.text\nmingwfunc:\nret\n" > %T/libs/mingwfunc.s
 # RUN: llvm-mc -triple=x86_64-windows-gnu %T/libs/mingwfunc.s -filetype=obj -o %T/libs/mingwfunc.o
 # RUN: rm -f %T/libs/libmingwex.a
 # RUN: llvm-ar rcs %T/libs/libmingwex.a %T/libs/mingwfunc.o
 # RUN: echo -e ".global crtfunc\n.text\ncrtfunc:\nret\n" > %T/libs/crtfunc.s
 # RUN: llvm-mc -triple=x86_64-windows-gnu %T/libs/crtfunc.s -filetype=obj -o %T/libs/crt2.o
-# RUN: lld-link -out:%t.dll -dll -entry:DllMainCRTStartup %t.main.obj -lldmingw %T/libs/crt2.o %T/libs/libmingwex.a -output-def:%t.def
+# RUN: lld-link -safeseh:no -out:%t.dll -dll -entry:DllMainCRTStartup %t.main.obj -lldmingw %T/libs/crt2.o %T/libs/libmingwex.a -output-def:%t.def
 # RUN: echo "EOF" >> %t.def
 # RUN: cat %t.def | FileCheck -check-prefix=CHECK-EXCLUDE %s
 
 # CHECK-EXCLUDE: EXPORTS
 # CHECK-EXCLUDE-NEXT: foobar @1
 # CHECK-EXCLUDE-NEXT: EOF
 
 # Test that libraries included with -wholearchive: are autoexported, even if
 # they are in a library that otherwise normally would be excluded.
 
-# RUN: lld-link -out:%t.dll -dll -entry:DllMainCRTStartup %t.main.obj -lldmingw %T/libs/crt2.o -wholearchive:%T/libs/libmingwex.a -output-def:%t.def
+# RUN: lld-link -safeseh:no -out:%t.dll -dll -entry:DllMainCRTStartup %t.main.obj -lldmingw %T/libs/crt2.o -wholearchive:%T/libs/libmingwex.a -output-def:%t.def
 # RUN: echo "EOF" >> %t.def
 # RUN: cat %t.def | FileCheck -check-prefix=CHECK-WHOLEARCHIVE %s
 
 # CHECK-WHOLEARCHIVE: EXPORTS
 # CHECK-WHOLEARCHIVE-NEXT: foobar @1
 # CHECK-WHOLEARCHIVE-NEXT: mingwfunc @2
 # CHECK-WHOLEARCHIVE-NEXT: EOF
 

lld/trunk/test/COFF/export-stdcall.s

 # REQUIRES: x86
 # RUN: llvm-mc -triple i686-windows-msvc %s -o %t.obj -filetype=obj
-# RUN: lld-link %t.obj -out:%t.dll -dll -nodefaultlib -noentry -export:foo_std=bar_std -export:foo_fast=bar_fast
+# RUN: lld-link -safeseh:no %t.obj -out:%t.dll -dll -nodefaultlib -noentry -export:foo_std=bar_std -export:foo_fast=bar_fast
 # RUN: llvm-nm %t.lib | FileCheck %s
 
 # MSVC fudges the lookup of 'bar' to allow it to find the stdcall function
 # _bar_std@8, and then exports _foo_std@8. Same for fastcall and other mangling
 # schemes.
 
 # CHECK: export-stdcall.s.tmp.dll:
 # CHECK: 00000000 T @foo_fast@8

lld/trunk/test/COFF/export32.test

 # RUN: yaml2obj < %s > %t.obj
 #
-# RUN: lld-link /out:%t.dll /dll %t.obj /export:exportfn1 /export:exportfn2
+# RUN: lld-link -safeseh:no /out:%t.dll /dll %t.obj /export:exportfn1 /export:exportfn2
 # RUN: llvm-objdump -p %t.dll | FileCheck -check-prefix=CHECK1 %s
 #
-# RUN: lld-link /out:%t.dll /dll %t.obj /export:exportfn1 /export:exportfn2 /merge:.edata=.rdata
+# RUN: lld-link -safeseh:no /out:%t.dll /dll %t.obj /export:exportfn1 /export:exportfn2 /merge:.edata=.rdata
 # RUN: llvm-objdump -p %t.dll | FileCheck -check-prefix=CHECK1 %s
 # RUN: llvm-readobj --file-headers --sections %t.dll | FileCheck -check-prefix=HEADER-MERGE %s
 
 # CHECK1:      Export Table:
 # CHECK1:      DLL name: export32.test.tmp.dll
 # CHECK1:      Ordinal      RVA  Name
 # CHECK1-NEXT:       0        0
 # CHECK1-NEXT:       1   0x1008  exportfn1
 # CHECK1-NEXT:       2   0x1010  exportfn2
 
 # HEADER-MERGE: ExportTableRVA: 0x2000
 # HEADER-MERGE-NEXT: ExportTableSize: 0x7E
 # HEADER-MERGE: Name: .rdata
 # HEADER-MERGE-NEXT: VirtualSize: 0x7E
 # HEADER-MERGE-NEXT: VirtualAddress: 0x2000
 
-# RUN: lld-link /out:%t.dll /dll %t.obj /export:exportfn1,@5 \
+# RUN: lld-link -safeseh:no /out:%t.dll /dll %t.obj /export:exportfn1,@5 \
 # RUN:   /export:exportfn2 /export:mangled
 # RUN: llvm-objdump -p %t.dll | FileCheck -check-prefix=CHECK2 %s
 
 # CHECK2:      Export Table:
 # CHECK2:      DLL name: export32.test.tmp.dll
 # CHECK2:      Ordinal      RVA  Name
 # CHECK2-NEXT:       0        0
 # CHECK2-NEXT:       1        0
 # CHECK2-NEXT:       2        0
 # CHECK2-NEXT:       3        0
 # CHECK2-NEXT:       4        0
 # CHECK2-NEXT:       5   0x1008  exportfn1
 # CHECK2-NEXT:       6   0x1010  exportfn2
 # CHECK2-NEXT:       7   0x1010  exportfn3
 # CHECK2-NEXT:       8   0x1010  mangled
 
-# RUN: lld-link /out:%t.dll /dll %t.obj /export:exportfn1,@5,noname /export:exportfn2
+# RUN: lld-link -safeseh:no /out:%t.dll /dll %t.obj /export:exportfn1,@5,noname /export:exportfn2
 # RUN: llvm-objdump -p %t.dll | FileCheck -check-prefix=CHECK3 %s
 
 # CHECK3:      Export Table:
 # CHECK3:      DLL name: export32.test.tmp.dll
 # CHECK3:      Ordinal      RVA  Name
 # CHECK3-NEXT:       0        0
 # CHECK3-NEXT:       1        0
 # CHECK3-NEXT:       2        0
 # CHECK3-NEXT:       3        0
 # CHECK3-NEXT:       4        0
 # CHECK3-NEXT:       5   0x1008
 # CHECK3-NEXT:       6   0x1010  exportfn2
 
-# RUN: lld-link /out:%t.dll /dll %t.obj /export:f1=exportfn1 /export:f2=exportfn2
+# RUN: lld-link -safeseh:no /out:%t.dll /dll %t.obj /export:f1=exportfn1 /export:f2=exportfn2
 # RUN: llvm-objdump -p %t.dll | FileCheck -check-prefix=CHECK4 %s
 
 # CHECK4:      Export Table:
 # CHECK4:      DLL name: export32.test.tmp.dll
 # CHECK4:      Ordinal      RVA  Name
 # CHECK4-NEXT:       0        0
 # CHECK4-NEXT:       1   0x1010  exportfn3
 # CHECK4-NEXT:       2   0x1008  f1
 # CHECK4-NEXT:       3   0x1010  f2
 
 # RUN: echo "EXPORTS exportfn1 @3" > %t.def
 # RUN: echo "fn2=exportfn2 @2" >> %t.def
-# RUN: lld-link /out:%t.dll /dll %t.obj /def:%t.def
+# RUN: lld-link -safeseh:no /out:%t.dll /dll %t.obj /def:%t.def
 # RUN: llvm-objdump -p %t.dll | FileCheck -check-prefix=CHECK5 %s
 
 # RUN: echo "EXPORTS exportfn1 @ 3" > %t.def
 # RUN: echo "fn2=exportfn2 @ 2" >> %t.def
-# RUN: lld-link /out:%t.dll /dll %t.obj /def:%t.def
+# RUN: lld-link -safeseh:no /out:%t.dll /dll %t.obj /def:%t.def
 # RUN: llvm-objdump -p %t.dll | FileCheck -check-prefix=CHECK5 %s
 
 # CHECK5:      Export Table:
 # CHECK5:      DLL name: export32.test.tmp.dll
 # CHECK5:      Ordinal      RVA  Name
 # CHECK5-NEXT:       0        0
 # CHECK5-NEXT:       1        0
 # CHECK5-NEXT:       2   0x1010  fn2
 # CHECK5-NEXT:       3   0x1008  exportfn1
 # CHECK5-NEXT:       4   0x1010  exportfn3
 
-# RUN: lld-link /out:%t.dll /dll %t.obj /export:exportfn1 /export:exportfn2 \
+# RUN: lld-link -safeseh:no /out:%t.dll /dll %t.obj /export:exportfn1 /export:exportfn2 \
 # RUN:   /export:exportfn1 /export:exportfn2,@5 >& %t.log
 # RUN: FileCheck -check-prefix=CHECK6 %s < %t.log
 
 # CHECK6:     duplicate /export option: _exportfn2
 # CHECK6-NOT: duplicate /export option: _exportfn1
 
-# RUN: lld-link /out:%t.dll /dll %t.obj /export:foo=mangled
+# RUN: lld-link -safeseh:no /out:%t.dll /dll %t.obj /export:foo=mangled
 # RUN: llvm-objdump -p %t.dll | FileCheck -check-prefix=CHECK7 %s
 
 # CHECK7:      Export Table:
 # CHECK7:      DLL name: export32.test.tmp.dll
 # CHECK7:      Ordinal      RVA  Name
 # CHECK7-NEXT:       0        0
 # CHECK7-NEXT:       1        0
 # CHECK7-NEXT:       2   0x1010  foo

lld/trunk/test/COFF/fixed.test

 # REQUIRES: x86
 # RUN: yaml2obj < %p/Inputs/hello32.yaml > %t.obj
 #
-# RUN: lld-link %t.obj /fixed %p/Inputs/std32.lib /subsystem:console \
+# RUN: lld-link -safeseh:no %t.obj /fixed %p/Inputs/std32.lib /subsystem:console \
 # RUN:   /entry:main@0 /debug /out:%t.fixed.exe
 # RUN: llvm-readobj --file-headers %t.fixed.exe | \
 # RUN:   FileCheck -check-prefix=EXEFIXED %s
 #
-# RUN: lld-link %t.obj %p/Inputs/std32.lib /subsystem:console \
+# RUN: lld-link -safeseh:no %t.obj %p/Inputs/std32.lib /subsystem:console \
 # RUN:   /entry:main@0 /debug /out:%t.exe
 # RUN: llvm-readobj --file-headers %t.exe | FileCheck -check-prefix=EXEREL %s
 #
 # RUN: yaml2obj < %p/Inputs/export.yaml > %t.obj
 #
-# RUN: lld-link %t.obj /dll /fixed /debug /out:%t.fixed.dll
+# RUN: lld-link -safeseh:no %t.obj /dll /fixed /debug /out:%t.fixed.dll
 # RUN: llvm-readobj --file-headers %t.fixed.dll | FileCheck -check-prefix=DLLFIXED %s
 #
-# RUN: lld-link %t.obj /dll /debug /out:%t.dll
+# RUN: lld-link -safeseh:no %t.obj /dll /debug /out:%t.dll
 # RUN: llvm-readobj --file-headers %t.dll | FileCheck -check-prefix=DLLREL %s
 
 EXEFIXED-NOT: IMAGE_DLL_CHARACTERISTICS_DYNAMIC_BASE
 DLLFIXED-NOT: IMAGE_DLL_CHARACTERISTICS_DYNAMIC_BASE
 EXEREL: IMAGE_DLL_CHARACTERISTICS_DYNAMIC_BASE
 DLLREL: IMAGE_DLL_CHARACTERISTICS_DYNAMIC_BASE

lld/trunk/test/COFF/gfids-relocations32.s

 # REQUIRES: x86
 # RUN: llvm-mc -triple i686-pc-win32 %s -filetype=obj -o %t.obj
-# RUN: lld-link %t.obj -guard:cf -out:%t.exe -entry:main
+# RUN: lld-link -safeseh:no %t.obj -guard:cf -out:%t.exe -entry:main
 # RUN: llvm-readobj --coff-load-config %t.exe | FileCheck %s --check-prefix=CHECK
 
 # Only f and _main should go in the table.
 # (use /lldmap:map.txt to check their addresses).
 #
 # CHECK: GuardFidTable [
 # CHECK-NEXT: 0x401000
 # CHECK-NEXT: 0x401030

lld/trunk/test/COFF/hello32.test

 # RUN: yaml2obj < %p/Inputs/hello32.yaml > %t.obj
-# RUN: lld-link %t.obj %p/Inputs/std32.lib /subsystem:console \
+# RUN: lld-link -safeseh:no %t.obj %p/Inputs/std32.lib /subsystem:console \
 # RUN:   /entry:main@0 /out:%t.exe /appcontainer
 # RUN: llvm-readobj --file-headers %t.exe | FileCheck -check-prefix=HEADER %s
 # RUN: llvm-readobj --coff-imports %t.exe | FileCheck -check-prefix=IMPORTS %s
 # RUN: llvm-readobj --coff-basereloc %t.exe | FileCheck -check-prefix=BASEREL %s
 
 HEADER:      Format: COFF-i386
 HEADER-NEXT: Arch: i386
 HEADER-NEXT: AddressSize: 32bit

 HEADER-NEXT:   MinorOperatingSystemVersion: 0
 HEADER-NEXT:   MajorImageVersion: 0
 HEADER-NEXT:   MinorImageVersion: 0
 HEADER-NEXT:   MajorSubsystemVersion: 6
 HEADER-NEXT:   MinorSubsystemVersion: 0
 HEADER-NEXT:   SizeOfImage: 20480
 HEADER-NEXT:   SizeOfHeaders: 1024
 HEADER-NEXT:   Subsystem: IMAGE_SUBSYSTEM_WINDOWS_CUI (0x3)
-HEADER-NEXT:   Characteristics [ (0x9540)
+HEADER-NEXT:   Characteristics [ (0x9140)
 HEADER-NEXT:     IMAGE_DLL_CHARACTERISTICS_APPCONTAINER (0x1000)
 HEADER-NEXT:     IMAGE_DLL_CHARACTERISTICS_DYNAMIC_BASE (0x40)
-HEADER-NEXT:     IMAGE_DLL_CHARACTERISTICS_NO_SEH (0x400)
 HEADER-NEXT:     IMAGE_DLL_CHARACTERISTICS_NX_COMPAT (0x100)
 HEADER-NEXT:     IMAGE_DLL_CHARACTERISTICS_TERMINAL_SERVER_AWARE (0x8000)
 HEADER-NEXT:   ]
 HEADER-NEXT:   SizeOfStackReserve: 1048576
 HEADER-NEXT:   SizeOfStackCommit: 4096
 HEADER-NEXT:   SizeOfHeapReserve: 1048576
 HEADER-NEXT:   SizeOfHeapCommit: 4096
 HEADER-NEXT:   NumberOfRvaAndSize: 16

lld/trunk/test/COFF/largeaddressaware.test

 # RUN: yaml2obj < %p/Inputs/hello32.yaml > %t.obj
-# RUN: lld-link %t.obj %p/Inputs/std32.lib /subsystem:console \
+# RUN: lld-link -safeseh:no %t.obj %p/Inputs/std32.lib /subsystem:console \
 # RUN:   /entry:main@0 /out:%t.exe /largeaddressaware
 # RUN: llvm-readobj --file-headers %t.exe | FileCheck -check-prefix=HEADER %s
 
 HEADER:      Format: COFF-i386
 HEADER-NEXT: Arch: i386
 HEADER-NEXT: AddressSize: 32bit
 HEADER-NEXT: ImageFileHeader {
 HEADER-NEXT:   Machine: IMAGE_FILE_MACHINE_I386 (0x14C)

lld/trunk/test/COFF/loadcfg32.test

 # RUN: yaml2obj < %s > %t.obj
-# RUN: lld-link /out:%t.exe %t.obj /entry:main /subsystem:console
+# RUN: lld-link -safeseh:no /out:%t.exe %t.obj /entry:main /subsystem:console
 # RUN: llvm-readobj --file-headers %t.exe | FileCheck %s
 
 # CHECK: LoadConfigTableRVA: 0x2000
 # CHECK: LoadConfigTableSize: 0x40
 
 --- !COFF
 header:
   Machine:         IMAGE_FILE_MACHINE_I386

lld/trunk/test/COFF/locally-imported32.test

 # RUN: yaml2obj < %s > %t.obj
-# RUN: lld-link /out:%t.exe /entry:main %t.obj
+# RUN: lld-link -safeseh:no /out:%t.exe /entry:main %t.obj
 # RUN: llvm-objdump -s %t.exe | FileCheck %s
 
 # CHECK:      Contents of section .text:
 # CHECK-NEXT: 1000 00200000
 
 # CHECK:      Contents of section .rdata:
 # CHECK-NEXT: 2000 04104000
 

lld/trunk/test/COFF/machine.test

 # RUN: yaml2obj %p/Inputs/machine-x64.yaml > %t.obj
-# RUN: lld-link /entry:main /subsystem:console /out:%t.exe %t.obj
+# RUN: lld-link -safeseh:no /entry:main /subsystem:console /out:%t.exe %t.obj
 # RUN: llvm-readobj --file-headers %t.exe | FileCheck -check-prefix=AMD64 %s
-# RUN: lld-link /entry:main /subsystem:console /machine:x64 \
+# RUN: lld-link -safeseh:no /entry:main /subsystem:console /machine:x64 \
 # RUN:   /out:%t.exe %t.obj
 # RUN: llvm-readobj --file-headers %t.exe | FileCheck -check-prefix=AMD64 %s
 
 AMD64: Machine: IMAGE_FILE_MACHINE_AMD64
 
 # RUN: yaml2obj %p/Inputs/machine-x86.yaml > %t.obj
-# RUN: lld-link /entry:main /subsystem:console /out:%t.exe %t.obj
+# RUN: lld-link -safeseh:no /entry:main /subsystem:console /out:%t.exe %t.obj
 # RUN: llvm-readobj --file-headers %t.exe | FileCheck -check-prefix=I386 %s
-# RUN: lld-link /entry:main /subsystem:console /machine:x86 \
+# RUN: lld-link -safeseh:no /entry:main /subsystem:console /machine:x86 \
 # RUN:   /out:%t.exe %t.obj /fixed
 # RUN: llvm-readobj --file-headers %t.exe | FileCheck -check-prefix=I386 %s
 
 I386: Machine: IMAGE_FILE_MACHINE_I386
 
 # RUN: yaml2obj %p/Inputs/machine-x64.yaml > %t.obj
 # RUN: not lld-link /entry:main /subsystem:console /machine:x86 \
 # RUN:   /out:%t.exe %t.obj /fixed >& %t.log

lld/trunk/test/COFF/no-ipi-stream.test

 # RUN: rm -rf %t && mkdir %t
 # RUN: yaml2obj < %p/Inputs/no-ipi-stream-obj.obj.yaml > %t/no-ipi-stream-obj.obj
 # RUN: llvm-pdbutil yaml2pdb %p/Inputs/no-ipi-stream-pdb.pdb.yaml -pdb=%t/no-ipi-stream-pdb.pdb
-# RUN: lld-link /dll /noentry /debug %t/no-ipi-stream-obj.obj
+# RUN: lld-link -safeseh:no /dll /noentry /debug %t/no-ipi-stream-obj.obj

lld/trunk/test/COFF/order-i386.test

 # RUN: yaml2obj < %s > %t.obj
 
 # RUN: echo fn1 > %t.order
 # RUN: echo fn2 >> %t.order
 
-# RUN: lld-link -entry:fn1 -subsystem:console -opt:noref %t.obj \
+# RUN: lld-link -safeseh:no -entry:fn1 -subsystem:console -opt:noref %t.obj \
 # RUN:   -lldmap:- -out:%t.exe -order:@%t.order | FileCheck %s
 # CHECK: fn1
 # CHECK: fn2
 
-# RUN: lld-link -entry:fn1 -subsystem:console -opt:noref %t.obj \
+# RUN: lld-link -safeseh:no -entry:fn1 -subsystem:console -opt:noref %t.obj \
 # RUN:   -lldmap:- -out:%t.exe | FileCheck -check-prefix=DEFAULT %s
 # DEFAULT: fn2
 # DEFAULT: fn1
 
 --- !COFF
 header:
   Machine:         IMAGE_FILE_MACHINE_I386
   Characteristics: [  ]

lld/trunk/test/COFF/pdb-debug-f.s

 # REQUIRES: x86
 # RUN: llvm-mc -triple=i386-pc-win32 -filetype=obj -o %t.obj %s
-# RUN: lld-link /subsystem:console /debug /nodefaultlib /entry:foo /out:%t.exe /pdb:%t.pdb %t.obj
+# RUN: lld-link -safeseh:no /subsystem:console /debug /nodefaultlib /entry:foo /out:%t.exe /pdb:%t.pdb %t.obj
 # RUN: llvm-pdbutil dump -fpo %t.pdb | FileCheck %s
 
 # CHECK:                         Old FPO Data
 # CHECK-NEXT: ============================================================
 # CHECK-NEXT:   RVA    | Code | Locals | Params | Prolog | Saved Regs | Use BP | Has SEH | Frame Type
 # CHECK-NEXT: 00001002 |    1 |      2 |      3 |      4 |          0 |  false |   false |       FPO
 
 .text
.section .debug$F,"dr"
   .short 3 # cdwParams;
   .short 4 # flags
   # cbProlog : 8;
   # cbRegs : 3;
   # fHasSEH : 1;
   # fUseBP : 1;
   # reserved : 1;
   # cbFrame : 2;
 No newline at end of file

lld/trunk/test/COFF/pdb-lib.s

 # REQUIRES: x86
 # RUN: rm -rf %t && mkdir -p %t && cd %t
 # RUN: llvm-mc -filetype=obj -triple=i686-windows-msvc %s -o foo.obj
 # RUN: llc %S/Inputs/bar.ll -filetype=obj -mtriple=i686-windows-msvc -o bar.obj
 # RUN: llvm-lib bar.obj -out:bar.lib
-# RUN: lld-link -debug -pdb:foo.pdb foo.obj bar.lib -out:foo.exe -entry:main
+# RUN: lld-link -safeseh:no -debug -pdb:foo.pdb foo.obj bar.lib -out:foo.exe -entry:main
 # RUN: llvm-pdbutil dump -modules %t/foo.pdb | FileCheck %s
 
 # Make sure that the PDB has module descriptors. foo.obj and bar.lib should be
 # absolute paths, and bar.obj should be the relative path passed to llvm-lib.
 
 # CHECK:                               Modules
 # CHECK-NEXT: ============================================================
 # CHECK-NEXT:   Mod 0000 | `{{.*pdb-lib.s.tmp[/\\]foo.obj}}`:

lld/trunk/test/COFF/pdb-safeseh.yaml

 # RUN: yaml2obj %s -o %t.obj
-# RUN: lld-link -debug -entry:main -out:%t.exe -pdb:%t.pdb %t.obj
+# RUN: lld-link -safeseh:no -debug -entry:main -out:%t.exe -pdb:%t.pdb %t.obj
 # RUN: llvm-pdbutil dump -globals %t.pdb | FileCheck %s
 
 # There is an S_GDATA32 symbol record with .secrel32 and .secidx relocations in
 # it in this debug info. This is similar to the relocations in the loadcfg.obj
 # file in the MSVC CRT. We need to make sure that our relocation logic matches
 # MSVC's for these absolute, linker-provided symbols.
 
 # CHECK:                             Global Symbols

lld/trunk/test/COFF/pdb-unknown-subsection.s

 # Check that unknown symbol subsections are ignored with a warning, and a PDB
 # is produced anyway.
 
 # REQUIRES: x86
 # RUN: llvm-mc -triple=i386-pc-win32 -filetype=obj -o %t.obj %s
-# RUN: lld-link -subsystem:console -debug -nodefaultlib -entry:foo -out:%t.exe -pdb:%t.pdb %t.obj 2>&1 | FileCheck %s --check-prefix=WARNING
+# RUN: lld-link -safeseh:no -subsystem:console -debug -nodefaultlib -entry:foo -out:%t.exe -pdb:%t.pdb %t.obj 2>&1 | FileCheck %s --check-prefix=WARNING
 # RUN: llvm-pdbutil dump -symbols %t.pdb | FileCheck %s
 
 # WARNING-NOT: ignoring unknown
 # WARNING: ignoring unknown debug$S subsection kind 0xFF
 # WARNING-NOT: ignoring unknown
 
 # CHECK:                           Symbols
 # CHECK:        4 | S_COMPILE3 [size = 52]

lld/trunk/test/COFF/reloc-x86.test

 # REQUIRES: x86
 # RUN: yaml2obj < %s > %t.obj
-# RUN: lld-link /out:%t.exe /entry:main /base:0x400000 %t.obj
+# RUN: lld-link -safeseh:no /out:%t.exe /entry:main /base:0x400000 %t.obj
 # RUN: llvm-objdump -d %t.exe | FileCheck %s
 
 # CHECK: .text:
 # CHECK: 1000: a1 00 00 00 00
 # CHECK: 1005: a1 03 20 40 00
 # CHECK: 100a: a1 03 20 00 00
 # CHECK: 100f: a1 ef 0f 00 00
 # CHECK: 1014: a1 00 00 02 00

lld/trunk/test/COFF/safeseh-no.s

+# RUN: llvm-mc -triple i686-windows-msvc %s -filetype=obj -o %t.obj
+# RUN: not lld-link %t.obj -safeseh -out:%t.exe -entry:main 2>&1 | FileCheck %s --check-prefix=ERROR
+# safe seh should be on by default.
+# RUN: not lld-link %t.obj -out:%t.exe -entry:main 2>&1 | FileCheck %s --check-prefix=ERROR
+# RUN: lld-link %t.obj -safeseh:no -out:%t.exe -entry:main
+# RUN: llvm-readobj --file-headers --coff-load-config %t.exe | FileCheck %s
+# -lldmingw should also turn off safeseh by default.
+# RUN: lld-link %t.obj -lldmingw -out:%t.exe -entry:main
+# RUN: llvm-readobj --file-headers --coff-load-config %t.exe | FileCheck %s
+
+# ERROR: /safeseh: {{.*}}safeseh-no.s.tmp.obj is not compatible with SEH
+
+# CHECK: Characteristics [
+# CHECK-NOT:   IMAGE_DLL_CHARACTERISTICS_NO_SEH
+# CHECK: ]
+# CHECK: LoadConfig [
+# CHECK:   Size: 0x48
+# CHECK:   SEHandlerTable: 0x0
+# CHECK:   SEHandlerCount: 0
+# CHECK: ]
+# CHECK-NOT: SEHTable
+
+
+# Explicitly mark the object as not having safeseh. LLD should error unless
+# -safeseh:no is passed.
+        .def     @feat.00; .scl    3; .type   0; .endef
+        .globl  @feat.00
+@feat.00 = 0
+
+        .def     _main;
+        .scl    2;
+        .type   32;
+        .endef
+        .section        .text,"xr",one_only,_main
+        .globl  _main
+_main:
+        movl $42, %eax
+        ret
+
+# Add a handler to create an .sxdata section, which -safeseh:no should ignore.
+        .def     _my_handler; .scl    3; .type   32;
+        .endef
+        .section        .text,"xr",one_only,_my_handler
+_my_handler:
+        ret
+.safeseh _my_handler
+
+
+        .section .rdata,"dr"
+.globl __load_config_used
+__load_config_used:
+        .long 72
+        .fill 60, 1, 0
+        .long ___safe_se_handler_table
+        .long ___safe_se_handler_count
+

lld/trunk/test/COFF/subsystem-drectve.test

 # RUN: yaml2obj < %s > %t.obj
-# RUN: lld-link /dll /noentry /out:%t.dll %t.obj
+# RUN: lld-link -safeseh:no /dll /noentry /out:%t.dll %t.obj
 # RUN: llvm-readobj --file-headers %t.dll | FileCheck %s
 
 # CHECK: MajorOperatingSystemVersion: 42
 # CHECK: MinorOperatingSystemVersion: 43
 # CHECK: MajorSubsystemVersion: 42
 # CHECK: MinorSubsystemVersion: 43
 # CHECK: Subsystem: IMAGE_SUBSYSTEM_WINDOWS_CUI
 

lld/trunk/test/COFF/subsystem-inference32.test

 # RUN: sed -e s/ENTRYNAME/_main/ %s | yaml2obj > %t.obj
-# RUN: lld-link /out:%t.exe %t.obj
+# RUN: lld-link -safeseh:no /out:%t.exe %t.obj
 # RUN: llvm-readobj --file-headers %t.exe | FileCheck -check-prefix=MAIN %s
 
 # RUN: sed s/ENTRYNAME/_wmain/ %s | yaml2obj > %t.obj
-# RUN: lld-link /out:%t.exe %t.obj
+# RUN: lld-link -safeseh:no /out:%t.exe %t.obj
 # RUN: llvm-readobj --file-headers %t.exe | FileCheck -check-prefix=WMAIN %s
 
 # RUN: sed s/ENTRYNAME/_WinMain@16/ %s | yaml2obj > %t.obj
-# RUN: lld-link /out:%t.exe %t.obj
+# RUN: lld-link -safeseh:no /out:%t.exe %t.obj
 # RUN: llvm-readobj --file-headers %t.exe | FileCheck -check-prefix=WINMAIN %s
 
 # RUN: sed s/ENTRYNAME/_wWinMain@16/ %s | yaml2obj > %t.obj
-# RUN: lld-link /out:%t.exe %t.obj
+# RUN: lld-link -safeseh:no /out:%t.exe %t.obj
 # RUN: llvm-readobj --file-headers %t.exe | FileCheck -check-prefix=WWINMAIN %s
 
 # MAIN:     Subsystem: IMAGE_SUBSYSTEM_WINDOWS_CUI
 # WMAIN:    Subsystem: IMAGE_SUBSYSTEM_WINDOWS_CUI
 # WINMAIN:  Subsystem: IMAGE_SUBSYSTEM_WINDOWS_GUI
 # WWINMAIN: Subsystem: IMAGE_SUBSYSTEM_WINDOWS_GUI
 
 --- !COFF

lld/trunk/test/COFF/tls32.test

 # RUN: yaml2obj < %s > %t.obj
-# RUN: lld-link /out:%t.exe /entry:main %t.obj
+# RUN: lld-link -safeseh:no /out:%t.exe /entry:main %t.obj
 # RUN: llvm-readobj --file-headers %t.exe | FileCheck %s
 
 # CHECK: TLSTableRVA: 0x1000
 # CHECK: TLSTableSize: 0x18
 
 --- !COFF
 header:
   Machine:         IMAGE_FILE_MACHINE_I386