Fix a Mach-O assembler segfault for a subtraction expression with an undefined symbol.

[oota-llvm.git] / lib / Target / X86 / MCTargetDesc / X86MCAsmInfo.cpp

diff --git a/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp b/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp
index 724ea358f40ffa873565fd489da4d5593853a436..3a67f6a5f9135b9e9930d2018802380cb7dac5fa 100644 (file)
--- a/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp
+++ b/lib/Target/X86/MCTargetDesc/X86MCAsmInfo.cpp
@@ -51,7 +51,7 @@ X86MCAsmInfoDarwin::X86MCAsmInfoDarwin(const Triple &T) {
   TextAlignFillValue = 0x90;
 
   if (!is64Bit)
-    Data64bitsDirective = 0;       // we can't emit a 64-bit unit
+    Data64bitsDirective = nullptr;       // we can't emit a 64-bit unit
 
   // Use ## as a comment string so that .s files generated by llvm can go
   // through the GCC preprocessor without causing an error.  This is needed
@@ -72,10 +72,10 @@ X86MCAsmInfoDarwin::X86MCAsmInfoDarwin(const Triple &T) {
   if (T.isMacOSX() && T.isMacOSXVersionLT(10, 6))
     HasWeakDefCanBeHiddenDirective = false;
 
-  // FIXME: this should not depend on the target OS version, but on the ld64
-  // version in use.  From at least >= ld64-97.17 (Xcode 3.2.6) the abs-ified
-  // FDE relocs may be used.
-  DwarfFDESymbolsUseAbsDiff = T.isMacOSX() && !T.isMacOSXVersionLT(10, 6);
+  // Assume ld64 is new enough that the abs-ified FDE relocs may be used
+  // (actually, must, since otherwise the non-extern relocations we produce
+  // overwhelm ld64's tiny little mind and it fails).
+  DwarfFDESymbolsUseAbsDiff = true;
 
   UseIntegratedAssembler = true;
 }
@@ -102,9 +102,6 @@ X86ELFMCAsmInfo::X86ELFMCAsmInfo(const Triple &T) {
 
   TextAlignFillValue = 0x90;
 
-  // Set up DWARF directives
-  HasLEB128 = true;  // Target asm supports leb128 directives (little-endian)
-
   // Debug Information
   SupportsDebugInformation = true;
 
@@ -115,7 +112,7 @@ X86ELFMCAsmInfo::X86ELFMCAsmInfo(const Triple &T) {
   // into two .words.
   if ((T.getOS() == Triple::OpenBSD || T.getOS() == Triple::Bitrig) &&
        T.getArch() == Triple::x86)
-    Data64bitsDirective = 0;
+    Data64bitsDirective = nullptr;
 
   // Always enable the integrated assembler by default.
   // Clang also enabled it when the OS is Solaris but that is redundant here.
@@ -133,17 +130,15 @@ X86_64MCAsmInfoDarwin::getExprForPersonalitySymbol(const MCSymbol *Sym,
   return MCBinaryExpr::CreateAdd(Res, Four, Context);
 }
 
-const MCSection *X86ELFMCAsmInfo::
-getNonexecutableStackSection(MCContext &Ctx) const {
-  return Ctx.getELFSection(".note.GNU-stack", ELF::SHT_PROGBITS,
-                           0, SectionKind::getMetadata());
-}
-
 void X86MCAsmInfoMicrosoft::anchor() { }
 
 X86MCAsmInfoMicrosoft::X86MCAsmInfoMicrosoft(const Triple &Triple) {
-  if (Triple.getArch() == Triple::x86_64)
+  if (Triple.getArch() == Triple::x86_64) {
     PrivateGlobalPrefix = ".L";
+    PointerSize = 8;
+    WinEHEncodingType = WinEH::EncodingType::Itanium;
+    ExceptionsType = ExceptionHandling::WinEH;
+  }
 
   AssemblerDialect = AsmWriterFlavor;
 
@@ -157,17 +152,19 @@ X86MCAsmInfoMicrosoft::X86MCAsmInfoMicrosoft(const Triple &Triple) {
 void X86MCAsmInfoGNUCOFF::anchor() { }
 
 X86MCAsmInfoGNUCOFF::X86MCAsmInfoGNUCOFF(const Triple &Triple) {
+  assert(Triple.isOSWindows() && "Windows is the only supported COFF target");
   if (Triple.getArch() == Triple::x86_64) {
     PrivateGlobalPrefix = ".L";
     PointerSize = 8;
+    WinEHEncodingType = WinEH::EncodingType::Itanium;
+    ExceptionsType = ExceptionHandling::WinEH;
+  } else {
+    ExceptionsType = ExceptionHandling::DwarfCFI;
   }
 
   AssemblerDialect = AsmWriterFlavor;
 
   TextAlignFillValue = 0x90;
 
-  // Exceptions handling
-  ExceptionsType = ExceptionHandling::DwarfCFI;
-
   UseIntegratedAssembler = true;
 }