Fixed MCSectionMachO::ParseSectionSpecifier to allow an attribute of "none" so
that a symbol stub section with no attributes can be parsed as in:
.section __TEXT,__picsymbolstub4,symbol_stubs,none,16


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83488 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCSectionMachO.cpp b/lib/MC/MCSectionMachO.cpp
index 33f5087..b3aeb9c 100644
--- a/lib/MC/MCSectionMachO.cpp
+++ b/lib/MC/MCSectionMachO.cpp
@@ -40,8 +40,8 @@
 
 /// SectionAttrDescriptors - This is an array of descriptors for section
 /// attributes.  Unlike the SectionTypeDescriptors, this is not directly indexed
-/// by attribute, instead it is searched.  The last entry has a zero AttrFlag
-/// value.
+/// by attribute, instead it is searched.  The last entry has an AttrFlagEnd
+/// AttrFlag value.
 static const struct {
   unsigned AttrFlag;
   const char *AssemblerName, *EnumName;
@@ -59,7 +59,9 @@
 ENTRY(0 /*FIXME*/,           S_ATTR_EXT_RELOC)
 ENTRY(0 /*FIXME*/,           S_ATTR_LOC_RELOC)
 #undef ENTRY
-  { 0, "none", 0 }
+  { 0, "none", 0 }, // used if section has no attributes but has a stub size
+#define AttrFlagEnd 0xffffffff // non legal value, multiple attribute bits set
+  { AttrFlagEnd, 0, 0 }
 };
 
 
@@ -228,7 +230,7 @@
 
     // Look up the attribute.
     for (unsigned i = 0; ; ++i) {
-      if (SectionAttrDescriptors[i].AttrFlag == 0)
+      if (SectionAttrDescriptors[i].AttrFlag == AttrFlagEnd)
         return "mach-o section specifier has invalid attribute";
       
       if (SectionAttrDescriptors[i].AssemblerName &&