The integrated darwin assembler can hang in an infinite loop (or get an assert

with a debug build) with this buggy .indirect_symbol directive usage:

% cat test.s
x: .indirect_symbol _y

The assertion is because it is trying to get the symbol index for the
symbol _y when it is writing out the indirect symbol table. This line of
code in MachObjectWriter::WriteObject() :

        Write32(Asm.getSymbolData(*it->Symbol).getIndex());

And while there is a symbol _y it does not have any getSymbolData set which
is only done in MachObjectWriter::BindIndirectSymbols() for pointer sections
or stub sections.  I added a check and an error in there to catch this in case
something slips through.

But to get a better error the parser should detect when a .indirect_symbol
directive is used and it is not in a pointer section or stub section.  To make
that work I moved the handling of the indirect symbol out of the target
independent AsmParser code into the DarwinAsmParser code that can check
for the proper Mach-O section types.

rdar://14825505

llvm-svn: 189497

1 files changed, 16 insertions, 0 deletions

diff --git a/llvm/lib/MC/MachObjectWriter.cpp b/llvm/lib/MC/MachObjectWriter.cpp
index a5ba3c3..3c1888c 100644
--- a/llvm/lib/MC/MachObjectWriter.cpp
+++ b/llvm/lib/MC/MachObjectWriter.cpp
@@ -428,6 +428,22 @@ void MachObjectWriter::BindIndirectSymbols(MCAssembler &Asm) {
   //
   // FIXME: Revisit this when the dust settles.
 
+  // Report errors for use of .indirect_symbol not in a symbol pointer section
+  // or stub section.
+  for (MCAssembler::indirect_symbol_iterator it = Asm.indirect_symbol_begin(),
+         ie = Asm.indirect_symbol_end(); it != ie; ++it) {
+    const MCSectionMachO &Section =
+      cast<MCSectionMachO>(it->SectionData->getSection());
+
+    if (Section.getType() != MCSectionMachO::S_NON_LAZY_SYMBOL_POINTERS &&
+        Section.getType() != MCSectionMachO::S_LAZY_SYMBOL_POINTERS &&
+        Section.getType() != MCSectionMachO::S_SYMBOL_STUBS) {
+	MCSymbol &Symbol = *it->Symbol;
+	report_fatal_error("indirect symbol '" + Symbol.getName() +
+                           "' not in a symbol pointer or stub section");
+    }
+  }
+
   // Bind non lazy symbol pointers first.
   unsigned IndirectIndex = 0;
   for (MCAssembler::indirect_symbol_iterator it = Asm.indirect_symbol_begin(),