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
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189497 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCParser/DarwinAsmParser.cpp b/lib/MC/MCParser/DarwinAsmParser.cpp
index 0aeeaf6..f08270c 100644
--- a/lib/MC/MCParser/DarwinAsmParser.cpp
+++ b/lib/MC/MCParser/DarwinAsmParser.cpp
@@ -45,6 +45,8 @@
this->MCAsmParserExtension::Initialize(Parser);
addDirectiveHandler<&DarwinAsmParser::ParseDirectiveDesc>(".desc");
+ addDirectiveHandler<&DarwinAsmParser::ParseDirectiveIndirectSymbol>(
+ ".indirect_symbol");
addDirectiveHandler<&DarwinAsmParser::ParseDirectiveLsym>(".lsym");
addDirectiveHandler<&DarwinAsmParser::ParseDirectiveSubsectionsViaSymbols>(
".subsections_via_symbols");
@@ -163,6 +165,7 @@
}
bool ParseDirectiveDesc(StringRef, SMLoc);
+ bool ParseDirectiveIndirectSymbol(StringRef, SMLoc);
bool ParseDirectiveDumpOrLoad(StringRef, SMLoc);
bool ParseDirectiveLsym(StringRef, SMLoc);
bool ParseDirectiveLinkerOption(StringRef, SMLoc);
@@ -415,6 +418,39 @@
return false;
}
+/// ParseDirectiveIndirectSymbol
+/// ::= .indirect_symbol identifier
+bool DarwinAsmParser::ParseDirectiveIndirectSymbol(StringRef, SMLoc Loc) {
+ const MCSectionMachO *Current = static_cast<const MCSectionMachO*>(
+ getStreamer().getCurrentSection().first);
+ unsigned SectionType = Current->getType();
+ if (SectionType != MCSectionMachO::S_NON_LAZY_SYMBOL_POINTERS &&
+ SectionType != MCSectionMachO::S_LAZY_SYMBOL_POINTERS &&
+ SectionType != MCSectionMachO::S_SYMBOL_STUBS)
+ return Error(Loc, "indirect symbol not in a symbol pointer or stub "
+ "section");
+
+ StringRef Name;
+ if (getParser().parseIdentifier(Name))
+ return TokError("expected identifier in .indirect_symbol directive");
+
+ MCSymbol *Sym = getContext().GetOrCreateSymbol(Name);
+
+ // Assembler local symbols don't make any sense here. Complain loudly.
+ if (Sym->isTemporary())
+ return TokError("non-local symbol required in directive");
+
+ if (!getStreamer().EmitSymbolAttribute(Sym, MCSA_IndirectSymbol))
+ return TokError("unable to emit indirect symbol attribute for: " + Name);
+
+ if (getLexer().isNot(AsmToken::EndOfStatement))
+ return TokError("unexpected token in '.indirect_symbol' directive");
+
+ Lex();
+
+ return false;
+}
+
/// ParseDirectiveDumpOrLoad
/// ::= ( .dump | .load ) "filename"
bool DarwinAsmParser::ParseDirectiveDumpOrLoad(StringRef Directive,