[llvm-commits] [llvm] r79899 - in /llvm/trunk: include/llvm/MC/MCAssembler.h lib/MC/MCAssembler.cpp lib/MC/MCMachOStreamer.cpp test/MC/MachO/symbol-flags.s
Daniel Dunbar
daniel at zuster.org
Mon Aug 24 01:40:12 PDT 2009
Author: ddunbar
Date: Mon Aug 24 03:40:12 2009
New Revision: 79899
URL: http://llvm.org/viewvc/llvm-project?rev=79899&view=rev
Log:
llvm-mc/Mach-O: Support symbol attributes.
- This is mostly complete, the main thing missing is .indirect_symbol support
(which would be straight-forward, except that the way it is implemented in
'as' makes getting an exact .o match interesting).
Added:
llvm/trunk/test/MC/MachO/symbol-flags.s
Modified:
llvm/trunk/include/llvm/MC/MCAssembler.h
llvm/trunk/lib/MC/MCAssembler.cpp
llvm/trunk/lib/MC/MCMachOStreamer.cpp
Modified: llvm/trunk/include/llvm/MC/MCAssembler.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/MC/MCAssembler.h?rev=79899&r1=79898&r2=79899&view=diff
==============================================================================
--- llvm/trunk/include/llvm/MC/MCAssembler.h (original)
+++ llvm/trunk/include/llvm/MC/MCAssembler.h Mon Aug 24 03:40:12 2009
@@ -317,6 +317,13 @@
/// unit.
unsigned IsExternal : 1;
+ /// IsPrivateExtern - True if this symbol is private extern.
+ unsigned IsPrivateExtern : 1;
+
+ /// Flags - The Flags field is used by object file implementations to store
+ /// additional per symbol information which is not easily classified.
+ uint32_t Flags;
+
public:
// Only for use as sentinel.
MCSymbolData();
@@ -334,13 +341,22 @@
uint64_t getOffset() const { return Offset; }
void setOffset(uint64_t Value) { Offset = Value; }
- /// @}
- /// @name Symbol Attributes
- /// @{
-
- bool isExternal() const { return IsExternal; }
- void setExternal(bool Value) { IsExternal = Value; }
+ /// @}
+ /// @name Symbol Attributes
+ /// @{
+
+ bool isExternal() const { return IsExternal; }
+ void setExternal(bool Value) { IsExternal = Value; }
+
+ bool isPrivateExtern() const { return IsPrivateExtern; }
+ void setPrivateExtern(bool Value) { IsPrivateExtern = Value; }
+
+ /// getFlags - Get the (implementation defined) symbol flags.
+ uint32_t getFlags() const { return Flags; }
+ /// setFlags - Set the (implementation defined) symbol flags.
+ void setFlags(uint32_t Value) { Flags = Value; }
+
/// @}
};
Modified: llvm/trunk/lib/MC/MCAssembler.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCAssembler.cpp?rev=79899&r1=79898&r2=79899&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCAssembler.cpp (original)
+++ llvm/trunk/lib/MC/MCAssembler.cpp Mon Aug 24 03:40:12 2009
@@ -291,7 +291,8 @@
// FIXME: Set STAB bits.
- // FIXME: Set private external bit.
+ if (MSD.SymbolData->isPrivateExtern())
+ Type |= STF_PrivateExtern;
// Set external bit.
if (MSD.SymbolData->isExternal() || Symbol.isUndefined())
@@ -302,7 +303,11 @@
Write32(MSD.StringIndex);
Write8(Type);
Write8(MSD.SectionIndex);
- Write16(0); // FIXME: Desc
+
+ // The Mach-O streamer uses the lowest 16-bits of the flags for the 'desc'
+ // value.
+ Write16(MSD.SymbolData->getFlags() & 0xFFFF);
+
Write32(0); // FIXME: Value
}
@@ -544,7 +549,7 @@
MCSymbolData::MCSymbolData(MCSymbol &_Symbol, MCFragment *_Fragment,
uint64_t _Offset, MCAssembler *A)
: Symbol(_Symbol), Fragment(_Fragment), Offset(_Offset),
- IsExternal(false)
+ IsExternal(false), IsPrivateExtern(false), Flags(0)
{
if (A)
A->getSymbolList().push_back(this);
Modified: llvm/trunk/lib/MC/MCMachOStreamer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCMachOStreamer.cpp?rev=79899&r1=79898&r2=79899&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCMachOStreamer.cpp (original)
+++ llvm/trunk/lib/MC/MCMachOStreamer.cpp Mon Aug 24 03:40:12 2009
@@ -19,6 +19,27 @@
namespace {
class MCMachOStreamer : public MCStreamer {
+ /// SymbolFlags - We store the value for the 'desc' symbol field in the lowest
+ /// 16 bits of the implementation defined flags.
+ enum SymbolFlags { // See <mach-o/nlist.h>.
+ SF_DescFlagsMask = 0xFFFF,
+
+ // Reference type flags.
+ SF_ReferenceTypeMask = 0x0007,
+ SF_ReferenceTypeUndefinedNonLazy = 0x0000,
+ SF_ReferenceTypeUndefinedLazy = 0x0001,
+ SF_ReferenceTypeDefined = 0x0002,
+ SF_ReferenceTypePrivateDefined = 0x0003,
+ SF_ReferenceTypePrivateUndefinedNonLazy = 0x0004,
+ SF_ReferenceTypePrivateUndefinedLazy = 0x0005,
+
+ // Other 'desc' flags.
+ SF_NoDeadStrip = 0x0020,
+ SF_WeakReference = 0x0040,
+ SF_WeakDefinition = 0x0080
+ };
+
+private:
MCAssembler Assembler;
MCSectionData *CurSectionData;
@@ -121,6 +142,9 @@
assert(!SD.getFragment() && "Unexpected fragment on symbol data!");
SD.setFragment(F);
SD.setOffset(F->getContents().size());
+
+ // This causes the reference type and weak reference flags to be cleared.
+ SD.setFlags(SD.getFlags() & ~(SF_WeakReference | SF_ReferenceTypeMask));
Symbol->setSection(*CurSection);
}
@@ -141,18 +165,71 @@
void MCMachOStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
SymbolAttr Attribute) {
+ // Adding a symbol attribute always introduces the symbol, note that an
+ // important side effect of calling getSymbolData here is to register the
+ // symbol with the assembler.
+ MCSymbolData &SD = getSymbolData(*Symbol);
+
+ // The implementation of symbol attributes is designed to match 'as', but it
+ // leaves much to desired. It doesn't really make sense to arbitrarily add and
+ // remove flags, but 'as' allows this (in particular, see .desc).
+ //
+ // In the future it might be worth trying to make these operations more well
+ // defined.
switch (Attribute) {
- default:
- llvm_unreachable("FIXME: Not yet implemented!");
+ case MCStreamer::Hidden:
+ case MCStreamer::Internal:
+ case MCStreamer::Protected:
+ case MCStreamer::Weak:
+ assert(0 && "Invalid symbol attribute for Mach-O!");
+ break;
case MCStreamer::Global:
getSymbolData(*Symbol).setExternal(true);
break;
+
+ case MCStreamer::LazyReference:
+ // FIXME: This requires -dynamic.
+ SD.setFlags(SD.getFlags() | SF_NoDeadStrip);
+ if (Symbol->isUndefined())
+ SD.setFlags(SD.getFlags() | SF_ReferenceTypeUndefinedLazy);
+ break;
+
+ case MCStreamer::IndirectSymbol:
+ llvm_unreachable("FIXME: Not yet implemented!");
+ break;
+
+ // Since .reference sets the no dead strip bit, it is equivalent to
+ // .no_dead_strip in practice.
+ case MCStreamer::Reference:
+ case MCStreamer::NoDeadStrip:
+ SD.setFlags(SD.getFlags() | SF_NoDeadStrip);
+ break;
+
+ case MCStreamer::PrivateExtern:
+ SD.setExternal(true);
+ SD.setPrivateExtern(true);
+ break;
+
+ case MCStreamer::WeakReference:
+ // FIXME: This requires -dynamic.
+ if (Symbol->isUndefined())
+ SD.setFlags(SD.getFlags() | SF_WeakReference);
+ break;
+
+ case MCStreamer::WeakDefinition:
+ // FIXME: 'as' enforces that this is defined and global. The manual claims
+ // it has to be in a coalesced section, but this isn't enforced.
+ SD.setFlags(SD.getFlags() | SF_WeakDefinition);
+ break;
}
}
void MCMachOStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
- llvm_unreachable("FIXME: Not yet implemented!");
+ // Encode the 'desc' value into the lowest implementation defined bits.
+ assert(DescValue == (DescValue & SF_DescFlagsMask) &&
+ "Invalid .desc value!");
+ getSymbolData(*Symbol).setFlags(DescValue & SF_DescFlagsMask);
}
void MCMachOStreamer::EmitLocalSymbol(MCSymbol *Symbol, const MCValue &Value) {
Added: llvm/trunk/test/MC/MachO/symbol-flags.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/MC/MachO/symbol-flags.s?rev=79899&view=auto
==============================================================================
--- llvm/trunk/test/MC/MachO/symbol-flags.s (added)
+++ llvm/trunk/test/MC/MachO/symbol-flags.s Mon Aug 24 03:40:12 2009
@@ -0,0 +1,254 @@
+// RUN: llvm-mc -triple i386-apple-darwin9 %s -filetype=obj -o - | macho-dump | FileCheck %s
+
+ .reference sym_ref_A
+ .reference sym_ref_def_A
+sym_ref_def_A:
+sym_ref_def_C:
+ .reference sym_ref_def_C
+
+ .weak_reference sym_weak_ref_A
+ .weak_reference sym_weak_ref_def_A
+sym_weak_ref_def_A:
+sym_weak_ref_def_B:
+ .weak_reference sym_weak_ref_def_B
+
+ .data
+ .globl sym_weak_def_A
+ .weak_definition sym_weak_def_A
+sym_weak_def_A:
+
+ .lazy_reference sym_lazy_ref_A
+ .lazy_reference sym_lazy_ref_B
+sym_lazy_ref_B:
+sym_lazy_ref_C:
+ .lazy_reference sym_lazy_ref_C
+
+ .private_extern sym_private_ext_A
+ .private_extern sym_private_ext_B
+sym_private_ext_B:
+sym_private_ext_C:
+ .private_extern sym_private_ext_C
+ .private_extern sym_private_ext_D
+ .globl sym_private_ext_D
+
+ .no_dead_strip sym_no_dead_strip_A
+
+ .reference sym_ref_A
+ .desc sym_ref_A, 1
+ .desc sym_ref_A, 0x1234
+
+ .desc sym_desc_flags,0x47
+sym_desc_flags:
+
+// CHECK: ('cputype', 7)
+// CHECK: ('cpusubtype', 3)
+// CHECK: ('filetype', 1)
+// CHECK: ('num_load_commands', 1)
+// CHECK: ('load_commands_size', 296)
+// CHECK: ('flag', 0)
+// CHECK: ('load_commands', [
+// CHECK: # Load Command 0
+// CHECK: (('command', 1)
+// CHECK: ('size', 192)
+// CHECK: ('segment_name', '\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')
+// CHECK: ('vm_addr', 0)
+// CHECK: ('vm_size', 0)
+// CHECK: ('file_offset', 324)
+// CHECK: ('file_size', 0)
+// CHECK: ('maxprot', 7)
+// CHECK: ('initprot', 7)
+// CHECK: ('num_sections', 2)
+// CHECK: ('flags', 0)
+// CHECK: ('sections', [
+// CHECK: # Section 0
+// CHECK: (('section_name', '__text\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')
+// CHECK: ('segment_name', '__TEXT\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')
+// CHECK: ('address', 0)
+// CHECK: ('size', 0)
+// CHECK: ('offset', 324)
+// CHECK: ('alignment', 0)
+// CHECK: ('reloc_offset', 0)
+// CHECK: ('num_reloc', 0)
+// CHECK: ('flags', 0x80000000)
+// CHECK: ('reserved1', 0)
+// CHECK: ('reserved2', 0)
+// CHECK: ),
+// CHECK: # Section 1
+// CHECK: (('section_name', '__data\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')
+// CHECK: ('segment_name', '__DATA\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00')
+// CHECK: ('address', 0)
+// CHECK: ('size', 0)
+// CHECK: ('offset', 324)
+// CHECK: ('alignment', 0)
+// CHECK: ('reloc_offset', 0)
+// CHECK: ('num_reloc', 0)
+// CHECK: ('flags', 0x0)
+// CHECK: ('reserved1', 0)
+// CHECK: ('reserved2', 0)
+// CHECK: ),
+// CHECK: ])
+// CHECK: ),
+// CHECK: # Load Command 1
+// CHECK: (('command', 2)
+// CHECK: ('size', 24)
+// CHECK: ('symoff', 324)
+// CHECK: ('nsyms', 16)
+// CHECK: ('stroff', 516)
+// CHECK: ('strsize', 260)
+// CHECK: ('_string_data', '\x00sym_ref_A\x00sym_weak_ref_A\x00sym_weak_def_A\x00sym_lazy_ref_A\x00sym_private_ext_A\x00sym_private_ext_B\x00sym_private_ext_C\x00sym_private_ext_D\x00sym_no_dead_strip_A\x00sym_ref_def_A\x00sym_ref_def_C\x00sym_weak_ref_def_A\x00sym_weak_ref_def_B\x00sym_lazy_ref_B\x00sym_lazy_ref_C\x00sym_desc_flags\x00\x00')
+// CHECK: ('_symbols', [
+// CHECK: # Symbol 0
+// CHECK: (('n_strx', 148)
+// CHECK: ('n_type', 0xe)
+// CHECK: ('n_sect', 1)
+// CHECK: ('n_desc', 32)
+// CHECK: ('n_value', 0)
+// CHECK: ('_string', 'sym_ref_def_A')
+// CHECK: ),
+// CHECK: # Symbol 1
+// CHECK: (('n_strx', 162)
+// CHECK: ('n_type', 0xe)
+// CHECK: ('n_sect', 1)
+// CHECK: ('n_desc', 32)
+// CHECK: ('n_value', 0)
+// CHECK: ('_string', 'sym_ref_def_C')
+// CHECK: ),
+// CHECK: # Symbol 2
+// CHECK: (('n_strx', 176)
+// CHECK: ('n_type', 0xe)
+// CHECK: ('n_sect', 1)
+// CHECK: ('n_desc', 0)
+// CHECK: ('n_value', 0)
+// CHECK: ('_string', 'sym_weak_ref_def_A')
+// CHECK: ),
+// CHECK: # Symbol 3
+// CHECK: (('n_strx', 195)
+// CHECK: ('n_type', 0xe)
+// CHECK: ('n_sect', 1)
+// CHECK: ('n_desc', 0)
+// CHECK: ('n_value', 0)
+// CHECK: ('_string', 'sym_weak_ref_def_B')
+// CHECK: ),
+// CHECK: # Symbol 4
+// CHECK: (('n_strx', 214)
+// CHECK: ('n_type', 0xe)
+// CHECK: ('n_sect', 2)
+// CHECK: ('n_desc', 32)
+// CHECK: ('n_value', 0)
+// CHECK: ('_string', 'sym_lazy_ref_B')
+// CHECK: ),
+// CHECK: # Symbol 5
+// CHECK: (('n_strx', 229)
+// CHECK: ('n_type', 0xe)
+// CHECK: ('n_sect', 2)
+// CHECK: ('n_desc', 32)
+// CHECK: ('n_value', 0)
+// CHECK: ('_string', 'sym_lazy_ref_C')
+// CHECK: ),
+// CHECK: # Symbol 6
+// CHECK: (('n_strx', 244)
+// CHECK: ('n_type', 0xe)
+// CHECK: ('n_sect', 2)
+// CHECK: ('n_desc', 0)
+// CHECK: ('n_value', 0)
+// CHECK: ('_string', 'sym_desc_flags')
+// CHECK: ),
+// CHECK: # Symbol 7
+// CHECK: (('n_strx', 74)
+// CHECK: ('n_type', 0x1f)
+// CHECK: ('n_sect', 2)
+// CHECK: ('n_desc', 0)
+// CHECK: ('n_value', 0)
+// CHECK: ('_string', 'sym_private_ext_B')
+// CHECK: ),
+// CHECK: # Symbol 8
+// CHECK: (('n_strx', 92)
+// CHECK: ('n_type', 0x1f)
+// CHECK: ('n_sect', 2)
+// CHECK: ('n_desc', 0)
+// CHECK: ('n_value', 0)
+// CHECK: ('_string', 'sym_private_ext_C')
+// CHECK: ),
+// CHECK: # Symbol 9
+// CHECK: (('n_strx', 26)
+// CHECK: ('n_type', 0xf)
+// CHECK: ('n_sect', 2)
+// CHECK: ('n_desc', 128)
+// CHECK: ('n_value', 0)
+// CHECK: ('_string', 'sym_weak_def_A')
+// CHECK: ),
+// CHECK: # Symbol 10
+// CHECK: (('n_strx', 41)
+// CHECK: ('n_type', 0x1)
+// CHECK: ('n_sect', 0)
+// CHECK: ('n_desc', 33)
+// CHECK: ('n_value', 0)
+// CHECK: ('_string', 'sym_lazy_ref_A')
+// CHECK: ),
+// CHECK: # Symbol 11
+// CHECK: (('n_strx', 128)
+// CHECK: ('n_type', 0x1)
+// CHECK: ('n_sect', 0)
+// CHECK: ('n_desc', 32)
+// CHECK: ('n_value', 0)
+// CHECK: ('_string', 'sym_no_dead_strip_A')
+// CHECK: ),
+// CHECK: # Symbol 12
+// CHECK: (('n_strx', 56)
+// CHECK: ('n_type', 0x11)
+// CHECK: ('n_sect', 0)
+// CHECK: ('n_desc', 0)
+// CHECK: ('n_value', 0)
+// CHECK: ('_string', 'sym_private_ext_A')
+// CHECK: ),
+// CHECK: # Symbol 13
+// CHECK: (('n_strx', 110)
+// CHECK: ('n_type', 0x11)
+// CHECK: ('n_sect', 0)
+// CHECK: ('n_desc', 0)
+// CHECK: ('n_value', 0)
+// CHECK: ('_string', 'sym_private_ext_D')
+// CHECK: ),
+// CHECK: # Symbol 14
+// CHECK: (('n_strx', 1)
+// CHECK: ('n_type', 0x1)
+// CHECK: ('n_sect', 0)
+// CHECK: ('n_desc', 4660)
+// CHECK: ('n_value', 0)
+// CHECK: ('_string', 'sym_ref_A')
+// CHECK: ),
+// CHECK: # Symbol 15
+// CHECK: (('n_strx', 11)
+// CHECK: ('n_type', 0x1)
+// CHECK: ('n_sect', 0)
+// CHECK: ('n_desc', 64)
+// CHECK: ('n_value', 0)
+// CHECK: ('_string', 'sym_weak_ref_A')
+// CHECK: ),
+// CHECK: ])
+// CHECK: ),
+// CHECK: # Load Command 2
+// CHECK: (('command', 11)
+// CHECK: ('size', 80)
+// CHECK: ('ilocalsym', 0)
+// CHECK: ('nlocalsym', 7)
+// CHECK: ('iextdefsym', 7)
+// CHECK: ('nextdefsym', 3)
+// CHECK: ('iundefsym', 10)
+// CHECK: ('nundefsym', 6)
+// CHECK: ('tocoff', 0)
+// CHECK: ('ntoc', 0)
+// CHECK: ('modtaboff', 0)
+// CHECK: ('nmodtab', 0)
+// CHECK: ('extrefsymoff', 0)
+// CHECK: ('nextrefsyms', 0)
+// CHECK: ('indirectsymoff', 0)
+// CHECK: ('nindirectsyms', 0)
+// CHECK: ('extreloff', 0)
+// CHECK: ('nextrel', 0)
+// CHECK: ('locreloff', 0)
+// CHECK: ('nlocrel', 0)
+// CHECK: ('_indirect_symbols', [
+// CHECK: ])
+// CHECK: ),
+// CHECK: ])
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