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-rw-r--r--include/llvm/MC/MCAssembler.h37
-rw-r--r--lib/MC/MCAssembler.cpp46
-rw-r--r--lib/MC/MCMachOStreamer.cpp9
-rw-r--r--test/MC/MachO/comm-1.s114
4 files changed, 191 insertions, 15 deletions
diff --git a/include/llvm/MC/MCAssembler.h b/include/llvm/MC/MCAssembler.h
index 4b66159d4d..182d2fe4d0 100644
--- a/include/llvm/MC/MCAssembler.h
+++ b/include/llvm/MC/MCAssembler.h
@@ -452,6 +452,17 @@ public:
/// IsPrivateExtern - True if this symbol is private extern.
unsigned IsPrivateExtern : 1;
+ /// CommonSize - The size of the symbol, if it is 'common', or 0.
+ //
+ // FIXME: Pack this in with other fields? We could put it in offset, since a
+ // common symbol can never get a definition.
+ uint64_t CommonSize;
+
+ /// CommonAlign - The alignment of the symbol, if it is 'common'.
+ //
+ // FIXME: Pack this in with other fields?
+ unsigned CommonAlign;
+
/// Flags - The Flags field is used by object file implementations to store
/// additional per symbol information which is not easily classified.
uint32_t Flags;
@@ -485,7 +496,31 @@ public:
bool isPrivateExtern() const { return IsPrivateExtern; }
void setPrivateExtern(bool Value) { IsPrivateExtern = Value; }
-
+
+ /// isCommon - Is this a 'common' symbol.
+ bool isCommon() const { return CommonSize != 0; }
+
+ /// setCommon - Mark this symbol as being 'common'.
+ ///
+ /// \param Size - The size of the symbol.
+ /// \param Align - The alignment of the symbol.
+ void setCommon(uint64_t Size, unsigned Align) {
+ CommonSize = Size;
+ CommonAlign = Align;
+ }
+
+ /// getCommonSize - Return the size of a 'common' symbol.
+ uint64_t getCommonSize() const {
+ assert(isCommon() && "Not a 'common' symbol!");
+ return CommonSize;
+ }
+
+ /// getCommonAlignment - Return the alignment of a 'common' symbol.
+ unsigned getCommonAlignment() const {
+ assert(isCommon() && "Not a 'common' symbol!");
+ return CommonAlign;
+ }
+
/// getFlags - Get the (implementation defined) symbol flags.
uint32_t getFlags() const { return Flags; }
diff --git a/lib/MC/MCAssembler.cpp b/lib/MC/MCAssembler.cpp
index 8057fcb359..0d9b540d15 100644
--- a/lib/MC/MCAssembler.cpp
+++ b/lib/MC/MCAssembler.cpp
@@ -25,6 +25,11 @@ class MachObjectWriter;
STATISTIC(EmittedFragments, "Number of emitted assembler fragments");
+// FIXME FIXME FIXME: There are number of places in this file where we convert
+// what is a 64-bit assembler value used for computation into a value in the
+// object file, which may truncate it. We should detect that truncation where
+// invalid and report errors back.
+
static void WriteFileData(raw_ostream &OS, const MCSectionData &SD,
MachObjectWriter &MOW);
@@ -328,6 +333,8 @@ public:
MCSymbolData &Data = *MSD.SymbolData;
MCSymbol &Symbol = Data.getSymbol();
uint8_t Type = 0;
+ uint16_t Flags = Data.getFlags();
+ uint32_t Address = 0;
// Set the N_TYPE bits. See <mach-o/nlist.h>.
//
@@ -348,6 +355,30 @@ public:
if (Data.isExternal() || Symbol.isUndefined())
Type |= STF_External;
+ // Compute the symbol address.
+ if (Symbol.isDefined()) {
+ if (Symbol.isAbsolute()) {
+ llvm_unreachable("FIXME: Not yet implemented!");
+ } else {
+ Address = Data.getFragment()->getAddress() + Data.getOffset();
+ }
+ } else if (Data.isCommon()) {
+ // Common symbols are encoded with the size in the address
+ // field, and their alignment in the flags.
+ Address = Data.getCommonSize();
+
+ // Common alignment is packed into the 'desc' bits.
+ if (unsigned Align = Data.getCommonAlignment()) {
+ unsigned Log2Size = Log2_32(Align);
+ assert((1U << Log2Size) == Align && "Invalid 'common' alignment!");
+ if (Log2Size > 15)
+ llvm_report_error("invalid 'common' alignment '" +
+ Twine(Align) + "'");
+ // FIXME: Keep this mask with the SymbolFlags enumeration.
+ Flags = (Flags & 0xF0FF) | (Log2Size << 8);
+ }
+ }
+
// struct nlist (12 bytes)
Write32(MSD.StringIndex);
@@ -356,17 +387,7 @@ public:
// The Mach-O streamer uses the lowest 16-bits of the flags for the 'desc'
// value.
- Write16(Data.getFlags() & 0xFFFF);
-
- // Write the symbol address.
- uint32_t Address = 0;
- if (Symbol.isDefined()) {
- if (Symbol.isAbsolute()) {
- llvm_unreachable("FIXME: Not yet implemented!");
- } else {
- Address = Data.getFragment()->getAddress() + Data.getOffset();
- }
- }
+ Write16(Flags);
Write32(Address);
}
@@ -910,7 +931,8 @@ MCSymbolData::MCSymbolData() : Symbol(*(MCSymbol*)0) {}
MCSymbolData::MCSymbolData(MCSymbol &_Symbol, MCFragment *_Fragment,
uint64_t _Offset, MCAssembler *A)
: Symbol(_Symbol), Fragment(_Fragment), Offset(_Offset),
- IsExternal(false), IsPrivateExtern(false), Flags(0), Index(0)
+ IsExternal(false), IsPrivateExtern(false),
+ CommonSize(0), CommonAlign(0), Flags(0), Index(0)
{
if (A)
A->getSymbolList().push_back(this);
diff --git a/lib/MC/MCMachOStreamer.cpp b/lib/MC/MCMachOStreamer.cpp
index b53a82e958..e9722251c6 100644
--- a/lib/MC/MCMachOStreamer.cpp
+++ b/lib/MC/MCMachOStreamer.cpp
@@ -224,7 +224,7 @@ void MCMachOStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
break;
case MCStreamer::Global:
- getSymbolData(*Symbol).setExternal(true);
+ SD.setExternal(true);
break;
case MCStreamer::LazyReference:
@@ -273,7 +273,12 @@ void MCMachOStreamer::EmitLocalSymbol(MCSymbol *Symbol, const MCValue &Value) {
void MCMachOStreamer::EmitCommonSymbol(MCSymbol *Symbol, unsigned Size,
unsigned Pow2Alignment) {
- llvm_unreachable("FIXME: Not yet implemented!");
+ // FIXME: Darwin 'as' does appear to allow redef of a .comm by itself.
+ assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
+
+ MCSymbolData &SD = getSymbolData(*Symbol);
+ SD.setExternal(true);
+ SD.setCommon(Size, 1 << Pow2Alignment);
}
void MCMachOStreamer::EmitZerofill(const MCSection *Section, MCSymbol *Symbol,
diff --git a/test/MC/MachO/comm-1.s b/test/MC/MachO/comm-1.s
new file mode 100644
index 0000000000..e979fb1392
--- /dev/null
+++ b/test/MC/MachO/comm-1.s
@@ -0,0 +1,114 @@
+// RUN: llvm-mc -triple i386-apple-darwin9 %s -filetype=obj -o - | macho-dump | FileCheck %s
+
+ .comm sym_comm_B, 2
+ .comm sym_comm_A, 4
+ .comm sym_comm_C, 8, 2
+ .comm sym_comm_D, 2, 3
+
+ .no_dead_strip sym_comm_C
+
+// CHECK: ('cputype', 7)
+// CHECK: ('cpusubtype', 3)
+// CHECK: ('filetype', 1)
+// CHECK: ('num_load_commands', 1)
+// CHECK: ('load_commands_size', 228)
+// CHECK: ('flag', 0)
+// CHECK: ('load_commands', [
+// CHECK: # Load Command 0
+// CHECK: (('command', 1)
+// CHECK: ('size', 124)
+// 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', 256)
+// CHECK: ('file_size', 0)
+// CHECK: ('maxprot', 7)
+// CHECK: ('initprot', 7)
+// CHECK: ('num_sections', 1)
+// 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', 256)
+// CHECK: ('alignment', 0)
+// CHECK: ('reloc_offset', 0)
+// CHECK: ('num_reloc', 0)
+// CHECK: ('flags', 0x80000000)
+// CHECK: ('reserved1', 0)
+// CHECK: ('reserved2', 0)
+// CHECK: ),
+// CHECK: ('_relocations', [
+// CHECK: ])
+// CHECK: ])
+// CHECK: ),
+// CHECK: # Load Command 1
+// CHECK: (('command', 2)
+// CHECK: ('size', 24)
+// CHECK: ('symoff', 256)
+// CHECK: ('nsyms', 4)
+// CHECK: ('stroff', 304)
+// CHECK: ('strsize', 48)
+// CHECK: ('_string_data', '\x00sym_comm_B\x00sym_comm_A\x00sym_comm_C\x00sym_comm_D\x00\x00\x00\x00')
+// CHECK: ('_symbols', [
+// CHECK: # Symbol 0
+// CHECK: (('n_strx', 12)
+// CHECK: ('n_type', 0x1)
+// CHECK: ('n_sect', 0)
+// CHECK: ('n_desc', 0)
+// CHECK: ('n_value', 4)
+// CHECK: ('_string', 'sym_comm_A')
+// CHECK: ),
+// CHECK: # Symbol 1
+// CHECK: (('n_strx', 1)
+// CHECK: ('n_type', 0x1)
+// CHECK: ('n_sect', 0)
+// CHECK: ('n_desc', 0)
+// CHECK: ('n_value', 2)
+// CHECK: ('_string', 'sym_comm_B')
+// CHECK: ),
+// CHECK: # Symbol 2
+// CHECK: (('n_strx', 23)
+// CHECK: ('n_type', 0x1)
+// CHECK: ('n_sect', 0)
+// CHECK: ('n_desc', 544)
+// CHECK: ('n_value', 8)
+// CHECK: ('_string', 'sym_comm_C')
+// CHECK: ),
+// CHECK: # Symbol 3
+// CHECK: (('n_strx', 34)
+// CHECK: ('n_type', 0x1)
+// CHECK: ('n_sect', 0)
+// CHECK: ('n_desc', 768)
+// CHECK: ('n_value', 2)
+// CHECK: ('_string', 'sym_comm_D')
+// CHECK: ),
+// CHECK: ])
+// CHECK: ),
+// CHECK: # Load Command 2
+// CHECK: (('command', 11)
+// CHECK: ('size', 80)
+// CHECK: ('ilocalsym', 0)
+// CHECK: ('nlocalsym', 0)
+// CHECK: ('iextdefsym', 0)
+// CHECK: ('nextdefsym', 0)
+// CHECK: ('iundefsym', 0)
+// CHECK: ('nundefsym', 4)
+// 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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