/// the file, and then emit during finalization.
MachOHeader Header;
- private:
-
/// MachOSegment - This struct contains the necessary information to
/// emit the load commands for each section in the file.
struct MachOSegment {
reserved3(0) { }
};
+ private:
+
/// SectionList - This is the list of sections that we have emitted to the
/// file. Once the file has been completely built, the segment load command
/// SectionCommands are constructed from this info.
/// turned into a real symbol table in the file.
struct MachOSym {
const GlobalValue *GV; // The global value this corresponds to.
- uint32_t n_strx; // index into the string table
- uint8_t n_type; // type flag
- uint8_t n_sect; // section number or NO_SECT
- int16_t n_desc; // see <mach-o/stab.h>
- uint64_t n_value; // value for this symbol (or stab offset)
+ std::string GVName; // The mangled name of the global value.
+ uint32_t n_strx; // index into the string table
+ uint8_t n_type; // type flag
+ uint8_t n_sect; // section number or NO_SECT
+ int16_t n_desc; // see <mach-o/stab.h>
+ uint64_t n_value; // value for this symbol (or stab offset)
// Constants for the n_sect field
// see <mach-o/nlist.h>
N_WEAK_DEF = 0x0080 // coalesced symbol is a weak definition
};
- /// entrySize - This routine returns the size of a symbol table entry as
- /// written to disk.
- static unsigned entrySize() { return 12; }
+ MachOSym(const GlobalValue *gv, std::string name, uint8_t sect) : GV(gv),
+ GVName(name), n_strx(0), n_type(sect == NO_SECT ? N_UNDF : N_SECT),
+ n_sect(sect), n_desc(0), n_value(0) {
+ // FIXME: names aren't getting the proper global/local prefix
+ }
+ };
- MachOSym(const GlobalValue *gv, uint8_t sect) : GV(gv), n_strx(0),
- n_type(sect == NO_SECT ? N_UNDF : N_SECT), n_sect(sect), n_desc(0),
- n_value(0) {}
+ struct MachOSymCmp {
+ bool operator()(const MachOSym &LHS, const MachOSym &RHS) {
+ return LHS.GVName < RHS.GVName;
+ }
};
+ /// PartitionByLocal - Simple boolean predicate that returns true if Sym is
+ /// a local symbol rather than an external symbol.
+ static bool PartitionByLocal(const MachOSym &Sym);
+
+ /// PartitionByDefined - Simple boolean predicate that returns true if Sym
+ /// is defined in this module.
+ static bool PartitionByDefined(const MachOWriter::MachOSym &Sym);
+
/// SymbolTable - This is the list of symbols we have emitted to the file.
/// This actually gets rearranged before emission to the file (to put the
/// local symbols first in the list).
std::vector<MachOSym> SymbolTable;
+ /// SymT - A buffer to hold the symbol table before we write it out at the
+ /// appropriate location in the file.
+ DataBuffer SymT;
+
+ /// StrT - A buffer to hold the string table before we write it out at the
+ /// appropriate location in the file.
+ DataBuffer StrT;
+
/// PendingSyms - This is a list of externally defined symbols that we have
/// been asked to emit, but have not seen a reference to. When a reference
/// is seen, the symbol will move from this list to the SymbolTable.
/// SymbolTable to aid in emitting the DYSYMTAB load command.
std::vector<unsigned> DynamicSymbolTable;
- /// StringTable - The table of strings referenced by SymbolTable entries
- std::vector<std::string> StringTable;
-
// align - Emit padding into the file until the current output position is
// aligned to the specified power of two boundary.
static void align(DataBuffer &Output, unsigned Boundary) {
void EmitHeaderAndLoadCommands();
void EmitSections();
void EmitRelocations();
- void EmitSymbolTable();
- void EmitStringTable();
+ void BufferSymbolAndStringTable();
};
}
#include "llvm/Target/TargetJITInfo.h"
#include "llvm/Support/Mangler.h"
#include "llvm/Support/MathExtras.h"
+#include <algorithm>
#include <iostream>
using namespace llvm;
MOS->size += CurBufferPtr - BufferBegin;
// Get a symbol for the function to add to the symbol table
- MachOWriter::MachOSym FnSym(F.getFunction(), MOS->Index);
+ const GlobalValue *FuncV = F.getFunction();
+ MachOWriter::MachOSym FnSym(FuncV, MOW.Mang->getValueName(FuncV), MOS->Index);
// Figure out the binding (linkage) of the symbol.
- switch (F.getFunction()->getLinkage()) {
+ switch (FuncV->getLinkage()) {
default:
// appending linkage is illegal for functions.
assert(0 && "Unknown linkage type!");
// until the sections are all layed out, but we still need to
// record them. Maybe emit TargetRelocations and then resolve
// those at file writing time?
- std::cerr << "whee!\n";
}
}
Relocations.clear();
unsigned Size = TM.getTargetData()->getTypeSize(Ty);
unsigned Align = Log2_32(TM.getTargetData()->getTypeAlignment(Ty));
- MachOSym Sym(GV, Sec.Index);
+ MachOSym Sym(GV, Mang->getValueName(GV), Sec.Index);
// Reserve space in the .bss section for this symbol while maintaining the
// desired section alignment, which must be at least as much as required by
// this symbol.
const Type *Ty = GV->getType()->getElementType();
unsigned Size = TM.getTargetData()->getTypeSize(Ty);
bool NoInit = !GV->hasInitializer();
-
+
// If this global has a zero initializer, it is part of the .bss or common
// section.
if (NoInit || GV->getInitializer()->isNullValue()) {
// part of the common block if they are zero initialized and allowed to be
// merged with other symbols.
if (NoInit || GV->hasLinkOnceLinkage() || GV->hasWeakLinkage()) {
- MachOWriter::MachOSym ExtOrCommonSym(GV, MachOSym::NO_SECT);
+ MachOWriter::MachOSym ExtOrCommonSym(GV, Mang->getValueName(GV),
+ MachOSym::NO_SECT);
ExtOrCommonSym.n_type |= MachOSym::N_EXT;
// For undefined (N_UNDF) external (N_EXT) types, n_value is the size in
// bytes of the symbol.
/// doFinalization - Now that the module has been completely processed, emit
/// the Mach-O file to 'O'.
bool MachOWriter::doFinalization(Module &M) {
+ // FIXME: we don't handle debug info yet, we should probably do that.
+
// Okay, the.text section has been completed, build the .data, .bss, and
// "common" sections next.
for (Module::global_iterator I = M.global_begin(), E = M.global_end();
I != E; ++I)
EmitGlobal(I);
+ // Emit the symbol table to temporary buffers, so that we know the size of
+ // the string table when we write the load commands in the next phase.
+ BufferSymbolAndStringTable();
+
// Emit the header and load commands.
EmitHeaderAndLoadCommands();
// have different relocation types.
EmitRelocations();
- // Emit the symbol table.
- // FIXME: we don't handle debug info yet, we should probably do that.
- EmitSymbolTable();
-
- // Emit the string table for the sections we have.
- EmitStringTable();
+ // Write the symbol table and the string table to the end of the file.
+ O.write((char*)&SymT[0], SymT.size());
+ O.write((char*)&StrT[0], StrT.size());
// We are done with the abstract symbols.
SectionList.clear();
}
// Step #6: Emit LC_SYMTAB/LC_DYSYMTAB load commands
- // FIXME: We'll need to scan over the symbol table and possibly do the sort
- // here so that we can set the proper indices in the dysymtab load command for
- // the index and number of external symbols defined in this module.
- // FIXME: We'll also need to scan over all the symbols so that we can
- // calculate the size of the string table.
// FIXME: add size of relocs
SymTab.symoff = SEG.fileoff + SEG.filesize;
SymTab.nsyms = SymbolTable.size();
- SymTab.stroff = SymTab.symoff + SymTab.nsyms * MachOSym::entrySize();
- SymTab.strsize = 10;
+ SymTab.stroff = SymTab.symoff + SymT.size();
+ SymTab.strsize = StrT.size();
outword(FH, SymTab.cmd);
outword(FH, SymTab.cmdsize);
outword(FH, SymTab.symoff);
outword(FH, SymTab.strsize);
// FIXME: set DySymTab fields appropriately
+ // We should probably just update these in BufferSymbolAndStringTable since
+ // thats where we're partitioning up the different kinds of symbols.
outword(FH, DySymTab.cmd);
outword(FH, DySymTab.cmdsize);
outword(FH, DySymTab.ilocalsym);
// specific.
}
-/// EmitSymbolTable - Sort the symbols we encountered and assign them each a
-/// string table index so that they appear in the correct order in the output
-/// file.
-void MachOWriter::EmitSymbolTable() {
+/// PartitionByLocal - Simple boolean predicate that returns true if Sym is
+/// a local symbol rather than an external symbol.
+bool MachOWriter::PartitionByLocal(const MachOSym &Sym) {
+ // FIXME: Not totally sure if private extern counts as external
+ return (Sym.n_type & (MachOSym::N_EXT | MachOSym::N_PEXT)) == 0;
+}
+
+/// PartitionByDefined - Simple boolean predicate that returns true if Sym is
+/// defined in this module.
+bool MachOWriter::PartitionByDefined(const MachOSym &Sym) {
+ // FIXME: Do N_ABS or N_INDR count as defined?
+ return (Sym.n_type & MachOSym::N_SECT) == MachOSym::N_SECT;
+}
+
+/// BufferSymbolAndStringTable - Sort the symbols we encountered and assign them
+/// each a string table index so that they appear in the correct order in the
+/// output file.
+void MachOWriter::BufferSymbolAndStringTable() {
// The order of the symbol table is:
- // local symbols
- // defined external symbols (sorted by name)
- // undefined external symbols (sorted by name)
- DataBuffer ST;
+ // 1. local symbols
+ // 2. defined external symbols (sorted by name)
+ // 3. undefined external symbols (sorted by name)
- // FIXME: enforce the above ordering, presumably by sorting by name,
- // then partitioning twice.
- unsigned stringIndex;
+ // Sort the symbols by name, so that when we partition the symbols by scope
+ // of definition, we won't have to sort by name within each partition.
+ std::sort(SymbolTable.begin(), SymbolTable.end(), MachOSymCmp());
+
+ // Parition the symbol table entries so that all local symbols come before
+ // all symbols with external linkage. { 1 | 2 3 }
+ std::partition(SymbolTable.begin(), SymbolTable.end(), PartitionByLocal);
+
+ // Advance iterator to beginning of external symbols and partition so that
+ // all external symbols defined in this module come before all external
+ // symbols defined elsewhere. { 1 | 2 | 3 }
for (std::vector<MachOSym>::iterator I = SymbolTable.begin(),
E = SymbolTable.end(); I != E; ++I) {
- // FIXME: remove when we actually calculate these correctly
- I->n_strx = 1;
- StringTable.push_back(Mang->getValueName(I->GV));
- // Emit nlist to buffer
- outword(ST, I->n_strx);
- outbyte(ST, I->n_type);
- outbyte(ST, I->n_sect);
- outhalf(ST, I->n_desc);
- outaddr(ST, I->n_value);
+ if (!PartitionByLocal(*I)) {
+ std::partition(I, E, PartitionByDefined);
+ break;
+ }
}
- O.write((char*)&ST[0], ST.size());
-}
-
-/// EmitStringTable - This method adds and emits a section for the Mach-O
-/// string table.
-void MachOWriter::EmitStringTable() {
- // The order of the string table is:
- // strings for external symbols
- // strings for local symbols
- // This is the symbol table, but backwards. This allows us to avoid a sorting
- // the symbol table again; all we have to do is use a reverse iterator.
- DataBuffer ST;
-
// Write out a leading zero byte when emitting string table, for n_strx == 0
// which means an empty string.
- outbyte(ST, 0);
+ outbyte(StrT, 0);
- for (std::vector<std::string>::iterator I = StringTable.begin(),
- E = StringTable.end(); I != E; ++I) {
- // FIXME: do not arbitrarily cap symbols to 16 characters
- // FIXME: do something more efficient than outstring
- outstring(ST, *I, 16);
+ // The order of the string table is:
+ // 1. strings for external symbols
+ // 2. strings for local symbols
+ // Since this is the opposite order from the symbol table, which we have just
+ // sorted, we can walk the symbol table backwards to output the string table.
+ for (std::vector<MachOSym>::reverse_iterator I = SymbolTable.rbegin(),
+ E = SymbolTable.rend(); I != E; ++I) {
+ if (I->GVName == "") {
+ I->n_strx = 0;
+ } else {
+ I->n_strx = StrT.size();
+ outstring(StrT, I->GVName, I->GVName.length()+1);
+ }
+ }
+
+ for (std::vector<MachOSym>::iterator I = SymbolTable.begin(),
+ E = SymbolTable.end(); I != E; ++I) {
+ // Emit nlist to buffer
+ outword(SymT, I->n_strx);
+ outbyte(SymT, I->n_type);
+ outbyte(SymT, I->n_sect);
+ outhalf(SymT, I->n_desc);
+ outaddr(SymT, I->n_value);
}
- O.write((char*)&ST[0], ST.size());
}
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