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merge D2 pull #1540
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@WalterBright
WalterBright committed Jan 25, 2013
1 parent 4f2ccf8 commit f71b5e7
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Showing 4 changed files with 126 additions and 62 deletions.
2 changes: 1 addition & 1 deletion src/backend/cdef.h
View file
Expand Up @@ -572,7 +572,7 @@ typedef targ_uns targ_size_t; /* size_t for the target machine */
#define DATA 2 /* initialized data */
#define CDATA 3 /* constant data */
#define UDATA 4 /* uninitialized data */
#define UNKNOWN 0x7FFF // unknown segment
#define UNKNOWN -1 /* unknown segment */
#define DGROUPIDX 1 /* group index of DGROUP */

#define KEEPBITFIELDS 0 /* 0 means code generator cannot handle bit fields, */
Expand Down
164 changes: 112 additions & 52 deletions src/backend/elfobj.c
View file
Expand Up @@ -216,17 +216,17 @@ Outbuffer *SECbuf; // Buffer to build section table in
// not used.
static int section_cnt; // Number of sections in table

#define SHI_TEXT 1
#define SHI_RELTEXT 2
#define SHI_DATA 3
#define SHI_RELDATA 4
#define SHI_BSS 5
#define SHI_RODAT 6
#define SHI_STRINGS 7
#define SHI_SYMTAB 8
#define SHI_SECNAMES 9
#define SHI_COM 10
#define SHI_NOTE 11
#define SHN_TEXT 1
#define SHN_RELTEXT 2
#define SHN_DATA 3
#define SHN_RELDATA 4
#define SHN_BSS 5
#define SHN_RODAT 6
#define SHN_STRINGS 7
#define SHN_SYMTAB 8
#define SHN_SECNAMES 9
#define SHN_COM 10
#define SHN_NOTE 11

IDXSYM *mapsec2sym;
#define S2S_INC 20
Expand All @@ -252,6 +252,10 @@ static int local_cnt; // Number of symbols with STB_LOCAL
// Symbol Table
Outbuffer *SYMbuf; // Buffer to build symbol table in

// Extended section header indices
static Outbuffer *shndx_data;
static const IDXSEC secidx_shndx = SHN_HIRESERVE + 1;

// Notes data (note currently used)
static Outbuffer *note_data;
static IDXSEC secidx_note; // Final table index for note data
Expand Down Expand Up @@ -458,9 +462,22 @@ static IDXSYM elf_addsym(IDXSTR nam, targ_size_t val, unsigned sz,
*/
if(sz == 0 && (bind == STB_GLOBAL || bind == STB_WEAK) &&
(typ == STT_OBJECT || typ == STT_TLS) &&
sec != SHT_UNDEF)
sec != SHN_UNDEF)
sz = 1; // so fake it if it doesn't

if (sec > SHN_HIRESERVE)
{ // If the section index is too big we need to store it as
// extended section header index.
if (!shndx_data)
shndx_data = new Outbuffer(50 * sizeof(Elf64_Word));
// fill with zeros up to symbol_idx
const size_t shndx_idx = shndx_data->size() / sizeof(Elf64_Word);
shndx_data->writezeros((symbol_idx - shndx_idx) * sizeof(Elf64_Word));

shndx_data->write32(sec);
sec = SHN_XINDEX;
}

if (I64)
{
if (!SYMbuf)
Expand Down Expand Up @@ -539,6 +556,14 @@ static IDXSEC elf_newsection2(
{ SECbuf = new Outbuffer(4 * sizeof(Elf32_Shdr));
SECbuf->reserve(16 * sizeof(Elf32_Shdr));
}
if (section_cnt == SHN_LORESERVE)
{ // insert dummy null sections to skip reserved section indices
section_cnt = SHN_HIRESERVE + 1;
SECbuf->writezeros((SHN_HIRESERVE + 1 - SHN_LORESERVE) * sizeof(sec));
// shndx itself becomes the first section with an extended index
IDXSTR namidx = Obj::addstr(section_names, ".symtab_shndx");
elf_newsection2(namidx,SHT_SYMTAB_SHNDX,0,0,0,0,SHN_SYMTAB,0,4,4);
}
SECbuf->write((void *)&sec, sizeof(sec));
return section_cnt++;
}
Expand Down Expand Up @@ -702,9 +727,9 @@ Obj *Obj::init(Outbuffer *objbuf, const char *filename, const char *csegname)
// name,type,flags,addr,offset,size,link,info,addralign,entsize
elf_newsection2(0, SHT_NULL, 0, 0,0,0,0,0, 0,0);
elf_newsection2(NAMIDX_TEXT,SHT_PROGDEF,SHF_ALLOC|SHF_EXECINSTR,0,0,0,0,0, 4,0);
elf_newsection2(NAMIDX_RELTEXT,SHT_RELA, 0,0,0,0,SHI_SYMTAB, SHI_TEXT, 8,0x18);
elf_newsection2(NAMIDX_RELTEXT,SHT_RELA, 0,0,0,0,SHN_SYMTAB, SHN_TEXT, 8,0x18);
elf_newsection2(NAMIDX_DATA,SHT_PROGDEF,SHF_ALLOC|SHF_WRITE, 0,0,0,0,0, 8,0);
elf_newsection2(NAMIDX_RELDATA64,SHT_RELA, 0,0,0,0,SHI_SYMTAB, SHI_DATA, 8,0x18);
elf_newsection2(NAMIDX_RELDATA64,SHT_RELA, 0,0,0,0,SHN_SYMTAB, SHN_DATA, 8,0x18);
elf_newsection2(NAMIDX_BSS, SHT_NOBITS,SHF_ALLOC|SHF_WRITE, 0,0,0,0,0, 16,0);
elf_newsection2(NAMIDX_RODATA,SHT_PROGDEF,SHF_ALLOC, 0,0,0,0,0, 16,0);
elf_newsection2(NAMIDX_STRTAB,SHT_STRTAB, 0, 0,0,0,0,0, 1,0);
Expand Down Expand Up @@ -748,9 +773,9 @@ Obj *Obj::init(Outbuffer *objbuf, const char *filename, const char *csegname)
// name,type,flags,addr,offset,size,link,info,addralign,entsize
elf_newsection2(0, SHT_NULL, 0, 0,0,0,0,0, 0,0);
elf_newsection2(NAMIDX_TEXT,SHT_PROGDEF,SHF_ALLOC|SHF_EXECINSTR,0,0,0,0,0, 16,0);
elf_newsection2(NAMIDX_RELTEXT,SHT_REL, 0,0,0,0,SHI_SYMTAB, SHI_TEXT, 4,8);
elf_newsection2(NAMIDX_RELTEXT,SHT_REL, 0,0,0,0,SHN_SYMTAB, SHN_TEXT, 4,8);
elf_newsection2(NAMIDX_DATA,SHT_PROGDEF,SHF_ALLOC|SHF_WRITE, 0,0,0,0,0, 4,0);
elf_newsection2(NAMIDX_RELDATA,SHT_REL, 0,0,0,0,SHI_SYMTAB, SHI_DATA, 4,8);
elf_newsection2(NAMIDX_RELDATA,SHT_REL, 0,0,0,0,SHN_SYMTAB, SHN_DATA, 4,8);
elf_newsection2(NAMIDX_BSS, SHT_NOBITS,SHF_ALLOC|SHF_WRITE, 0,0,0,0,0, 32,0);
elf_newsection2(NAMIDX_RODATA,SHT_PROGDEF,SHF_ALLOC, 0,0,0,0,0, 1,0);
elf_newsection2(NAMIDX_STRTAB,SHT_STRTAB, 0, 0,0,0,0,0, 1,0);
Expand All @@ -777,37 +802,39 @@ Obj *Obj::init(Outbuffer *objbuf, const char *filename, const char *csegname)

if (SYMbuf)
SYMbuf->setsize(0);
if (shndx_data)
shndx_data->setsize(0);
symbol_idx = 0;
local_cnt = 0;
// The symbols that every object file has
elf_addsym(0, 0, 0, STT_NOTYPE, STB_LOCAL, 0);
elf_addsym(0, 0, 0, STT_FILE, STB_LOCAL, SHT_ABS); // STI_FILE
elf_addsym(0, 0, 0, STT_SECTION, STB_LOCAL, SHI_TEXT); // STI_TEXT
elf_addsym(0, 0, 0, STT_SECTION, STB_LOCAL, SHI_DATA); // STI_DATA
elf_addsym(0, 0, 0, STT_SECTION, STB_LOCAL, SHI_BSS); // STI_BSS
elf_addsym(0, 0, 0, STT_NOTYPE, STB_LOCAL, SHI_TEXT); // STI_GCC
elf_addsym(0, 0, 0, STT_SECTION, STB_LOCAL, SHI_RODAT); // STI_RODAT
elf_addsym(0, 0, 0, STT_SECTION, STB_LOCAL, SHI_NOTE); // STI_NOTE
elf_addsym(0, 0, 0, STT_SECTION, STB_LOCAL, SHI_COM); // STI_COM
elf_addsym(0, 0, 0, STT_FILE, STB_LOCAL, SHN_ABS); // STI_FILE
elf_addsym(0, 0, 0, STT_SECTION, STB_LOCAL, SHN_TEXT); // STI_TEXT
elf_addsym(0, 0, 0, STT_SECTION, STB_LOCAL, SHN_DATA); // STI_DATA
elf_addsym(0, 0, 0, STT_SECTION, STB_LOCAL, SHN_BSS); // STI_BSS
elf_addsym(0, 0, 0, STT_NOTYPE, STB_LOCAL, SHN_TEXT); // STI_GCC
elf_addsym(0, 0, 0, STT_SECTION, STB_LOCAL, SHN_RODAT); // STI_RODAT
elf_addsym(0, 0, 0, STT_SECTION, STB_LOCAL, SHN_NOTE); // STI_NOTE
elf_addsym(0, 0, 0, STT_SECTION, STB_LOCAL, SHN_COM); // STI_COM

// Initialize output buffers for CODE, DATA and COMMENTS
// (NOTE not supported, BSS not required)

seg_count = 0;

elf_getsegment2(SHI_TEXT, STI_TEXT, SHI_RELTEXT);
elf_getsegment2(SHN_TEXT, STI_TEXT, SHN_RELTEXT);
assert(SegData[CODE]->SDseg == CODE);

elf_getsegment2(SHI_DATA, STI_DATA, SHI_RELDATA);
elf_getsegment2(SHN_DATA, STI_DATA, SHN_RELDATA);
assert(SegData[DATA]->SDseg == DATA);

elf_getsegment2(SHI_RODAT, STI_RODAT, 0);
elf_getsegment2(SHN_RODAT, STI_RODAT, 0);
assert(SegData[CDATA]->SDseg == CDATA);

elf_getsegment2(SHI_BSS, STI_BSS, 0);
elf_getsegment2(SHN_BSS, STI_BSS, 0);
assert(SegData[UDATA]->SDseg == UDATA);

elf_getsegment2(SHI_COM, STI_COM, 0);
elf_getsegment2(SHN_COM, STI_COM, 0);
assert(SegData[COMD]->SDseg == COMD);

if (config.fulltypes)
Expand Down Expand Up @@ -927,6 +954,24 @@ void *elf_renumbersyms()
}
}

// Reorder extended section header indices
if (shndx_data && shndx_data->size())
{
// fill with zeros up to symbol_idx
const size_t shndx_idx = shndx_data->size() / sizeof(Elf64_Word);
shndx_data->writezeros((symbol_idx - shndx_idx) * sizeof(Elf64_Word));

Elf64_Word *old_buf = (Elf64_Word *)shndx_data->buf;
Elf64_Word *tmp_buf = (Elf64_Word *)util_malloc(sizeof(Elf64_Word), symbol_idx);
for (SYMIDX old_idx = 0; old_idx < symbol_idx; ++old_idx)
{
const SYMIDX new_idx = sym_map[old_idx];
tmp_buf[new_idx] = old_buf[old_idx];
}
memcpy(old_buf, tmp_buf, sizeof(Elf64_Word) * symbol_idx);
util_free(tmp_buf);
}

// Renumber the relocations
for (int i = 1; i <= seg_count; i++)
{ // Map indicies in the segment table
Expand All @@ -938,7 +983,7 @@ void *elf_renumbersyms()
unsigned oidx = SecHdrTab[pseg->SDshtidx].sh_info;
assert(oidx < symbol_idx);
// we only have one symbol table
assert(SecHdrTab[pseg->SDshtidx].sh_link == SHI_SYMTAB);
assert(SecHdrTab[pseg->SDshtidx].sh_link == SHN_SYMTAB);
SecHdrTab[pseg->SDshtidx].sh_info = sym_map[oidx];
}

Expand Down Expand Up @@ -1064,8 +1109,13 @@ void Obj::term(const char *objfilename)
};
int hdrsize = I64 ? sizeof(Elf64_Ehdr) : sizeof(Elf32_Hdr);

elf_header.e_shnum = section_cnt;
elf_header.e_shstrndx = SHI_SECNAMES;
if (section_cnt < SHN_LORESERVE)
elf_header.e_shnum = section_cnt;
else
{ elf_header.e_shnum = SHN_UNDEF;
SecHdrTab[0].sh_size = section_cnt;
}
elf_header.e_shstrndx = SHN_SECNAMES;
fobjbuf->writezeros(hdrsize);

// Walk through sections determining size and file offsets
Expand Down Expand Up @@ -1139,7 +1189,7 @@ void Obj::term(const char *objfilename)

if (comment_data)
{
sechdr = &SecHdrTab[SHI_COM]; // Comments
sechdr = &SecHdrTab[SHN_COM]; // Comments
sechdr->sh_size = comment_data->size();
sechdr->sh_offset = foffset;
fobjbuf->write(comment_data->buf, sechdr->sh_size);
Expand All @@ -1149,7 +1199,7 @@ void Obj::term(const char *objfilename)
//
// Then output string table for section names
//
sechdr = &SecHdrTab[SHI_SECNAMES]; // Section Names
sechdr = &SecHdrTab[SHN_SECNAMES]; // Section Names
sechdr->sh_size = section_names->size();
sechdr->sh_offset = foffset;
//dbg_printf("section names offset %d\n",foffset);
Expand All @@ -1160,19 +1210,29 @@ void Obj::term(const char *objfilename)
// Symbol table and string table for symbols next
//
//dbg_printf("output symbol table size %d\n",SYMbuf->size());
sechdr = &SecHdrTab[SHI_SYMTAB]; // Symbol Table
sechdr = &SecHdrTab[SHN_SYMTAB]; // Symbol Table
sechdr->sh_size = SYMbuf->size();
sechdr->sh_entsize = I64 ? sizeof(Elf64_Sym) : sizeof(Elf32_Sym);
sechdr->sh_link = SHI_STRINGS;
sechdr->sh_link = SHN_STRINGS;
sechdr->sh_info = local_cnt;
foffset = elf_align(4,foffset);
sechdr->sh_offset = foffset;
fobjbuf->write(symtab, sechdr->sh_size);
foffset += sechdr->sh_size;
util_free(symtab);

if (shndx_data && shndx_data->size())
{
assert(section_cnt >= secidx_shndx);
sechdr = &SecHdrTab[secidx_shndx];
sechdr->sh_size = shndx_data->size();
sechdr->sh_offset = foffset;
fobjbuf->write(shndx_data->buf, sechdr->sh_size);
foffset += sechdr->sh_size;
}

//dbg_printf("output section strings size 0x%x,offset 0x%x\n",symtab_strings->size(),foffset);
sechdr = &SecHdrTab[SHI_STRINGS]; // Symbol Strings
sechdr = &SecHdrTab[SHN_STRINGS]; // Symbol Strings
sechdr->sh_size = symtab_strings->size();
sechdr->sh_offset = foffset;
fobjbuf->write(symtab_strings->buf, sechdr->sh_size);
Expand Down Expand Up @@ -1435,7 +1495,7 @@ void obj_filename(const char *modname)
{
//dbg_printf("obj_filename(char *%s)\n",modname);
unsigned strtab_idx = Obj::addstr(symtab_strings,modname);
elf_addsym(strtab_idx,0,0,STT_FILE,STB_LOCAL,SHT_ABS);
elf_addsym(strtab_idx,0,0,STT_FILE,STB_LOCAL,SHN_ABS);
}

/*******************************
Expand Down Expand Up @@ -2177,7 +2237,7 @@ int Obj::external_def(const char *name)
//dbg_printf("Obj::external_def('%s')\n",name);
assert(name);
IDXSTR namidx = Obj::addstr(symtab_strings,name);
IDXSYM symidx = elf_addsym(namidx, 0, 0, STT_NOTYPE, STB_GLOBAL, SHT_UNDEF);
IDXSYM symidx = elf_addsym(namidx, 0, 0, STT_NOTYPE, STB_GLOBAL, SHN_UNDEF);
return symidx;
}

Expand Down Expand Up @@ -2205,14 +2265,14 @@ int Obj::external(Symbol *s)
if (s->Sscope && !tyfunc(s->ty()))
{
symtype = STT_OBJECT;
sectype = SHT_COMMON;
sectype = SHN_COMMON;
size = type_size(s->Stype);
}
else
#endif
{
symtype = STT_NOTYPE;
sectype = SHT_UNDEF;
sectype = SHN_UNDEF;
size = 0;
}
if (s->ty() & mTYthread)
Expand Down Expand Up @@ -2270,7 +2330,7 @@ int Obj::common_block(Symbol *s,targ_size_t size,targ_size_t count)
alignOffset(UDATA,size);
IDXSYM symidx = elf_addsym(namidx, SegData[UDATA]->SDoffset, size*count,
(s->ty() & mTYthread) ? STT_TLS : STT_OBJECT,
STB_WEAK, SHI_BSS);
STB_WEAK, SHN_BSS);
//dbg_printf("\tObj::common_block returning symidx %d\n",symidx);
s->Sseg = UDATA;
s->Sfl = FLudata;
Expand Down Expand Up @@ -2429,10 +2489,10 @@ void ElfObj::addrel(int seg, targ_size_t offset, unsigned type,
if (segdata->SDrel->size() == 0)
{ IDXSEC relidx;

if (secidx == SHI_TEXT)
relidx = SHI_RELTEXT;
else if (secidx == SHI_DATA)
relidx = SHI_RELDATA;
if (secidx == SHN_TEXT)
relidx = SHN_RELTEXT;
else if (secidx == SHN_DATA)
relidx = SHN_RELDATA;
else
{
// Get the section name, and make a copy because
Expand All @@ -2453,15 +2513,15 @@ void ElfObj::addrel(int seg, targ_size_t offset, unsigned type,
* Elf64_Shdr.
*/
Elf32_Shdr *relsec = &SecHdrTab[relidx];
relsec->sh_link = SHI_SYMTAB;
relsec->sh_link = SHN_SYMTAB;
relsec->sh_info = secidx;
relsec->sh_entsize = sizeof(Elf64_Rela);
relsec->sh_addralign = 8;
}
else
{
Elf32_Shdr *relsec = &SecHdrTab[relidx];
relsec->sh_link = SHI_SYMTAB;
relsec->sh_link = SHN_SYMTAB;
relsec->sh_info = secidx;
relsec->sh_entsize = sizeof(Elf32_Rel);
relsec->sh_addralign = 4;
Expand Down Expand Up @@ -2681,12 +2741,12 @@ int Obj::reftoident(int seg, targ_size_t offset, Symbol *s, targ_size_t val,
{ // identifier is defined somewhere else
if (I64)
{
if (SymbolTable64[s->Sxtrnnum].st_shndx != SHT_UNDEF)
if (SymbolTable64[s->Sxtrnnum].st_shndx != SHN_UNDEF)
external = FALSE;
}
else
{
if (SymbolTable[s->Sxtrnnum].st_shndx != SHT_UNDEF)
if (SymbolTable[s->Sxtrnnum].st_shndx != SHN_UNDEF)
external = FALSE;
}
}
Expand Down Expand Up @@ -3220,7 +3280,7 @@ static void obj_rtinit()

// use a weak reference for _d_dso_registry
namidx = ElfObj::addstr(symtab_strings, "_d_dso_registry");
const IDXSYM symidx = elf_addsym(namidx, 0, 0, STT_NOTYPE, STB_WEAK, SHT_UNDEF);
const IDXSYM symidx = elf_addsym(namidx, 0, 0, STT_NOTYPE, STB_WEAK, SHN_UNDEF);

if (config.flags3 & CFG3pic)
{
Expand Down Expand Up @@ -3345,7 +3405,7 @@ static void obj_rtinit()
// set group section infos
Offset(groupseg) = SegData[groupseg]->SDbuf->size();
Elf32_Shdr *p = MAP_SEG2SEC(groupseg);
p->sh_link = SHI_SYMTAB;
p->sh_link = SHN_SYMTAB;
p->sh_info = dso_rec; // set the dso_rec as group symbol
p->sh_entsize = sizeof(IDXSYM);
p->sh_size = Offset(groupseg);
Expand Down

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