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Commit eb572e01 authored by Luuk van Dijk's avatar Luuk van Dijk
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6l/8l: emit DWARF frame info. 

R=rsc, ken2, r
CC=golang-dev
https://golang.org/cl/2151044
parent 8e5f673d
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Showing with 330 additions and 102 deletions
src/cmd/6l/l.h
View file @ eb572e01
......@@ -95,6 +95,7 @@ struct Prog
Prog* dlink;
Prog* pcond; /* work on this */
vlong pc;
int32 spadj;
int32 line;
short as;
char ft; /* oclass cache */
......@@ -102,7 +103,7 @@ struct Prog
uchar mark; /* work on these */
uchar back;
char width; /* fake for DATA */
char width; /* fake for DATA */
char mode; /* 16, 32, or 64 */
};
struct Auto
......@@ -397,7 +398,7 @@ void buildop(void);
void cflush(void);
void ckoff(Sym*, int32);
Prog* copyp(Prog*);
vlong cpos(void);
vlong cpos(void);
double cputime(void);
void datblk(int32, int32);
void deadcode(void);
......@@ -463,3 +464,9 @@ uint32 machheadr(void);
#pragma varargck type "R" int
#pragma varargck type "A" int
#pragma varargck argpos diag 1
/* Used by ../ld/dwarf.c */
enum
{
DWARFREGSP = 7
};
src/cmd/6l/pass.c
View file @ eb572e01
......@@ -692,7 +692,7 @@ dostkoff(void)
p->from.type = D_INDIR+D_GS;
p->from.offset = tlsoffset+0;
p->to.type = D_CX;
if(debug['K']) {
// 6l -K means check not only for stack
// overflow but stack underflow.
......@@ -843,6 +843,7 @@ dostkoff(void)
p->as = AADJSP;
p->from.type = D_CONST;
p->from.offset = autoffset;
p->spadj = autoffset;
if(q != P)
q->pcond = p;
}
......@@ -903,26 +904,32 @@ dostkoff(void)
case APUSHL:
case APUSHFL:
deltasp += 4;
p->spadj = 4;
continue;
case APUSHQ:
case APUSHFQ:
deltasp += 8;
p->spadj = 8;
continue;
case APUSHW:
case APUSHFW:
deltasp += 2;
p->spadj = 2;
continue;
case APOPL:
case APOPFL:
deltasp -= 4;
p->spadj = -4;
continue;
case APOPQ:
case APOPFQ:
deltasp -= 8;
p->spadj = -8;
continue;
case APOPW:
case APOPFW:
deltasp -= 2;
p->spadj = -2;
continue;
case ARET:
break;
......@@ -937,7 +944,7 @@ dostkoff(void)
p->as = AADJSP;
p->from.type = D_CONST;
p->from.offset = -autoffset;
p->spadj = -autoffset;
p = appendp(p);
p->as = ARET;
}
......@@ -954,6 +961,7 @@ dostkoff(void)
q->from = zprg.from;
q->from.type = D_CONST;
q->from.offset = -autoffset;
q->spadj = -autoffset;
q->to = zprg.to;
continue;
}
......
src/cmd/8l/l.h
View file @ eb572e01
......@@ -95,6 +95,7 @@ struct Prog
Prog* dlink;
Prog* pcond; /* work on this */
int32 pc;
int32 spadj;
int32 line;
short as;
char width; /* fake for DATA */
......@@ -346,7 +347,7 @@ Prog* brloop(Prog*);
void cflush(void);
void ckoff(Sym*, int32);
Prog* copyp(Prog*);
vlong cpos(void);
vlong cpos(void);
double cputime(void);
void datblk(int32, int32, int32);
void diag(char*, ...);
......@@ -412,3 +413,9 @@ void deadcode(void);
#pragma varargck type "P" Prog*
#pragma varargck type "R" int
#pragma varargck type "A" int
/* Used by ../ld/dwarf.c */
enum
{
DWARFREGSP = 4
};
src/cmd/8l/pass.c
View file @ eb572e01
......@@ -392,10 +392,10 @@ patch(void)
for(p = firstp; p != P; p = p->link) {
if(HEADTYPE == 10) { // Windows
// Convert
// op n(GS), reg
// op n(GS), reg
// to
// MOVL 0x2C(FS), reg
// op n(reg), reg
// op n(reg), reg
// The purpose of this patch is to fix some accesses
// to extern register variables (TLS) on Windows, as
// a different method is used to access them.
......@@ -770,6 +770,7 @@ dostkoff(void)
p->as = AADJSP;
p->from.type = D_CONST;
p->from.offset = autoffset;
p->spadj = autoffset;
if(q != P)
q->pcond = p;
}
......@@ -792,18 +793,22 @@ dostkoff(void)
case APUSHL:
case APUSHFL:
deltasp += 4;
p->spadj = 4;
continue;
case APUSHW:
case APUSHFW:
deltasp += 2;
p->spadj = 2;
continue;
case APOPL:
case APOPFL:
deltasp -= 4;
p->spadj = -4;
continue;
case APOPW:
case APOPFW:
deltasp -= 2;
p->spadj = -2;
continue;
case ARET:
break;
......@@ -822,6 +827,7 @@ dostkoff(void)
q->as = AADJSP;
q->from.type = D_CONST;
q->from.offset = -autoffset;
p->spadj = -autoffset;
}
continue;
......@@ -836,6 +842,7 @@ dostkoff(void)
q->from = zprg.from;
q->from.type = D_CONST;
q->from.offset = -autoffset;
p->spadj = -autoffset;
q->to = zprg.to;
continue;
}
......
src/cmd/ld/dwarf.c
View file @ eb572e01
......@@ -10,7 +10,7 @@
#include "../ld/macho.h"
/*
* Offsets and sizes of the .debug_* sections in the cout file.
* Offsets and sizes of the debug_* sections in the cout file.
*/
static vlong abbrevo;
......@@ -19,7 +19,78 @@ static vlong lineo;
static vlong linesize;
static vlong infoo;
static vlong infosize;
static vlong frameo;
static vlong framesize;
/*
* Basic I/O
*/
static void
addrput(vlong addr)
{
switch(PtrSize) {
case 4:
LPUT(addr);
break;
case 8:
VPUT(addr);
break;
}
}
static int
uleb128enc(uvlong v, char* dst)
{
uint8 c, len;
len = 0;
do {
c = v & 0x7f;
v >>= 7;
if (v)
c |= 0x80;
if (dst)
*dst++ = c;
len++;
} while (c & 0x80);
return len;
};
static int
sleb128enc(vlong v, char *dst)
{
uint8 c, s, len;
len = 0;
do {
c = v & 0x7f;
s = v & 0x40;
v >>= 7;
if ((v != -1 || !s) && (v != 0 || s))
c |= 0x80;
if (dst)
*dst++ = c;
len++;
} while(c & 0x80);
return len;
}
static void
uleb128put(vlong v)
{
char buf[10];
strnput(buf, uleb128enc(v, buf));
}
static void
sleb128put(vlong v)
{
char buf[10];
strnput(buf, sleb128enc(v, buf));
}
/*
* Defining Abbrevs. This is hardcoded, and there will be
......@@ -72,13 +143,34 @@ struct DWAbbrev {
},
};
static void
writeabbrev(void)
{
int i, n;
abbrevo = cpos();
for (i = 1; i < DW_NABRV; i++) {
// See section 7.5.3
uleb128put(i);
uleb128put(abbrevs[i].tag);
cput(abbrevs[i].children);
// 0 is not a valid attr or form, so we can treat this as
// a string
n = strlen((char*)abbrevs[i].attr) / 2;
strnput((char*)abbrevs[i].attr,
(n+1) * sizeof(DWAttrForm));
}
cput(0);
abbrevsize = cpos() - abbrevo;
}
/*
* Debugging Information Entries and their attributes
*/
// for string and block, value contains the length, and data the data,
// for all others, value is the whole thing and data is null.
// For DW_CLS_string and _block, value should contain the length, and
// data the data, for all others, value is the whole thing and data is
// null.
typedef struct DWAttr DWAttr;
struct DWAttr {
......@@ -126,46 +218,6 @@ newattr(DWDie *die, uint8 attr, int cls, vlong value, char *data)
return a;
}
static void addrput(vlong addr)
{
switch(PtrSize) {
case 4:
LPUT(addr);
break;
case 8:
VPUT(addr);
break;
}
}
static void
uleb128put(uvlong v)
{
uint8 c;
do {
c = v & 0x7f;
v >>= 7;
if (v) c |= 0x80;
cput(c);
} while (c & 0x80);
};
static void
sleb128put(vlong v)
{
uint8 c, s;
do {
c = v & 0x7f;
s = c & 0x40;
v >>= 7;
if ((v != -1 || !s) && (v != 0 || s))
c |= 0x80;
cput(c);
} while(c & 0x80);
};
static void
putattr(int form, int cls, vlong value, char *data)
{
......@@ -209,11 +261,11 @@ putattr(int form, int cls, vlong value, char *data)
WPUT(value);
break;
case DW_FORM_data4: // constant, lineptr, loclistptr, macptr, rangelistptr
case DW_FORM_data4: // constant, {line,loclist,mac,rangelist}ptr
LPUT(value);
break;
case DW_FORM_data8: // constant, lineptr, loclistptr, macptr, rangelistptr
case DW_FORM_data8: // constant, {line,loclist,mac,rangelist}ptr
VPUT(value);
break;
......@@ -542,28 +594,6 @@ searchhist(vlong absline)
return lh;
}
static void
writeabbrev(void)
{
int i, n;
abbrevo = cpos();
for (i = 1; i < DW_NABRV; i++) {
// See section 7.5.3
uleb128put(i);
uleb128put(abbrevs[i].tag);
cput(abbrevs[i].children);
// 0 is not a valid attr or form, so we can treat this as
// a string
n = strlen((char *) abbrevs[i].attr) / 2;
strnput((char *) abbrevs[i].attr,
(n + 1) * sizeof(DWAttrForm));
}
cput(0);
abbrevsize = cpos() - abbrevo;
}
static int
guesslang(char *s)
{
......@@ -596,8 +626,8 @@ putpclcdelta(vlong delta_pc, vlong delta_lc)
}
if (delta_pc) {
cput(DW_LNS_advance_pc);
sleb128put(delta_pc);
cput(DW_LNS_advance_pc);
sleb128put(delta_pc);
}
cput(DW_LNS_advance_line);
......@@ -616,8 +646,8 @@ flushunit(vlong pc, vlong unitstart)
{
vlong here;
if (dwinfo != 0 && pc != 0) {
newattr(dwinfo, DW_AT_high_pc, DW_CLS_ADDRESS, pc, 0);
if (dwinfo != nil && pc != 0) {
newattr(dwinfo, DW_AT_high_pc, DW_CLS_ADDRESS, pc+1, 0);
}
if (unitstart >= 0) {
......@@ -641,19 +671,22 @@ writelines(void)
Sym *s;
char *unitname;
vlong unitstart;
vlong pc, lc, llc, lline;
vlong pc, epc, lc, llc, lline;
int currfile;
int i;
Linehist *lh;
q = nil;
unitstart = -1;
pc = 0;
epc = pc = 0;
lc = 1;
llc = 1;
currfile = -1;
lineo = cpos();
for (p = textp; p != P; p = p->pcond) {
curtext = p; // for diag
s = p->from.sym;
if (s == nil || s->type != STEXT) {
diag("->pcond was supposed to loop over STEXT: %P", p);
......@@ -663,7 +696,7 @@ writelines(void)
// Look for history stack. If we find one,
// we're entering a new compilation unit
if ((unitname = inithist(p->to.autom)) != 0) {
flushunit(pc, unitstart);
flushunit(epc, unitstart);
unitstart = cpos();
if(debug['v'] > 1) {
print("dwarf writelines found %s\n", unitname);
......@@ -675,8 +708,8 @@ writelines(void)
dwinfo = newdie(dwinfo, DW_ABRV_COMPUNIT);
newattr(dwinfo, DW_AT_name, DW_CLS_STRING, strlen(unitname), unitname);
newattr(dwinfo, DW_AT_language, DW_CLS_CONSTANT, guesslang(unitname), 0);
newattr(dwinfo, DW_AT_stmt_list, DW_CLS_PTR, unitstart - lineo, 0);
newattr(dwinfo, DW_AT_low_pc, DW_CLS_ADDRESS, p->pc, 0);
newattr(dwinfo, DW_AT_stmt_list, DW_CLS_PTR, unitstart - lineo, 0);
newattr(dwinfo, DW_AT_low_pc, DW_CLS_ADDRESS, p->pc, 0);
// Write .debug_line Line Number Program Header (sec 6.2.4)
// Fields marked with (*) must be changed for 64-bit dwarf
LPUT(0); // unit_length (*), will be filled in later.
......@@ -701,7 +734,7 @@ writelines(void)
// 4 zeros: the string termination + 3 fields.
}
pc = p->pc;
epc = pc = p->pc;
currfile = 1;
lc = 1;
llc = 1;
......@@ -711,7 +744,7 @@ writelines(void)
cput(DW_LNE_set_address);
addrput(pc);
}
if (!p->from.sym->reachable)
if (!s->reachable)
continue;
if (unitstart < 0) {
diag("reachable code before seeing any history: %P", p);
......@@ -721,11 +754,9 @@ writelines(void)
dwinfo->child = newdie(dwinfo->child, DW_ABRV_FUNCTION);
newattr(dwinfo->child, DW_AT_name, DW_CLS_STRING, strlen(s->name), s->name);
newattr(dwinfo->child, DW_AT_low_pc, DW_CLS_ADDRESS, p->pc, 0);
if (debug['v'] > 1)
print("frame offset: %d\n", p->to.offset);
// newattr(dwinfo->child, DW_AT_return_addr, DW_CLS_BLOCK, p->to.offset, 0);
for(q = p; q != P && (q == p || q->as != ATEXT); q = q->link) {
epc = q->pc;
lh = searchhist(q->line);
if (lh == nil) {
diag("corrupt history or bad absolute line: %P", q);
......@@ -734,7 +765,7 @@ writelines(void)
lline = lh->line + q->line - lh->absline;
if (debug['v'] > 1)
print("%6llux %s[%lld] %P\n", q->pc, histfile[lh->file], lline, q);
// Only emit a line program statement if line has changed.
if (q->line == lc)
continue;
if (currfile != lh->file) {
......@@ -747,12 +778,130 @@ writelines(void)
lc = q->line;
llc = lline;
}
newattr(dwinfo->child, DW_AT_high_pc, DW_CLS_ADDRESS, pc, 0);
newattr(dwinfo->child, DW_AT_high_pc, DW_CLS_ADDRESS, epc+1, 0);
}
flushunit(pc, unitstart);
flushunit(epc, unitstart);
linesize = cpos() - lineo;
}
/*
* Emit .debug_frame
*/
enum
{
CIERESERVE = 16,
DATAALIGNMENTFACTOR = -4,
FAKERETURNCOLUMN = 16
};
static void
putpccfadelta(vlong deltapc, vlong cfa)
{
if (deltapc < 0x40) {
cput(DW_CFA_advance_loc + deltapc);
} else if (deltapc < 0x100) {
cput(DW_CFA_advance_loc1);
cput(deltapc);
} else if (deltapc < 0x10000) {
cput(DW_CFA_advance_loc2);
WPUT(deltapc);
} else {
cput(DW_CFA_advance_loc4);
LPUT(deltapc);
}
cput(DW_CFA_def_cfa_offset_sf);
sleb128put(cfa / DATAALIGNMENTFACTOR);
}
static void
writeframes(void)
{
Prog *p, *q;
Sym *s;
vlong fdeo, fdesize, pad, cfa, pc, epc;
frameo = cpos();
// Emit the CIE, Section 6.4.1
LPUT(CIERESERVE); // initial length, must be multiple of PtrSize
LPUT(0xffffffff); // cid.
cput(3); // dwarf version
cput(0); // augmentation ""
uleb128put(1); // code_alignment_factor
sleb128put(DATAALIGNMENTFACTOR); // guess
uleb128put(FAKERETURNCOLUMN); // return_address_register
cput(DW_CFA_def_cfa);
uleb128put(DWARFREGSP); // register SP (**ABI-dependent, defined in l.h)
uleb128put(PtrSize); // offset
cput(DW_CFA_offset + FAKERETURNCOLUMN); // return address
uleb128put(-PtrSize / DATAALIGNMENTFACTOR); // at cfa - x*4
// 4 is to exclude the length field.
pad = CIERESERVE + frameo + 4 - cpos();
if (pad < 0) {
diag("CIERESERVE too small by %lld bytes.", -pad);
errorexit();
}
strnput("", pad);
for (p = textp; p != P; p = p->pcond) {
curtext = p; // for diag
s = p->from.sym;
if (s == nil || s->type != STEXT) {
diag("->pcond was supposed to loop over STEXT: %P", p);
continue;
}
if (!s->reachable)
continue;
fdeo = cpos();
// Emit a FDE, Section 6.4.1, starting wit a placeholder.
LPUT(0); // length, must be multiple of PtrSize
LPUT(0); // Pointer to the CIE above, at offset 0
addrput(0); // initial location
addrput(0); // address range
cfa = PtrSize; // CFA starts at sp+PtrSize
pc = p->pc;
epc = p->pc;
for(q = p; q != P && (q == p || q->as != ATEXT); q = q->link) {
epc = q->pc;
if (q->spadj == 0)
continue;
cfa += q->spadj;
putpccfadelta(q->pc - pc, cfa);
pc = q->pc;
}
fdesize = cpos() - fdeo - 4; // exclude the length field.
pad = rnd(fdesize, PtrSize) - fdesize;
strnput("", pad);
fdesize += pad;
cflush();
// Emit the FDE header for real, Section 6.4.1.
seek(cout, fdeo, 0);
LPUT(fdesize);
LPUT(0);
addrput(p->pc);
addrput(epc - p->pc);
cflush();
seek(cout, fdeo + 4 + fdesize, 0);
}
cflush();
framesize = cpos() - frameo;
}
/*
* Walk DWarfDebugInfoEntries, and emit .debug_info
*/
......@@ -790,8 +939,17 @@ writeinfo(void)
infosize = cpos() - infoo;
}
void
dwarfemitdebugsections(void)
{
writeabbrev();
writelines();
writeframes();
writeinfo();
}
/*
* Elf sections.
* Elf.
*/
enum
{
......@@ -827,14 +985,6 @@ dwarfaddshstrings(Sym *shstrtab)
elfstrdbg[ElfStrDebugStr] = addstring(shstrtab, ".debug_str");
}
void
dwarfemitdebugsections(void)
{
writeabbrev();
writelines();
writeinfo();
}
void
dwarfaddelfheaders(void)
{
......@@ -852,6 +1002,12 @@ dwarfaddelfheaders(void)
sh->size = linesize;
sh->addralign = 1;
sh = newElfShdr(elfstrdbg[ElfStrDebugFrame]);
sh->type = SHT_PROGBITS;
sh->off = frameo;
sh->size = framesize;
sh->addralign = 1;
sh = newElfShdr(elfstrdbg[ElfStrDebugInfo]);
sh->type = SHT_PROGBITS;
sh->off = infoo;
......@@ -859,6 +1015,9 @@ dwarfaddelfheaders(void)
sh->addralign = 1;
}
/*
* Macho
*/
void
dwarfaddmachoheaders(void)
{
......@@ -873,7 +1032,7 @@ dwarfaddmachoheaders(void)
ms = newMachoSeg("__DWARF", 3);
ms->fileoffset = fakestart;
ms->filesize = abbrevo-fakestart + abbrevsize+linesize+infosize;
ms->filesize = abbrevo-fakestart + abbrevsize+linesize+framesize+infosize;
msect = newMachoSect(ms, "__debug_abbrev");
msect->off = abbrevo;
......@@ -883,6 +1042,10 @@ dwarfaddmachoheaders(void)
msect->off = lineo;
msect->size = linesize;
msect = newMachoSect(ms, "__debug_frame");
msect->off = frameo;
msect->size = framesize;
msect = newMachoSect(ms, "__debug_info");
msect->off = infoo;
msect->size = infosize;
......
src/cmd/ld/dwarf_defs.h
View file @ eb572e01
......@@ -452,3 +452,39 @@ enum
DW_MACINFO_end_file = 0x04,
DW_MACINFO_vendor_ext = 0xff,
};
// Table 40.
enum
{ // operand,...
DW_CFA_nop = 0x00,
DW_CFA_set_loc = 0x01, // address
DW_CFA_advance_loc1 = 0x02, // 1-byte delta
DW_CFA_advance_loc2 = 0x03, // 2-byte delta
DW_CFA_advance_loc4 = 0x04, // 4-byte delta
DW_CFA_offset_extended = 0x05, // ULEB128 register, ULEB128 offset
DW_CFA_restore_extended = 0x06, // ULEB128 register
DW_CFA_undefined = 0x07, // ULEB128 register
DW_CFA_same_value = 0x08, // ULEB128 register
DW_CFA_register = 0x09, // ULEB128 register, ULEB128 register
DW_CFA_remember_state = 0x0a,
DW_CFA_restore_state = 0x0b,
DW_CFA_def_cfa = 0x0c, // ULEB128 register, ULEB128 offset
DW_CFA_def_cfa_register = 0x0d, // ULEB128 register
DW_CFA_def_cfa_offset = 0x0e, // ULEB128 offset
DW_CFA_def_cfa_expression = 0x0f, // BLOCK
DW_CFA_expression = 0x10, // ULEB128 register, BLOCK
DW_CFA_offset_extended_sf = 0x11, // ULEB128 register, SLEB128 offset
DW_CFA_def_cfa_sf = 0x12, // ULEB128 register, SLEB128 offset
DW_CFA_def_cfa_offset_sf = 0x13, // SLEB128 offset
DW_CFA_val_offset = 0x14, // ULEB128, ULEB128
DW_CFA_val_offset_sf = 0x15, // ULEB128, SLEB128
DW_CFA_val_expression = 0x16, // ULEB128, BLOCK
DW_CFA_lo_user = 0x1c,
DW_CFA_hi_user = 0x3f,
// Opcodes that take an addend operand.
DW_CFA_advance_loc = 0x1<<6, // +delta
DW_CFA_offset = 0x2<<6, // +register (ULEB128 offset)
DW_CFA_restore = 0x3<<6, // +register
};
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