6l -e: emit external ELF symbol table.

enough to make nm and oprofile work.

R=r
http://go/go-review/1017016

diff --git a/src/cmd/6l/asm.c b/src/cmd/6l/asm.c
index 9ae5409cfcf4f7c0c44d6f3c50bfc1f6f880e310..077755105dab228b02333268d242734a992318cd 100644 (file)
--- a/src/cmd/6l/asm.c
+++ b/src/cmd/6l/asm.c
@@ -255,6 +255,8 @@ enum {
        ElfStrGosymtab,
        ElfStrGopclntab,
        ElfStrShstrtab,
+       ElfStrSymtab,
+       ElfStrStrtab,
        NElfStr
 };
 
@@ -294,6 +296,10 @@ doelf(void)
        if(!debug['s']) {
                elfstr[ElfStrGosymtab] = addstring(shstrtab, ".gosymtab");
                elfstr[ElfStrGopclntab] = addstring(shstrtab, ".gopclntab");
+               if(debug['e']) {
+                       elfstr[ElfStrSymtab] = addstring(shstrtab, ".symtab");
+                       elfstr[ElfStrStrtab] = addstring(shstrtab, ".strtab");
+               }
        }
        elfstr[ElfStrShstrtab] = addstring(shstrtab, ".shstrtab");
 
@@ -426,7 +432,7 @@ asmb(void)
        int32 v, magic;
        int a, dynsym;
        uchar *op1;
-       vlong vl, va, startva, fo, w, symo, machlink;
+       vlong vl, va, startva, fo, w, symo, elfsymo, elfstro, elfsymsize, machlink;
        vlong symdatva = 0x99LL<<32;
        ElfEhdr *eh;
        ElfPhdr *ph, *pph;
@@ -436,6 +442,10 @@ asmb(void)
                Bprint(&bso, "%5.2f asmb\n", cputime());
        Bflush(&bso);
 
+       elftextsh = 0;
+       elfsymsize = 0;
+       elfstro = 0;
+       elfsymo = 0;
        seek(cout, HEADR, 0);
        pc = INITTEXT;
        curp = firstp;
@@ -498,6 +508,12 @@ asmb(void)
                debug['8'] = 1; /* 64-bit addresses */
                v = rnd(HEADR+textsize, INITRND);
                seek(cout, v, 0);
+               
+               /* index of elf text section; needed by asmelfsym, double-checked below */
+               /* debug['d'] causes 8 extra sections before the .text section */
+               elftextsh = 1;
+               if(!debug['d'])
+                       elftextsh += 8;
                break;
        }
 
@@ -546,6 +562,13 @@ asmb(void)
                        symo = rnd(symo, INITRND);
                        break;
                }
+               /*
+                * the symbol information is stored as
+                *      32-bit symbol table size
+                *      32-bit line number table size
+                *      symbol table
+                *      line number table
+                */
                seek(cout, symo+8, 0);
                if(!debug['s'])
                        asmsym();
@@ -564,6 +587,15 @@ asmb(void)
                lputl(symsize);
                lputl(lcsize);
                cflush();
+               if(!debug['s'] && debug['e']) {
+                       elfsymo = symo+8+symsize+lcsize;
+                       seek(cout, elfsymo, 0);
+                       asmelfsym();
+                       cflush();
+                       elfstro = seek(cout, 0, 1);
+                       elfsymsize = elfstro - elfsymo;
+                       write(cout, elfstrdat, elfstrsize);
+               }               
        } else
        if(dlm){
                seek(cout, HEADR+textsize+datsize, 0);
@@ -752,6 +784,8 @@ asmb(void)
                va = startva + fo;
                w = textsize;
 
+               if(elftextsh != eh->shnum)
+                       diag("elftextsh = %d, want %d", elftextsh, eh->shnum);
                sh = newElfShdr(elfstr[ElfStrText]);
                sh->type = SHT_PROGBITS;
                sh->flags = SHF_ALLOC+SHF_EXECINSTR;
@@ -802,6 +836,22 @@ asmb(void)
                        sh->off = fo;
                        sh->size = w;
                        sh->addralign = 1;
+                       
+                       if(debug['e']) {
+                               sh = newElfShdr(elfstr[ElfStrSymtab]);
+                               sh->type = SHT_SYMTAB;
+                               sh->off = elfsymo;
+                               sh->size = elfsymsize;
+                               sh->addralign = 8;
+                               sh->entsize = 24;
+                               sh->link = eh->shnum;   // link to strtab
+                       
+                               sh = newElfShdr(elfstr[ElfStrStrtab]);
+                               sh->type = SHT_STRTAB;
+                               sh->off = elfstro;
+                               sh->size = elfstrsize;
+                               sh->addralign = 1;
+                       }
                }
 
                sh = newElfShstrtab(elfstr[ElfStrShstrtab]);

diff --git a/src/cmd/6l/l.h b/src/cmd/6l/l.h
index 2b5c8864979f42300663c63d7ea1cc1915d35403..91cfbabfd1017a1d772197b98f5e02decf4cbb45 100644 (file)
--- a/src/cmd/6l/l.h
+++ b/src/cmd/6l/l.h
@@ -350,6 +350,9 @@ EXTERN      vlong   textstksiz;
 EXTERN vlong   textarg;
 extern char    thechar;
 EXTERN int     dynptrsize;
+EXTERN int     elfstrsize;
+EXTERN char*   elfstrdat;
+EXTERN int     elftextsh;
 
 #define        UP      (&undefp)
 
@@ -376,6 +379,7 @@ void        asmins(Prog*);
 void   asmlc(void);
 void   asmsp(void);
 void   asmsym(void);
+void   asmelfsym(void);
 vlong  atolwhex(char*);
 Prog*  brchain(Prog*);
 Prog*  brloop(Prog*);

diff --git a/src/cmd/6l/span.c b/src/cmd/6l/span.c
index 41f20fac91e79814f07084a05d20ac265a2fb128..4930e545b37f09538f6e7af2a9547a0fdb100727 100644 (file)
--- a/src/cmd/6l/span.c
+++ b/src/cmd/6l/span.c
@@ -30,6 +30,7 @@
 
 #include       "l.h"
 #include       "../ld/lib.h"
+#include       "../ld/elf.h"
 
 static int     rexflag;
 static int     asmode;
@@ -151,7 +152,7 @@ xdefine(char *p, int t, vlong v)
 }
 
 void
-putsymb(char *s, int t, vlong v, int ver, Sym *go)
+putsymb(char *s, int t, vlong v, vlong size, int ver, Sym *go)
 {
        int i, f, l;
        vlong gv;
@@ -212,7 +213,7 @@ putsymb(char *s, int t, vlong v, int ver, Sym *go)
 }
 
 void
-asmsym(void)
+genasmsym(void (*put)(char*, int, vlong, vlong, int, Sym*))
 {
        Prog *p;
        Auto *a;
@@ -221,7 +222,7 @@ asmsym(void)
 
        s = lookup("etext", 0);
        if(s->type == STEXT)
-               putsymb(s->name, 'T', s->value, s->version, 0);
+               put(s->name, 'T', s->value, s->size, s->version, 0);
 
        for(h=0; h<NHASH; h++) {
                for(s=hash[h]; s!=S; s=s->link) {
@@ -229,29 +230,29 @@ asmsym(void)
                        case SCONST:
                                if(!s->reachable)
                                        continue;
-                               putsymb(s->name, 'D', s->value, s->version, s->gotype);
+                               put(s->name, 'D', s->value, s->size, s->version, s->gotype);
                                continue;
 
                        case SDATA:
                                if(!s->reachable)
                                        continue;
-                               putsymb(s->name, 'D', s->value+INITDAT, s->version, s->gotype);
+                               put(s->name, 'D', s->value+INITDAT, s->size, s->version, s->gotype);
                                continue;
 
                        case SMACHO:
                                if(!s->reachable)
                                        continue;
-                               putsymb(s->name, 'D', s->value+INITDAT+datsize+bsssize, s->version, s->gotype);
+                               put(s->name, 'D', s->value+INITDAT+datsize+bsssize, s->size, s->version, s->gotype);
                                continue;
 
                        case SBSS:
                                if(!s->reachable)
                                        continue;
-                               putsymb(s->name, 'B', s->value+INITDAT, s->version, s->gotype);
+                               put(s->name, 'B', s->value+INITDAT, s->size, s->version, s->gotype);
                                continue;
 
                        case SFILE:
-                               putsymb(s->name, 'f', s->value, s->version, 0);
+                               put(s->name, 'f', s->value, 0, s->version, 0);
                                continue;
                        }
                }
@@ -265,30 +266,99 @@ asmsym(void)
                /* filenames first */
                for(a=p->to.autom; a; a=a->link)
                        if(a->type == D_FILE)
-                               putsymb(a->asym->name, 'z', a->aoffset, 0, 0);
+                               put(a->asym->name, 'z', a->aoffset, 0, 0, 0);
                        else
                        if(a->type == D_FILE1)
-                               putsymb(a->asym->name, 'Z', a->aoffset, 0, 0);
+                               put(a->asym->name, 'Z', a->aoffset, 0, 0, 0);
 
                if(!s->reachable)
                        continue;
-               putsymb(s->name, 'T', s->value, s->version, s->gotype);
+               put(s->name, 'T', s->value, s->size, s->version, s->gotype);
 
                /* frame, auto and param after */
-               putsymb(".frame", 'm', p->to.offset+8, 0, 0);
+               put(".frame", 'm', p->to.offset+8, 0, 0, 0);
 
                for(a=p->to.autom; a; a=a->link)
                        if(a->type == D_AUTO)
-                               putsymb(a->asym->name, 'a', -a->aoffset, 0, a->gotype);
+                               put(a->asym->name, 'a', -a->aoffset, 0, 0, a->gotype);
                        else
                        if(a->type == D_PARAM)
-                               putsymb(a->asym->name, 'p', a->aoffset, 0, a->gotype);
+                               put(a->asym->name, 'p', a->aoffset, 0, 0, a->gotype);
        }
        if(debug['v'] || debug['n'])
                Bprint(&bso, "symsize = %lud\n", symsize);
        Bflush(&bso);
 }
 
+void
+asmsym(void)
+{
+       genasmsym(putsymb);
+}
+
+char *elfstrdat;
+int elfstrsize;
+int maxelfstr;
+
+int
+putelfstr(char *s)
+{
+       int off, n;
+
+       if(elfstrsize == 0 && s[0] != 0) {
+               // first entry must be empty string
+               putelfstr("");
+       }
+
+       n = strlen(s)+1;
+       if(elfstrsize+n > maxelfstr) {
+               maxelfstr = 2*(elfstrsize+n+(1<<20));
+               elfstrdat = realloc(elfstrdat, maxelfstr);
+       }
+       off = elfstrsize;
+       elfstrsize += n;
+       memmove(elfstrdat+off, s, n);
+       return off;
+}
+
+void
+putelfsymb(char *s, int t, vlong addr, vlong size, int ver, Sym *go)
+{
+       int bind, type, shndx, stroff;
+       
+       bind = STB_GLOBAL;
+       switch(t) {
+       default:
+               return;
+       case 'T':
+               type = STT_FUNC;
+               shndx = elftextsh + 0;
+               break;
+       case 'D':
+               type = STT_OBJECT;
+               shndx = elftextsh + 1;
+               break;
+       case 'B':
+               type = STT_OBJECT;
+               shndx = elftextsh + 2;
+               break;
+       }
+       
+       stroff = putelfstr(s);
+       lputl(stroff);  // string
+       cput((bind<<4)|(type&0xF));
+       cput(0);
+       wputl(shndx);
+       vputl(addr);
+       vputl(size);
+}
+
+void
+asmelfsym(void)
+{
+       genasmsym(putelfsymb);
+}
+
 void
 asmlc(void)
 {

diff --git a/src/cmd/ld/elf.c b/src/cmd/ld/elf.c
index a556d92aa2e2790f35fbd6d21c259d27b16e62d0..f4809e07cf70a579195a2413eff4060b8809215e 100644 (file)
--- a/src/cmd/ld/elf.c
+++ b/src/cmd/ld/elf.c
@@ -11,7 +11,7 @@
  * in order to write the code just once.  The 64-bit data structure is
  * written in the 32-bit format on the 32-bit machines.
  */
-#define        NSECT   16
+#define        NSECT   32
 
 static int     elf64;
 static ElfEhdr hdr;