5l, 6l, 8l: introduce sub-symbols

Sub-symbols are laid out inside a larger symbol
but can be addressed directly.

Use to make Mach-O pointer array not a special case.

Will use later to describe ELF sections.

Glimpses of the beginning of ELF loading.

R=ken2
CC=golang-dev
https://golang.org/cl/2623043

diff --git a/src/cmd/5l/l.h b/src/cmd/5l/l.h
index 86885b421a8d3578984fdb708aea473bc9eb3330..3a54e20f8fe5c9772bf5c206719df1f34c6ae891 100644 (file)
--- a/src/cmd/5l/l.h
+++ b/src/cmd/5l/l.h
@@ -56,11 +56,9 @@ typedef      struct  Optab   Optab;
 typedef        struct  Oprang  Oprang;
 typedef        uchar   Opcross[32][2][32];
 typedef        struct  Count   Count;
-typedef        struct  Use     Use;
 
 #define        P               ((Prog*)0)
 #define        S               ((Sym*)0)
-#define        U               ((Use*)0)
 #define        TNAME           (cursym?cursym->name:noname)
 
 struct Adr
@@ -139,9 +137,9 @@ struct      Sym
        uchar   thumb;  // thumb code
        uchar   foreign;        // called by arm if thumb, by thumb if arm
        uchar   fnptr;  // used as fn ptr
-       Use*            use;
        Sym*    hash;   // in hash table
        Sym*    next;   // in text or data list
+       Sym*    sub;
        Sym*    gotype;
        char*   file;
        char*   dynimpname;
@@ -191,12 +189,6 @@ struct     Count
        int32   count;
        int32   outof;
 };
-struct Use
-{
-       Prog*   p;      /* use */
-       Prog*   ct;     /* curtext */
-       Use*            link;
-};
 
 enum
 {
@@ -213,6 +205,8 @@ enum
        SFILE,
        SCONST,
 
+       SSUB    = 1<<8,
+
        LFROM           = 1<<0,
        LTO             = 1<<1,
        LPOOL           = 1<<2,

diff --git a/src/cmd/6l/l.h b/src/cmd/6l/l.h
index 4f56fe983fecf0fe8186cbd22761f630ec8afa52..39b3866d2d99e53e31c1fda535ec5721b7fe4b72 100644 (file)
--- a/src/cmd/6l/l.h
+++ b/src/cmd/6l/l.h
@@ -131,6 +131,7 @@ struct      Sym
        int32   sig;
        Sym*    hash;   // in hash table
        Sym*    next;   // in text or data list
+       Sym*    sub;    // in SSUB list
        vlong   value;
        vlong   size;
        Sym*    gotype;
@@ -175,12 +176,13 @@ enum
        SELFDATA,
        SRODATA,
        SDATA,
+       SMACHO,
        SBSS,
 
        SXREF,
-       SMACHO,
        SFILE,
        SCONST,
+       SSUB    = 1<<8,
 
        NHASH           = 10007,
        NHUNK           = 100000,
@@ -354,7 +356,6 @@ EXTERN      Sym*    fromgotype;     // type symbol on last p->from read
 EXTERN vlong   textstksiz;
 EXTERN vlong   textarg;
 extern char    thechar;
-EXTERN int     dynptrsize;
 EXTERN int     elfstrsize;
 EXTERN char*   elfstrdat;
 EXTERN int     elftextsh;

diff --git a/src/cmd/6l/span.c b/src/cmd/6l/span.c
index 605a1a627eeb580cb9193a75d32c0d28ac8fb377..6cb3586f5d7391a16cd66a27398476be91181da7 100644 (file)
--- a/src/cmd/6l/span.c
+++ b/src/cmd/6l/span.c
@@ -46,6 +46,9 @@ span1(Sym *s)
        int n, m, i;
 
        cursym = s;
+       
+       if(s->p != nil)
+               return;
 
        for(p = s->text; p != P; p = p->link) {
                p->back = 2;    // use short branches first time through
@@ -145,6 +148,8 @@ span(void)
        // NOTE(rsc): If we get rid of the globals we should
        // be able to parallelize these iterations.
        for(cursym = textp; cursym != nil; cursym = cursym->next) {
+               if(cursym->p != nil)
+                       continue;
                // TODO: move into span1
                for(p = cursym->text; p != P; p = p->link) {
                        n = 0;
@@ -671,15 +676,9 @@ relput8(Prog *p, Adr *a)
 vlong
 symaddr(Sym *s)
 {
-       switch(s->type) {
-       case SMACHO:
-               return segdata.vaddr + segdata.filelen - dynptrsize + s->value;
-
-       default:
-               if(!s->reachable)
-                       diag("unreachable symbol in symaddr - %s", s->name);
-               return s->value;
-       }
+       if(!s->reachable)
+               diag("unreachable symbol in symaddr - %s", s->name);
+       return s->value;
 }
 
 static vlong

diff --git a/src/cmd/8l/l.h b/src/cmd/8l/l.h
index 0049c3f1f3859d5678fed878abff6ae6e65bf2a6..fd0b6424480b619e00634d8851db4112561c3d72 100644 (file)
--- a/src/cmd/8l/l.h
+++ b/src/cmd/8l/l.h
@@ -132,6 +132,7 @@ struct      Sym
        int32   sig;
        Sym*    hash;   // in hash table
        Sym*    next;   // in text or data list
+       Sym*    sub;    // in sub list
        Sym*    gotype;
        char*   file;
        char*   dynimpname;
@@ -164,14 +165,16 @@ enum
        /* order here is order in output file */
        STEXT,
        SELFDATA,
-       SRODATA,        // TODO(rsc): move
+       SRODATA,
        SDATA,
+       SMACHO, /* Mach-O __nl_symbol_ptr */
        SBSS,
 
        SXREF,
-       SMACHO, // TODO(rsc): maybe move between DATA1 and BSS?
        SFILE,
        SCONST,
+       
+       SSUB = 1<<8,    /* sub-symbol, linked from parent via ->sub list */
 
        NHASH           = 10007,
        NHUNK           = 100000,
@@ -287,7 +290,6 @@ EXTERN      Prog*   curp;
 EXTERN Sym*    cursym;
 EXTERN Sym*    datap;
 EXTERN int32   elfdatsize;
-EXTERN int32   dynptrsize;
 EXTERN char    debug[128];
 EXTERN char    literal[32];
 EXTERN Sym*    etextp;

diff --git a/src/cmd/8l/span.c b/src/cmd/8l/span.c
index 3aab95874ac611643a9cfac2b0a228f641efbdfc..7f083eebde91f8644f4c66485d8d454473825c24 100644 (file)
--- a/src/cmd/8l/span.c
+++ b/src/cmd/8l/span.c
@@ -503,15 +503,9 @@ relput4(Prog *p, Adr *a)
 int32
 symaddr(Sym *s)
 {
-       switch(s->type) {
-       case SMACHO:
-               return segdata.vaddr + segdata.filelen - dynptrsize + s->value;
-       
-       default:
-               if(!s->reachable)
-                       diag("unreachable symbol in symaddr - %s", s->name);
-               return s->value;
-       }
+       if(!s->reachable)
+               diag("unreachable symbol in symaddr - %s", s->name);
+       return s->value;
 }
 
 static int32

diff --git a/src/cmd/ld/data.c b/src/cmd/ld/data.c
index 461a39950b33f25dd3782e2ababc16c88d35abcb..55925f15c3b7f2369fdb6896aff090a9f1c49f64 100644 (file)
--- a/src/cmd/ld/data.c
+++ b/src/cmd/ld/data.c
@@ -393,6 +393,23 @@ codeblk(int32 addr, int32 size)
                        Bprint(&bso, "\n");
                }
                p = sym->text;
+               if(p == nil) {
+                       Bprint(&bso, "%.6llux\t%-20s | foreign text\n", (vlong)addr, sym->name);
+                       n = sym->size;
+                       q = sym->p;
+                       
+                       while(n >= 16) {
+                               Bprint(&bso, "%.6ux\t%-20.16I\n",  addr, q);
+                               addr += 16;
+                               q += 16;
+                               n -= 16;
+                       }
+                       if(n > 0)
+                               Bprint(&bso, "%.6ux\t%-20.*I\n", addr, n, q);
+                       addr += n;
+                       continue;
+               }
+                       
                Bprint(&bso, "%.6llux\t%-20s | %P\n", (vlong)addr, sym->name, p);
                for(p = p->link; p != P; p = p->link) {
                        if(p->link != P)
@@ -671,7 +688,6 @@ dodata(void)
                datsize += t;
        }
        sect->len = datsize - sect->vaddr;
-       datsize += dynptrsize;
 
        /* bss */
        sect = addsection(&segdata, ".bss", 06);
@@ -702,7 +718,7 @@ void
 address(void)
 {
        Section *s, *text, *data, *rodata, *bss;
-       Sym *sym;
+       Sym *sym, *sub;
        uvlong va;
 
        va = INITTEXT;
@@ -723,11 +739,9 @@ address(void)
        for(s=segdata.sect; s != nil; s=s->next) {
                s->vaddr = va;
                va += s->len;
-               if(s == segdata.sect)
-                       va += dynptrsize;
                segdata.len = va - segdata.vaddr;
        }
-       segdata.filelen = segdata.sect->len + dynptrsize;       // assume .data is first
+       segdata.filelen = segdata.sect->len;    // assume .data is first
        
        text = segtext.sect;
        rodata = segtext.sect->next;
@@ -740,6 +754,8 @@ address(void)
                        sym->value += rodata->vaddr;
                else
                        sym->value += data->vaddr;
+               for(sub = sym->sub; sub != nil; sub = sub->sub)
+                       sub->value += sym->value;
        }
        
        xdefine("text", STEXT, text->vaddr);

diff --git a/src/cmd/ld/macho.c b/src/cmd/ld/macho.c
index 75c3ad865a32ef19aa0a1a9aecb26b6592829b3e..67264233c7779efd4d08da607ab95cf3d364f0dd 100644 (file)
--- a/src/cmd/ld/macho.c
+++ b/src/cmd/ld/macho.c
@@ -281,7 +281,7 @@ domacho(void)
        char *p;
        uchar *dat;
        uint32 x;
-       Sym *s;
+       Sym *s, *smacho;
        Sym **impsym;
 
        ptrsize = 4;
@@ -352,10 +352,16 @@ domacho(void)
                }
        }
 
+       smacho = lookup("__nl_symbol_ptr", 0);
+       smacho->type = SMACHO;
+       smacho->reachable = 1;
        for(h=0; h<nimpsym; h++) {
                s = impsym[h];
-               s->type = SMACHO;
+               s->type = SMACHO | SSUB;
+               s->sub = smacho->sub;
+               smacho->sub = s;
                s->value = (nexpsym+h) * ptrsize;
+               s->reachable = 1;
 
                /* symbol table entry - darwin still puts _ prefixes on all C symbols */
                x = nstrtab;
@@ -398,7 +404,9 @@ domacho(void)
                dat[3] = x>>24;
        }
 
-       dynptrsize = (nexpsym+nimpsym) * ptrsize;
+       smacho->size = (nexpsym+nimpsym) * ptrsize;
+       if(smacho->size == 0)
+               smacho->reachable = 0;
 }
 
 vlong
@@ -408,10 +416,13 @@ domacholink(void)
        uchar *p;
        Sym *s;
        uint64 val;
+       Sym *smacho;
+       
+       smacho = lookup("__nl_symbol_ptr", 0);
 
        linkoff = 0;
        if(nlinkdata > 0 || nstrtab > 0) {
-               linkoff = rnd(HEADR+segtext.len, INITRND) + rnd(segdata.filelen - dynptrsize, INITRND);
+               linkoff = rnd(HEADR+segtext.len, INITRND) + rnd(segdata.filelen - smacho->size, INITRND);
                seek(cout, linkoff, 0);
 
                for(i = 0; i<nexpsym; ++i) {
@@ -452,6 +463,7 @@ asmbmacho(void)
        MachoSeg *ms;
        MachoDebug *md;
        MachoLoad *ml;
+       Sym *smacho;
 
        /* apple MACH */
        va = INITTEXT - HEADR;
@@ -492,8 +504,9 @@ asmbmacho(void)
        msect->flag = 0x400;    /* flag - some instructions */
 
        /* data */
+       smacho = lookup("__nl_symbol_ptr", 0);
        w = segdata.len;
-       ms = newMachoSeg("__DATA", 2+(dynptrsize>0));
+       ms = newMachoSeg("__DATA", 2+(smacho->size > 0));
        ms->vaddr = va+v;
        ms->vsize = w;
        ms->fileoffset = v;
@@ -503,14 +516,14 @@ asmbmacho(void)
 
        msect = newMachoSect(ms, "__data");
        msect->addr = va+v;
-       msect->size = segdata.filelen - dynptrsize;
+       msect->size = segdata.filelen - smacho->size;
        msect->off = v;
 
-       if(dynptrsize > 0) {
+       if(smacho->size > 0) {
                msect = newMachoSect(ms, "__nl_symbol_ptr");
-               msect->addr = va+v+segdata.filelen - dynptrsize;
-               msect->size = dynptrsize;
-               msect->off = v+segdata.filelen - dynptrsize;
+               msect->addr = smacho->value;
+               msect->size = smacho->size;
+               msect->off = datoff(msect->addr);
                msect->align = 2;
                msect->flag = 6;        /* section with nonlazy symbol pointers */
                /*
@@ -551,7 +564,7 @@ asmbmacho(void)
        if(!debug['d']) {
                int nsym;
 
-               nsym = dynptrsize/ptrsize;
+               nsym = smacho->size/ptrsize;
 
                ms = newMachoSeg("__LINKEDIT", 0);
                ms->vaddr = va+v+rnd(segdata.len, INITRND);