6l/5l: PIC and shared library support for the linkers.

Added the -shared flag to 5l/6l to output a PIC executable with the required
dynamic relocations and RIP-relative addressing in machine code.
Added dummy support to 8l to avoid compilation errors

See also:
https://golang.org/cl/6822078
https://golang.org/cl/7064048

and

https://groups.google.com/d/topic/golang-nuts/P05BDjLcQ5k/discussion

R=rsc, iant
CC=golang-dev
https://golang.org/cl/6926049

diff --git a/src/cmd/5l/asm.c b/src/cmd/5l/asm.c
index a38c063d54e457f9d66bb098fda14dc92bb8f99f..f4124905618e5b3af0c72b80bc6df78c04e13370 100644 (file)
--- a/src/cmd/5l/asm.c
+++ b/src/cmd/5l/asm.c
@@ -93,6 +93,19 @@ braddoff(int32 a, int32 b)
        return (((uint32)a) & 0xff000000U) | (0x00ffffffU & (uint32)(a + b));
 }
 
+Sym *
+lookuprel(void)
+{
+       return lookup(".rel", 0);
+}
+
+void
+adddynrela(Sym *rel, Sym *s, Reloc *r)
+{
+       addaddrplus(rel, s, r->off);
+       adduint32(rel, R_ARM_RELATIVE);
+}
+
 void
 adddynrel(Sym *s, Reloc *r)
 {
@@ -859,15 +872,22 @@ if(debug['G']) print("%ux: %s: arm %d\n", (uint32)(p->pc), p->from.sym->name, p-
                        rel = addrel(cursym);
                        rel->off = pc - cursym->value;
                        rel->siz = 4;
-                       rel->type = D_ADDR;
                        rel->sym = p->to.sym;
                        rel->add = p->to.offset;
+                       if(flag_shared) {
+                               rel->type = D_PCREL;
+                               rel->add += pc - p->pcrel->pc - 8;
+                       } else
+                               rel->type = D_ADDR;
                        o1 = 0;
                }
                break;
 
        case 12:        /* movw $lcon, reg */
                o1 = omvl(p, &p->from, p->to.reg);
+               if(o->flag & LPCREL) {
+                       o2 = oprrr(AADD, p->scond) | p->to.reg | REGPC << 16 | p->to.reg << 12;
+               }
                break;
 
        case 13:        /* op $lcon, [R], R */
@@ -1172,13 +1192,23 @@ if(debug['G']) print("%ux: %s: arm %d\n", (uint32)(p->pc), p->from.sym->name, p-
                break;
 
        case 62:        /* case R -> movw       R<<2(PC),PC */
-               o1 = olrr(p->from.reg, REGPC, REGPC, p->scond);
-               o1 |= 2<<7;
+               if(o->flag & LPCREL) {
+                       o1 = oprrr(AADD, p->scond) | immrot(1) | p->from.reg << 16 | REGTMP << 12;
+                       o2 = olrr(REGTMP, REGPC, REGTMP, p->scond);
+                       o2 |= 2<<7;
+                       o3 = oprrr(AADD, p->scond) | REGTMP | REGPC << 16 | REGPC << 12;
+               } else {
+                       o1 = olrr(p->from.reg, REGPC, REGPC, p->scond);
+                       o1 |= 2<<7;
+               }
                break;
 
        case 63:        /* bcase */
-               if(p->cond != P)
+               if(p->cond != P) {
                        o1 = p->cond->pc;
+                       if(flag_shared)
+                               o1 = o1 - p->pcrel->pc - 16;
+               }
                break;
 
        /* reloc ops */
@@ -1187,6 +1217,10 @@ if(debug['G']) print("%ux: %s: arm %d\n", (uint32)(p->pc), p->from.sym->name, p-
                if(!o1)
                        break;
                o2 = osr(p->as, p->from.reg, 0, REGTMP, p->scond);
+               if(o->flag & LPCREL) {
+                       o3 = o2;
+                       o2 = oprrr(AADD, p->scond) | REGTMP | REGPC << 16 | REGTMP << 12;
+               }
                break;
 
        case 65:        /* mov/movbu addr,R */
@@ -1196,6 +1230,10 @@ if(debug['G']) print("%ux: %s: arm %d\n", (uint32)(p->pc), p->from.sym->name, p-
                o2 = olr(0, REGTMP, p->to.reg, p->scond);
                if(p->as == AMOVBU || p->as == AMOVB)
                        o2 |= 1<<22;
+               if(o->flag & LPCREL) {
+                       o3 = o2;
+                       o2 = oprrr(AADD, p->scond) | REGTMP | REGPC << 16 | REGTMP << 12;
+               }
                break;
 
        case 68:        /* floating point store -> ADDR */
@@ -1203,6 +1241,10 @@ if(debug['G']) print("%ux: %s: arm %d\n", (uint32)(p->pc), p->from.sym->name, p-
                if(!o1)
                        break;
                o2 = ofsr(p->as, p->from.reg, 0, REGTMP, p->scond, p);
+               if(o->flag & LPCREL) {
+                       o3 = o2;
+                       o2 = oprrr(AADD, p->scond) | REGTMP | REGPC << 16 | REGTMP << 12;
+               }
                break;
 
        case 69:        /* floating point load <- ADDR */
@@ -1210,6 +1252,10 @@ if(debug['G']) print("%ux: %s: arm %d\n", (uint32)(p->pc), p->from.sym->name, p-
                if(!o1)
                        break;
                o2 = ofsr(p->as, p->to.reg, 0, REGTMP, p->scond, p) | (1<<20);
+               if(o->flag & LPCREL) {
+                       o3 = o2;
+                       o2 = oprrr(AADD, p->scond) | REGTMP | REGPC << 16 | REGTMP << 12;
+               }
                break;
 
        /* ArmV4 ops: */
@@ -1406,12 +1452,20 @@ if(debug['G']) print("%ux: %s: arm %d\n", (uint32)(p->pc), p->from.sym->name, p-
                        o2 ^= (1<<5)|(1<<6);
                else if(p->as == AMOVH)
                        o2 ^= (1<<6);
+               if(o->flag & LPCREL) {
+                       o3 = o2;
+                       o2 = oprrr(AADD, p->scond) | REGTMP | REGPC << 16 | REGTMP << 12;
+               }
                break;
        case 94:        /* movh/movhu R,addr -> strh */
                o1 = omvl(p, &p->to, REGTMP);
                if(!o1)
                        break;
                o2 = oshr(p->from.reg, 0, REGTMP, p->scond);
+               if(o->flag & LPCREL) {
+                       o3 = o2;
+                       o2 = oprrr(AADD, p->scond) | REGTMP | REGPC << 16 | REGTMP << 12;
+               }
                break;
        case 95:        /* PLD off(reg) */
                o1 = 0xf5d0f000;

diff --git a/src/cmd/5l/l.h b/src/cmd/5l/l.h
index dfa86df6e231522142b554feacc07c34e296daa1..abfd7e12ab774957ad5acbb5c01425ddd98dd20b 100644 (file)
--- a/src/cmd/5l/l.h
+++ b/src/cmd/5l/l.h
@@ -111,6 +111,7 @@ struct      Prog
        } u0;
        Prog*   cond;
        Prog*   link;
+       Prog*   pcrel;
        int32   pc;
        int32   line;
        int32   spadj;
@@ -175,6 +176,7 @@ struct      Sym
        Reloc*  r;
        int32   nr;
        int32   maxr;
+       int     rel_ro;
 };
 
 #define SIGNINTERN     (1729*325*1729)
@@ -197,6 +199,7 @@ struct      Optab
        char    size;
        char    param;
        char    flag;
+       uchar   pcrelsiz;
 };
 struct Oprang
 {
@@ -214,6 +217,7 @@ enum
        LFROM           = 1<<0,
        LTO             = 1<<1,
        LPOOL           = 1<<2,
+       LPCREL          = 1<<3,
 
        C_NONE          = 0,
        C_REG,
@@ -228,6 +232,7 @@ enum
        C_NCON,         /* ~RCON */
        C_SCON,         /* 0xffff */
        C_LCON,
+       C_LCONADDR,
        C_ZFCON,
        C_SFCON,
        C_LFCON,
@@ -281,6 +286,7 @@ EXTERN      int32   INITDAT;                /* data location */
 EXTERN int32   INITRND;                /* data round above text location */
 EXTERN int32   INITTEXT;               /* text location */
 EXTERN char*   INITENTRY;              /* entry point */
+EXTERN char*   LIBINITENTRY;           /* shared library entry point */
 EXTERN int32   autosize;
 EXTERN Auto*   curauto;
 EXTERN Auto*   curhist;

diff --git a/src/cmd/5l/list.c b/src/cmd/5l/list.c
index d05ec3b95d1915461356e5c55aae0ab838d530a0..a051774b4140aae2fdee5b9f6403973176b6c563 100644 (file)
--- a/src/cmd/5l/list.c
+++ b/src/cmd/5l/list.c
@@ -435,6 +435,7 @@ cnames[] =
        [C_LAUTO]       = "C_LAUTO",
        [C_LBRA]        = "C_LBRA",
        [C_LCON]        = "C_LCON",
+       [C_LCONADDR]    = "C_LCONADDR",
        [C_LOREG]       = "C_LOREG",
        [C_NCON]        = "C_NCON",
        [C_NONE]        = "C_NONE",

diff --git a/src/cmd/5l/noop.c b/src/cmd/5l/noop.c
index c50a108f38e2175e9e7dc1fa9927483790dcffc0..99a096a31f07e10152bdbb41df3bf02c137ca086 100644 (file)
--- a/src/cmd/5l/noop.c
+++ b/src/cmd/5l/noop.c
@@ -45,6 +45,20 @@ static       Sym*    sym_divu;
 static Sym*    sym_mod;
 static Sym*    sym_modu;
 
+static void
+linkcase(Prog *casep)
+{
+       Prog *p;
+
+       for(p = casep; p != P; p = p->link){
+               if(p->as == ABCASE) {
+                       for(; p != P && p->as == ABCASE; p = p->link)
+                               p->pcrel = casep;
+                       break;
+               }
+       }
+}
+
 void
 noops(void)
 {
@@ -76,6 +90,11 @@ noops(void)
        for(cursym = textp; cursym != nil; cursym = cursym->next) {
                for(p = cursym->text; p != P; p = p->link) {
                        switch(p->as) {
+                       case ACASE:
+                               if(flag_shared)
+                                       linkcase(p);
+                               break;
+
                        case ATEXT:
                                p->mark |= LEAF;
                                break;

diff --git a/src/cmd/5l/obj.c b/src/cmd/5l/obj.c
index 6a95a5e5729570a997802fb356ee398191ec7251..1f961748d5cd15cedc746a0a278fef0143765780 100644 (file)
--- a/src/cmd/5l/obj.c
+++ b/src/cmd/5l/obj.c
@@ -80,6 +80,7 @@ main(int argc, char *argv[])
        INITDAT = -1;
        INITRND = -1;
        INITENTRY = 0;
+       LIBINITENTRY = 0;
        nuxiinit();
        
        p = getgoarm();
@@ -123,6 +124,7 @@ main(int argc, char *argv[])
        flagcount("u", "reject unsafe packages", &debug['u']);
        flagcount("v", "print link trace", &debug['v']);
        flagcount("w", "disable DWARF generation", &debug['w']);
+       flagcount("shared", "generate shared object", &flag_shared);
        
        flagparse(&argc, &argv, usage);
 

diff --git a/src/cmd/5l/optab.c b/src/cmd/5l/optab.c
index 9e95c096de2cfd80f8062d3e193a96150cf54d34..1e93a3113bdcde08d55f7cc9e35cabb639fff7f6 100644 (file)
--- a/src/cmd/5l/optab.c
+++ b/src/cmd/5l/optab.c
@@ -77,10 +77,12 @@ Optab       optab[] =
        { ASWI,         C_NONE, C_NONE, C_LCON,         10, 4, 0 },
 
        { AWORD,        C_NONE, C_NONE, C_LCON,         11, 4, 0 },
+       { AWORD,        C_NONE, C_NONE, C_LCONADDR,     11, 4, 0 },
        { AWORD,        C_NONE, C_NONE, C_ADDR,         11, 4, 0 },
 
        { AMOVW,        C_NCON, C_NONE, C_REG,          12, 4, 0 },
        { AMOVW,        C_LCON, C_NONE, C_REG,          12, 4, 0,       LFROM },
+       { AMOVW,        C_LCONADDR,     C_NONE, C_REG,  12, 4, 0,       LFROM | LPCREL, 4},
 
        { AADD,         C_NCON, C_REG,  C_REG,          13, 8, 0 },
        { AADD,         C_NCON, C_NONE, C_REG,          13, 8, 0 },
@@ -119,20 +121,20 @@ Optab     optab[] =
 
        { AMOVW,        C_REG,  C_NONE, C_LAUTO,        30, 8, REGSP,   LTO },
        { AMOVW,        C_REG,  C_NONE, C_LOREG,        30, 8, 0,       LTO },
-       { AMOVW,        C_REG,  C_NONE, C_ADDR,         64, 8, 0,       LTO },
+       { AMOVW,        C_REG,  C_NONE, C_ADDR,         64, 8, 0,       LTO | LPCREL, 4 },
        { AMOVB,        C_REG,  C_NONE, C_LAUTO,        30, 8, REGSP,   LTO },
        { AMOVB,        C_REG,  C_NONE, C_LOREG,        30, 8, 0,       LTO },
-       { AMOVB,        C_REG,  C_NONE, C_ADDR,         64, 8, 0,       LTO },
+       { AMOVB,        C_REG,  C_NONE, C_ADDR,         64, 8, 0,       LTO | LPCREL, 4 },
        { AMOVBU,       C_REG,  C_NONE, C_LAUTO,        30, 8, REGSP,   LTO },
        { AMOVBU,       C_REG,  C_NONE, C_LOREG,        30, 8, 0,       LTO },
-       { AMOVBU,       C_REG,  C_NONE, C_ADDR,         64, 8, 0,       LTO },
+       { AMOVBU,       C_REG,  C_NONE, C_ADDR,         64, 8, 0,       LTO | LPCREL, 4 },
 
        { AMOVW,        C_LAUTO,C_NONE, C_REG,          31, 8, REGSP,   LFROM },
        { AMOVW,        C_LOREG,C_NONE, C_REG,          31, 8, 0,       LFROM },
-       { AMOVW,        C_ADDR, C_NONE, C_REG,          65, 8, 0,       LFROM },
+       { AMOVW,        C_ADDR, C_NONE, C_REG,          65, 8, 0,       LFROM | LPCREL, 4 },
        { AMOVBU,       C_LAUTO,C_NONE, C_REG,          31, 8, REGSP,   LFROM },
        { AMOVBU,       C_LOREG,C_NONE, C_REG,          31, 8, 0,       LFROM },
-       { AMOVBU,       C_ADDR, C_NONE, C_REG,          65, 8, 0,       LFROM },
+       { AMOVBU,       C_ADDR, C_NONE, C_REG,          65, 8, 0,       LFROM | LPCREL, 4 },
 
        { AMOVW,        C_LACON,C_NONE, C_REG,          34, 8, REGSP,   LFROM },
 
@@ -159,8 +161,8 @@ Optab       optab[] =
        { AMOVF,        C_LAUTO,C_NONE, C_FREG,         53, 12, REGSP,  LFROM },
        { AMOVF,        C_LOREG,C_NONE, C_FREG,         53, 12, 0,      LFROM },
 
-       { AMOVF,        C_FREG, C_NONE, C_ADDR,         68, 8, 0,       LTO },
-       { AMOVF,        C_ADDR, C_NONE, C_FREG,         69, 8, 0,       LFROM },
+       { AMOVF,        C_FREG, C_NONE, C_ADDR,         68, 8, 0,       LTO | LPCREL, 4 },
+       { AMOVF,        C_ADDR, C_NONE, C_FREG,         69, 8, 0,       LFROM | LPCREL, 4},
 
        { AADDF,        C_FREG, C_NONE, C_FREG,         54, 4, 0 },
        { AADDF,        C_FREG, C_REG,  C_FREG,         54, 4, 0 },
@@ -178,7 +180,7 @@ Optab       optab[] =
        { AMOVB,        C_REG,  C_NONE, C_SHIFT,        61, 4, 0 },
        { AMOVBU,       C_REG,  C_NONE, C_SHIFT,        61, 4, 0 },
 
-       { ACASE,        C_REG,  C_NONE, C_NONE,         62, 4, 0 },
+       { ACASE,        C_REG,  C_NONE, C_NONE,         62, 4, 0, LPCREL, 8 },
        { ABCASE,       C_NONE, C_NONE, C_SBRA,         63, 4, 0 },
 
        { AMOVH,        C_REG,  C_NONE, C_HAUTO,        70, 4, REGSP,   0 },
@@ -195,20 +197,20 @@ Optab     optab[] =
 
        { AMOVH,        C_REG,  C_NONE, C_LAUTO,        72, 8, REGSP,   LTO },
        { AMOVH,        C_REG,  C_NONE, C_LOREG,        72, 8, 0,       LTO },
-       { AMOVH,        C_REG,  C_NONE, C_ADDR, 94, 8, 0,       LTO },
+       { AMOVH,        C_REG,  C_NONE, C_ADDR, 94, 8, 0,       LTO | LPCREL, 4 },
        { AMOVHU,       C_REG,  C_NONE, C_LAUTO,        72, 8, REGSP,   LTO },
        { AMOVHU,       C_REG,  C_NONE, C_LOREG,        72, 8, 0,       LTO },
-       { AMOVHU,       C_REG,  C_NONE, C_ADDR, 94, 8, 0,       LTO },
+       { AMOVHU,       C_REG,  C_NONE, C_ADDR, 94, 8, 0,       LTO | LPCREL, 4 },
 
        { AMOVB,        C_LAUTO,C_NONE, C_REG,          73, 8, REGSP,   LFROM },
        { AMOVB,        C_LOREG,C_NONE, C_REG,          73, 8, 0,       LFROM },
-       { AMOVB,        C_ADDR, C_NONE, C_REG,          93, 8, 0,       LFROM },
+       { AMOVB,        C_ADDR, C_NONE, C_REG,          93, 8, 0,       LFROM | LPCREL, 4 },
        { AMOVH,        C_LAUTO,C_NONE, C_REG,          73, 8, REGSP,   LFROM },
        { AMOVH,        C_LOREG,C_NONE, C_REG,          73, 8, 0,       LFROM },
-       { AMOVH,        C_ADDR, C_NONE, C_REG,          93, 8, 0,       LFROM },
+       { AMOVH,        C_ADDR, C_NONE, C_REG,          93, 8, 0,       LFROM | LPCREL, 4 },
        { AMOVHU,       C_LAUTO,C_NONE, C_REG,          73, 8, REGSP,   LFROM },
        { AMOVHU,       C_LOREG,C_NONE, C_REG,          73, 8, 0,       LFROM },
-       { AMOVHU,       C_ADDR, C_NONE, C_REG,          93, 8, 0,       LFROM },
+       { AMOVHU,       C_ADDR, C_NONE, C_REG,          93, 8, 0,       LFROM | LPCREL, 4 },
 
        { ALDREX,       C_SOREG,C_NONE, C_REG,          77, 4, 0 },
        { ASTREX,       C_SOREG,C_REG,  C_REG,          78, 4, 0 },

diff --git a/src/cmd/5l/span.c b/src/cmd/5l/span.c
index 8266e5d2aeff825f40cfda3b6977182ed45b504c..ece1ff89ce9511c3ec1bdea542f6063bc74c04bb 100644 (file)
--- a/src/cmd/5l/span.c
+++ b/src/cmd/5l/span.c
@@ -330,9 +330,11 @@ addpool(Prog *p, Adr *a)
        switch(c) {
        default:
                t.to = *a;
+               if(flag_shared && t.to.sym != S)
+                       t.pcrel = p;
                break;
 
-       case    C_SROREG:
+       case C_SROREG:
        case C_LOREG:
        case C_ROREG:
        case C_FOREG:
@@ -347,11 +349,13 @@ addpool(Prog *p, Adr *a)
                break;
        }
 
-       for(q = blitrl; q != P; q = q->link)    /* could hash on t.t0.offset */
-               if(memcmp(&q->to, &t.to, sizeof(t.to)) == 0) {
-                       p->cond = q;
-                       return;
-               }
+       if(t.pcrel == P) {
+               for(q = blitrl; q != P; q = q->link)    /* could hash on t.t0.offset */
+                       if(q->pcrel == P && memcmp(&q->to, &t.to, sizeof(t.to)) == 0) {
+                               p->cond = q;
+                               return;
+                       }
+       }
 
        q = prg();
        *q = t;
@@ -570,7 +574,10 @@ aclass(Adr *a)
                        if(s == S)
                                break;
                        instoffset = 0; // s.b. unused but just in case
-                       return C_LCON;
+                       if(flag_shared)
+                               return C_LCONADDR;
+                       else
+                               return C_LCON;
 
                case D_AUTO:
                        instoffset = autosize + a->offset;
@@ -736,8 +743,14 @@ buildop(void)
        for(i=0; i<C_GOK; i++)
                for(n=0; n<C_GOK; n++)
                        xcmp[i][n] = cmp(n, i);
-       for(n=0; optab[n].as != AXXX; n++)
-               ;
+       for(n=0; optab[n].as != AXXX; n++) {
+               if((optab[n].flag & LPCREL) != 0) {
+                       if(flag_shared)
+                               optab[n].size += optab[n].pcrelsiz;
+                       else
+                               optab[n].flag &= ~LPCREL;
+               }
+       }
        qsort(optab, n, sizeof(optab[0]), ocmp);
        for(i=0; i<n; i++) {
                r = optab[i].as;

diff --git a/src/cmd/6l/asm.c b/src/cmd/6l/asm.c
index ebe412074cec1fb7b6a3717393bf6eaa7d986a9e..eb2c79ca157a6c6c25ce36caf46b22d1662a9fbd 100644 (file)
--- a/src/cmd/6l/asm.c
+++ b/src/cmd/6l/asm.c
@@ -99,6 +99,20 @@ int nelfsym = 1;
 static void addpltsym(Sym*);
 static void addgotsym(Sym*);
 
+Sym *
+lookuprel(void)
+{
+       return lookup(".rela", 0);
+}
+
+void
+adddynrela(Sym *rela, Sym *s, Reloc *r)
+{
+       addaddrplus(rela, s, r->off);
+       adduint64(rela, R_X86_64_RELATIVE);
+       addaddrplus(rela, r->sym, r->add); // Addend
+}
+
 void
 adddynrel(Sym *s, Reloc *r)
 {
@@ -463,7 +477,7 @@ adddynsym(Sym *s)
                        addaddr(d, s);
        
                /* size of object */
-               adduint64(d, 0);
+               adduint64(d, s->size);
        
                if(!s->dynexport && s->dynimplib && needlib(s->dynimplib)) {
                        elfwritedynent(lookup(".dynamic", 0), DT_NEEDED,

diff --git a/src/cmd/6l/l.h b/src/cmd/6l/l.h
index 054ae5e02c963830efc41fb415cf100d8f3a60c3..b8b79133080459fd8d831009547890e8248ada3d 100644 (file)
--- a/src/cmd/6l/l.h
+++ b/src/cmd/6l/l.h
@@ -181,6 +181,7 @@ struct      Sym
        Reloc*  r;
        int32   nr;
        int32   maxr;
+       int     rel_ro;
 };
 struct Optab
 {
@@ -320,6 +321,7 @@ EXTERN      int32   INITRND;
 EXTERN int64   INITTEXT;
 EXTERN int64   INITDAT;
 EXTERN char*   INITENTRY;              /* entry point */
+EXTERN char*   LIBINITENTRY;           /* shared library entry point */
 EXTERN char*   pcstr;
 EXTERN Auto*   curauto;
 EXTERN Auto*   curhist;

diff --git a/src/cmd/6l/obj.c b/src/cmd/6l/obj.c
index 433044e22ccda2c882316a6127ac09c05037c522..e381b90a7609ca7322a177862f71ca8879c15439 100644 (file)
--- a/src/cmd/6l/obj.c
+++ b/src/cmd/6l/obj.c
@@ -82,6 +82,7 @@ main(int argc, char *argv[])
        INITDAT = -1;
        INITRND = -1;
        INITENTRY = 0;
+       LIBINITENTRY = 0;
        nuxiinit();
 
        flagcount("1", "use alternate profiling code", &debug['1']);
@@ -117,6 +118,7 @@ main(int argc, char *argv[])
        flagcount("u", "reject unsafe packages", &debug['u']);
        flagcount("v", "print link trace", &debug['v']);
        flagcount("w", "disable DWARF generation", &debug['w']);
+       flagcount("shared", "generate shared object", &flag_shared);
        
        flagparse(&argc, &argv, usage);
 

diff --git a/src/cmd/6l/span.c b/src/cmd/6l/span.c
index a181178680ae571206d6b2ce0e9bac8afccc494b..283a0e3495ee210aebe447963411a1ef0921db87 100644 (file)
--- a/src/cmd/6l/span.c
+++ b/src/cmd/6l/span.c
@@ -372,7 +372,10 @@ oclass(Adr *a)
                                switch(a->index) {
                                case D_EXTERN:
                                case D_STATIC:
-                                       return Yi32;    /* TO DO: Yi64 */
+                                       if(flag_shared)
+                                               return Yiauto;
+                                       else
+                                               return Yi32;    /* TO DO: Yi64 */
                                case D_AUTO:
                                case D_PARAM:
                                        return Yiauto;
@@ -731,7 +734,10 @@ vaddr(Adr *a, Reloc *r)
                        diag("need reloc for %D", a);
                        errorexit();
                }
-               r->type = D_ADDR;
+               if(flag_shared)
+                       r->type = D_PCREL;
+               else
+                       r->type = D_ADDR;
                r->siz = 4;     // TODO: 8 for external symbols
                r->off = -1;    // caller must fill in
                r->sym = s;
@@ -760,6 +766,8 @@ asmandsz(Adr *a, int r, int rex, int m64)
                                goto bad;
                        case D_STATIC:
                        case D_EXTERN:
+                               if(flag_shared)
+                                       goto bad;
                                t = D_NONE;
                                v = vaddr(a, &rel);
                                break;
@@ -820,7 +828,7 @@ asmandsz(Adr *a, int r, int rex, int m64)
 
        rexflag |= (regrex[t] & Rxb) | rex;
        if(t == D_NONE || (D_CS <= t && t <= D_GS)) {
-               if(asmode != 64){
+               if(flag_shared && t == D_NONE && (a->type == D_STATIC || a->type == D_EXTERN) || asmode != 64) {
                        *andptr++ = (0 << 6) | (5 << 0) | (r << 3);
                        goto putrelv;
                }
@@ -1776,13 +1784,17 @@ asmins(Prog *p)
                        if(c != 0xf2 && c != 0xf3 && (c < 0x64 || c > 0x67) && c != 0x2e && c != 0x3e && c != 0x26)
                                break;
                }
-               for(r=cursym->r+cursym->nr; r-- > cursym->r; ) {
-                       if(r->off < p->pc)
-                               break;
-                       r->off++;
-               }
                memmove(and+np+1, and+np, n-np);
                and[np] = 0x40 | rexflag;
                andptr++;
        }
+       n = andptr - and;
+       for(r=cursym->r+cursym->nr; r-- > cursym->r; ) {
+               if(r->off < p->pc)
+                       break;
+               if(rexflag)
+                       r->off++;
+               if(r->type == D_PCREL)
+                       r->add -= p->pc + n - (r->off + r->siz);
+       }
 }

diff --git a/src/cmd/8l/asm.c b/src/cmd/8l/asm.c
index c5121f0b96966a123e4f3c63f79759fa3e9983fb..2cdf4ff2abadbc39f97161f9d6c4fbf4f6e07b59 100644 (file)
--- a/src/cmd/8l/asm.c
+++ b/src/cmd/8l/asm.c
@@ -95,6 +95,18 @@ int  nelfsym = 1;
 static void    addpltsym(Sym*);
 static void    addgotsym(Sym*);
 
+Sym *
+lookuprel(void)
+{
+       return lookup(".rel", 0);
+}
+
+void
+adddynrela(Sym *rela, Sym *s, Reloc *r)
+{
+       sysfatal("adddynrela not implemented");
+}
+
 void
 adddynrel(Sym *s, Reloc *r)
 {

diff --git a/src/cmd/8l/l.h b/src/cmd/8l/l.h
index 8452e4bd4dc3ea3daf19d6e141c9177815e936be..8b172f40473a57346e9305f398ea3d473be30930 100644 (file)
--- a/src/cmd/8l/l.h
+++ b/src/cmd/8l/l.h
@@ -163,6 +163,7 @@ struct      Sym
        Reloc*  r;
        int32   nr;
        int32   maxr;
+       int     rel_ro;
 };
 struct Optab
 {
@@ -275,6 +276,7 @@ EXTERN      int32   INITRND;
 EXTERN int32   INITTEXT;
 EXTERN int32   INITDAT;
 EXTERN char*   INITENTRY;              /* entry point */
+EXTERN char*   LIBINITENTRY;           /* shared library entry point */
 EXTERN int32   casepc;
 EXTERN char*   pcstr;
 EXTERN Auto*   curauto;

diff --git a/src/cmd/8l/obj.c b/src/cmd/8l/obj.c
index 3336764af7e3b7d3f4deaa884c41535f89c07e91..74820e63348b9f39563fdc2790d55c8aeaa9b402 100644 (file)
--- a/src/cmd/8l/obj.c
+++ b/src/cmd/8l/obj.c
@@ -89,6 +89,7 @@ main(int argc, char *argv[])
        INITDAT = -1;
        INITRND = -1;
        INITENTRY = 0;
+       LIBINITENTRY = 0;
        nuxiinit();
 
        flagcount("1", "use alternate profiling code", &debug['1']);

diff --git a/src/cmd/ld/data.c b/src/cmd/ld/data.c
index 28e3848fd94b803d4719b54f3f5b7ed6cc0b6903..30e1309d2482705af463083cac5472f7317a9e41 100644 (file)
--- a/src/cmd/ld/data.c
+++ b/src/cmd/ld/data.c
@@ -232,7 +232,9 @@ void
 dynrelocsym(Sym *s)
 {
        Reloc *r;
-
+       Sym *rel;
+       Sym *got;
+       
        if(HEADTYPE == Hwindows) {
                Sym *rel, *targ;
 
@@ -268,9 +270,23 @@ dynrelocsym(Sym *s)
                return;
        }
 
-       for(r=s->r; r<s->r+s->nr; r++)
+       got = rel = nil;
+       if(flag_shared) {
+               rel = lookuprel();
+               got = lookup(".got", 0);
+       }
+       s->rel_ro = 0;
+       for(r=s->r; r<s->r+s->nr; r++) {
                if(r->sym != S && r->sym->type == SDYNIMPORT || r->type >= 256)
                        adddynrel(s, r);
+               if(flag_shared && r->sym != S && (r->sym->dynimpname == nil || r->sym->dynexport) && r->type == D_ADDR
+                               && (s == got || s->type == SDATA || s->type == SGOSTRING || s->type == STYPE || s->type == SRODATA)) {
+                       // Create address based RELATIVE relocation
+                       adddynrela(rel, s, r);
+                       if(s->type < SNOPTRDATA)
+                               s->rel_ro = 1;
+               }
+       }
 }
 
 void
@@ -714,6 +730,29 @@ setuint64(Sym *s, vlong r, uint64 v)
        setuintxx(s, r, v, 8);
 }
 
+/*
+static vlong
+addaddrpcrelplus(Sym *s, Sym *t, int32 add)
+{
+       vlong i;
+       Reloc *r;
+
+       if(s->type == 0)
+               s->type = SDATA;
+       s->reachable = 1;
+       i = s->size;
+       s->size += PtrSize;
+       symgrow(s, s->size);
+       r = addrel(s);
+       r->sym = t;
+       r->off = i;
+       r->siz = PtrSize;
+       r->type = D_PCREL;
+       r->add = add;
+       return i;
+}
+*/
+
 vlong
 addaddrplus(Sym *s, Sym *t, int32 add)
 {
@@ -968,6 +1007,12 @@ dodata(void)
        }
        *l = nil;
 
+       if(flag_shared) {
+               for(s=datap; s != nil; s = s->next) {
+                       if(s->rel_ro)
+                               s->type = SDATARELRO;
+               }
+       }
        datap = datsort(datap);
 
        /*
@@ -1004,7 +1049,7 @@ dodata(void)
        sect->vaddr = datsize;
        lookup("noptrdata", 0)->sect = sect;
        lookup("enoptrdata", 0)->sect = sect;
-       for(; s != nil && s->type < SDATA; s = s->next) {
+       for(; s != nil && s->type < SDATARELRO; s = s->next) {
                s->sect = sect;
                s->type = SDATA;
                t = alignsymsize(s->size);
@@ -1015,12 +1060,34 @@ dodata(void)
        sect->len = datsize - sect->vaddr;
        datsize = rnd(datsize, PtrSize);
 
+       /* dynamic relocated rodata */
+       if(flag_shared) {
+               sect = addsection(&segdata, ".data.rel.ro", 06);
+               sect->vaddr = datsize;
+               lookup("datarelro", 0)->sect = sect;
+               lookup("edatarelro", 0)->sect = sect;
+               for(; s != nil && s->type == SDATARELRO; s = s->next) {
+                       if(s->align != 0)
+                               datsize = rnd(datsize, s->align);
+                       s->sect = sect;
+                       s->type = SDATA;
+                       s->value = datsize;
+                       datsize += rnd(s->size, PtrSize);
+               }
+               sect->len = datsize - sect->vaddr;
+               datsize = rnd(datsize, PtrSize);
+       }
+
        /* data */
        sect = addsection(&segdata, ".data", 06);
        sect->vaddr = datsize;
        lookup("data", 0)->sect = sect;
        lookup("edata", 0)->sect = sect;
        for(; s != nil && s->type < SBSS; s = s->next) {
+               if(s->type == SDATARELRO) {
+                       cursym = s;
+                       diag("unexpected symbol type %d", s->type);
+               }
                s->sect = sect;
                s->type = SDATA;
                t = alignsymsize(s->size);
@@ -1080,6 +1147,7 @@ dodata(void)
        sect->vaddr = 0;
        lookup("rodata", 0)->sect = sect;
        lookup("erodata", 0)->sect = sect;
+       lookup("reloffset", 0)->sect = sect;
        datsize = 0;
        s = datap;
        for(; s != nil && s->type < STYPELINK; s = s->next) {
@@ -1227,7 +1295,7 @@ textaddress(void)
 void
 address(void)
 {
-       Section *s, *text, *data, *rodata, *symtab, *pclntab, *noptr, *bss, *noptrbss;
+       Section *s, *text, *data, *rodata, *symtab, *pclntab, *noptr, *bss, *noptrbss, *datarelro;
        Section *gcdata, *gcbss, *typelink;
        Sym *sym, *sub;
        uvlong va;
@@ -1257,6 +1325,7 @@ address(void)
        noptr = nil;
        bss = nil;
        noptrbss = nil;
+       datarelro = nil;
        for(s=segdata.sect; s != nil; s=s->next) {
                s->vaddr = va;
                va += s->len;
@@ -1270,6 +1339,8 @@ address(void)
                        bss = s;
                if(strcmp(s->name, ".noptrbss") == 0)
                        noptrbss = s;
+               if(strcmp(s->name, ".data.rel.ro") == 0)
+                       datarelro = s;
        }
        segdata.filelen -= bss->len + noptrbss->len; // deduct .bss
 
@@ -1297,6 +1368,10 @@ address(void)
        xdefine("erodata", SRODATA, rodata->vaddr + rodata->len);
        xdefine("typelink", SRODATA, typelink->vaddr);
        xdefine("etypelink", SRODATA, typelink->vaddr + typelink->len);
+       if(datarelro != nil) {
+               xdefine("datarelro", SRODATA, datarelro->vaddr);
+               xdefine("edatarelro", SRODATA, datarelro->vaddr + datarelro->len);
+       }
        xdefine("gcdata", SGCDATA, gcdata->vaddr);
        xdefine("egcdata", SGCDATA, gcdata->vaddr + gcdata->len);
        xdefine("gcbss", SGCBSS, gcbss->vaddr);

diff --git a/src/cmd/ld/elf.c b/src/cmd/ld/elf.c
index 485d74c6a3b6527217272750e0a16b3d8952b10f..d0b5fa8304bc9ec45f1a677ff164318d93623a9c 100644 (file)
--- a/src/cmd/ld/elf.c
+++ b/src/cmd/ld/elf.c
@@ -794,6 +794,8 @@ doelf(void)
        addstring(shstrtab, ".elfdata");
        addstring(shstrtab, ".rodata");
        addstring(shstrtab, ".typelink");
+       if(flag_shared)
+               addstring(shstrtab, ".data.rel.ro");
        addstring(shstrtab, ".gcdata");
        addstring(shstrtab, ".gcbss");
        addstring(shstrtab, ".gosymtab");
@@ -927,6 +929,13 @@ doelf(void)
                
                elfwritedynent(s, DT_DEBUG, 0);
 
+               if(flag_shared) {
+                       Sym *init_sym = lookup(LIBINITENTRY, 0);
+                       if(init_sym->type != STEXT)
+                               diag("entry not text: %s", init_sym->name);
+                       elfwritedynentsym(s, DT_INIT, init_sym);
+               }
+
                // Do not write DT_NULL.  elfdynhash will finish it.
        }
 }
@@ -1277,7 +1286,11 @@ asmbelf(vlong symo)
        eh->ident[EI_DATA] = ELFDATA2LSB;
        eh->ident[EI_VERSION] = EV_CURRENT;
 
-       eh->type = ET_EXEC;
+       if(flag_shared)
+               eh->type = ET_DYN;
+       else
+               eh->type = ET_EXEC;
+
        eh->version = EV_CURRENT;
        eh->entry = entryvalue();
 

diff --git a/src/cmd/ld/go.c b/src/cmd/ld/go.c
index b2c5243dfd211bae57071166dd36559ea3fa80fb..c5b9aa5384c7bed4dcca3d6992d29b674af165d3 100644 (file)
--- a/src/cmd/ld/go.c
+++ b/src/cmd/ld/go.c
@@ -732,6 +732,8 @@ deadcode(void)
                Bprint(&bso, "%5.2f deadcode\n", cputime());
 
        mark(lookup(INITENTRY, 0));
+       if(flag_shared)
+               mark(lookup(LIBINITENTRY, 0));
        for(i=0; i<nelem(morename); i++)
                mark(lookup(morename[i], 0));
 

diff --git a/src/cmd/ld/lib.c b/src/cmd/ld/lib.c
index 70c2b5540d2f8934a253a2ce2cf72a823dd559a6..152cd052c599bf3cb1e5ce66860ea44faffb7179 100644 (file)
--- a/src/cmd/ld/lib.c
+++ b/src/cmd/ld/lib.c
@@ -104,6 +104,13 @@ libinit(void)
                sprint(INITENTRY, "_rt0_%s_%s", goarch, goos);
        }
        lookup(INITENTRY, 0)->type = SXREF;
+       if(flag_shared) {
+               if(LIBINITENTRY == nil) {
+                       LIBINITENTRY = mal(strlen(goarch)+strlen(goos)+20);
+                       sprint(LIBINITENTRY, "_rt0_%s_%s_lib", goarch, goos);
+               }
+               lookup(LIBINITENTRY, 0)->type = SXREF;
+       }
 }
 
 void
@@ -305,7 +312,7 @@ loadlib(void)
        //
        // Exception: on OS X, programs such as Shark only work with dynamic
        // binaries, so leave it enabled on OS X (Mach-O) binaries.
-       if(!havedynamic && HEADTYPE != Hdarwin)
+       if(!flag_shared && !havedynamic && HEADTYPE != Hdarwin)
                debug['d'] = 1;
        
        importcycles();

diff --git a/src/cmd/ld/lib.h b/src/cmd/ld/lib.h
index 05363fc14d6279775fe5cb7eb540774317fcc0a3..0f3ce7f6933914e6b9be0f6dd2bbdff69783c403 100644 (file)
--- a/src/cmd/ld/lib.h
+++ b/src/cmd/ld/lib.h
@@ -47,6 +47,7 @@ enum
        SELFROSECT,
        SELFSECT,
        SNOPTRDATA,
+       SDATARELRO,
        SDATA,
        SMACHO, /* Mach-O __nl_symbol_ptr */
        SMACHOGOT,
@@ -138,6 +139,7 @@ EXTERN      int     havedynamic;
 EXTERN int     iscgo;
 EXTERN int     elfglobalsymndx;
 EXTERN int     flag_race;
+EXTERN int flag_shared;
 EXTERN char*   tracksym;
 EXTERN char*   interpreter;
 
@@ -176,6 +178,8 @@ void        symtab(void);
 void   Lflag(char *arg);
 void   usage(void);
 void   adddynrel(Sym*, Reloc*);
+void   adddynrela(Sym*, Sym*, Reloc*);
+Sym*   lookuprel();
 void   ldobj1(Biobuf *f, char*, int64 len, char *pn);
 void   ldobj(Biobuf*, char*, int64, char*, int);
 void   ldelf(Biobuf*, char*, int64, char*);

diff --git a/src/cmd/ld/symtab.c b/src/cmd/ld/symtab.c
index 87b72659b1322464e439509ce8ba3c216ee4bb81..12fad085d65cd7bc8feb4f89210abd1ef1708100 100644 (file)
--- a/src/cmd/ld/symtab.c
+++ b/src/cmd/ld/symtab.c
@@ -387,6 +387,11 @@ symtab(void)
        xdefine("etypelink", SRODATA, 0);
        xdefine("rodata", SRODATA, 0);
        xdefine("erodata", SRODATA, 0);
+       xdefine("reloffset", SRODATA, 0);
+       if(flag_shared) {
+               xdefine("datarelro", SDATARELRO, 0);
+               xdefine("edatarelro", SDATARELRO, 0);
+       }
        xdefine("gcdata", SGCDATA, 0);
        xdefine("egcdata", SGCDATA, 0);
        xdefine("gcbss", SGCBSS, 0);