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-rw-r--r--src/cmd/6l/pass.c722
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diff --git a/src/cmd/6l/pass.c b/src/cmd/6l/pass.c
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+++ b/src/cmd/6l/pass.c
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+// Inferno utils/6l/pass.c
+// http://code.google.com/p/inferno-os/source/browse/utils/6l/pass.c
+//
+// Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved.
+// Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
+// Portions Copyright © 1997-1999 Vita Nuova Limited
+// Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
+// Portions Copyright © 2004,2006 Bruce Ellis
+// Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
+// Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
+// Portions Copyright © 2009 The Go Authors. All rights reserved.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+// Code and data passes.
+
+#include "l.h"
+#include "../ld/lib.h"
+#include "../../pkg/runtime/stack.h"
+
+static void xfol(Prog*, Prog**);
+
+Prog*
+brchain(Prog *p)
+{
+ int i;
+
+ for(i=0; i<20; i++) {
+ if(p == P || p->as != AJMP)
+ return p;
+ p = p->pcond;
+ }
+ return P;
+}
+
+void
+follow(void)
+{
+ Prog *firstp, *lastp;
+
+ if(debug['v'])
+ Bprint(&bso, "%5.2f follow\n", cputime());
+ Bflush(&bso);
+
+ for(cursym = textp; cursym != nil; cursym = cursym->next) {
+ firstp = prg();
+ lastp = firstp;
+ xfol(cursym->text, &lastp);
+ lastp->link = nil;
+ cursym->text = firstp->link;
+ }
+}
+
+static int
+nofollow(int a)
+{
+ switch(a) {
+ case AJMP:
+ case ARET:
+ case AIRETL:
+ case AIRETQ:
+ case AIRETW:
+ case ARETFL:
+ case ARETFQ:
+ case ARETFW:
+ return 1;
+ }
+ return 0;
+}
+
+static int
+pushpop(int a)
+{
+ switch(a) {
+ case APUSHL:
+ case APUSHFL:
+ case APUSHQ:
+ case APUSHFQ:
+ case APUSHW:
+ case APUSHFW:
+ case APOPL:
+ case APOPFL:
+ case APOPQ:
+ case APOPFQ:
+ case APOPW:
+ case APOPFW:
+ return 1;
+ }
+ return 0;
+}
+
+static void
+xfol(Prog *p, Prog **last)
+{
+ Prog *q;
+ int i;
+ enum as a;
+
+loop:
+ if(p == P)
+ return;
+ if(p->as == AJMP)
+ if((q = p->pcond) != P && q->as != ATEXT) {
+ /* mark instruction as done and continue layout at target of jump */
+ p->mark = 1;
+ p = q;
+ if(p->mark == 0)
+ goto loop;
+ }
+ if(p->mark) {
+ /*
+ * p goes here, but already used it elsewhere.
+ * copy up to 4 instructions or else branch to other copy.
+ */
+ for(i=0,q=p; i<4; i++,q=q->link) {
+ if(q == P)
+ break;
+ if(q == *last)
+ break;
+ a = q->as;
+ if(a == ANOP) {
+ i--;
+ continue;
+ }
+ if(nofollow(a) || pushpop(a))
+ break; // NOTE(rsc): arm does goto copy
+ if(q->pcond == P || q->pcond->mark)
+ continue;
+ if(a == ACALL || a == ALOOP)
+ continue;
+ for(;;) {
+ if(p->as == ANOP) {
+ p = p->link;
+ continue;
+ }
+ q = copyp(p);
+ p = p->link;
+ q->mark = 1;
+ (*last)->link = q;
+ *last = q;
+ if(q->as != a || q->pcond == P || q->pcond->mark)
+ continue;
+
+ q->as = relinv(q->as);
+ p = q->pcond;
+ q->pcond = q->link;
+ q->link = p;
+ xfol(q->link, last);
+ p = q->link;
+ if(p->mark)
+ return;
+ goto loop;
+ }
+ } /* */
+ q = prg();
+ q->as = AJMP;
+ q->line = p->line;
+ q->to.type = D_BRANCH;
+ q->to.offset = p->pc;
+ q->pcond = p;
+ p = q;
+ }
+
+ /* emit p */
+ p->mark = 1;
+ (*last)->link = p;
+ *last = p;
+ a = p->as;
+
+ /* continue loop with what comes after p */
+ if(nofollow(a))
+ return;
+ if(p->pcond != P && a != ACALL) {
+ /*
+ * some kind of conditional branch.
+ * recurse to follow one path.
+ * continue loop on the other.
+ */
+ q = brchain(p->link);
+ if(q != P && q->mark)
+ if(a != ALOOP) {
+ p->as = relinv(a);
+ p->link = p->pcond;
+ p->pcond = q;
+ }
+ xfol(p->link, last);
+ q = brchain(p->pcond);
+ if(q->mark) {
+ p->pcond = q;
+ return;
+ }
+ p = q;
+ goto loop;
+ }
+ p = p->link;
+ goto loop;
+}
+
+Prog*
+byteq(int v)
+{
+ Prog *p;
+
+ p = prg();
+ p->as = ABYTE;
+ p->from.type = D_CONST;
+ p->from.offset = v&0xff;
+ return p;
+}
+
+int
+relinv(int a)
+{
+
+ switch(a) {
+ case AJEQ: return AJNE;
+ case AJNE: return AJEQ;
+ case AJLE: return AJGT;
+ case AJLS: return AJHI;
+ case AJLT: return AJGE;
+ case AJMI: return AJPL;
+ case AJGE: return AJLT;
+ case AJPL: return AJMI;
+ case AJGT: return AJLE;
+ case AJHI: return AJLS;
+ case AJCS: return AJCC;
+ case AJCC: return AJCS;
+ case AJPS: return AJPC;
+ case AJPC: return AJPS;
+ case AJOS: return AJOC;
+ case AJOC: return AJOS;
+ }
+ diag("unknown relation: %s in %s", anames[a], TNAME);
+ errorexit();
+ return a;
+}
+
+void
+patch(void)
+{
+ int32 c;
+ Prog *p, *q;
+ Sym *s;
+ int32 vexit;
+
+ if(debug['v'])
+ Bprint(&bso, "%5.2f mkfwd\n", cputime());
+ Bflush(&bso);
+ mkfwd();
+ if(debug['v'])
+ Bprint(&bso, "%5.2f patch\n", cputime());
+ Bflush(&bso);
+
+ s = lookup("exit", 0);
+ vexit = s->value;
+ for(cursym = textp; cursym != nil; cursym = cursym->next)
+ for(p = cursym->text; p != P; p = p->link) {
+ if(HEADTYPE == Hwindows) {
+ // Windows
+ // Convert
+ // op n(GS), reg
+ // to
+ // MOVL 0x58(GS), 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.
+ if(p->from.type == D_INDIR+D_GS
+ && p->to.type >= D_AX && p->to.type <= D_DI
+ && p->from.offset <= 8) {
+ q = appendp(p);
+ q->from = p->from;
+ q->from.type = D_INDIR + p->to.type;
+ q->to = p->to;
+ q->as = p->as;
+ p->as = AMOVQ;
+ p->from.type = D_INDIR+D_GS;
+ p->from.offset = 0x58;
+ }
+ }
+ if(HEADTYPE == Hlinux || HEADTYPE == Hfreebsd
+ || HEADTYPE == Hopenbsd) {
+ // ELF uses FS instead of GS.
+ if(p->from.type == D_INDIR+D_GS)
+ p->from.type = D_INDIR+D_FS;
+ if(p->to.type == D_INDIR+D_GS)
+ p->to.type = D_INDIR+D_FS;
+ }
+ if(p->as == ACALL || (p->as == AJMP && p->to.type != D_BRANCH)) {
+ s = p->to.sym;
+ if(s) {
+ if(debug['c'])
+ Bprint(&bso, "%s calls %s\n", TNAME, s->name);
+ if((s->type&~SSUB) != STEXT) {
+ /* diag prints TNAME first */
+ diag("undefined: %s", s->name);
+ s->type = STEXT;
+ s->value = vexit;
+ continue; // avoid more error messages
+ }
+ if(s->text == nil)
+ continue;
+ p->to.type = D_BRANCH;
+ p->to.offset = s->text->pc;
+ p->pcond = s->text;
+ continue;
+ }
+ }
+ if(p->to.type != D_BRANCH)
+ continue;
+ c = p->to.offset;
+ for(q = cursym->text; q != P;) {
+ if(c == q->pc)
+ break;
+ if(q->forwd != P && c >= q->forwd->pc)
+ q = q->forwd;
+ else
+ q = q->link;
+ }
+ if(q == P) {
+ diag("branch out of range in %s (%#ux)\n%P [%s]",
+ TNAME, c, p, p->to.sym ? p->to.sym->name : "<nil>");
+ p->to.type = D_NONE;
+ }
+ p->pcond = q;
+ }
+
+ for(cursym = textp; cursym != nil; cursym = cursym->next)
+ for(p = cursym->text; p != P; p = p->link) {
+ p->mark = 0; /* initialization for follow */
+ if(p->pcond != P) {
+ p->pcond = brloop(p->pcond);
+ if(p->pcond != P)
+ if(p->to.type == D_BRANCH)
+ p->to.offset = p->pcond->pc;
+ }
+ }
+}
+
+Prog*
+brloop(Prog *p)
+{
+ int c;
+ Prog *q;
+
+ c = 0;
+ for(q = p; q != P; q = q->pcond) {
+ if(q->as != AJMP)
+ break;
+ c++;
+ if(c >= 5000)
+ return P;
+ }
+ return q;
+}
+
+static char*
+morename[] =
+{
+ "runtime.morestack00",
+ "runtime.morestack10",
+ "runtime.morestack01",
+ "runtime.morestack11",
+
+ "runtime.morestack8",
+ "runtime.morestack16",
+ "runtime.morestack24",
+ "runtime.morestack32",
+ "runtime.morestack40",
+ "runtime.morestack48",
+};
+Prog* pmorestack[nelem(morename)];
+Sym* symmorestack[nelem(morename)];
+
+void
+dostkoff(void)
+{
+ Prog *p, *q, *q1;
+ int32 autoffset, deltasp;
+ int a, pcsize;
+ uint32 moreconst1, moreconst2, i;
+
+ for(i=0; i<nelem(morename); i++) {
+ symmorestack[i] = lookup(morename[i], 0);
+ if(symmorestack[i]->type != STEXT)
+ diag("morestack trampoline not defined - %s", morename[i]);
+ pmorestack[i] = symmorestack[i]->text;
+ }
+
+ for(cursym = textp; cursym != nil; cursym = cursym->next) {
+ if(cursym->text == nil || cursym->text->link == nil)
+ continue;
+
+ p = cursym->text;
+ parsetextconst(p->to.offset);
+ autoffset = textstksiz;
+ if(autoffset < 0)
+ autoffset = 0;
+
+ q = P;
+ if((p->from.scale & NOSPLIT) && autoffset >= StackSmall)
+ diag("nosplit func likely to overflow stack");
+
+ if(!(p->from.scale & NOSPLIT)) {
+ p = appendp(p); // load g into CX
+ p->as = AMOVQ;
+ if(HEADTYPE == Hlinux || HEADTYPE == Hfreebsd
+ || HEADTYPE == Hopenbsd) // ELF uses FS
+ p->from.type = D_INDIR+D_FS;
+ else
+ p->from.type = D_INDIR+D_GS;
+ p->from.offset = tlsoffset+0;
+ p->to.type = D_CX;
+ if(HEADTYPE == Hwindows) {
+ // movq %gs:0x58, %rcx
+ // movq (%rcx), %rcx
+ p->as = AMOVQ;
+ p->from.type = D_INDIR+D_GS;
+ p->from.offset = 0x58;
+ p->to.type = D_CX;
+
+
+ p = appendp(p);
+ p->as = AMOVQ;
+ p->from.type = D_INDIR+D_CX;
+ p->from.offset = 0;
+ p->to.type = D_CX;
+ }
+
+ if(debug['K']) {
+ // 6l -K means check not only for stack
+ // overflow but stack underflow.
+ // On underflow, INT 3 (breakpoint).
+ // Underflow itself is rare but this also
+ // catches out-of-sync stack guard info
+
+ p = appendp(p);
+ p->as = ACMPQ;
+ p->from.type = D_INDIR+D_CX;
+ p->from.offset = 8;
+ p->to.type = D_SP;
+
+ p = appendp(p);
+ p->as = AJHI;
+ p->to.type = D_BRANCH;
+ p->to.offset = 4;
+ q1 = p;
+
+ p = appendp(p);
+ p->as = AINT;
+ p->from.type = D_CONST;
+ p->from.offset = 3;
+
+ p = appendp(p);
+ p->as = ANOP;
+ q1->pcond = p;
+ }
+
+ if(autoffset < StackBig) { // do we need to call morestack?
+ if(autoffset <= StackSmall) {
+ // small stack
+ p = appendp(p);
+ p->as = ACMPQ;
+ p->from.type = D_SP;
+ p->to.type = D_INDIR+D_CX;
+ } else {
+ // large stack
+ p = appendp(p);
+ p->as = ALEAQ;
+ p->from.type = D_INDIR+D_SP;
+ p->from.offset = -(autoffset-StackSmall);
+ p->to.type = D_AX;
+
+ p = appendp(p);
+ p->as = ACMPQ;
+ p->from.type = D_AX;
+ p->to.type = D_INDIR+D_CX;
+ }
+
+ // common
+ p = appendp(p);
+ p->as = AJHI;
+ p->to.type = D_BRANCH;
+ p->to.offset = 4;
+ q = p;
+ }
+
+ /* 160 comes from 3 calls (3*8) 4 safes (4*8) and 104 guard */
+ moreconst1 = 0;
+ if(autoffset+160+textarg > 4096)
+ moreconst1 = (autoffset+160) & ~7LL;
+ moreconst2 = textarg;
+
+ // 4 varieties varieties (const1==0 cross const2==0)
+ // and 6 subvarieties of (const1==0 and const2!=0)
+ p = appendp(p);
+ if(moreconst1 == 0 && moreconst2 == 0) {
+ p->as = ACALL;
+ p->to.type = D_BRANCH;
+ p->pcond = pmorestack[0];
+ p->to.sym = symmorestack[0];
+ } else
+ if(moreconst1 != 0 && moreconst2 == 0) {
+ p->as = AMOVL;
+ p->from.type = D_CONST;
+ p->from.offset = moreconst1;
+ p->to.type = D_AX;
+
+ p = appendp(p);
+ p->as = ACALL;
+ p->to.type = D_BRANCH;
+ p->pcond = pmorestack[1];
+ p->to.sym = symmorestack[1];
+ } else
+ if(moreconst1 == 0 && moreconst2 <= 48 && moreconst2%8 == 0) {
+ i = moreconst2/8 + 3;
+ p->as = ACALL;
+ p->to.type = D_BRANCH;
+ p->pcond = pmorestack[i];
+ p->to.sym = symmorestack[i];
+ } else
+ if(moreconst1 == 0 && moreconst2 != 0) {
+ p->as = AMOVL;
+ p->from.type = D_CONST;
+ p->from.offset = moreconst2;
+ p->to.type = D_AX;
+
+ p = appendp(p);
+ p->as = ACALL;
+ p->to.type = D_BRANCH;
+ p->pcond = pmorestack[2];
+ p->to.sym = symmorestack[2];
+ } else {
+ p->as = AMOVQ;
+ p->from.type = D_CONST;
+ p->from.offset = (uint64)moreconst2 << 32;
+ p->from.offset |= moreconst1;
+ p->to.type = D_AX;
+
+ p = appendp(p);
+ p->as = ACALL;
+ p->to.type = D_BRANCH;
+ p->pcond = pmorestack[3];
+ p->to.sym = symmorestack[3];
+ }
+ }
+
+ if(q != P)
+ q->pcond = p->link;
+
+ if(autoffset) {
+ p = appendp(p);
+ p->as = AADJSP;
+ p->from.type = D_CONST;
+ p->from.offset = autoffset;
+ p->spadj = autoffset;
+ if(q != P)
+ q->pcond = p;
+ }
+ deltasp = autoffset;
+
+ if(debug['K'] > 1 && autoffset) {
+ // 6l -KK means double-check for stack overflow
+ // even after calling morestack and even if the
+ // function is marked as nosplit.
+ p = appendp(p);
+ p->as = AMOVQ;
+ p->from.type = D_INDIR+D_CX;
+ p->from.offset = 0;
+ p->to.type = D_BX;
+
+ p = appendp(p);
+ p->as = ASUBQ;
+ p->from.type = D_CONST;
+ p->from.offset = StackSmall+32;
+ p->to.type = D_BX;
+
+ p = appendp(p);
+ p->as = ACMPQ;
+ p->from.type = D_SP;
+ p->to.type = D_BX;
+
+ p = appendp(p);
+ p->as = AJHI;
+ p->to.type = D_BRANCH;
+ q1 = p;
+
+ p = appendp(p);
+ p->as = AINT;
+ p->from.type = D_CONST;
+ p->from.offset = 3;
+
+ p = appendp(p);
+ p->as = ANOP;
+ q1->pcond = p;
+ }
+
+ for(; p != P; p = p->link) {
+ pcsize = p->mode/8;
+ a = p->from.type;
+ if(a == D_AUTO)
+ p->from.offset += deltasp;
+ if(a == D_PARAM)
+ p->from.offset += deltasp + pcsize;
+ a = p->to.type;
+ if(a == D_AUTO)
+ p->to.offset += deltasp;
+ if(a == D_PARAM)
+ p->to.offset += deltasp + pcsize;
+
+ switch(p->as) {
+ default:
+ continue;
+ 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;
+ }
+
+ if(autoffset != deltasp)
+ diag("unbalanced PUSH/POP");
+
+ if(autoffset) {
+ p->as = AADJSP;
+ p->from.type = D_CONST;
+ p->from.offset = -autoffset;
+ p->spadj = -autoffset;
+ p = appendp(p);
+ p->as = ARET;
+ // If there are instructions following
+ // this ARET, they come from a branch
+ // with the same stackframe, so undo
+ // the cleanup.
+ p->spadj = +autoffset;
+ }
+ }
+ }
+}
+
+vlong
+atolwhex(char *s)
+{
+ vlong n;
+ int f;
+
+ n = 0;
+ f = 0;
+ while(*s == ' ' || *s == '\t')
+ s++;
+ if(*s == '-' || *s == '+') {
+ if(*s++ == '-')
+ f = 1;
+ while(*s == ' ' || *s == '\t')
+ s++;
+ }
+ if(s[0]=='0' && s[1]){
+ if(s[1]=='x' || s[1]=='X'){
+ s += 2;
+ for(;;){
+ if(*s >= '0' && *s <= '9')
+ n = n*16 + *s++ - '0';
+ else if(*s >= 'a' && *s <= 'f')
+ n = n*16 + *s++ - 'a' + 10;
+ else if(*s >= 'A' && *s <= 'F')
+ n = n*16 + *s++ - 'A' + 10;
+ else
+ break;
+ }
+ } else
+ while(*s >= '0' && *s <= '7')
+ n = n*8 + *s++ - '0';
+ } else
+ while(*s >= '0' && *s <= '9')
+ n = n*10 + *s++ - '0';
+ if(f)
+ n = -n;
+ return n;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2025-07-26 01:53:31 +0000