blob: f889aba8a98db5a033742180a6c6eb1846b51097 [file] [log] [blame]
// Derived from Inferno utils/6l/obj.c and utils/6l/span.c
// http://code.google.com/p/inferno-os/source/browse/utils/6l/obj.c
// http://code.google.com/p/inferno-os/source/browse/utils/6l/span.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.
#include "l.h"
#include "lib.h"
#include "../ld/elf.h"
#include "../ld/dwarf.h"
#include "../../runtime/stack.h"
#include "../../runtime/funcdata.h"
#include <ar.h>
#if !(defined(_WIN32) || defined(PLAN9))
#include <sys/stat.h>
#endif
enum
{
// Whether to assume that the external linker is "gold"
// (http://sourceware.org/ml/binutils/2008-03/msg00162.html).
AssumeGoldLinker = 0,
};
int iconv(Fmt*);
char symname[] = SYMDEF;
char pkgname[] = "__.PKGDEF";
static int cout = -1;
extern int version;
// Set if we see an object compiled by the host compiler that is not
// from a package that is known to support internal linking mode.
static int externalobj = 0;
static void hostlinksetup(void);
char* goroot;
char* goarch;
char* goos;
char* theline;
void
Lflag(char *arg)
{
char **p;
if(ctxt->nlibdir >= ctxt->maxlibdir) {
if (ctxt->maxlibdir == 0)
ctxt->maxlibdir = 8;
else
ctxt->maxlibdir *= 2;
p = erealloc(ctxt->libdir, ctxt->maxlibdir * sizeof(*p));
ctxt->libdir = p;
}
ctxt->libdir[ctxt->nlibdir++] = arg;
}
/*
* Unix doesn't like it when we write to a running (or, sometimes,
* recently run) binary, so remove the output file before writing it.
* On Windows 7, remove() can force a subsequent create() to fail.
* S_ISREG() does not exist on Plan 9.
*/
static void
mayberemoveoutfile(void)
{
#if !(defined(_WIN32) || defined(PLAN9))
struct stat st;
if(lstat(outfile, &st) == 0 && !S_ISREG(st.st_mode))
return;
#endif
remove(outfile);
}
void
libinit(void)
{
char *suffix, *suffixsep;
funcalign = FuncAlign;
fmtinstall('i', iconv);
fmtinstall('Y', Yconv);
fmtinstall('Z', Zconv);
mywhatsys(); // get goroot, goarch, goos
// add goroot to the end of the libdir list.
suffix = "";
suffixsep = "";
if(flag_installsuffix != nil) {
suffixsep = "_";
suffix = flag_installsuffix;
} else if(flag_race) {
suffixsep = "_";
suffix = "race";
}
Lflag(smprint("%s/pkg/%s_%s%s%s", goroot, goos, goarch, suffixsep, suffix));
mayberemoveoutfile();
cout = create(outfile, 1, 0775);
if(cout < 0) {
diag("cannot create %s: %r", outfile);
errorexit();
}
if(INITENTRY == nil) {
INITENTRY = mal(strlen(goarch)+strlen(goos)+20);
if(!flag_shared) {
sprint(INITENTRY, "_rt0_%s_%s", goarch, goos);
} else {
sprint(INITENTRY, "_rt0_%s_%s_lib", goarch, goos);
}
}
linklookup(ctxt, INITENTRY, 0)->type = SXREF;
}
void
errorexit(void)
{
if(cout >= 0) {
// For rmtemp run at atexit time on Windows.
close(cout);
}
if(nerrors) {
if(cout >= 0)
mayberemoveoutfile();
exits("error");
}
exits(0);
}
void
loadinternal(char *name)
{
char pname[1024];
int i, found;
found = 0;
for(i=0; i<ctxt->nlibdir; i++) {
snprint(pname, sizeof pname, "%s/%s.a", ctxt->libdir[i], name);
if(debug['v'])
Bprint(&bso, "searching for %s.a in %s\n", name, pname);
if(access(pname, AEXIST) >= 0) {
addlibpath(ctxt, "internal", "internal", pname, name);
found = 1;
break;
}
}
if(!found)
Bprint(&bso, "warning: unable to find %s.a\n", name);
}
void
loadlib(void)
{
int i, w, x;
LSym *s, *tlsg;
char* cgostrsym;
if(flag_shared) {
s = linklookup(ctxt, "runtime.islibrary", 0);
s->dupok = 1;
adduint8(ctxt, s, 1);
}
loadinternal("runtime");
if(thechar == '5')
loadinternal("math");
if(flag_race)
loadinternal("runtime/race");
for(i=0; i<ctxt->libraryp; i++) {
if(debug['v'] > 1)
Bprint(&bso, "%5.2f autolib: %s (from %s)\n", cputime(), ctxt->library[i].file, ctxt->library[i].objref);
iscgo |= strcmp(ctxt->library[i].pkg, "runtime/cgo") == 0;
objfile(ctxt->library[i].file, ctxt->library[i].pkg);
}
if(linkmode == LinkExternal && !iscgo) {
// This indicates a user requested -linkmode=external.
// The startup code uses an import of runtime/cgo to decide
// whether to initialize the TLS. So give it one. This could
// be handled differently but it's an unusual case.
loadinternal("runtime/cgo");
if(i < ctxt->libraryp)
objfile(ctxt->library[i].file, ctxt->library[i].pkg);
// Pretend that we really imported the package.
s = linklookup(ctxt, "go.importpath.runtime/cgo.", 0);
s->type = SDATA;
s->dupok = 1;
s->reachable = 1;
// Provided by the code that imports the package.
// Since we are simulating the import, we have to provide this string.
cgostrsym = "go.string.\"runtime/cgo\"";
if(linkrlookup(ctxt, cgostrsym, 0) == nil) {
s = linklookup(ctxt, cgostrsym, 0);
s->type = SRODATA;
s->reachable = 1;
addstrdata(cgostrsym, "runtime/cgo");
}
}
if(linkmode == LinkAuto) {
if(iscgo && externalobj)
linkmode = LinkExternal;
else
linkmode = LinkInternal;
// Force external linking for android.
if(strcmp(goos, "android") == 0)
linkmode = LinkExternal;
}
if(linkmode == LinkInternal) {
// Drop all the cgo_import_static declarations.
// Turns out we won't be needing them.
for(s = ctxt->allsym; s != S; s = s->allsym)
if(s->type == SHOSTOBJ) {
// If a symbol was marked both
// cgo_import_static and cgo_import_dynamic,
// then we want to make it cgo_import_dynamic
// now.
if(s->extname != nil && s->dynimplib != nil && s->cgoexport == 0) {
s->type = SDYNIMPORT;
} else
s->type = 0;
}
}
tlsg = linklookup(ctxt, "runtime.tlsg", 0);
tlsg->type = STLSBSS;
tlsg->size = PtrSize;
tlsg->hide = 1;
tlsg->reachable = 1;
ctxt->tlsg = tlsg;
// Now that we know the link mode, trim the dynexp list.
x = CgoExportDynamic;
if(linkmode == LinkExternal)
x = CgoExportStatic;
w = 0;
for(i=0; i<ndynexp; i++)
if(dynexp[i]->cgoexport & x)
dynexp[w++] = dynexp[i];
ndynexp = w;
// In internal link mode, read the host object files.
if(linkmode == LinkInternal)
hostobjs();
else
hostlinksetup();
// We've loaded all the code now.
// If there are no dynamic libraries needed, gcc disables dynamic linking.
// Because of this, glibc's dynamic ELF loader occasionally (like in version 2.13)
// assumes that a dynamic binary always refers to at least one dynamic library.
// Rather than be a source of test cases for glibc, disable dynamic linking
// the same way that gcc would.
//
// Exception: on OS X, programs such as Shark only work with dynamic
// binaries, so leave it enabled on OS X (Mach-O) binaries.
// Also leave it enabled on Solaris which doesn't support
// statically linked binaries.
if(!flag_shared && !havedynamic && HEADTYPE != Hdarwin && HEADTYPE != Hsolaris)
debug['d'] = 1;
importcycles();
}
/*
* look for the next file in an archive.
* adapted from libmach.
*/
static vlong
nextar(Biobuf *bp, vlong off, struct ar_hdr *a)
{
int r;
int32 arsize;
char *buf;
if (off&01)
off++;
Bseek(bp, off, 0);
buf = Brdline(bp, '\n');
r = Blinelen(bp);
if(buf == nil) {
if(r == 0)
return 0;
return -1;
}
if(r != SAR_HDR)
return -1;
memmove(a, buf, SAR_HDR);
if(strncmp(a->fmag, ARFMAG, sizeof a->fmag))
return -1;
arsize = strtol(a->size, 0, 0);
if (arsize&1)
arsize++;
return arsize + r;
}
void
objfile(char *file, char *pkg)
{
vlong off, l;
Biobuf *f;
char magbuf[SARMAG];
char pname[150];
struct ar_hdr arhdr;
pkg = smprint("%i", pkg);
if(debug['v'] > 1)
Bprint(&bso, "%5.2f ldobj: %s (%s)\n", cputime(), file, pkg);
Bflush(&bso);
f = Bopen(file, 0);
if(f == nil) {
diag("cannot open file: %s", file);
errorexit();
}
l = Bread(f, magbuf, SARMAG);
if(l != SARMAG || strncmp(magbuf, ARMAG, SARMAG)){
/* load it as a regular file */
l = Bseek(f, 0L, 2);
Bseek(f, 0L, 0);
ldobj(f, pkg, l, file, file, FileObj);
Bterm(f);
free(pkg);
return;
}
/* skip over optional __.GOSYMDEF and process __.PKGDEF */
off = Boffset(f);
l = nextar(f, off, &arhdr);
if(l <= 0) {
diag("%s: short read on archive file symbol header", file);
goto out;
}
if(strncmp(arhdr.name, symname, strlen(symname)) == 0) {
off += l;
l = nextar(f, off, &arhdr);
if(l <= 0) {
diag("%s: short read on archive file symbol header", file);
goto out;
}
}
if(strncmp(arhdr.name, pkgname, strlen(pkgname))) {
diag("%s: cannot find package header", file);
goto out;
}
off += l;
if(debug['u'])
ldpkg(f, pkg, atolwhex(arhdr.size), file, Pkgdef);
/*
* load all the object files from the archive now.
* this gives us sequential file access and keeps us
* from needing to come back later to pick up more
* objects. it breaks the usual C archive model, but
* this is Go, not C. the common case in Go is that
* we need to load all the objects, and then we throw away
* the individual symbols that are unused.
*
* loading every object will also make it possible to
* load foreign objects not referenced by __.GOSYMDEF.
*/
for(;;) {
l = nextar(f, off, &arhdr);
if(l == 0)
break;
if(l < 0) {
diag("%s: malformed archive", file);
goto out;
}
off += l;
l = SARNAME;
while(l > 0 && arhdr.name[l-1] == ' ')
l--;
snprint(pname, sizeof pname, "%s(%.*s)", file, utfnlen(arhdr.name, l), arhdr.name);
l = atolwhex(arhdr.size);
ldobj(f, pkg, l, pname, file, ArchiveObj);
}
out:
Bterm(f);
free(pkg);
}
static void
dowrite(int fd, char *p, int n)
{
int m;
while(n > 0) {
m = write(fd, p, n);
if(m <= 0) {
ctxt->cursym = S;
diag("write error: %r");
errorexit();
}
n -= m;
p += m;
}
}
typedef struct Hostobj Hostobj;
struct Hostobj
{
void (*ld)(Biobuf*, char*, int64, char*);
char *pkg;
char *pn;
char *file;
int64 off;
int64 len;
};
Hostobj *hostobj;
int nhostobj;
int mhostobj;
// These packages can use internal linking mode.
// Others trigger external mode.
const char *internalpkg[] = {
"crypto/x509",
"net",
"os/user",
"runtime/cgo",
"runtime/race"
};
void
ldhostobj(void (*ld)(Biobuf*, char*, int64, char*), Biobuf *f, char *pkg, int64 len, char *pn, char *file)
{
int i, isinternal;
Hostobj *h;
isinternal = 0;
for(i=0; i<nelem(internalpkg); i++) {
if(strcmp(pkg, internalpkg[i]) == 0) {
isinternal = 1;
break;
}
}
// DragonFly declares errno with __thread, which results in a symbol
// type of R_386_TLS_GD or R_X86_64_TLSGD. The Go linker does not
// currently know how to handle TLS relocations, hence we have to
// force external linking for any libraries that link in code that
// uses errno. This can be removed if the Go linker ever supports
// these relocation types.
if(HEADTYPE == Hdragonfly)
if(strcmp(pkg, "net") == 0 || strcmp(pkg, "os/user") == 0)
isinternal = 0;
if(!isinternal)
externalobj = 1;
if(nhostobj >= mhostobj) {
if(mhostobj == 0)
mhostobj = 16;
else
mhostobj *= 2;
hostobj = erealloc(hostobj, mhostobj*sizeof hostobj[0]);
}
h = &hostobj[nhostobj++];
h->ld = ld;
h->pkg = estrdup(pkg);
h->pn = estrdup(pn);
h->file = estrdup(file);
h->off = Boffset(f);
h->len = len;
}
void
hostobjs(void)
{
int i;
Biobuf *f;
Hostobj *h;
for(i=0; i<nhostobj; i++) {
h = &hostobj[i];
f = Bopen(h->file, OREAD);
if(f == nil) {
ctxt->cursym = S;
diag("cannot reopen %s: %r", h->pn);
errorexit();
}
Bseek(f, h->off, 0);
h->ld(f, h->pkg, h->len, h->pn);
Bterm(f);
}
}
// provided by lib9
int runcmd(char**);
char* mktempdir(void);
void removeall(char*);
static void
rmtemp(void)
{
removeall(tmpdir);
}
static void
hostlinksetup(void)
{
char *p;
if(linkmode != LinkExternal)
return;
// create temporary directory and arrange cleanup
if(tmpdir == nil) {
tmpdir = mktempdir();
atexit(rmtemp);
}
// change our output to temporary object file
close(cout);
p = smprint("%s/go.o", tmpdir);
cout = create(p, 1, 0775);
if(cout < 0) {
diag("cannot create %s: %r", p);
errorexit();
}
free(p);
}
void
hostlink(void)
{
char *p, **argv;
int c, i, w, n, argc, len;
Hostobj *h;
Biobuf *f;
static char buf[64<<10];
if(linkmode != LinkExternal || nerrors > 0)
return;
c = 0;
p = extldflags;
while(p != nil) {
while(*p == ' ')
p++;
if(*p == '\0')
break;
c++;
p = strchr(p + 1, ' ');
}
argv = malloc((14+nhostobj+nldflag+c)*sizeof argv[0]);
argc = 0;
if(extld == nil)
extld = "gcc";
argv[argc++] = extld;
switch(thechar){
case '8':
argv[argc++] = "-m32";
break;
case '6':
argv[argc++] = "-m64";
break;
case '5':
argv[argc++] = "-marm";
break;
}
if(!debug['s'] && !debug_s) {
argv[argc++] = "-gdwarf-2";
} else {
argv[argc++] = "-s";
}
if(HEADTYPE == Hdarwin)
argv[argc++] = "-Wl,-no_pie,-pagezero_size,4000000";
if(HEADTYPE == Hopenbsd)
argv[argc++] = "-Wl,-nopie";
if(iself && AssumeGoldLinker)
argv[argc++] = "-Wl,--rosegment";
if(flag_shared) {
argv[argc++] = "-Wl,-Bsymbolic";
argv[argc++] = "-shared";
}
argv[argc++] = "-o";
argv[argc++] = outfile;
if(rpath)
argv[argc++] = smprint("-Wl,-rpath,%s", rpath);
// Force global symbols to be exported for dlopen, etc.
if(iself)
argv[argc++] = "-rdynamic";
if(strstr(argv[0], "clang") != nil)
argv[argc++] = "-Qunused-arguments";
// already wrote main object file
// copy host objects to temporary directory
for(i=0; i<nhostobj; i++) {
h = &hostobj[i];
f = Bopen(h->file, OREAD);
if(f == nil) {
ctxt->cursym = S;
diag("cannot reopen %s: %r", h->pn);
errorexit();
}
Bseek(f, h->off, 0);
p = smprint("%s/%06d.o", tmpdir, i);
argv[argc++] = p;
w = create(p, 1, 0775);
if(w < 0) {
ctxt->cursym = S;
diag("cannot create %s: %r", p);
errorexit();
}
len = h->len;
while(len > 0 && (n = Bread(f, buf, sizeof buf)) > 0){
if(n > len)
n = len;
dowrite(w, buf, n);
len -= n;
}
if(close(w) < 0) {
ctxt->cursym = S;
diag("cannot write %s: %r", p);
errorexit();
}
Bterm(f);
}
argv[argc++] = smprint("%s/go.o", tmpdir);
for(i=0; i<nldflag; i++)
argv[argc++] = ldflag[i];
p = extldflags;
while(p != nil) {
while(*p == ' ')
*p++ = '\0';
if(*p == '\0')
break;
argv[argc++] = p;
// clang, unlike GCC, passes -rdynamic to the linker
// even when linking with -static, causing a linker
// error when using GNU ld. So take out -rdynamic if
// we added it. We do it in this order, rather than
// only adding -rdynamic later, so that -extldflags
// can override -rdynamic without using -static.
if(iself && strncmp(p, "-static", 7) == 0 && (p[7]==' ' || p[7]=='\0')) {
for(i=0; i<argc; i++) {
if(strcmp(argv[i], "-rdynamic") == 0)
argv[i] = "-static";
}
}
p = strchr(p + 1, ' ');
}
argv[argc] = nil;
quotefmtinstall();
if(debug['v']) {
Bprint(&bso, "host link:");
for(i=0; i<argc; i++)
Bprint(&bso, " %q", argv[i]);
Bprint(&bso, "\n");
Bflush(&bso);
}
if(runcmd(argv) < 0) {
ctxt->cursym = S;
diag("%s: running %s failed: %r", argv0, argv[0]);
errorexit();
}
}
void
ldobj(Biobuf *f, char *pkg, int64 len, char *pn, char *file, int whence)
{
char *line;
int n, c1, c2, c3, c4;
uint32 magic;
vlong import0, import1, eof;
char *t;
eof = Boffset(f) + len;
pn = estrdup(pn);
c1 = BGETC(f);
c2 = BGETC(f);
c3 = BGETC(f);
c4 = BGETC(f);
Bungetc(f);
Bungetc(f);
Bungetc(f);
Bungetc(f);
magic = c1<<24 | c2<<16 | c3<<8 | c4;
if(magic == 0x7f454c46) { // \x7F E L F
ldhostobj(ldelf, f, pkg, len, pn, file);
return;
}
if((magic&~1) == 0xfeedface || (magic&~0x01000000) == 0xcefaedfe) {
ldhostobj(ldmacho, f, pkg, len, pn, file);
return;
}
if(c1 == 0x4c && c2 == 0x01 || c1 == 0x64 && c2 == 0x86) {
ldhostobj(ldpe, f, pkg, len, pn, file);
return;
}
/* check the header */
line = Brdline(f, '\n');
if(line == nil) {
if(Blinelen(f) > 0) {
diag("%s: not an object file", pn);
return;
}
goto eof;
}
n = Blinelen(f) - 1;
line[n] = '\0';
if(strncmp(line, "go object ", 10) != 0) {
if(strlen(pn) > 3 && strcmp(pn+strlen(pn)-3, ".go") == 0) {
print("%cl: input %s is not .%c file (use %cg to compile .go files)\n", thechar, pn, thechar, thechar);
errorexit();
}
if(strcmp(line, thestring) == 0) {
// old header format: just $GOOS
diag("%s: stale object file", pn);
return;
}
diag("%s: not an object file", pn);
free(pn);
return;
}
// First, check that the basic goos, goarch, and version match.
t = smprint("%s %s %s ", goos, getgoarch(), getgoversion());
line[n] = ' ';
if(strncmp(line+10, t, strlen(t)) != 0 && !debug['f']) {
line[n] = '\0';
diag("%s: object is [%s] expected [%s]", pn, line+10, t);
free(t);
free(pn);
return;
}
// Second, check that longer lines match each other exactly,
// so that the Go compiler and write additional information
// that must be the same from run to run.
line[n] = '\0';
if(n-10 > strlen(t)) {
if(theline == nil)
theline = estrdup(line+10);
else if(strcmp(theline, line+10) != 0) {
line[n] = '\0';
diag("%s: object is [%s] expected [%s]", pn, line+10, theline);
free(t);
free(pn);
return;
}
}
free(t);
line[n] = '\n';
/* skip over exports and other info -- ends with \n!\n */
import0 = Boffset(f);
c1 = '\n'; // the last line ended in \n
c2 = BGETC(f);
c3 = BGETC(f);
while(c1 != '\n' || c2 != '!' || c3 != '\n') {
c1 = c2;
c2 = c3;
c3 = BGETC(f);
if(c3 == Beof)
goto eof;
}
import1 = Boffset(f);
Bseek(f, import0, 0);
ldpkg(f, pkg, import1 - import0 - 2, pn, whence); // -2 for !\n
Bseek(f, import1, 0);
ldobjfile(ctxt, f, pkg, eof - Boffset(f), pn);
free(pn);
return;
eof:
diag("truncated object file: %s", pn);
free(pn);
}
void
zerosig(char *sp)
{
LSym *s;
s = linklookup(ctxt, sp, 0);
s->sig = 0;
}
void
mywhatsys(void)
{
goroot = getgoroot();
goos = getgoos();
goarch = getgoarch();
if(strncmp(goarch, thestring, strlen(thestring)) != 0)
sysfatal("cannot use %cc with GOARCH=%s", thechar, goarch);
}
int
pathchar(void)
{
return '/';
}
static uchar* hunk;
static uint32 nhunk;
#define NHUNK (10UL<<20)
void*
mal(uint32 n)
{
void *v;
n = (n+7)&~7;
if(n > NHUNK) {
v = malloc(n);
if(v == nil) {
diag("out of memory");
errorexit();
}
memset(v, 0, n);
return v;
}
if(n > nhunk) {
hunk = malloc(NHUNK);
if(hunk == nil) {
diag("out of memory");
errorexit();
}
nhunk = NHUNK;
}
v = hunk;
nhunk -= n;
hunk += n;
memset(v, 0, n);
return v;
}
void
unmal(void *v, uint32 n)
{
n = (n+7)&~7;
if(hunk - n == v) {
hunk -= n;
nhunk += n;
}
}
// Copied from ../gc/subr.c:/^pathtoprefix; must stay in sync.
/*
* Convert raw string to the prefix that will be used in the symbol table.
* Invalid bytes turn into %xx. Right now the only bytes that need
* escaping are %, ., and ", but we escape all control characters too.
*
* If you edit this, edit ../gc/subr.c:/^pathtoprefix too.
* If you edit this, edit ../../debug/goobj/read.go:/importPathToPrefix too.
*/
static char*
pathtoprefix(char *s)
{
static char hex[] = "0123456789abcdef";
char *p, *r, *w, *l;
int n;
// find first character past the last slash, if any.
l = s;
for(r=s; *r; r++)
if(*r == '/')
l = r+1;
// check for chars that need escaping
n = 0;
for(r=s; *r; r++)
if(*r <= ' ' || (*r == '.' && r >= l) || *r == '%' || *r == '"' || *r >= 0x7f)
n++;
// quick exit
if(n == 0)
return s;
// escape
p = mal((r-s)+1+2*n);
for(r=s, w=p; *r; r++) {
if(*r <= ' ' || (*r == '.' && r >= l) || *r == '%' || *r == '"' || *r >= 0x7f) {
*w++ = '%';
*w++ = hex[(*r>>4)&0xF];
*w++ = hex[*r&0xF];
} else
*w++ = *r;
}
*w = '\0';
return p;
}
int
iconv(Fmt *fp)
{
char *p;
p = va_arg(fp->args, char*);
if(p == nil) {
fmtstrcpy(fp, "<nil>");
return 0;
}
p = pathtoprefix(p);
fmtstrcpy(fp, p);
return 0;
}
Section*
addsection(Segment *seg, char *name, int rwx)
{
Section **l;
Section *sect;
for(l=&seg->sect; *l; l=&(*l)->next)
;
sect = mal(sizeof *sect);
sect->rwx = rwx;
sect->name = name;
sect->seg = seg;
sect->align = PtrSize; // everything is at least pointer-aligned
*l = sect;
return sect;
}
uint16
le16(uchar *b)
{
return b[0] | b[1]<<8;
}
uint32
le32(uchar *b)
{
return b[0] | b[1]<<8 | b[2]<<16 | (uint32)b[3]<<24;
}
uint64
le64(uchar *b)
{
return le32(b) | (uint64)le32(b+4)<<32;
}
uint16
be16(uchar *b)
{
return b[0]<<8 | b[1];
}
uint32
be32(uchar *b)
{
return (uint32)b[0]<<24 | b[1]<<16 | b[2]<<8 | b[3];
}
uint64
be64(uchar *b)
{
return (uvlong)be32(b)<<32 | be32(b+4);
}
Endian be = { be16, be32, be64 };
Endian le = { le16, le32, le64 };
typedef struct Chain Chain;
struct Chain
{
LSym *sym;
Chain *up;
int limit; // limit on entry to sym
};
static int stkcheck(Chain*, int);
static void stkprint(Chain*, int);
static void stkbroke(Chain*, int);
static LSym *morestack;
static LSym *newstack;
enum
{
HasLinkRegister = (thechar == '5'),
};
// TODO: Record enough information in new object files to
// allow stack checks here.
static int
callsize(void)
{
if(thechar == '5')
return 0;
return RegSize;
}
void
dostkcheck(void)
{
Chain ch;
LSym *s;
morestack = linklookup(ctxt, "runtime.morestack", 0);
newstack = linklookup(ctxt, "runtime.newstack", 0);
// Every splitting function ensures that there are at least StackLimit
// bytes available below SP when the splitting prologue finishes.
// If the splitting function calls F, then F begins execution with
// at least StackLimit - callsize() bytes available.
// Check that every function behaves correctly with this amount
// of stack, following direct calls in order to piece together chains
// of non-splitting functions.
ch.up = nil;
ch.limit = StackLimit - callsize();
// Check every function, but do the nosplit functions in a first pass,
// to make the printed failure chains as short as possible.
for(s = ctxt->textp; s != nil; s = s->next) {
// runtime.racesymbolizethunk is called from gcc-compiled C
// code running on the operating system thread stack.
// It uses more than the usual amount of stack but that's okay.
if(strcmp(s->name, "runtime.racesymbolizethunk") == 0)
continue;
if(s->nosplit) {
ctxt->cursym = s;
ch.sym = s;
stkcheck(&ch, 0);
}
}
for(s = ctxt->textp; s != nil; s = s->next) {
if(!s->nosplit) {
ctxt->cursym = s;
ch.sym = s;
stkcheck(&ch, 0);
}
}
}
static int
stkcheck(Chain *up, int depth)
{
Chain ch, ch1;
LSym *s;
int limit;
Reloc *r, *endr;
Pciter pcsp;
limit = up->limit;
s = up->sym;
// Don't duplicate work: only need to consider each
// function at top of safe zone once.
if(limit == StackLimit-callsize()) {
if(s->stkcheck)
return 0;
s->stkcheck = 1;
}
if(depth > 100) {
diag("nosplit stack check too deep");
stkbroke(up, 0);
return -1;
}
if(s->external || s->pcln == nil) {
// external function.
// should never be called directly.
// only diagnose the direct caller.
if(depth == 1 && s->type != SXREF)
diag("call to external function %s", s->name);
return -1;
}
if(limit < 0) {
stkbroke(up, limit);
return -1;
}
// morestack looks like it calls functions,
// but it switches the stack pointer first.
if(s == morestack)
return 0;
ch.up = up;
// Walk through sp adjustments in function, consuming relocs.
r = s->r;
endr = r + s->nr;
for(pciterinit(ctxt, &pcsp, &s->pcln->pcsp); !pcsp.done; pciternext(&pcsp)) {
// pcsp.value is in effect for [pcsp.pc, pcsp.nextpc).
// Check stack size in effect for this span.
if(limit - pcsp.value < 0) {
stkbroke(up, limit - pcsp.value);
return -1;
}
// Process calls in this span.
for(; r < endr && r->off < pcsp.nextpc; r++) {
switch(r->type) {
case R_CALL:
case R_CALLARM:
// Direct call.
ch.limit = limit - pcsp.value - callsize();
ch.sym = r->sym;
if(stkcheck(&ch, depth+1) < 0)
return -1;
// If this is a call to morestack, we've just raised our limit back
// to StackLimit beyond the frame size.
if(strncmp(r->sym->name, "runtime.morestack", 17) == 0) {
limit = StackLimit + s->locals;
if(thechar == '5')
limit += 4; // saved LR
}
break;
case R_CALLIND:
// Indirect call. Assume it is a call to a splitting function,
// so we have to make sure it can call morestack.
// Arrange the data structures to report both calls, so that
// if there is an error, stkprint shows all the steps involved.
ch.limit = limit - pcsp.value - callsize();
ch.sym = nil;
ch1.limit = ch.limit - callsize(); // for morestack in called prologue
ch1.up = &ch;
ch1.sym = morestack;
if(stkcheck(&ch1, depth+2) < 0)
return -1;
break;
}
}
}
return 0;
}
static void
stkbroke(Chain *ch, int limit)
{
diag("nosplit stack overflow");
stkprint(ch, limit);
}
static void
stkprint(Chain *ch, int limit)
{
char *name;
if(ch->sym)
name = ch->sym->name;
else
name = "function pointer";
if(ch->up == nil) {
// top of chain. ch->sym != nil.
if(ch->sym->nosplit)
print("\t%d\tassumed on entry to %s\n", ch->limit, name);
else
print("\t%d\tguaranteed after split check in %s\n", ch->limit, name);
} else {
stkprint(ch->up, ch->limit + (!HasLinkRegister)*PtrSize);
if(!HasLinkRegister)
print("\t%d\ton entry to %s\n", ch->limit, name);
}
if(ch->limit != limit)
print("\t%d\tafter %s uses %d\n", limit, name, ch->limit - limit);
}
int
Yconv(Fmt *fp)
{
LSym *s;
Fmt fmt;
int i;
char *str;
s = va_arg(fp->args, LSym*);
if (s == S) {
fmtprint(fp, "<nil>");
} else {
fmtstrinit(&fmt);
fmtprint(&fmt, "%s @0x%08llx [%lld]", s->name, (vlong)s->value, (vlong)s->size);
for (i = 0; i < s->size; i++) {
if (!(i%8)) fmtprint(&fmt, "\n\t0x%04x ", i);
fmtprint(&fmt, "%02x ", s->p[i]);
}
fmtprint(&fmt, "\n");
for (i = 0; i < s->nr; i++) {
fmtprint(&fmt, "\t0x%04x[%x] %d %s[%llx]\n",
s->r[i].off,
s->r[i].siz,
s->r[i].type,
s->r[i].sym->name,
(vlong)s->r[i].add);
}
str = fmtstrflush(&fmt);
fmtstrcpy(fp, str);
free(str);
}
return 0;
}
vlong coutpos;
void
cflush(void)
{
int n;
if(cbpmax < cbp)
cbpmax = cbp;
n = cbpmax - buf.cbuf;
dowrite(cout, buf.cbuf, n);
coutpos += n;
cbp = buf.cbuf;
cbc = sizeof(buf.cbuf);
cbpmax = cbp;
}
vlong
cpos(void)
{
return coutpos + cbp - buf.cbuf;
}
void
cseek(vlong p)
{
vlong start;
int delta;
if(cbpmax < cbp)
cbpmax = cbp;
start = coutpos;
if(start <= p && p <= start+(cbpmax - buf.cbuf)) {
//print("cseek %lld in [%lld,%lld] (%lld)\n", p, start, start+sizeof(buf.cbuf), cpos());
delta = p - (start + cbp - buf.cbuf);
cbp += delta;
cbc -= delta;
//print("now at %lld\n", cpos());
return;
}
cflush();
seek(cout, p, 0);
coutpos = p;
}
void
cwrite(void *buf, int n)
{
cflush();
if(n <= 0)
return;
dowrite(cout, buf, n);
coutpos += n;
}
void
usage(void)
{
fprint(2, "usage: %cl [options] main.%c\n", thechar, thechar);
flagprint(2);
exits("usage");
}
void
setheadtype(char *s)
{
int h;
h = headtype(s);
if(h < 0) {
fprint(2, "unknown header type -H %s\n", s);
errorexit();
}
headstring = s;
HEADTYPE = headtype(s);
}
void
setinterp(char *s)
{
debug['I'] = 1; // denote cmdline interpreter override
interpreter = s;
}
void
doversion(void)
{
print("%cl version %s\n", thechar, getgoversion());
errorexit();
}
void
genasmsym(void (*put)(LSym*, char*, int, vlong, vlong, int, LSym*))
{
Auto *a;
LSym *s;
int32 off;
// These symbols won't show up in the first loop below because we
// skip STEXT symbols. Normal STEXT symbols are emitted by walking textp.
s = linklookup(ctxt, "runtime.text", 0);
if(s->type == STEXT)
put(s, s->name, 'T', s->value, s->size, s->version, 0);
s = linklookup(ctxt, "runtime.etext", 0);
if(s->type == STEXT)
put(s, s->name, 'T', s->value, s->size, s->version, 0);
for(s=ctxt->allsym; s!=S; s=s->allsym) {
if(s->hide || (s->name[0] == '.' && s->version == 0 && strcmp(s->name, ".rathole") != 0))
continue;
switch(s->type&SMASK) {
case SCONST:
case SRODATA:
case SSYMTAB:
case SPCLNTAB:
case SDATA:
case SNOPTRDATA:
case SELFROSECT:
case SMACHOGOT:
case STYPE:
case SSTRING:
case SGOSTRING:
case SWINDOWS:
if(!s->reachable)
continue;
put(s, s->name, 'D', symaddr(s), s->size, s->version, s->gotype);
continue;
case SBSS:
case SNOPTRBSS:
if(!s->reachable)
continue;
if(s->np > 0)
diag("%s should not be bss (size=%d type=%d special=%d)", s->name, (int)s->np, s->type, s->special);
put(s, s->name, 'B', symaddr(s), s->size, s->version, s->gotype);
continue;
case SFILE:
put(nil, s->name, 'f', s->value, 0, s->version, 0);
continue;
}
}
for(s = ctxt->textp; s != nil; s = s->next) {
put(s, s->name, 'T', s->value, s->size, s->version, s->gotype);
// NOTE(ality): acid can't produce a stack trace without .frame symbols
put(nil, ".frame", 'm', s->locals+PtrSize, 0, 0, 0);
for(a=s->autom; a; a=a->link) {
// Emit a or p according to actual offset, even if label is wrong.
// This avoids negative offsets, which cannot be encoded.
if(a->type != A_AUTO && a->type != A_PARAM)
continue;
// compute offset relative to FP
if(a->type == A_PARAM)
off = a->aoffset;
else
off = a->aoffset - PtrSize;
// FP
if(off >= 0) {
put(nil, a->asym->name, 'p', off, 0, 0, a->gotype);
continue;
}
// SP
if(off <= -PtrSize) {
put(nil, a->asym->name, 'a', -(off+PtrSize), 0, 0, a->gotype);
continue;
}
// Otherwise, off is addressing the saved program counter.
// Something underhanded is going on. Say nothing.
}
}
if(debug['v'] || debug['n'])
Bprint(&bso, "%5.2f symsize = %ud\n", cputime(), symsize);
Bflush(&bso);
}
vlong
symaddr(LSym *s)
{
if(!s->reachable)
diag("unreachable symbol in symaddr - %s", s->name);
return s->value;
}
void
xdefine(char *p, int t, vlong v)
{
LSym *s;
s = linklookup(ctxt, p, 0);
s->type = t;
s->value = v;
s->reachable = 1;
s->special = 1;
}
vlong
datoff(vlong addr)
{
if(addr >= segdata.vaddr)
return addr - segdata.vaddr + segdata.fileoff;
if(addr >= segtext.vaddr)
return addr - segtext.vaddr + segtext.fileoff;
diag("datoff %#llx", addr);
return 0;
}
vlong
entryvalue(void)
{
char *a;
LSym *s;
a = INITENTRY;
if(*a >= '0' && *a <= '9')
return atolwhex(a);
s = linklookup(ctxt, a, 0);
if(s->type == 0)
return INITTEXT;
if(s->type != STEXT)
diag("entry not text: %s", s->name);
return s->value;
}
static void
undefsym(LSym *s)
{
int i;
Reloc *r;
ctxt->cursym = s;
for(i=0; i<s->nr; i++) {
r = &s->r[i];
if(r->sym == nil) // happens for some external ARM relocs
continue;
if(r->sym->type == Sxxx || r->sym->type == SXREF)
diag("undefined: %s", r->sym->name);
if(!r->sym->reachable)
diag("use of unreachable symbol: %s", r->sym->name);
}
}
void
undef(void)
{
LSym *s;
for(s = ctxt->textp; s != nil; s = s->next)
undefsym(s);
for(s = datap; s != nil; s = s->next)
undefsym(s);
if(nerrors > 0)
errorexit();
}
void
callgraph(void)
{
LSym *s;
Reloc *r;
int i;
if(!debug['c'])
return;
for(s = ctxt->textp; s != nil; s = s->next) {
for(i=0; i<s->nr; i++) {
r = &s->r[i];
if(r->sym == nil)
continue;
if((r->type == R_CALL || r->type == R_CALLARM) && r->sym->type == STEXT)
Bprint(&bso, "%s calls %s\n", s->name, r->sym->name);
}
}
}
void
diag(char *fmt, ...)
{
char buf[1024], *tn, *sep;
va_list arg;
tn = "";
sep = "";
if(ctxt->cursym != S) {
tn = ctxt->cursym->name;
sep = ": ";
}
va_start(arg, fmt);
vseprint(buf, buf+sizeof(buf), fmt, arg);
va_end(arg);
print("%s%s%s\n", tn, sep, buf);
nerrors++;
if(nerrors > 20) {
print("too many errors\n");
errorexit();
}
}
void
checkgo(void)
{
LSym *s;
Reloc *r;
int i;
int changed;
if(!debug['C'])
return;
// TODO(rsc,khr): Eventually we want to get to no Go-called C functions at all,
// which would simplify this logic quite a bit.
// Mark every Go-called C function with cfunc=2, recursively.
do {
changed = 0;
for(s = ctxt->textp; s != nil; s = s->next) {
if(s->cfunc == 0 || (s->cfunc == 2 && s->nosplit)) {
for(i=0; i<s->nr; i++) {
r = &s->r[i];
if(r->sym == nil)
continue;
if((r->type == R_CALL || r->type == R_CALLARM) && r->sym->type == STEXT) {
if(r->sym->cfunc == 1) {
changed = 1;
r->sym->cfunc = 2;
}
}
}
}
}
}while(changed);
// Complain about Go-called C functions that can split the stack
// (that can be preempted for garbage collection or trigger a stack copy).
for(s = ctxt->textp; s != nil; s = s->next) {
if(s->cfunc == 0 || (s->cfunc == 2 && s->nosplit)) {
for(i=0; i<s->nr; i++) {
r = &s->r[i];
if(r->sym == nil)
continue;
if((r->type == R_CALL || r->type == R_CALLARM) && r->sym->type == STEXT) {
if(s->cfunc == 0 && r->sym->cfunc == 2 && !r->sym->nosplit)
print("Go %s calls C %s\n", s->name, r->sym->name);
else if(s->cfunc == 2 && s->nosplit && !r->sym->nosplit)
print("Go calls C %s calls %s\n", s->name, r->sym->name);
}
}
}
}
}