# endif
#endif
+#ifdef USE_C_BACKTRACE
+# ifdef I_BFD
+# define USE_BFD
+# ifdef PERL_DARWIN
+# undef USE_BFD /* BFD is useless in OS X. */
+# endif
+# ifdef USE_BFD
+# include <bfd.h>
+# endif
+# endif
+# ifdef I_DLFCN
+# include <dlfcn.h>
+# endif
+# ifdef I_EXECINFO
+# include <execinfo.h>
+# endif
+#endif
+
#ifdef PERL_DEBUG_READONLY_COW
# include <sys/mman.h>
#endif
#define FLUSH
-#if defined(HAS_FCNTL) && defined(F_SETFD) && !defined(FD_CLOEXEC)
-# define FD_CLOEXEC 1 /* NeXT needs this */
-#endif
-
/* NOTE: Do not call the next three routines directly. Use the macros
* in handy.h, so that we can easily redefine everything to do tracking of
* allocated hunks back to the original New to track down any memory leaks.
{
const MAGIC *const mg = mg_find(littlestr, PERL_MAGIC_bm);
- const unsigned char * const table = (const unsigned char *) mg->mg_ptr;
const unsigned char *oldlittle;
+ assert(mg);
+
--littlelen; /* Last char found by table lookup */
s = big + littlelen;
little += littlelen; /* last char */
oldlittle = little;
if (s < bigend) {
+ const unsigned char * const table = (const unsigned char *) mg->mg_ptr;
I32 tmp;
top2:
/* This function must only ever be called on a scalar with study magic,
but those do not happen any more. */
Perl_croak(aTHX_ "panic: screaminstr");
- return NULL;
+ NORETURN_FUNCTION_END;
}
/*
Perl's version of C<strdup()>. Returns a pointer to a newly allocated
string which is a duplicate of C<pv>. The size of the string is
-determined by C<strlen()>. The memory allocated for the new string can
-be freed with the C<Safefree()> function.
+determined by C<strlen()>, which means it may not contain embedded C<NUL>
+characters and must have a trailing C<NUL>. The memory allocated for the new
+string can be freed with the C<Safefree()> function.
On some platforms, Windows for example, all allocated memory owned by a thread
is deallocated when that thread ends. So if you need that not to happen, you
Perl's version of what C<strndup()> would be if it existed. Returns a
pointer to a newly allocated string which is a duplicate of the first
C<len> bytes from C<pv>, plus a trailing
-NUL byte. The memory allocated for
+C<NUL> byte. The memory allocated for
the new string can be freed with the C<Safefree()> function.
On some platforms, Windows for example, all allocated memory owned by a thread
{
char *newaddr;
STRLEN pvlen;
+
+ PERL_UNUSED_CONTEXT;
+
if (!pv)
return NULL;
{
char *const newaddr = (char*)PerlMemShared_malloc(len + 1);
+ PERL_UNUSED_CONTEXT;
/* PERL_ARGS_ASSERT_SAVESHAREDPVN; */
if (!newaddr) {
dVAR;
SV *sv;
+#if defined(USE_C_BACKTRACE) && defined(USE_C_BACKTRACE_ON_ERROR)
+ {
+ char *ws;
+ int wi;
+ /* The PERL_C_BACKTRACE_ON_WARN must be an integer of one or more. */
+ if ((ws = PerlEnv_getenv("PERL_C_BACKTRACE_ON_ERROR")) &&
+ (wi = atoi(ws)) > 0) {
+ Perl_dump_c_backtrace(aTHX_ Perl_debug_log, wi, 1);
+ }
+ }
+#endif
+
PERL_ARGS_ASSERT_MESS_SV;
if (SvROK(basemsg)) {
PERL_ARGS_ASSERT_DIE_SV;
croak_sv(baseex);
assert(0); /* NOTREACHED */
- return NULL;
+ NORETURN_FUNCTION_END;
}
/*
vcroak(pat, &args);
assert(0); /* NOTREACHED */
va_end(args);
- return NULL;
+ NORETURN_FUNCTION_END;
}
#endif /* PERL_IMPLICIT_CONTEXT */
vcroak(pat, &args);
assert(0); /* NOTREACHED */
va_end(args);
- return NULL;
+ NORETURN_FUNCTION_END;
}
/*
Perl_croak_no_mem(void)
{
dTHX;
- int rc;
- /* Can't use PerlIO to write as it allocates memory */
- rc = PerlLIO_write(PerlIO_fileno(Perl_error_log),
- PL_no_mem, sizeof(PL_no_mem)-1);
- /* silently ignore failures */
- PERL_UNUSED_VAR(rc);
+ int fd = PerlIO_fileno(Perl_error_log);
+ if (fd < 0)
+ SETERRNO(EBADF,RMS_IFI);
+ else {
+ /* Can't use PerlIO to write as it allocates memory */
+ PERL_UNUSED_RESULT(PerlLIO_write(fd, PL_no_mem, sizeof(PL_no_mem)-1));
+ }
my_exit(1);
}
{
#ifndef PERL_USE_SAFE_PUTENV
if (!PL_use_safe_putenv) {
- /* most putenv()s leak, so we manipulate environ directly */
- I32 i;
- const I32 len = strlen(nam);
- int nlen, vlen;
-
- /* where does it go? */
- for (i = 0; environ[i]; i++) {
- if (strnEQ(environ[i],nam,len) && environ[i][len] == '=')
- break;
- }
-
- if (environ == PL_origenviron) { /* need we copy environment? */
- I32 j;
- I32 max;
- char **tmpenv;
-
- max = i;
- while (environ[max])
- max++;
- tmpenv = (char**)safesysmalloc((max+2) * sizeof(char*));
- for (j=0; j<max; j++) { /* copy environment */
- const int len = strlen(environ[j]);
- tmpenv[j] = (char*)safesysmalloc((len+1)*sizeof(char));
- Copy(environ[j], tmpenv[j], len+1, char);
- }
- tmpenv[max] = NULL;
- environ = tmpenv; /* tell exec where it is now */
- }
- if (!val) {
- safesysfree(environ[i]);
- while (environ[i]) {
- environ[i] = environ[i+1];
- i++;
- }
- return;
- }
- if (!environ[i]) { /* does not exist yet */
- environ = (char**)safesysrealloc(environ, (i+2) * sizeof(char*));
- environ[i+1] = NULL; /* make sure it's null terminated */
- }
- else
- safesysfree(environ[i]);
- nlen = strlen(nam);
- vlen = strlen(val);
+ /* most putenv()s leak, so we manipulate environ directly */
+ I32 i;
+ const I32 len = strlen(nam);
+ int nlen, vlen;
+
+ /* where does it go? */
+ for (i = 0; environ[i]; i++) {
+ if (strnEQ(environ[i],nam,len) && environ[i][len] == '=')
+ break;
+ }
+
+ if (environ == PL_origenviron) { /* need we copy environment? */
+ I32 j;
+ I32 max;
+ char **tmpenv;
+
+ max = i;
+ while (environ[max])
+ max++;
+ tmpenv = (char**)safesysmalloc((max+2) * sizeof(char*));
+ for (j=0; j<max; j++) { /* copy environment */
+ const int len = strlen(environ[j]);
+ tmpenv[j] = (char*)safesysmalloc((len+1)*sizeof(char));
+ Copy(environ[j], tmpenv[j], len+1, char);
+ }
+ tmpenv[max] = NULL;
+ environ = tmpenv; /* tell exec where it is now */
+ }
+ if (!val) {
+ safesysfree(environ[i]);
+ while (environ[i]) {
+ environ[i] = environ[i+1];
+ i++;
+ }
+ return;
+ }
+ if (!environ[i]) { /* does not exist yet */
+ environ = (char**)safesysrealloc(environ, (i+2) * sizeof(char*));
+ environ[i+1] = NULL; /* make sure it's null terminated */
+ }
+ else
+ safesysfree(environ[i]);
+ nlen = strlen(nam);
+ vlen = strlen(val);
- environ[i] = (char*)safesysmalloc((nlen+vlen+2) * sizeof(char));
- /* all that work just for this */
- my_setenv_format(environ[i], nam, nlen, val, vlen);
+ environ[i] = (char*)safesysmalloc((nlen+vlen+2) * sizeof(char));
+ /* all that work just for this */
+ my_setenv_format(environ[i], nam, nlen, val, vlen);
} else {
# endif
# if defined(__CYGWIN__)|| defined(__SYMBIAN32__) || defined(__riscos__)
PerlLIO_close(pp[0]);
#if defined(HAS_FCNTL) && defined(F_SETFD)
/* Close error pipe automatically if exec works */
- fcntl(pp[1], F_SETFD, FD_CLOEXEC);
+ if (fcntl(pp[1], F_SETFD, FD_CLOEXEC) < 0)
+ return NULL;
#endif
}
/* Now dup our end of _the_ pipe to right position */
if (did_pipes) {
PerlLIO_close(pp[0]);
#if defined(HAS_FCNTL) && defined(F_SETFD)
- fcntl(pp[1], F_SETFD, FD_CLOEXEC);
+ if (fcntl(pp[1], F_SETFD, FD_CLOEXEC) < 0)
+ return NULL;
#endif
}
if (p[THIS] != (*mode == 'r')) {
PERL_UNUSED_CONTEXT;
return (vtbl_id < 0 || vtbl_id >= magic_vtable_max)
- ? NULL : PL_magic_vtables + vtbl_id;
+ ? NULL : (MGVTBL*)PL_magic_vtables + vtbl_id;
}
I32
if (name && HEK_LEN(name))
Perl_warner(aTHX_ packWARN(WARN_IO),
"Filehandle %"HEKf" opened only for %sput",
- name, direction);
+ HEKfARG(name), direction);
else
Perl_warner(aTHX_ packWARN(WARN_IO),
"Filehandle opened only for %sput", direction);
#ifdef HAS_TM_TM_ZONE
Time_t now;
const struct tm* my_tm;
+ PERL_UNUSED_CONTEXT;
PERL_ARGS_ASSERT_INIT_TM;
(void)time(&now);
my_tm = localtime(&now);
if (my_tm)
Copy(my_tm, ptm, 1, struct tm);
#else
+ PERL_UNUSED_CONTEXT;
PERL_ARGS_ASSERT_INIT_TM;
PERL_UNUSED_ARG(ptm);
#endif
if (strchr(pmlenv, 't')) {
len = my_snprintf(buf, sizeof(buf),
MEM_LOG_TIME_FMT, MEM_LOG_TIME_ARG);
- PerlLIO_write(fd, buf, len);
+ PERL_UNUSED_RESULT(PerlLIO_write(fd, buf, len));
}
switch (mlt) {
case MLT_ALLOC:
default:
len = 0;
}
- PerlLIO_write(fd, buf, len);
+ PERL_UNUSED_RESULT(PerlLIO_write(fd, buf, len));
}
}
}
int retval;
va_list ap;
PERL_ARGS_ASSERT_MY_SNPRINTF;
+#ifndef HAS_VSNPRINTF
+ PERL_UNUSED_VAR(len);
+#endif
va_start(ap, format);
#ifdef HAS_VSNPRINTF
retval = vsnprintf(buffer, len, format, ap);
va_list apc;
PERL_ARGS_ASSERT_MY_VSNPRINTF;
-
+#ifndef HAS_VSNPRINTF
+ PERL_UNUSED_VAR(len);
+#endif
Perl_va_copy(ap, apc);
# ifdef HAS_VSNPRINTF
retval = vsnprintf(buffer, len, format, apc);
else {
/* XXX GV_ADDWARN */
vn = "XS_VERSION";
- sv = get_sv(Perl_form(aTHX_ "%"SVf"::%s", module, vn), 0);
+ sv = get_sv(Perl_form(aTHX_ "%"SVf"::%s", SVfARG(module), vn), 0);
if (!sv || !SvOK(sv)) {
vn = "VERSION";
- sv = get_sv(Perl_form(aTHX_ "%"SVf"::%s", module, vn), 0);
+ sv = get_sv(Perl_form(aTHX_ "%"SVf"::%s", SVfARG(module), vn), 0);
}
}
if (sv) {
if ( vcmp(pmsv,xssv) ) {
SV *string = vstringify(xssv);
SV *xpt = Perl_newSVpvf(aTHX_ "%"SVf" object version %"SVf
- " does not match ", module, string);
+ " does not match ", SVfARG(module), SVfARG(string));
SvREFCNT_dec(string);
string = vstringify(pmsv);
if (vn) {
- Perl_sv_catpvf(aTHX_ xpt, "$%"SVf"::%s %"SVf, module, vn,
- string);
+ Perl_sv_catpvf(aTHX_ xpt, "$%"SVf"::%s %"SVf, SVfARG(module), vn,
+ SVfARG(string));
} else {
- Perl_sv_catpvf(aTHX_ xpt, "bootstrap parameter %"SVf, string);
+ Perl_sv_catpvf(aTHX_ xpt, "bootstrap parameter %"SVf, SVfARG(string));
}
SvREFCNT_dec(string);
SV *runver_string = vstringify(runver);
xpt = Perl_newSVpvf(aTHX_ "Perl API version %"SVf
" of %"SVf" does not match %"SVf,
- compver_string, module, runver_string);
+ SVfARG(compver_string), SVfARG(module),
+ SVfARG(runver_string));
Perl_sv_2mortal(aTHX_ xpt);
SvREFCNT_dec(compver_string);
=for apidoc my_strlcat
The C library C<strlcat> if available, or a Perl implementation of it.
-This operates on C NUL-terminated strings.
+This operates on C C<NUL>-terminated strings.
C<my_strlcat()> appends string C<src> to the end of C<dst>. It will append at
-most S<C<size - strlen(dst) - 1>> characters. It will then NUL-terminate,
+most S<C<size - strlen(dst) - 1>> characters. It will then C<NUL>-terminate,
unless C<size> is 0 or the original C<dst> string was longer than C<size> (in
practice this should not happen as it means that either C<size> is incorrect or
-that C<dst> is not a proper NUL-terminated string).
+that C<dst> is not a proper C<NUL>-terminated string).
Note that C<size> is the full size of the destination buffer and
-the result is guaranteed to be NUL-terminated if there is room. Note that room
-for the NUL should be included in C<size>.
+the result is guaranteed to be C<NUL>-terminated if there is room. Note that
+room for the C<NUL> should be included in C<size>.
=cut
=for apidoc my_strlcpy
The C library C<strlcpy> if available, or a Perl implementation of it.
-This operates on C NUL-terminated strings.
+This operates on C C<NUL>-terminated strings.
C<my_strlcpy()> copies up to S<C<size - 1>> characters from the string C<src>
-to C<dst>, NUL-terminating the result if C<size> is not 0.
+to C<dst>, C<NUL>-terminating the result if C<size> is not 0.
=cut
if(!dir)
return -1;
#ifdef HAS_DIRFD
+ PERL_UNUSED_CONTEXT;
return dirfd(dir);
#elif defined(HAS_DIR_DD_FD)
+ PERL_UNUSED_CONTEXT;
return dir->dd_fd;
#else
Perl_die(aTHX_ PL_no_func, "dirfd");
}
#endif
}
-
+
+#ifdef USE_C_BACKTRACE
+
+/* Possibly move all this USE_C_BACKTRACE code into a new file. */
+
+#ifdef USE_BFD
+
+typedef struct {
+ /* abfd is the BFD handle. */
+ bfd* abfd;
+ /* bfd_syms is the BFD symbol table. */
+ asymbol** bfd_syms;
+ /* bfd_text is handle to the the ".text" section of the object file. */
+ asection* bfd_text;
+ /* Since opening the executable and scanning its symbols is quite
+ * heavy operation, we remember the filename we used the last time,
+ * and do the opening and scanning only if the filename changes.
+ * This removes most (but not all) open+scan cycles. */
+ const char* fname_prev;
+} bfd_context;
+
+/* Given a dl_info, update the BFD context if necessary. */
+static void bfd_update(bfd_context* ctx, Dl_info* dl_info)
+{
+ /* BFD open and scan only if the filename changed. */
+ if (ctx->fname_prev == NULL ||
+ strNE(dl_info->dli_fname, ctx->fname_prev)) {
+ ctx->abfd = bfd_openr(dl_info->dli_fname, 0);
+ if (ctx->abfd) {
+ if (bfd_check_format(ctx->abfd, bfd_object)) {
+ IV symbol_size = bfd_get_symtab_upper_bound(ctx->abfd);
+ if (symbol_size > 0) {
+ Safefree(ctx->bfd_syms);
+ Newx(ctx->bfd_syms, symbol_size, asymbol*);
+ ctx->bfd_text =
+ bfd_get_section_by_name(ctx->abfd, ".text");
+ }
+ else
+ ctx->abfd = NULL;
+ }
+ else
+ ctx->abfd = NULL;
+ }
+ ctx->fname_prev = dl_info->dli_fname;
+ }
+}
+
+/* Given a raw frame, try to symbolize it and store
+ * symbol information (source file, line number) away. */
+static void bfd_symbolize(bfd_context* ctx,
+ void* raw_frame,
+ char** symbol_name,
+ STRLEN* symbol_name_size,
+ char** source_name,
+ STRLEN* source_name_size,
+ STRLEN* source_line)
+{
+ *symbol_name = NULL;
+ *symbol_name_size = 0;
+ if (ctx->abfd) {
+ IV offset = PTR2IV(raw_frame) - PTR2IV(ctx->bfd_text->vma);
+ if (offset > 0 &&
+ bfd_canonicalize_symtab(ctx->abfd, ctx->bfd_syms) > 0) {
+ const char *file;
+ const char *func;
+ unsigned int line = 0;
+ if (bfd_find_nearest_line(ctx->abfd, ctx->bfd_text,
+ ctx->bfd_syms, offset,
+ &file, &func, &line) &&
+ file && func && line > 0) {
+ /* Size and copy the source file, use only
+ * the basename of the source file.
+ *
+ * NOTE: the basenames are fine for the
+ * Perl source files, but may not always
+ * be the best idea for XS files. */
+ const char *p, *b = NULL;
+ /* Look for the last slash. */
+ for (p = file; *p; p++) {
+ if (*p == '/')
+ b = p + 1;
+ }
+ if (b == NULL || *b == 0) {
+ b = file;
+ }
+ *source_name_size = p - b + 1;
+ Newx(*source_name, *source_name_size + 1, char);
+ Copy(b, *source_name, *source_name_size + 1, char);
+
+ *symbol_name_size = strlen(func);
+ Newx(*symbol_name, *symbol_name_size + 1, char);
+ Copy(func, *symbol_name, *symbol_name_size + 1, char);
+
+ *source_line = line;
+ }
+ }
+ }
+}
+
+#endif /* #ifdef USE_BFD */
+
+#ifdef PERL_DARWIN
+
+/* OS X has no public API for for 'symbolicating' (Apple official term)
+ * stack addresses to {function_name, source_file, line_number}.
+ * Good news: there is command line utility atos(1) which does that.
+ * Bad news 1: it's a command line utility.
+ * Bad news 2: one needs to have the Developer Tools installed.
+ * Bad news 3: in newer releases it needs to be run as 'xcrun atos'.
+ *
+ * To recap: we need to open a pipe for reading for a utility which
+ * might not exist, or exists in different locations, and then parse
+ * the output. And since this is all for a low-level API, we cannot
+ * use high-level stuff. Thanks, Apple. */
+
+typedef struct {
+ /* tool is set to the absolute pathname of the tool to use:
+ * xcrun or atos. */
+ const char* tool;
+ /* format is set to a printf format string used for building
+ * the external command to run. */
+ const char* format;
+ /* unavail is set if e.g. xcrun cannot be found, or something
+ * else happens that makes getting the backtrace dubious. Note,
+ * however, that the context isn't persistent, the next call to
+ * get_c_backtrace() will start from scratch. */
+ bool unavail;
+ /* fname is the current object file name. */
+ const char* fname;
+ /* object_base_addr is the base address of the shared object. */
+ void* object_base_addr;
+} atos_context;
+
+/* Given |dl_info|, updates the context. If the context has been
+ * marked unavailable, return immediately. If not but the tool has
+ * not been set, set it to either "xcrun atos" or "atos" (also set the
+ * format to use for creating commands for piping), or if neither is
+ * unavailable (one needs the Developer Tools installed), mark the context
+ * an unavailable. Finally, update the filename (object name),
+ * and its base address. */
+
+static void atos_update(atos_context* ctx,
+ Dl_info* dl_info)
+{
+ if (ctx->unavail)
+ return;
+ if (ctx->tool == NULL) {
+ const char* tools[] = {
+ "/usr/bin/xcrun",
+ "/usr/bin/atos"
+ };
+ const char* formats[] = {
+ "/usr/bin/xcrun atos -o '%s' -l %08x %08x 2>&1",
+ "/usr/bin/atos -d -o '%s' -l %08x %08x 2>&1"
+ };
+ struct stat st;
+ UV i;
+ for (i = 0; i < C_ARRAY_LENGTH(tools); i++) {
+ if (stat(tools[i], &st) == 0 && S_ISREG(st.st_mode)) {
+ ctx->tool = tools[i];
+ ctx->format = formats[i];
+ break;
+ }
+ }
+ if (ctx->tool == NULL) {
+ ctx->unavail = TRUE;
+ return;
+ }
+ }
+ if (ctx->fname == NULL ||
+ strNE(dl_info->dli_fname, ctx->fname)) {
+ ctx->fname = dl_info->dli_fname;
+ ctx->object_base_addr = dl_info->dli_fbase;
+ }
+}
+
+/* Given an output buffer end |p| and its |start|, matches
+ * for the atos output, extracting the source code location
+ * if possible, returning NULL otherwise. */
+static const char* atos_parse(const char* p,
+ const char* start,
+ STRLEN* source_name_size,
+ STRLEN* source_line) {
+ /* atos() outputs is something like:
+ * perl_parse (in miniperl) (perl.c:2314)\n\n".
+ * We cannot use Perl regular expressions, because we need to
+ * stay low-level. Therefore here we have a rolled-out version
+ * of a state machine which matches _backwards_from_the_end_ and
+ * if there's a success, returns the starts of the filename,
+ * also setting the filename size and the source line number.
+ * The matched regular expression is roughly "\(.*:\d+\)\s*$" */
+ const char* source_number_start;
+ const char* source_name_end;
+ /* Skip trailing whitespace. */
+ while (p > start && isspace(*p)) p--;
+ /* Now we should be at the close paren. */
+ if (p == start || *p != ')')
+ return NULL;
+ p--;
+ /* Now we should be in the line number. */
+ if (p == start || !isdigit(*p))
+ return NULL;
+ /* Skip over the digits. */
+ while (p > start && isdigit(*p))
+ p--;
+ /* Now we should be at the colon. */
+ if (p == start || *p != ':')
+ return NULL;
+ source_number_start = p + 1;
+ source_name_end = p; /* Just beyond the end. */
+ p--;
+ /* Look for the open paren. */
+ while (p > start && *p != '(')
+ p--;
+ if (p == start)
+ return NULL;
+ p++;
+ *source_name_size = source_name_end - p;
+ *source_line = atoi(source_number_start);
+ return p;
+}
+
+/* Given a raw frame, read a pipe from the symbolicator (that's the
+ * technical term) atos, reads the result, and parses the source code
+ * location. We must stay low-level, so we use snprintf(), pipe(),
+ * and fread(), and then also parse the output ourselves. */
+static void atos_symbolize(atos_context* ctx,
+ void* raw_frame,
+ char** source_name,
+ STRLEN* source_name_size,
+ STRLEN* source_line)
+{
+ char cmd[1024];
+ const char* p;
+ Size_t cnt;
+
+ if (ctx->unavail)
+ return;
+ /* Simple security measure: if there's any funny business with
+ * the object name (used as "-o '%s'" ), leave since at least
+ * partially the user controls it. */
+ for (p = ctx->fname; *p; p++) {
+ if (*p == '\'' || iscntrl(*p)) {
+ ctx->unavail = TRUE;
+ return;
+ }
+ }
+ cnt = snprintf(cmd, sizeof(cmd), ctx->format,
+ ctx->fname, ctx->object_base_addr, raw_frame);
+ if (cnt < sizeof(cmd)) {
+ /* Undo nostdio.h #defines that disable stdio.
+ * This is somewhat naughty, but is used elsewhere
+ * in the core, and affects only OS X. */
+#undef FILE
+#undef popen
+#undef fread
+#undef pclose
+ FILE* fp = popen(cmd, "r");
+ /* At the moment we open a new pipe for each stack frame.
+ * This is naturally somewhat slow, but hopefully generating
+ * stack traces is never going to in a performance critical path.
+ *
+ * We could play tricks with atos by batching the stack
+ * addresses to be resolved: atos can either take multiple
+ * addresses from the command line, or read addresses from
+ * a file (though the mess of creating temporary files would
+ * probably negate much of any possible speedup).
+ *
+ * Normally there are only two objects present in the backtrace:
+ * perl itself, and the libdyld.dylib. (Note that the object
+ * filenames contain the full pathname, so perl may not always
+ * be in the same place.) Whenever the object in the
+ * backtrace changes, the base address also changes.
+ *
+ * The problem with batching the addresses, though, would be
+ * matching the results with the addresses: the parsing of
+ * the results is already painful enough with a single address. */
+ if (fp) {
+ char out[1024];
+ UV cnt = fread(out, 1, sizeof(out), fp);
+ if (cnt < sizeof(out)) {
+ const char* p = atos_parse(out + cnt, out,
+ source_name_size,
+ source_line);
+ if (p) {
+ Newx(*source_name,
+ *source_name_size + 1, char);
+ Copy(p, *source_name,
+ *source_name_size + 1, char);
+ }
+ }
+ pclose(fp);
+ }
+ }
+}
+
+#endif /* #ifdef PERL_DARWIN */
+
+/*
+=for apidoc get_c_backtrace
+
+Collects the backtrace (aka "stacktrace") into a single linear
+malloced buffer, which the caller B<must> Perl_free_c_backtrace().
+
+Scans the frames back by depth + skip, then drops the skip innermost,
+returning at most depth frames.
+
+=cut
+*/
+
+Perl_c_backtrace*
+Perl_get_c_backtrace(pTHX_ int depth, int skip)
+{
+ /* Note that here we must stay as low-level as possible: Newx(),
+ * Copy(), Safefree(); since we may be called from anywhere,
+ * so we should avoid higher level constructs like SVs or AVs.
+ *
+ * Since we are using safesysmalloc() via Newx(), don't try
+ * getting backtrace() there, unless you like deep recursion. */
+
+ /* Currently only implemented with backtrace() and dladdr(),
+ * for other platforms NULL is returned. */
+
+#if defined(HAS_BACKTRACE) && defined(HAS_DLADDR)
+ /* backtrace() is available via <execinfo.h> in glibc and in most
+ * modern BSDs; dladdr() is available via <dlfcn.h>. */
+
+ /* We try fetching this many frames total, but then discard
+ * the |skip| first ones. For the remaining ones we will try
+ * retrieving more information with dladdr(). */
+ int try_depth = skip + depth;
+
+ /* The addresses (program counters) returned by backtrace(). */
+ void** raw_frames;
+
+ /* Retrieved with dladdr() from the addresses returned by backtrace(). */
+ Dl_info* dl_infos;
+
+ /* Sizes _including_ the terminating \0 of the object name
+ * and symbol name strings. */
+ STRLEN* object_name_sizes;
+ STRLEN* symbol_name_sizes;
+
+#ifdef USE_BFD
+ /* The symbol names comes either from dli_sname,
+ * or if using BFD, they can come from BFD. */
+ char** symbol_names;
+#endif
+
+ /* The source code location information. Dug out with e.g. BFD. */
+ char** source_names;
+ STRLEN* source_name_sizes;
+ STRLEN* source_lines;
+
+ Perl_c_backtrace* bt = NULL; /* This is what will be returned. */
+ int got_depth; /* How many frames were returned from backtrace(). */
+ UV frame_count = 0; /* How many frames we return. */
+ UV total_bytes = 0; /* The size of the whole returned backtrace. */
+
+#ifdef USE_BFD
+ bfd_context bfd_ctx;
+#endif
+#ifdef PERL_DARWIN
+ atos_context atos_ctx;
+#endif
+
+ /* Here are probably possibilities for optimizing. We could for
+ * example have a struct that contains most of these and then
+ * allocate |try_depth| of them, saving a bunch of malloc calls.
+ * Note, however, that |frames| could not be part of that struct
+ * because backtrace() will want an array of just them. Also be
+ * careful about the name strings. */
+ Newx(raw_frames, try_depth, void*);
+ Newx(dl_infos, try_depth, Dl_info);
+ Newx(object_name_sizes, try_depth, STRLEN);
+ Newx(symbol_name_sizes, try_depth, STRLEN);
+ Newx(source_names, try_depth, char*);
+ Newx(source_name_sizes, try_depth, STRLEN);
+ Newx(source_lines, try_depth, STRLEN);
+#ifdef USE_BFD
+ Newx(symbol_names, try_depth, char*);
+#endif
+
+ /* Get the raw frames. */
+ got_depth = (int)backtrace(raw_frames, try_depth);
+
+ /* We use dladdr() instead of backtrace_symbols() because we want
+ * the full details instead of opaque strings. This is useful for
+ * two reasons: () the details are needed for further symbolic
+ * digging, for example in OS X (2) by having the details we fully
+ * control the output, which in turn is useful when more platforms
+ * are added: we can keep out output "portable". */
+
+ /* We want a single linear allocation, which can then be freed
+ * with a single swoop. We will do the usual trick of first
+ * walking over the structure and seeing how much we need to
+ * allocate, then allocating, and then walking over the structure
+ * the second time and populating it. */
+
+ /* First we must compute the total size of the buffer. */
+ total_bytes = sizeof(Perl_c_backtrace_header);
+ if (got_depth > skip) {
+ int i;
+#ifdef USE_BFD
+ bfd_init(); /* Is this safe to call multiple times? */
+ Zero(&bfd_ctx, 1, bfd_context);
+#endif
+#ifdef PERL_DARWIN
+ Zero(&atos_ctx, 1, atos_context);
+#endif
+ for (i = skip; i < try_depth; i++) {
+ Dl_info* dl_info = &dl_infos[i];
+
+ total_bytes += sizeof(Perl_c_backtrace_frame);
+
+ source_names[i] = NULL;
+ source_name_sizes[i] = 0;
+ source_lines[i] = 0;
+
+ /* Yes, zero from dladdr() is failure. */
+ if (dladdr(raw_frames[i], dl_info)) {
+ object_name_sizes[i] =
+ dl_info->dli_fname ? strlen(dl_info->dli_fname) : 0;
+ symbol_name_sizes[i] =
+ dl_info->dli_sname ? strlen(dl_info->dli_sname) : 0;
+#ifdef USE_BFD
+ bfd_update(&bfd_ctx, dl_info);
+ bfd_symbolize(&bfd_ctx, raw_frames[i],
+ &symbol_names[i],
+ &symbol_name_sizes[i],
+ &source_names[i],
+ &source_name_sizes[i],
+ &source_lines[i]);
+#endif
+#if PERL_DARWIN
+ atos_update(&atos_ctx, dl_info);
+ atos_symbolize(&atos_ctx,
+ raw_frames[i],
+ &source_names[i],
+ &source_name_sizes[i],
+ &source_lines[i]);
+#endif
+
+ /* Plus ones for the terminating \0. */
+ total_bytes += object_name_sizes[i] + 1;
+ total_bytes += symbol_name_sizes[i] + 1;
+ total_bytes += source_name_sizes[i] + 1;
+
+ frame_count++;
+ } else {
+ break;
+ }
+ }
+#ifdef USE_BFD
+ Safefree(bfd_ctx.bfd_syms);
+#endif
+ }
+
+ /* Now we can allocate and populate the result buffer. */
+ Newxc(bt, total_bytes, char, Perl_c_backtrace);
+ Zero(bt, total_bytes, char);
+ bt->header.frame_count = frame_count;
+ bt->header.total_bytes = total_bytes;
+ if (frame_count > 0) {
+ Perl_c_backtrace_frame* frame = bt->frame_info;
+ char* name_base = (char *)(frame + frame_count);
+ char* name_curr = name_base; /* Outputting the name strings here. */
+ UV i;
+ for (i = skip; i < skip + frame_count; i++) {
+ Dl_info* dl_info = &dl_infos[i];
+
+ frame->addr = raw_frames[i];
+ frame->object_base_addr = dl_info->dli_fbase;
+ frame->symbol_addr = dl_info->dli_saddr;
+
+ /* Copies a string, including the \0, and advances the name_curr.
+ * Also copies the start and the size to the frame. */
+#define PERL_C_BACKTRACE_STRCPY(frame, doffset, src, dsize, size) \
+ if (size && src) \
+ Copy(src, name_curr, size, char); \
+ frame->doffset = name_curr - (char*)bt; \
+ frame->dsize = size; \
+ name_curr += size; \
+ *name_curr++ = 0;
+
+ PERL_C_BACKTRACE_STRCPY(frame, object_name_offset,
+ dl_info->dli_fname,
+ object_name_size, object_name_sizes[i]);
+
+#ifdef USE_BFD
+ PERL_C_BACKTRACE_STRCPY(frame, symbol_name_offset,
+ symbol_names[i],
+ symbol_name_size, symbol_name_sizes[i]);
+ Safefree(symbol_names[i]);
+#else
+ PERL_C_BACKTRACE_STRCPY(frame, symbol_name_offset,
+ dl_info->dli_sname,
+ symbol_name_size, symbol_name_sizes[i]);
+#endif
+
+ PERL_C_BACKTRACE_STRCPY(frame, source_name_offset,
+ source_names[i],
+ source_name_size, source_name_sizes[i]);
+ Safefree(source_names[i]);
+
+#undef PERL_C_BACKTRACE_STRCPY
+
+ frame->source_line_number = source_lines[i];
+
+ frame++;
+ }
+ assert(total_bytes ==
+ (UV)(sizeof(Perl_c_backtrace_header) +
+ frame_count * sizeof(Perl_c_backtrace_frame) +
+ name_curr - name_base));
+ }
+#ifdef USE_BFD
+ Safefree(symbol_names);
+#endif
+ Safefree(source_lines);
+ Safefree(source_name_sizes);
+ Safefree(source_names);
+ Safefree(symbol_name_sizes);
+ Safefree(object_name_sizes);
+ /* Assuming the strings returned by dladdr() are pointers
+ * to read-only static memory (the object file), so that
+ * they do not need freeing (and cannot be). */
+ Safefree(dl_infos);
+ Safefree(raw_frames);
+ return bt;
+#else
+ PERL_UNUSED_ARGV(depth);
+ PERL_UNUSED_ARGV(skip);
+ return NULL;
+#endif
+}
+
+/*
+=for apidoc free_c_backtrace
+
+Deallocates a backtrace received from get_c_bracktrace.
+
+=cut
+*/
+
+/*
+=for apidoc get_c_backtrace_dump
+
+Returns a SV a dump of |depth| frames of the call stack, skipping
+the |skip| innermost ones. depth of 20 is usually enough.
+
+The appended output looks like:
+
+...
+1 10e004812:0082 Perl_croak util.c:1716 /usr/bin/perl
+2 10df8d6d2:1d72 perl_parse perl.c:3975 /usr/bin/perl
+...
+
+The fields are tab-separated. The first column is the depth (zero
+being the innermost non-skipped frame). In the hex:offset, the hex is
+where the program counter was in S_parse_body, and the :offset (might
+be missing) tells how much inside the S_parse_body the program counter was.
+
+The util.c:1716 is the source code file and line number.
+
+The /usr/bin/perl is obvious (hopefully).
+
+Unknowns are C<"-">. Unknowns can happen unfortunately quite easily:
+if the platform doesn't support retrieving the information;
+if the binary is missing the debug information;
+if the optimizer has transformed the code by for example inlining.
+
+=cut
+*/
+
+SV*
+Perl_get_c_backtrace_dump(pTHX_ int depth, int skip)
+{
+ Perl_c_backtrace* bt;
+
+ bt = get_c_backtrace(depth, skip + 1 /* Hide ourselves. */);
+ if (bt) {
+ Perl_c_backtrace_frame* frame;
+ SV* dsv = newSVpvs("");
+ UV i;
+ for (i = 0, frame = bt->frame_info;
+ i < bt->header.frame_count; i++, frame++) {
+ Perl_sv_catpvf(aTHX_ dsv, "%d", (int)i);
+ Perl_sv_catpvf(aTHX_ dsv, "\t%p", frame->addr ? frame->addr : "-");
+ /* Symbol (function) names might disappear without debug info.
+ *
+ * The source code location might disappear in case of the
+ * optimizer inlining or otherwise rearranging the code. */
+ if (frame->symbol_addr) {
+ Perl_sv_catpvf(aTHX_ dsv, ":%04x",
+ (int)
+ ((char*)frame->addr - (char*)frame->symbol_addr));
+ }
+ Perl_sv_catpvf(aTHX_ dsv, "\t%s",
+ frame->symbol_name_size &&
+ frame->symbol_name_offset ?
+ (char*)bt + frame->symbol_name_offset : "-");
+ if (frame->source_name_size &&
+ frame->source_name_offset &&
+ frame->source_line_number) {
+ Perl_sv_catpvf(aTHX_ dsv, "\t%s:%"UVuf,
+ (char*)bt + frame->source_name_offset,
+ (UV)frame->source_line_number);
+ } else {
+ Perl_sv_catpvf(aTHX_ dsv, "\t-");
+ }
+ Perl_sv_catpvf(aTHX_ dsv, "\t%s",
+ frame->object_name_size &&
+ frame->object_name_offset ?
+ (char*)bt + frame->object_name_offset : "-");
+ /* The frame->object_base_addr is not output,
+ * but it is used for symbolizing/symbolicating. */
+ sv_catpvs(dsv, "\n");
+ }
+
+ Perl_free_c_backtrace(aTHX_ bt);
+
+ return dsv;
+ }
+
+ return NULL;
+}
+
+/*
+=for apidoc dump_c_backtrace
+
+Dumps the C backtrace to the given fp.
+
+Returns true if a backtrace could be retrieved, false if not.
+
+=cut
+*/
+
+bool
+Perl_dump_c_backtrace(pTHX_ PerlIO* fp, int depth, int skip)
+{
+ SV* sv;
+
+ PERL_ARGS_ASSERT_DUMP_C_BACKTRACE;
+
+ sv = Perl_get_c_backtrace_dump(aTHX_ depth, skip);
+ if (sv) {
+ sv_2mortal(sv);
+ PerlIO_printf(fp, "%s", SvPV_nolen(sv));
+ return TRUE;
+ }
+ return FALSE;
+}
+
+#endif /* #ifdef USE_C_BACKTRACE */
/*
* Local variables:
https://perl5.git.perl.org / perl5.git / blobdiff