dt_cc.c

来自「Sun Solaris 10 中的 DTrace 组件的源代码。请参看: htt」· C语言 代码 · 共 2,025 行 · 第 1/4 页

/*
 * Fork and exec the cpp(1) preprocessor to run over the specified input file,
 * and return a FILE handle for the cpp output.  We use the /dev/fd filesystem
 * here to simplify the code by leveraging file descriptor inheritance.
 */
static FILE *
dt_preproc(dtrace_hdl_t *dtp, FILE *ifp)
{
	int argc = dtp->dt_cpp_argc;
	char **argv = malloc(sizeof (char *) * (argc + 5));
	FILE *ofp = tmpfile();

	char ipath[20], opath[20]; /* big enough for /dev/fd/ + INT_MAX + \0 */
	char verdef[32]; /* big enough for -D__SUNW_D_VERSION=0x%08x + \0 */

	struct sigaction act, oact;
	sigset_t mask, omask;

	int wstat, estat;
	pid_t pid;
	off64_t off;
	int c;

	if (argv == NULL || ofp == NULL) {
		(void) dt_set_errno(dtp, errno);
		goto err;
	}

	/*
	 * If the input is a seekable file, see if it is an interpreter file.
	 * If we see #!, seek past the first line because cpp will choke on it.
	 * We start cpp just prior to the \n at the end of this line so that
	 * it still sees the newline, ensuring that #line values are correct.
	 */
	if (isatty(fileno(ifp)) == 0 && (off = ftello64(ifp)) != -1) {
		if ((c = fgetc(ifp)) == '#' && (c = fgetc(ifp)) == '!') {
			for (off += 2; c != '\n'; off++) {
				if ((c = fgetc(ifp)) == EOF)
					break;
			}
			if (c == '\n')
				off--; /* start cpp just prior to \n */
		}
		(void) fflush(ifp);
		(void) fseeko64(ifp, off, SEEK_SET);
	}

	(void) snprintf(ipath, sizeof (ipath), "/dev/fd/%d", fileno(ifp));
	(void) snprintf(opath, sizeof (opath), "/dev/fd/%d", fileno(ofp));

	bcopy(dtp->dt_cpp_argv, argv, sizeof (char *) * argc);

	(void) snprintf(verdef, sizeof (verdef),
	    "-D__SUNW_D_VERSION=0x%08x", dtp->dt_vmax);
	argv[argc++] = verdef;

	switch (dtp->dt_stdcmode) {
	case DT_STDC_XA:
	case DT_STDC_XT:
		argv[argc++] = "-D__STDC__=0";
		break;
	case DT_STDC_XC:
		argv[argc++] = "-D__STDC__=1";
		break;
	}

	argv[argc++] = ipath;
	argv[argc++] = opath;
	argv[argc] = NULL;

	/*
	 * libdtrace must be able to be embedded in other programs that may
	 * include application-specific signal handlers.  Therefore, if we
	 * need to fork to run cpp(1), we must avoid generating a SIGCHLD
	 * that could confuse the containing application.  To do this,
	 * we block SIGCHLD and reset its disposition to SIG_DFL.
	 * We restore our signal state once we are done.
	 */
	(void) sigemptyset(&mask);
	(void) sigaddset(&mask, SIGCHLD);
	(void) sigprocmask(SIG_BLOCK, &mask, &omask);

	bzero(&act, sizeof (act));
	act.sa_handler = SIG_DFL;
	(void) sigaction(SIGCHLD, &act, &oact);

	if ((pid = fork1()) == -1) {
		(void) sigaction(SIGCHLD, &oact, NULL);
		(void) sigprocmask(SIG_SETMASK, &omask, NULL);
		(void) dt_set_errno(dtp, EDT_CPPFORK);
		goto err;
	}

	if (pid == 0) {
		(void) execvp(dtp->dt_cpp_path, argv);
		_exit(errno == ENOENT ? 127 : 126);
	}

	do {
		dt_dprintf("waiting for %s (PID %d)\n", dtp->dt_cpp_path,
		    (int)pid);
	} while (waitpid(pid, &wstat, 0) == -1 && errno == EINTR);

	(void) sigaction(SIGCHLD, &oact, NULL);
	(void) sigprocmask(SIG_SETMASK, &omask, NULL);

	dt_dprintf("%s returned exit status 0x%x\n", dtp->dt_cpp_path, wstat);
	estat = WIFEXITED(wstat) ? WEXITSTATUS(wstat) : -1;

	if (estat != 0) {
		switch (estat) {
		case 126:
			(void) dt_set_errno(dtp, EDT_CPPEXEC);
			break;
		case 127:
			(void) dt_set_errno(dtp, EDT_CPPENT);
			break;
		default:
			(void) dt_set_errno(dtp, EDT_CPPERR);
		}
		goto err;
	}

	free(argv);
	(void) fflush(ofp);
	(void) fseek(ofp, 0, SEEK_SET);
	return (ofp);

err:
	free(argv);
	(void) fclose(ofp);
	return (NULL);
}

/*
 * Open all of the .d library files found in the specified directory and try to
 * compile each one in order to cache its inlines and translators, etc.  We
 * silently ignore any missing directories and other files found therein.
 * We only fail (and thereby fail dt_load_libs()) if we fail to compile a
 * library and the error is something other than #pragma D depends_on.
 * Dependency errors are silently ignored to permit a library directory to
 * contain libraries which may not be accessible depending on our privileges.
 *
 * Note that at present, no ordering is defined between library files found in
 * the same directory: if cross-library dependencies are eventually required,
 * we will need to extend the #pragma D depends_on directive with an additional
 * class for libraries, and this function will need to create a graph of the
 * various library pathnames and then perform a topological ordering using the
 * dependency information before we attempt to compile any of them.
 */
static int
dt_load_libs_dir(dtrace_hdl_t *dtp, const char *path)
{
	struct dirent *dp, *ep;
	const char *p;
	DIR *dirp;

	char fname[PATH_MAX];
	dtrace_prog_t *pgp;
	FILE *fp;

	if ((dirp = opendir(path)) == NULL) {
		dt_dprintf("skipping lib dir %s: %s\n", path, strerror(errno));
		return (0);
	}

	ep = alloca(sizeof (struct dirent) + PATH_MAX + 1);
	bzero(ep, sizeof (struct dirent) + PATH_MAX + 1);

	while (readdir_r(dirp, ep, &dp) == 0 && dp != NULL) {
		if ((p = strrchr(dp->d_name, '.')) == NULL || strcmp(p, ".d"))
			continue; /* skip any filename not ending in .d */

		(void) snprintf(fname, sizeof (fname),
		    "%s/%s", path, dp->d_name);

		if ((fp = fopen(fname, "r")) == NULL) {
			dt_dprintf("skipping library %s: %s\n",
			    fname, strerror(errno));
			continue;
		}

		dtp->dt_filetag = fname;
		pgp = dtrace_program_fcompile(dtp, fp, DTRACE_C_EMPTY, 0, NULL);
		(void) fclose(fp);
		dtp->dt_filetag = NULL;

		if (pgp == NULL && (dtp->dt_errno != EDT_COMPILER ||
		    dtp->dt_errtag != dt_errtag(D_PRAGMA_DEPEND))) {
			(void) closedir(dirp);
			return (-1); /* preserve dt_errno */
		}

		if (pgp == NULL) {
			dt_dprintf("skipping library: %s\n",
			    dtrace_errmsg(dtp, dtrace_errno(dtp)));
		} else
			dtrace_program_destroy(dtp, pgp);
	}

	(void) closedir(dirp);
	return (0);
}

/*
 * Load the contents of any appropriate DTrace .d library files.  These files
 * contain inlines and translators that will be cached by the compiler.  We
 * defer this activity until the first compile to permit libdtrace clients to
 * add their own library directories and so that we can properly report errors.
 */
static int
dt_load_libs(dtrace_hdl_t *dtp)
{
	dt_dirpath_t *dirp;

	if (dtp->dt_cflags & DTRACE_C_NOLIBS)
		return (0); /* libraries already processed */

	dtp->dt_cflags |= DTRACE_C_NOLIBS;

	for (dirp = dt_list_next(&dtp->dt_lib_path);
	    dirp != NULL; dirp = dt_list_next(dirp)) {
		if (dt_load_libs_dir(dtp, dirp->dir_path) != 0) {
			dtp->dt_cflags &= ~DTRACE_C_NOLIBS;
			return (-1); /* errno is set for us */
		}
	}

	return (0);
}

static void *
dt_compile(dtrace_hdl_t *dtp, int context, dtrace_probespec_t pspec,
    dtrace_probedesc_t *pdp, uint_t cflags, int argc,
    char *const argv[], FILE *fp, const char *s)
{
	dt_node_t *dnp;
	dtrace_difo_t *difo;
	dt_pcb_t pcb;
	int err;

	if ((fp == NULL && s == NULL) || (cflags & ~DTRACE_C_MASK) != 0) {
		(void) dt_set_errno(dtp, EINVAL);
		return (NULL);
	}

	if (dt_list_next(&dtp->dt_lib_path) != NULL && dt_load_libs(dtp) != 0)
		return (NULL); /* errno is set for us */

	(void) ctf_discard(dtp->dt_cdefs->dm_ctfp);
	(void) ctf_discard(dtp->dt_ddefs->dm_ctfp);

	dt_idhash_iter(dtp->dt_globals, dt_idreset, NULL);
	dt_idhash_iter(dtp->dt_tls, dt_idreset, NULL);

	if (fp && (cflags & DTRACE_C_CPP) && (fp = dt_preproc(dtp, fp)) == NULL)
		return (NULL); /* errno is set for us */

	bzero(&pcb, sizeof (dt_pcb_t));
	dt_scope_create(&pcb.pcb_dstack);
	dt_irlist_create(&pcb.pcb_ir);

	pcb.pcb_hdl = dtp;
	pcb.pcb_fileptr = fp;
	pcb.pcb_string = s;
	pcb.pcb_strptr = s;
	pcb.pcb_strlen = s ? strlen(s) : 0;
	pcb.pcb_sargc = argc;
	pcb.pcb_sargv = argv;
	pcb.pcb_sflagv = argc ? calloc(argc, sizeof (ushort_t)) : NULL;
	pcb.pcb_pspec = pspec;
	pcb.pcb_cflags = dtp->dt_cflags | cflags;
	pcb.pcb_amin = dtp->dt_amin;
	pcb.pcb_yystate = -1;
	pcb.pcb_context = context;
	pcb.pcb_token = context;

	dtp->dt_pcb = &pcb;
	dtp->dt_gen++;

	yyinit(&pcb);

	if (context == DT_CTX_DPROG)
		yybegin(YYS_CLAUSE);
	else
		yybegin(YYS_EXPR);

	if ((err = setjmp(yypcb->pcb_jmpbuf)) != 0)
		goto out;

	if (yypcb->pcb_sargc != 0 && yypcb->pcb_sflagv == NULL)
		longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);

	yypcb->pcb_idents = dt_idhash_create("ambiguous", NULL, 0, 0);
	yypcb->pcb_locals = dt_idhash_create("clause local", NULL,
	    DIF_VAR_OTHER_UBASE, DIF_VAR_OTHER_MAX);

	if (yypcb->pcb_idents == NULL || yypcb->pcb_locals == NULL)
		longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);

	if (pdp != NULL)
		dt_setcontext(dtp, pdp);

	/*
	 * Invoke the parser to evaluate the D source code.  If any errors
	 * occur during parsing, an error function will be called and we
	 * will longjmp back to pcb_jmpbuf to abort.  If parsing succeeds,
	 * we optionally display the parse tree if debugging is enabled.
	 */
	if (yyparse() != 0 || yypcb->pcb_root == NULL)
		xyerror(D_EMPTY, "empty D program translation unit\n");

	if (DT_TREEDUMP_PASS(dtp, 1))
		dt_node_printr(yypcb->pcb_root, stderr, 0);

	if (yypcb->pcb_pragmas != NULL)
		dt_idhash_iter(yypcb->pcb_pragmas, dt_idpragma, NULL);

	if (argc > 1 && !(yypcb->pcb_cflags & DTRACE_C_ARGREF) &&
	    !(yypcb->pcb_sflagv[argc - 1] & DT_IDFLG_REF)) {
		xyerror(D_MACRO_UNUSED, "extraneous argument '%s' ($%d is "
		    "not referenced)\n", yypcb->pcb_sargv[argc - 1], argc - 1);
	}

	/*
	 * If we have successfully created a parse tree for a D program, loop
	 * over the clauses and actions and instantiate the corresponding
	 * libdtrace program.  If we are parsing a D expression, then we
	 * simply run the code generator and assembler on the resulting tree.
	 */
	if (context == DT_CTX_DPROG) {
		assert(yypcb->pcb_root->dn_kind == DT_NODE_PROG);

		if ((dnp = yypcb->pcb_root->dn_list) == NULL &&
		    !(yypcb->pcb_cflags & DTRACE_C_EMPTY))
			xyerror(D_EMPTY, "empty D program translation unit\n");

		if ((yypcb->pcb_prog = dtrace_program_create(dtp)) == NULL)
			longjmp(yypcb->pcb_jmpbuf, dtrace_errno(dtp));

		for (; dnp != NULL; dnp = dnp->dn_list) {
			if (dnp->dn_kind == DT_NODE_CLAUSE)
				dt_compile_clause(dtp, dnp);
		}

	} else {
		(void) dt_node_cook(yypcb->pcb_root, DT_IDFLG_REF);
		dt_cg(yypcb, yypcb->pcb_root);
		difo = dt_as(yypcb);
	}

out:
	if (DT_TREEDUMP_PASS(dtp, 3))
		dt_node_printr(yypcb->pcb_root, stderr, 0);

	if (dtp->dt_cdefs_fd != -1 && (ftruncate64(dtp->dt_cdefs_fd, 0) == -1 ||
	    lseek64(dtp->dt_cdefs_fd, 0, SEEK_SET) == -1 ||
	    ctf_write(dtp->dt_cdefs->dm_ctfp, dtp->dt_cdefs_fd) == CTF_ERR))
		dt_dprintf("failed to update CTF cache: %s\n", strerror(errno));

	if (dtp->dt_ddefs_fd != -1 && (ftruncate64(dtp->dt_ddefs_fd, 0) == -1 ||
	    lseek64(dtp->dt_ddefs_fd, 0, SEEK_SET) == -1 ||
	    ctf_write(dtp->dt_ddefs->dm_ctfp, dtp->dt_ddefs_fd) == CTF_ERR))
		dt_dprintf("failed to update CTF cache: %s\n", strerror(errno));

	while (yypcb->pcb_dstack.ds_next != NULL)
		(void) dt_scope_pop();

	dt_scope_destroy(&yypcb->pcb_dstack);
	dt_irlist_destroy(&yypcb->pcb_ir);

	dt_node_link_free(&yypcb->pcb_list);
	dt_node_link_free(&yypcb->pcb_hold);

	if (yypcb->pcb_pragmas != NULL)
		dt_idhash_destroy(yypcb->pcb_pragmas);
	if (yypcb->pcb_locals != NULL)
		dt_idhash_destroy(yypcb->pcb_locals);
	if (yypcb->pcb_idents != NULL)
		dt_idhash_destroy(yypcb->pcb_idents);
	if (yypcb->pcb_inttab != NULL)
		dt_inttab_destroy(yypcb->pcb_inttab);
	if (yypcb->pcb_strtab != NULL)
		dt_strtab_destroy(yypcb->pcb_strtab);
	if (yypcb->pcb_regs != NULL)
		dt_regset_destroy(yypcb->pcb_regs);
	if (yypcb->pcb_difo != NULL)
		dtrace_difo_release(yypcb->pcb_difo);

	while (yypcb->pcb_pargs != NULL) {
		dt_arg_t *old = yypcb->pcb_pargs;

		yypcb->pcb_pargs = old->da_next;
		free(old);
	}

	free(yypcb->pcb_filetag);
	free(yypcb->pcb_sflagv);

	if (yypcb->pcb_fileptr && (cflags & DTRACE_C_CPP))
		(void) fclose(yypcb->pcb_fileptr); /* close dt_preproc() file */

	if (err != 0) {
		dt_xlator_t *dxp, *nxp;
		dt_provider_t *pvp, *nvp;

		if (yypcb->pcb_pred != NULL)
			dtrace_difo_release(yypcb->pcb_pred);
		if (yypcb->pcb_prog != NULL)
			dtrace_program_destroy(dtp, yypcb->pcb_prog);
		if (yypcb->pcb_stmt != NULL)
			dtrace_stmt_destroy(yypcb->pcb_stmt);
		if (yypcb->pcb_ecbdesc != NULL)
			dtrace_ecbdesc_release(yypcb->pcb_ecbdesc);

		for (dxp = dt_list_next(&dtp->dt_xlators); dxp; dxp = nxp) {
			nxp = dt_list_next(dxp);
			if (dxp->dx_gen == dtp->dt_gen)
				dt_xlator_destroy(dtp, dxp);
		}

		for (pvp = dt_list_next(&dtp->dt_provlist); pvp; pvp = nvp) {
			nvp = dt_list_next(pvp);
			if (pvp->pv_gen == dtp->dt_gen)
				dt_provider_destroy(dtp, pvp);
		}

		dt_idhash_iter(dtp->dt_aggs, dt_idkill, (void *)dtp->dt_gen);
		dt_idhash_update(dtp->dt_aggs);

		dt_idhash_iter(dtp->dt_globals, dt_idkill, (void *)dtp->dt_gen);
		dt_idhash_update(dtp->dt_globals);

		dt_idhash_iter(dtp->dt_tls, dt_idkill, (void *)dtp->dt_gen);
		dt_idhash_update(dtp->dt_tls);

		(void) ctf_discard(dtp->dt_cdefs->dm_ctfp);
		(void) ctf_discard(dtp->dt_ddefs->dm_ctfp);

		(void) dt_set_errno(dtp, err);
		dtp->dt_pcb = NULL;
		yypcb = NULL;

		return (NULL);
	}

	(void) dt_set_errno(dtp, 0);
	dtp->dt_pcb = NULL;
	yypcb = NULL;

	if (context == DT_CTX_DPROG)
		return (pcb.pcb_prog);
	else
		return (difo);
}

dtrace_prog_t *
dtrace_program_strcompile(dtrace_hdl_t *dtp, const char *s,
    dtrace_probespec_t spec, uint_t cflags, int argc, char *const argv[])
{
	return (dt_compile(dtp, DT_CTX_DPROG,
	    spec, NULL, cflags, argc, argv, NULL, s));
}

dtrace_prog_t *
dtrace_program_fcompile(dtrace_hdl_t *dtp, FILE *fp,
    uint_t cflags, int argc, char *const argv[])
{
	return (dt_compile(dtp, DT_CTX_DPROG,
	    DTRACE_PROBESPEC_NAME, NULL, cflags, argc, argv, fp, NULL));
}

dtrace_difo_t *
dtrace_difo_create(dtrace_hdl_t *dtp, const char *s, dtrace_probedesc_t *pdp)
{
	return (dt_compile(dtp, DT_CTX_DEXPR,
	    DTRACE_PROBESPEC_NONE, pdp, 0, 0, NULL, NULL, s));
}

void
dtrace_difo_hold(dtrace_difo_t *dp)
{
	dp->dtdo_refcnt++;
	assert(dp->dtdo_refcnt != 0);
}

void
dtrace_difo_release(dtrace_difo_t *dp)
{
	assert(dp->dtdo_refcnt != 0);

	if (--dp->dtdo_refcnt != 0)
		return;

	free(dp->dtdo_buf);
	free(dp->dtdo_inttab);
	free(dp->dtdo_strtab);
	free(dp->dtdo_vartab);
	free(dp->dtdo_kreltab);
	free(dp->dtdo_ureltab);

	free(dp);
}