Add a plugin for processing static library dependencies.

	* libdep_plugin.c: New file: Processes archives that contain a
	special library dependencies element.
	* Makefile.am: Add build rules for libdep_plugin.
	* Makefile.in: Regenerate.
	* NEWS: Mention the new plugin.
	* ld.texi: Document the new plugin.

1 files changed, 366 insertions, 0 deletions

diff --git a/ld/libdep_plugin.c b/ld/libdep_plugin.c
new file mode 100644
index 0000000..2a7fdc4
--- /dev/null
+++ b/ld/libdep_plugin.c
@@ -0,0 +1,366 @@
+/* libdeps plugin for the GNU linker.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+
+   This file is part of the GNU Binutils.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+   MA 02110-1301, USA.  */
+
+#include "sysdep.h"
+#include "bfd.h"
+#if BFD_SUPPORTS_PLUGINS
+#include "plugin-api.h"
+
+#include <ctype.h> /* For isspace.  */
+
+extern enum ld_plugin_status onload (struct ld_plugin_tv *tv);
+
+/* Helper for calling plugin api message function.  */
+#define TV_MESSAGE if (tv_message) (*tv_message)
+
+/* Function pointers to cache hooks passed at onload time.  */
+static ld_plugin_register_claim_file tv_register_claim_file = 0;
+static ld_plugin_register_all_symbols_read tv_register_all_symbols_read = 0;
+static ld_plugin_register_cleanup tv_register_cleanup = 0;
+static ld_plugin_message tv_message = 0;
+static ld_plugin_add_input_library tv_add_input_library = 0;
+static ld_plugin_set_extra_library_path tv_set_extra_library_path = 0;
+
+/* Handle/record information received in a transfer vector entry.  */
+static enum ld_plugin_status
+parse_tv_tag (struct ld_plugin_tv *tv)
+{
+#define SETVAR(x) x = tv->tv_u.x
+  switch (tv->tv_tag)
+    {
+      case LDPT_REGISTER_CLAIM_FILE_HOOK:
+	SETVAR(tv_register_claim_file);
+	break;
+      case LDPT_REGISTER_ALL_SYMBOLS_READ_HOOK:
+	SETVAR(tv_register_all_symbols_read);
+	break;
+      case LDPT_REGISTER_CLEANUP_HOOK:
+	SETVAR(tv_register_cleanup);
+	break;
+      case LDPT_MESSAGE:
+	SETVAR(tv_message);
+	break;
+      case LDPT_ADD_INPUT_LIBRARY:
+	SETVAR(tv_add_input_library);
+	break;
+      case LDPT_SET_EXTRA_LIBRARY_PATH:
+	SETVAR(tv_set_extra_library_path);
+	break;
+      default:
+	break;
+    }
+#undef SETVAR
+  return LDPS_OK;
+}
+
+/* Defs for archive parsing.  */
+#define ARMAGSIZE	8
+typedef struct arhdr
+{
+  char ar_name[16];
+  char ar_date[12];
+  char ar_uid[6];
+  char ar_gid[6];
+  char ar_mode[8];
+  char ar_size[10];
+  char ar_fmag[2];
+} arhdr;
+
+typedef struct linerec
+{
+  struct linerec *next;
+  char line[];
+} linerec;
+
+#define LIBDEPS "__.LIBDEP/ "
+
+static linerec *line_head, **line_tail = &line_head;
+
+static enum ld_plugin_status
+get_libdeps (int fd)
+{
+  arhdr ah;
+  int len;
+  unsigned long mlen;
+  linerec *lr;
+  enum ld_plugin_status rc = LDPS_NO_SYMS;
+
+  lseek (fd, ARMAGSIZE, SEEK_SET);
+  for (;;)
+    {
+      len = read (fd, (void *) &ah, sizeof (ah));
+      if (len != sizeof (ah))
+	break;
+      mlen = strtoul (ah.ar_size, NULL, 10);
+      if (!mlen || strncmp (ah.ar_name, LIBDEPS, sizeof (LIBDEPS)-1))
+	{
+	  lseek (fd, mlen, SEEK_CUR);
+	  continue;
+	}
+      lr = malloc (sizeof (linerec) + mlen);
+      if (!lr)
+	return LDPS_ERR;
+      lr->next = NULL;
+      len = read (fd, lr->line, mlen);
+      lr->line[mlen-1] = '\0';
+      *line_tail = lr;
+      line_tail = &lr->next;
+      rc = LDPS_OK;
+      break;
+    }
+  return rc;
+}
+
+/* Turn a string into an argvec.  */
+static char **
+str2vec (char *in)
+{
+  char **res;
+  char *s, *first, *end;
+  char *sq, *dq;
+  int i;
+
+  end = in + strlen (in);
+  s = in;
+  while (isspace (*s)) s++;
+  first = s;
+
+  i = 1;
+  while ((s = strchr (s, ' ')))
+    {
+      s++;
+      i++;
+    }
+  res = (char **)malloc ((i+1) * sizeof (char *));
+  if (!res)
+    return res;
+
+  i = 0;
+  sq = NULL;
+  dq = NULL;
+  res[0] = first;
+  for (s = first; *s; s++)
+    {
+      if (*s == '\\')
+	{
+	  memmove (s, s+1, end-s-1);
+	  end--;
+	}
+      if (isspace (*s))
+	{
+	  if (sq || dq)
+	    continue;
+	  *s++ = '\0';
+	  while (isspace (*s)) s++;
+	  if (*s)
+	    res[++i] = s;
+	}
+      if (*s == '\'' && !dq)
+	{
+	  if (sq)
+	    {
+	      memmove (sq, sq+1, s-sq-1);
+	      memmove (s-2, s+1, end-s-1);
+	      end -= 2;
+	      s--;
+	      sq = NULL;
+	    }
+	  else
+	    {
+	      sq = s;
+	    }
+	}
+      if (*s == '"' && !sq)
+	{
+	  if (dq)
+	    {
+	      memmove (dq, dq+1, s-dq-1);
+	      memmove (s-2, s+1, end-s-1);
+	      end -= 2;
+	      s--;
+	      dq = NULL;
+	    }
+	  else
+	    {
+	      dq = s;
+	    }
+	}
+    }
+  res[++i] = NULL;
+  return res;
+}
+
+static char *prevfile;
+
+/* Standard plugin API registerable hook.  */
+static enum ld_plugin_status
+onclaim_file (const struct ld_plugin_input_file *file, int *claimed)
+{
+  enum ld_plugin_status rv;
+
+  *claimed = 0;
+
+  /* If we've already seen this file, ignore it.  */
+  if (prevfile && !strcmp (file->name, prevfile))
+    return LDPS_OK;
+
+  /* If it's not an archive member, ignore it.  */
+  if (!file->offset)
+    return LDPS_OK;
+
+  if (prevfile)
+    free (prevfile);
+
+  prevfile = strdup (file->name);
+  if (!prevfile)
+    return LDPS_ERR;
+
+  /* This hook only gets called on actual object files.
+   * We have to examine the archive ourselves, to find
+   * our LIBDEPS member.  */
+  rv = get_libdeps (file->fd);
+  if (rv == LDPS_ERR)
+    return rv;
+
+  if (rv == LDPS_OK)
+    {
+      linerec *lr = (linerec *)line_tail;
+      /* Inform the user/testsuite.  */
+      TV_MESSAGE (LDPL_INFO, "got deps for library %s: %s",
+		  file->name, lr->line);
+      fflush (NULL);
+    }
+
+  return LDPS_OK;
+}
+
+/* Standard plugin API registerable hook.  */
+static enum ld_plugin_status
+onall_symbols_read (void)
+{
+  linerec *lr;
+  char **vec;
+  enum ld_plugin_status rv = LDPS_OK;
+
+  while ((lr = line_head))
+    {
+      line_head = lr->next;
+      vec = str2vec (lr->line);
+      if (vec)
+	{
+	  int i;
+	  for (i = 0; vec[i]; i++)
+	    {
+	      if (vec[i][0] != '-')
+		{
+		  TV_MESSAGE (LDPL_WARNING, "ignoring libdep argument %s",
+			      vec[i]);
+		  fflush (NULL);
+		  continue;
+		}
+	      if (vec[i][1] == 'l')
+		rv = tv_add_input_library (vec[i]+2);
+	      else if (vec[i][1] == 'L')
+		rv = tv_set_extra_library_path (vec[i]+2);
+	      else
+		{
+		  TV_MESSAGE (LDPL_WARNING, "ignoring libdep argument %s",
+			      vec[i]);
+		  fflush (NULL);
+		}
+	      if (rv != LDPS_OK)
+		break;
+	    }
+	  free (vec);
+	}
+      free (lr);
+    }
+  line_tail = NULL;
+  return rv;
+}
+
+/* Standard plugin API registerable hook.  */
+static enum ld_plugin_status
+oncleanup (void)
+{
+  if (prevfile)
+    {
+      free (prevfile);
+      prevfile = NULL;
+    }
+  if (line_head)
+    {
+      linerec *lr;
+      while ((lr = line_head))
+	{
+	  line_head = lr->next;
+	  free (lr);
+	}
+      line_tail = NULL;
+    }
+  return LDPS_OK;
+}
+
+/* Standard plugin API entry point.  */
+enum ld_plugin_status
+onload (struct ld_plugin_tv *tv)
+{
+  enum ld_plugin_status rv;
+
+  /* This plugin requires a valid tv array.  */
+  if (!tv)
+    return LDPS_ERR;
+
+  /* First entry should always be LDPT_MESSAGE, letting us get
+     hold of it easily so we can send output straight away.  */
+  if (tv[0].tv_tag == LDPT_MESSAGE)
+    tv_message = tv[0].tv_u.tv_message;
+
+  do
+    if ((rv = parse_tv_tag (tv)) != LDPS_OK)
+      return rv;
+  while ((tv++)->tv_tag != LDPT_NULL);
+
+  /* Register hooks.  */
+  if (!tv_register_claim_file)
+    {
+      TV_MESSAGE (LDPL_FATAL, "No register_claim_file hook");
+      fflush (NULL);
+      return LDPS_ERR;
+    }
+  (*tv_register_claim_file) (onclaim_file);
+  if (!tv_register_all_symbols_read)
+    {
+      TV_MESSAGE (LDPL_FATAL, "No register_all_symbols_read hook");
+      fflush (NULL);
+      return LDPS_ERR;
+    }
+  (*tv_register_all_symbols_read) (onall_symbols_read);
+  if (!tv_register_cleanup)
+    {
+      TV_MESSAGE (LDPL_FATAL, "No register_cleanup hook");
+      fflush (NULL);
+      return LDPS_ERR;
+    }
+  (*tv_register_cleanup) (oncleanup);
+  fflush (NULL);
+  return LDPS_OK;
+}
+#endif /* BFD_SUPPORTS_PLUGINS */