Adjust for monotone.

1 files changed, 157 insertions, 0 deletions

diff --git a/libdwfl/find-debuginfo.c b/libdwfl/find-debuginfo.c
new file mode 100644
index 00000000..c9e640dd
--- /dev/null
+++ b/libdwfl/find-debuginfo.c
@@ -0,0 +1,157 @@
+/* Standard find_debuginfo callback for libdwfl.
+   Copyright (C) 2005 Red Hat, Inc.
+
+   This program is Open Source software; you can redistribute it and/or
+   modify it under the terms of the Open Software License version 1.0 as
+   published by the Open Source Initiative.
+
+   You should have received a copy of the Open Software License along
+   with this program; if not, you may obtain a copy of the Open Software
+   License version 1.0 from http://www.opensource.org/licenses/osl.php or
+   by writing the Open Source Initiative c/o Lawrence Rosen, Esq.,
+   3001 King Ranch Road, Ukiah, CA 95482.   */
+
+#include "libdwflP.h"
+#include <stdio.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include "system.h"
+
+
+#define DEFAULT_DEBUGINFO_PATH ":.debug:/usr/lib/debug"
+
+
+/* Try to open64 [DIR/][SUBDIR/]DEBUGLINK, return file descriptor or -1.
+   On success, *DEBUGINFO_FILE_NAME has the malloc'd name of the open file.  */
+static int
+try_open (const char *dir, const char *subdir, const char *debuglink,
+	  char **debuginfo_file_name)
+{
+  char *fname = NULL;
+  if (dir == NULL && subdir == NULL)
+    fname = strdup (debuglink);
+  else if (subdir == NULL)
+    asprintf (&fname, "%s/%s", dir, debuglink);
+  else if (dir == NULL)
+    asprintf (&fname, "%s/%s", subdir, debuglink);
+  else
+    asprintf (&fname, "%s/%s/%s", dir, subdir, debuglink);
+
+  if (fname == NULL)
+    return -1;
+
+  int fd = open64 (fname, O_RDONLY);
+  if (fd < 0)
+    free (fname);
+  else
+    *debuginfo_file_name = fname;
+
+  return fd;
+}
+
+/* Return true iff the FD's contents CRC matches DEBUGLINK_CRC.  */
+static inline bool
+check_crc (int fd, GElf_Word debuglink_crc)
+{
+  uint32_t file_crc;
+  return crc32_file (fd, &file_crc) == 0 && file_crc == debuglink_crc;
+}
+
+int
+dwfl_standard_find_debuginfo (Dwfl_Module *mod __attribute__ ((unused)),
+			      void **userdata __attribute__ ((unused)),
+			      const char *modname __attribute__ ((unused)),
+			      GElf_Addr base __attribute__ ((unused)),
+			      const char *file_name,
+			      const char *debuglink_file,
+			      GElf_Word debuglink_crc,
+			      char **debuginfo_file_name)
+{
+  bool cancheck = true;
+
+  const char *file_basename = file_name == NULL ? NULL : basename (file_name);
+  if (debuglink_file == NULL)
+    {
+      if (file_basename == NULL)
+	{
+	  errno = 0;
+	  return -1;
+	}
+
+      size_t len = strlen (file_basename);
+      char *localname = alloca (len + sizeof ".debug");
+      memcpy (localname, file_basename, len);
+      memcpy (&localname[len], ".debug", sizeof ".debug");
+      debuglink_file = localname;
+      cancheck = false;
+    }
+
+  /* Look for a file named DEBUGLINK_FILE in the directories
+     indicated by the debug directory path setting.  */
+
+  const Dwfl_Callbacks *const cb = mod->dwfl->callbacks;
+  char *path = strdupa ((cb->debuginfo_path ? *cb->debuginfo_path : NULL)
+			?: DEFAULT_DEBUGINFO_PATH);
+
+  /* A leading - or + in the whole path sets whether to check file CRCs.  */
+  bool defcheck = true;
+  if (path[0] == '-' || path[0] == '+')
+    {
+      defcheck = path[0] == '+';
+      ++path;
+    }
+
+  char *file_dirname = (file_basename == file_name ? NULL
+			: strndupa (file_name, file_basename - 1 - file_name));
+  char *p;
+  while ((p = strsep (&path, ":")) != NULL)
+    {
+      /* A leading - or + says whether to check file CRCs for this element.  */
+      bool check = defcheck;
+      if (*p == '+' || *p == '-')
+	check = *p++ == '+';
+      check = check && cancheck;
+
+      const char *dir, *subdir;
+      switch (p[0])
+	{
+	case '\0':
+	  /* An empty entry says to try the main file's directory.  */
+	  dir = file_dirname;
+	  subdir = NULL;
+	  break;
+	case '/':
+	  /* An absolute path says to look there for a subdirectory
+	     named by the main file's absolute directory.
+	     This cannot be applied to a relative file name.  */
+	  if (file_dirname == NULL || file_dirname[0] != '/')
+	    continue;
+	  dir = p;
+	  subdir = file_dirname + 1;
+	  break;
+	default:
+	  /* A relative path says to try a subdirectory of that name
+	     in the main file's directory.  */
+	  dir = file_dirname;
+	  subdir = p;
+	  break;
+	}
+
+      char *fname;
+      int fd = try_open (dir, subdir, debuglink_file, &fname);
+      if (fd < 0)
+	continue;
+      if (!check || check_crc (fd, debuglink_crc))
+	{
+	  *debuginfo_file_name = fname;
+	  return fd;
+	}
+      free (fname);
+      close (fd);
+    }
+
+  /* No dice.  */
+  errno = 0;
+  return -1;
+}
+INTDEF (dwfl_standard_find_debuginfo)