libsysprof-profile: add address mappings parser

This parses the contents of /proc/$pid/maps and has a crude helper to test
it against real world files (which found a missing capture we had).

src/libsysprof-profile/sysprof-maps-parser.c

@@ -0,0 +1,114 @@
+/* sysprof-maps-parser.c
+ *
+ * Copyright 2023 Christian Hergert <chergert@redhat.com>
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#include "config.h"
+
+#include "sysprof-maps-parser-private.h"
+
+static GRegex *address_range_regex;
+
+void
+sysprof_maps_parser_init (SysprofMapsParser *self,
+                          const char        *str,
+                          gssize             len)
+{
+  line_reader_init (&self->reader, (char *)str, len);
+
+  if (address_range_regex == NULL)
+    address_range_regex = g_regex_new ("^([0-9a-f]+)-([0-9a-f]+) [r\\-][w\\-][x\\-][ps\\-] ([0-9a-f]+) [0-9]{2}:[0-9]{2} ([0-9]+) +(.*)$",
+                                       G_REGEX_OPTIMIZE,
+                                       G_REGEX_MATCH_DEFAULT,
+                                       NULL);
+}
+
+gboolean
+sysprof_maps_parser_next (SysprofMapsParser  *self,
+                          guint64            *out_begin_addr,
+                          guint64            *out_end_addr,
+                          guint64            *out_offset,
+                          guint64            *out_inode,
+                          char              **out_filename)
+{
+  const char *line;
+  gsize len;
+
+  while ((line = line_reader_next (&self->reader, &len)))
+    {
+      g_autoptr(GMatchInfo) match_info = NULL;
+
+      if (g_regex_match_full (address_range_regex, line, len, 0, 0, &match_info, NULL))
+        {
+          g_autofree char *file = NULL;
+          guint64 begin_addr;
+          guint64 end_addr;
+          guint64 inode;
+          guint64 offset;
+          gboolean is_vdso;
+          int begin_addr_begin;
+          int begin_addr_end;
+          int end_addr_begin;
+          int end_addr_end;
+          int offset_begin;
+          int offset_end;
+          int inode_begin;
+          int inode_end;
+          int path_begin;
+          int path_end;
+
+
+          if (!g_match_info_fetch_pos (match_info, 1, &begin_addr_begin, &begin_addr_end) ||
+              !g_match_info_fetch_pos (match_info, 2, &end_addr_begin, &end_addr_end) ||
+              !g_match_info_fetch_pos (match_info, 3, &offset_begin, &offset_end) ||
+              !g_match_info_fetch_pos (match_info, 4, &inode_begin, &inode_end) ||
+              !g_match_info_fetch_pos (match_info, 5, &path_begin, &path_end))
+            continue;
+
+          begin_addr = g_ascii_strtoull (&line[begin_addr_begin], NULL, 16);
+          end_addr = g_ascii_strtoull (&line[end_addr_begin], NULL, 16);
+          offset = g_ascii_strtoull (&line[offset_begin], NULL, 16);
+          inode = g_ascii_strtoull (&line[inode_begin], NULL, 10);
+
+          if (memcmp (" (deleted",
+                      &line[path_end] - strlen (" (deleted"),
+                      strlen (" (deleted")) == 0)
+            path_end -= strlen (" (deleted)");
+
+          file = g_strndup (&line[path_begin], path_end-path_begin);
+
+          is_vdso = strcmp ("[vdso]", file) == 0;
+
+          if (is_vdso)
+            inode = 0;
+
+          if (is_vdso)
+            offset = 0;
+
+          *out_begin_addr = begin_addr;
+          *out_end_addr = end_addr;
+          *out_offset = offset;
+          *out_inode = inode;
+          *out_filename = g_steal_pointer (&file);
+
+          return TRUE;
+        }
+    }
+
+  return FALSE;
+}