1 files changed, 133 insertions, 0 deletions
diff --git a/lib/dpkg/debug.c b/lib/dpkg/debug.c
new file mode 100644
index 0000000..115d455
--- /dev/null
+++ b/lib/dpkg/debug.c
@@ -0,0 +1,133 @@
+/*
+ * libdpkg - Debian packaging suite library routines
+ * debug.c - debugging support
+ *
+ * Copyright © 1995 Ian Jackson <ijackson@chiark.greenend.org.uk>
+ * Copyright © 2011 Guillem Jover <guillem@debian.org>
+ *
+ * This 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 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This 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 <https://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+#include <compat.h>
+
+#include <errno.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+#include <dpkg/dpkg.h>
+#include <dpkg/i18n.h>
+#include <dpkg/report.h>
+#include <dpkg/debug.h>
+
+static int debug_mask = 0;
+static FILE *debug_output = NULL;
+
+/**
+ * Set the debugging output file.
+ *
+ * Marks the file descriptor as close-on-exec.
+ */
+void
+debug_set_output(FILE *output, const char *filename)
+{
+	setcloexec(fileno(output), filename);
+	dpkg_set_report_buffer(output);
+	debug_output = output;
+}
+
+/**
+ * Set the debugging mask.
+ *
+ * The mask determines what debugging flags are going to take effect at
+ * run-time. The output will be set to stderr if it has not been set before.
+ */
+void
+debug_set_mask(int mask)
+{
+	debug_mask = mask;
+	if (!debug_output)
+		debug_output = stderr;
+}
+
+/**
+ * Parse the debugging mask.
+ *
+ * The mask is parsed from the specified string and sets the global debugging
+ * mask. If there is any error while parsing a negative number is returned.
+ */
+int
+debug_parse_mask(const char *str)
+{
+	char *endp;
+	long mask;
+
+	errno = 0;
+	mask = strtol(str, &endp, 8);
+	if (str == endp || *endp || mask < 0 || errno == ERANGE)
+		return -1;
+
+	debug_set_mask(mask);
+
+	return mask;
+}
+
+/**
+ * Check if a debugging flag is currently set on the debugging mask.
+ */
+bool
+debug_has_flag(int flag)
+{
+	return debug_mask & flag;
+}
+
+/**
+ * Output a debugging message.
+ *
+ * The message will be printed to the previously specified output if the
+ * specified flag is present in the current debugging mask.
+ */
+void
+debug(int flag, const char *fmt, ...)
+{
+	va_list args;
+
+	if (!debug_has_flag(flag))
+		return;
+
+	fprintf(debug_output, "D0%05o: ", flag);
+	va_start(args, fmt);
+	vfprintf(debug_output, fmt, args);
+	va_end(args);
+	putc('\n', debug_output);
+}
+
+/**
+ * Initialize the debugging support.
+ */
+void
+dpkg_debug_init(void)
+{
+	const char envvar[] = "DPKG_DEBUG";
+	const char *env;
+
+	env = getenv(envvar);
+	if (env == NULL)
+		return;
+
+	if (debug_parse_mask(env) < 0)
+		warning(_("cannot parse debug mask from environment variable %s"),
+		        envvar);
+}