From 4241e27ee1c6739b5442f157bf167f050d546582 Mon Sep 17 00:00:00 2001
From: David Sterba <dsterba@suse.com>
Date: Fri, 19 Aug 2016 16:06:41 +0200
Subject: [PATCH] btrfs-progs: build: add more debugging features

Add options to show file and line or stack trace for error/warning
messages that use the common helpers. Possible to let any error stop
execution for ease of analysis and debugging.

Signed-off-by: David Sterba <dsterba@suse.com>
---
 Makefile.in | 23 ++++++++++++++++++++
 utils.h     | 61 +++++++++++++++++++++++++++++++++++++++++++++++++----
 2 files changed, 80 insertions(+), 4 deletions(-)

diff --git a/Makefile.in b/Makefile.in
index ac6b353b..9e0cb4c4 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -12,6 +12,11 @@
 #   V=1            verbose, print command lines (default: quiet)
 #   C=1            run checker before compilation (default checker: sparse)
 #   D=1            debugging build, turn off optimizations
+#   D=dflags       dtto, turn on additional debugging features:
+#                  verbose - print file:line along with error/warning messages
+#                  trace   - print trace before the error/warning messages
+#                  abort   - call abort() on first error (dumps core)
+#                  all     - shortcut for all of the above
 #   W=123          build with warnings (default: off)
 #   DEBUG_CFLAGS   additional compiler flags for debugging build
 #   EXTRA_CFLAGS   additional compiler flags
@@ -121,6 +126,24 @@ ifeq ("$(origin D)", "command line")
   DEBUG_CFLAGS_INTERNAL = $(DEBUG_CFLAGS_DEFAULT) $(DEBUG_CFLAGS)
 endif
 
+ifneq (,$(findstring verbose,$(D)))
+  DEBUG_CFLAGS_INTERNAL += -DDEBUG_VERBOSE_ERROR=1
+endif
+
+ifneq (,$(findstring trace,$(D)))
+  DEBUG_CFLAGS_INTERNAL += -DDEBUG_TRACE_ON_ERROR=1
+endif
+
+ifneq (,$(findstring abort,$(D)))
+  DEBUG_CFLAGS_INTERNAL += -DDEBUG_ABORT_ON_ERROR=1
+endif
+
+ifneq (,$(findstring all,$(D)))
+  DEBUG_CFLAGS_INTERNAL += -DDEBUG_VERBOSE_ERROR=1
+  DEBUG_CFLAGS_INTERNAL += -DDEBUG_TRACE_ON_ERROR=1
+  DEBUG_CFLAGS_INTERNAL += -DDEBUG_ABORT_ON_ERROR=1
+endif
+
 MAKEOPTS = --no-print-directory Q=$(Q)
 
 # build all by default
diff --git a/utils.h b/utils.h
index 58121ced..da23bfcc 100644
--- a/utils.h
+++ b/utils.h
@@ -311,8 +311,61 @@ void clean_args_no_options_relaxed(int argc, char *argv[],
 		const char * const *usagestr);
 int string_is_numerical(const char *str);
 
+#if DEBUG_VERBOSE_ERROR
+#define	PRINT_VERBOSE_ERROR	fprintf(stderr, "%s:%d:", __FILE__, __LINE__)
+#else
+#define PRINT_VERBOSE_ERROR
+#endif
+
+#if DEBUG_TRACE_ON_ERROR
+#define PRINT_TRACE_ON_ERROR	print_trace()
+#else
+#define PRINT_TRACE_ON_ERROR
+#endif
+
+#if DEBUG_ABORT_ON_ERROR
+#define DO_ABORT_ON_ERROR	abort()
+#else
+#define DO_ABORT_ON_ERROR
+#endif
+
+#define error(fmt, ...)							\
+	do {								\
+		PRINT_TRACE_ON_ERROR;					\
+		PRINT_VERBOSE_ERROR;					\
+		__error((fmt), ##__VA_ARGS__);				\
+		DO_ABORT_ON_ERROR;					\
+	} while (0)
+
+#define error_on(cond, fmt, ...)					\
+	do {								\
+		if ((cond))						\
+			PRINT_TRACE_ON_ERROR;				\
+		if ((cond))						\
+			PRINT_VERBOSE_ERROR;				\
+		__error_on((cond), (fmt), ##__VA_ARGS__);		\
+		if ((cond))						\
+			DO_ABORT_ON_ERROR;				\
+	} while (0)
+
+#define warning(fmt, ...)						\
+	do {								\
+		PRINT_TRACE_ON_ERROR;					\
+		PRINT_VERBOSE_ERROR;					\
+		__warning((fmt), ##__VA_ARGS__);			\
+	} while (0)
+
+#define warning_on(cond, fmt, ...)					\
+	do {								\
+		if ((cond))						\
+			PRINT_TRACE_ON_ERROR;				\
+		if ((cond))						\
+			PRINT_VERBOSE_ERROR;				\
+		__warning_on((cond), (fmt), ##__VA_ARGS__);		\
+	} while (0)
+
 __attribute__ ((format (printf, 1, 2)))
-static inline void warning(const char *fmt, ...)
+static inline void __warning(const char *fmt, ...)
 {
 	va_list args;
 
@@ -324,7 +377,7 @@ static inline void warning(const char *fmt, ...)
 }
 
 __attribute__ ((format (printf, 1, 2)))
-static inline void error(const char *fmt, ...)
+static inline void __error(const char *fmt, ...)
 {
 	va_list args;
 
@@ -336,7 +389,7 @@ static inline void error(const char *fmt, ...)
 }
 
 __attribute__ ((format (printf, 2, 3)))
-static inline int warning_on(int condition, const char *fmt, ...)
+static inline int __warning_on(int condition, const char *fmt, ...)
 {
 	va_list args;
 
@@ -353,7 +406,7 @@ static inline int warning_on(int condition, const char *fmt, ...)
 }
 
 __attribute__ ((format (printf, 2, 3)))
-static inline int error_on(int condition, const char *fmt, ...)
+static inline int __error_on(int condition, const char *fmt, ...)
 {
 	va_list args;