MINOR: debug: show return values of all functions in the debug output

If the program is configured using the --enable-debug option, then log
messages are printed to stdout during operation (or to a file specified
at program startup).  In the log one can then find (among other things)
the order in which the function is called and the value that the function
returns (if it is not a void type).

Prior to applying this patch, no value returned by a function was logged.

Log output example:
  [ 1][    0.000661] worker_thread(0x558c674ba200) {
  [ 1][    0.000672]    Worker started, thread id: 104866
  [ 1][    0.000716]    ev_backend_type(0x7f7858000b60) {
  [ 1][    0.000721]       ev_backend_name(4) {
  [ 1][    0.000722]       } = 0x558c6554b05c
  [ 1][    0.000722]    } = 0x558c6554b05c
  [ 1][    0.000723]    libev: using backend 'epoll'
  ..
  [ 1][    5.210447]    worker_thread_exit(0x558c674ba200) {
  [ 1][    5.210458]       Worker is stopped
  [ 1][    5.210459]    } = (nil)

Version of the program changed to v1.2.14.

VERSION

@@ -1 +1 @@
-1.2.13
+1.2.14

include/common/debug.h

@@ -40,6 +40,7 @@ enum DBG_LEVEL_enum {
 };
 
 #  define IFDEF_DBG(a, b)        a
+#  define DBG_INDENT_STEP        2
 #  define DBG_PARM(a, ...)       a, ##__VA_ARGS__
 #  define C_DBG(l,C,f, ...)                                 \
 	do {                                                \
@@ -56,18 +57,42 @@ enum DBG_LEVEL_enum {
 		if (cfg.debug_level & (1 << DBG_LEVEL_##l)) \
 			w_log((W), f, ##__VA_ARGS__);       \
 	} while (0)
-#  define DBG_FUNC(W,f, ...)                                                    \
-	do {                                                                    \
-		if (cfg.debug_level & (1 << DBG_LEVEL_ENABLED))                 \
-			W_DBG(FUNC, (W), "%s(" f ")", __func__, ##__VA_ARGS__); \
+#  define DBG_FUNC(W,f, ...)                                                      \
+	do {                                                                      \
+		if (cfg.debug_level & (1 << DBG_LEVEL_ENABLED))                   \
+			W_DBG(FUNC, (W), "%s(" f ") {", __func__, ##__VA_ARGS__); \
+		dbg_w_ptr   = (W);                                                \
+		dbg_indent += DBG_INDENT_STEP;                                    \
 	} while (0)
+#  define DBG_FUNC_END(f, ...)                                    \
+	do {                                                      \
+		dbg_indent -= DBG_INDENT_STEP;                    \
+		if (cfg.debug_level & (1 << DBG_LEVEL_ENABLED))   \
+			W_DBG(FUNC, dbg_w_ptr, f, ##__VA_ARGS__); \
+	} while (0)
+#  define DBG_RETURN()           do { DBG_FUNC_END("}"); return; } while (0)
+#  define DBG_RETURN_EX(a,t,f)   do { t _r = (a); DBG_FUNC_END("} = " f, _r); return _r; } while (0)
+#  define DBG_RETURN_INT(a)      DBG_RETURN_EX((a), int, "%d")
+#  define DBG_RETURN_U64(a)      DBG_RETURN_EX((a), uint64_t, "%lu")
+#  define DBG_RETURN_SIZE(a)     DBG_RETURN_EX((a), size_t, "%ld")
+#  define DBG_RETURN_SSIZE(a)    DBG_RETURN_EX((a), ssize_t, "%lu")
+#  define DBG_RETURN_PTR(a)      DBG_RETURN_EX((a), void *, "%p")
+#  define DBG_RETURN_CPTR(a)     DBG_RETURN_EX((a), const void *, "%p")
 #else
 #  define IFDEF_DBG(a, b)        b
 #  define DBG_PARM(...)
 #  define C_DBG(...)             while (0)
 #  define F_DBG(...)             while (0)
 #  define W_DBG(...)             while (0)
 #  define DBG_FUNC(...)          while (0)
+#  define DBG_RETURN()           return
+#  define DBG_RETURN_EX(a,t,f)   return a
+#  define DBG_RETURN_INT(a)      return a
+#  define DBG_RETURN_U64(a)      return a
+#  define DBG_RETURN_SIZE(a)     return a
+#  define DBG_RETURN_SSIZE(a)    return a
+#  define DBG_RETURN_PTR(a)      return a
+#  define DBG_RETURN_CPTR(a)     return a
 #endif /* DEBUG */
 
 #endif /* _COMMON_DEBUG_H */

include/types/curl.h

@@ -23,7 +23,7 @@
 #define CURL_STR              "cURL: "
 #define CURL_ERR_EASY(a,b)    w_log(NULL, _E(CURL_STR a ": %s (%u)"), curl_easy_strerror(b), (b))
 #define CURL_ERR_MULTI(a,b)   w_log(NULL, _E(CURL_STR a ": %s (%d)"), curl_multi_strerror(b), (b))
-#define CURL_DBG(a, ...)      W_DBG(CURL, NULL, "  " CURL_STR a, ##__VA_ARGS__)
+#define CURL_DBG(a, ...)      W_DBG(CURL, NULL, CURL_STR a, ##__VA_ARGS__)
 
 /* Time-out connect operations after this amount of milliseconds. */
 #define CURL_CON_TMOUT        20000

include/types/main.h

@@ -92,6 +92,11 @@ struct program_data {
 extern struct config_data  cfg;
 extern struct program_data prg;
 
+#ifdef DEBUG
+extern __THR const void *dbg_w_ptr;
+extern __THR int         dbg_indent;
+#endif
+
 #endif /* _TYPES_MAIN_H */
 
 /*

include/types/util.h

@@ -31,6 +31,14 @@
 #  define LOG_RUNTIME(a,b)   ((b) / 1000000.0)
 #endif
 
+#ifdef DEBUG
+#  define LOG_FMT_INDENT     "%.*s"
+#  define LOG_INDENT         dbg_indent, "                                                            >>>",
+#else
+#  define LOG_FMT_INDENT
+#  define LOG_INDENT
+#endif
+
 #define _F(s)                "(F) " s
 #define _E(s)                "(E) " s
 #define _W(s)                "(W) " s

src/.build-counter

@@ -1 +1 @@
-2439
+2491