logging?

Author: tsjensen

src/Makefile

@@ -23,11 +23,11 @@ GEN_HDR    = parser.h boxes.h lex.yy.h
 GEN_SRC    = parser.c lex.yy.c
 GEN_FILES  = $(GEN_SRC) $(GEN_HDR)
 ORIG_HDRCL = boxes.in.h config.h
-ORIG_HDR   = $(ORIG_HDRCL) bxstring.h cmdline.h detect.h discovery.h generate.h input.h list.h parsecode.h parsing.h \
-             query.h regulex.h remove.h shape.h tools.h unicode.h
+ORIG_HDR   = $(ORIG_HDRCL) bxstring.h cmdline.h detect.h discovery.h generate.h input.h list.h logging.h parsecode.h \
+             parsing.h query.h regulex.h remove.h shape.h tools.h unicode.h
 ORIG_GEN   = lexer.l parser.y
-ORIG_NORM  = boxes.c bxstring.c cmdline.c detect.c discovery.c generate.c input.c list.c parsecode.c parsing.c query.c \
-             regulex.c remove.c shape.c tools.c unicode.c
+ORIG_NORM  = boxes.c bxstring.c cmdline.c detect.c discovery.c generate.c input.c list.c logging.c parsecode.c \
+             parsing.c query.c regulex.c remove.c shape.c tools.c unicode.c
 ORIG_SRC   = $(ORIG_GEN) $(ORIG_NORM)
 ORIG_FILES = $(ORIG_SRC) $(ORIG_HDR)
 
@@ -116,6 +116,7 @@ generate.o:  generate.c generate.h boxes.h shape.h tools.h unicode.h config.h |
 input.o:     input.c boxes.h input.h regulex.h tools.h unicode.h config.h | check_dir
 lex.yy.o:    lex.yy.c parser.h boxes.h parsing.h tools.h shape.h unicode.h config.h | check_dir
 list.o:      list.c list.h boxes.h bxstring.h parsing.h query.h shape.h tools.h unicode.h config.h | check_dir
+logging.o:   logging.c logging.h tools.h config.h | check_dir
 parsecode.o: parsecode.c parsecode.h discovery.h lex.yy.h parsing.h parser.h query.h regulex.h shape.h tools.h unicode.h config.h | check_dir
 parser.o:    parser.c boxes.h bxstring.h lex.yy.h parsecode.h parser.h parsing.h shape.h tools.h unicode.h config.h | check_dir
 parsing.o:   parsing.c parsing.h bxstring.h parser.h lex.yy.h boxes.h tools.h config.h | check_dir

src/logging.c

@@ -14,48 +14,89 @@
  */
 
 /*
- * Simple makeshift log facility, mostly used for handling debug output.
+ * Simple makeshift log facility for handling debug output.
  */
 
+#include "config.h"
+
 #include <stdarg.h>
+#include <string.h>
+
 #include "tools.h"
 #include "logging.h"
 
-log_level_t current_log_level = INFO;
 
-char *log_level_name[] = {
-    "TRACE", "DEBUG", "INFO", "WARN", "ERROR"
-};
+static int debug_logging_active = 0;
+
+static int *areas_active = NULL;
 
 
-void log(log_level_t log_level, const char *module, const char *format, ...)
+
+void activate_debug_logging(log_area_t *log_areas)
 {
-    char *s = (char *) malloc(512);
-    va_list va;
-    va_start(va, format);
-    vsprintf(s, format, va);
-    va_end(va);
-
-    switch(log_level) {
-        case TRACE:
-        case DBG:
-            if (log_level >= current_log_level) {
-                bx_fprintf(stderr, "%5s %s: %s\n", log_level_name[log_level], module, s);
+    debug_logging_active = 0;
+
+    if (areas_active != NULL) {
+        BFREE(areas_active);
+    }
+    if (log_areas != NULL) {
+        size_t count = 0;
+        while (log_areas[count] != RESERVED) {
+            debug_logging_active = 1;
+            if (areas_active == NULL) {
+                areas_active = (int *) calloc(NUM_LOG_AREAS, sizeof(int));
             }
-            break;
-        
-        case INFO:
-            if (log_level >= current_log_level) {
-                bx_fprintf(stdout, s);
+            if (log_areas[count] == ALL) {
+                for (size_t i = 0; i < NUM_LOG_AREAS; i++) {
+                    areas_active[i] = 1;
+                }
             }
-            break;
+            else {
+                areas_active[log_areas[count] - 2] = 1;
+            }
+            count++;
+        }
+    }
+}
 
-        case WARN:
-        case ERROR:
-            if (log_level >= current_log_level) {
-                bx_fprintf(stderr, "%5s: %s\n", log_level_name[log_level], s);
+
+
+static int is_area_active(log_area_t log_area)
+{
+    if (debug_logging_active && areas_active != NULL && log_area != RESERVED && log_area < NUM_LOG_AREAS + 2) {
+        if (log_area == ALL) {
+            for (size_t i = 0; i < NUM_LOG_AREAS; i++) {
+                if (!areas_active[i]) {
+                    return 0;
+                }
             }
-            break;
+            return 1;
+        }
+        return areas_active[log_area - 2];
+    }
+    return 0;
+}
+
+
+
+int is_debug_logging(log_area_t log_area)
+{
+    return (debug_logging_active && is_area_active(log_area)) ? 1 : 0;
+}
+
+
+
+void log_debug(const char *module, log_area_t log_area, const char *format, ...)
+{
+    if (is_debug_logging(log_area)) {
+        char *s = (char *) malloc(512);
+        va_list va;
+        va_start(va, format);
+        vsprintf(s, format, va);
+        va_end(va);
+
+        bx_fprintf(stderr, "[DEBUG] %s: %s\n", module, s);
+        BFREE(s);
     }
 }
 

src/logging.h

@@ -14,46 +14,67 @@
  */
 
 /*
- * Simple makeshift log facility.
+ * Simple makeshift log facility for handling debug output.
+ *
+ * Debug output is printed on stderr. Each message is annotated with its module and "area".
+ * The "area" defines certain sections of code as a possible filter criterion.
  */
 
 #ifndef LOGGING_H
 #define LOGGING_H
 
 
-typedef enum _log_level_t {
-    /** the finest log level */
-    TRACE,
-    
-    /** a debug message, should be called `DEBUG` */
-    DBG,
+/** Enum of the log areas supported. `ALL` means all of them, `RESERVED` cannot be used. */
+typedef enum _log_area_t {
+    /** the 0 value is reserved and must not be used */
+    RESERVED,
+
+    /** all areas */
+    ALL,
+
+    /** the main areas of the code (activate this if unsure) */
+    MAIN,
 
-    /** normal informational message */
-    INFO,
-    
-    /** a warning message, which should not happen, but can be tolerated */
-    WARN,
-    
-    /** an error message, normally this will also lead to abnormal program termination */
-    ERROR
-} log_level_t;
+    /** regular expression handling */
+    REGEXP,
 
+    /** parser code */
+    PARSER,
 
-/** currently active log level, determine whether a message gets printed */
-extern log_level_t current_log_level;
+    /** lexer code */
+    LEXER,
 
+    /** config file discovery */
+    DISCOVERY
+} log_area_t;
 
-/** log level names for printing */
-extern char *log_level_name[];
+/** number of log areas in `log_area_t`, excluding `ALL` and `RESERVED` */
+const size_t NUM_LOG_AREAS = 5;
+
+
+/**
+ * Activate debug logging.
+ * @param log_areas an array of log areas to activate, zero-terminated, should not be empty. The value will by copied
+ *      and can be freed after returning from the function.
+ */
+void activate_debug_logging(log_area_t *log_areas);
+
+
+/**
+ * Determine if debug logging is active and the given area is active, too.
+ * @param log_area the log area to check
+ * @return 1 if active, 0 if not
+ */
+int is_debug_logging(log_area_t log_area);
 
 
 /**
- * Print a log message. Log messages of level INFO will be printed in `stdout`, others on `stderr`.
- * @param log_level the log level
+ * Print a debug log message. Debug log messages will be printed on `stderr`.
  * @param module the module name as per `__FILE__`
+ * @param log_area_t log_area
  * @param format format string for the mesage, followed by the placeholder arguments
  */
-void log(log_level_t log_level, const char *module, const char *format, ...);
+void log_debug(const char *module, log_area_t log_area, const char *format, ...);
 
 
 #endif