Add new functions emscripten_log() in emscripten.h which allows printing out log messages with callstack information, and function emscripten_get_callstack(), which allows programmatically obtaining the current callstack.

1 files changed, 61 insertions, 0 deletions

diff --git a/system/include/emscripten/emscripten.h b/system/include/emscripten/emscripten.h
index ddcbc43a..22fa9946 100644
--- a/system/include/emscripten/emscripten.h
+++ b/system/include/emscripten/emscripten.h
@@ -447,6 +447,67 @@ void emscripten_asm_const(const char *code);
 int emscripten_asm_const_int(const char *code, ...);
 double emscripten_asm_const_double(const char *code, ...);
 
+/* If specified, logs directly to the browser console/inspector 
+ * window. If not specified, logs via the application Module. */
+#define EM_LOG_CONSOLE   1
+/* If specified, prints a warning message. */
+#define EM_LOG_WARN      2
+/* If specified, prints an error message. If neither EM_LOG_WARN 
+ * or EM_LOG_ERROR is specified, an info message is printed.
+ * EM_LOG_WARN and EM_LOG_ERROR are mutually exclusive. */
+#define EM_LOG_ERROR     4
+/* If specified, prints a callstack that contains filenames referring 
+ * to original C sources using source map information. */
+#define EM_LOG_C_STACK   8
+/* If specified, prints a callstack that contains filenames referring
+ * to lines to the built .js/.html file along with the message. The 
+ * flags EM_LOG_C_STACK and EM_LOG_JS_STACK can be combined to output 
+ * both untranslated and translated file+line information. */
+#define EM_LOG_JS_STACK 16
+/* If specified, C/C++ function names are demangled before printing. 
+ * Otherwise, the mangled post-compilation JS function names are 
+ * displayed. */
+#define EM_LOG_DEMANGLE 32
+/* If specified, the pathnames of the file information in the call 
+ * stack will be omitted. */
+#define EM_LOG_NO_PATHS 64
+
+/*
+ * Prints out a message to the console, optionally with the 
+ * callstack information.
+ * @param flags A binary OR of items from the list of EM_LOG_xxx 
+ *                 flags that specify printing options.
+ * @param '...' A printf-style "format, ..." parameter list that 
+ *                 is parsed according to the printf formatting rules.
+ */
+void emscripten_log(int flags, ...);
+
+/*
+ * Programmatically obtains the current callstack.
+ * @param flags    A binary OR of items from the list of EM_LOG_xxx 
+ *                    flags that specify printing options. The 
+ *                    items EM_LOG_CONSOLE, EM_LOG_WARN and 
+ *                    EM_LOG_ERROR do not apply in this function and 
+ *                    are ignored.
+ * @param out      A pointer to a memory region where the callstack 
+ *                    string will be written to. The string outputted 
+ *                    by this function will always be null-terminated.
+ * @param maxbytes The maximum number of bytes that this function can
+ *                    write to the memory pointed to by 'out'. If 
+ *                    there is no enough space, the output will be 
+ *                    truncated (but always null-terminated).
+ * @return Returns the number of bytes written. (not number of 
+ *         characters, so this will also include the terminating zero)
+ 
+ * To query the amount of bytes needed for a callstack without writing 
+ * it, pass 0 to 'out' and 'maxbytes', in which case the function will
+ * return the number of bytes (including the terminating zero) that 
+ * will be needed to hold the full callstack. Note that this might be 
+ * fully accurate since subsequent calls will carry different line 
+ * numbers, so it is best to allocate a few bytes extra to be safe.
+ */
+int emscripten_get_callstack(int flags, char *out, int maxbytes);
+
 #ifdef __cplusplus
 }
 #endif