OVMS3/OVMS.V3/components/duktape/extras/console/duk_console.c

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/*
* Minimal 'console' binding.
*
* https://github.com/DeveloperToolsWG/console-object/blob/master/api.md
* https://developers.google.com/web/tools/chrome-devtools/debug/console/console-reference
* https://developer.mozilla.org/en/docs/Web/API/console
*/
#include <stdio.h>
#include <stdarg.h>
#include "duktape.h"
#include "duk_console.h"
/* XXX: Add some form of log level filtering. */
/* XXX: Should all output be written via e.g. console.write(formattedMsg)?
* This would make it easier for user code to redirect all console output
* to a custom backend.
*/
/* XXX: Init console object using duk_def_prop() when that call is available. */
static duk_ret_t duk__console_log_helper(duk_context *ctx, const char *error_name) {
duk_uint_t flags = (duk_uint_t) duk_get_current_magic(ctx);
FILE *output = (flags & DUK_CONSOLE_STDOUT_ONLY) ? stdout : stderr;
duk_idx_t n = duk_get_top(ctx);
duk_idx_t i;
duk_get_global_string(ctx, "console");
duk_get_prop_string(ctx, -1, "format");
for (i = 0; i < n; i++) {
if (duk_check_type_mask(ctx, i, DUK_TYPE_MASK_OBJECT)) {
/* Slow path formatting. */
duk_dup(ctx, -1); /* console.format */
duk_dup(ctx, i);
duk_call(ctx, 1);
duk_replace(ctx, i); /* arg[i] = console.format(arg[i]); */
}
}
duk_pop_2(ctx);
duk_push_string(ctx, " ");
duk_insert(ctx, 0);
duk_join(ctx, n);
if (error_name) {
duk_push_error_object(ctx, DUK_ERR_ERROR, "%s", duk_require_string(ctx, -1));
duk_push_string(ctx, "name");
duk_push_string(ctx, error_name);
duk_def_prop(ctx, -3, DUK_DEFPROP_FORCE | DUK_DEFPROP_HAVE_VALUE); /* to get e.g. 'Trace: 1 2 3' */
duk_get_prop_string(ctx, -1, "stack");
}
fprintf(output, "%s\n", duk_to_string(ctx, -1));
if (flags & DUK_CONSOLE_FLUSH) {
fflush(output);
}
return 0;
}
static duk_ret_t duk__console_assert(duk_context *ctx) {
if (duk_to_boolean(ctx, 0)) {
return 0;
}
duk_remove(ctx, 0);
return duk__console_log_helper(ctx, "AssertionError");
}
static duk_ret_t duk__console_log(duk_context *ctx) {
return duk__console_log_helper(ctx, NULL);
}
static duk_ret_t duk__console_trace(duk_context *ctx) {
return duk__console_log_helper(ctx, "Trace");
}
static duk_ret_t duk__console_info(duk_context *ctx) {
return duk__console_log_helper(ctx, NULL);
}
static duk_ret_t duk__console_warn(duk_context *ctx) {
return duk__console_log_helper(ctx, NULL);
}
static duk_ret_t duk__console_error(duk_context *ctx) {
return duk__console_log_helper(ctx, "Error");
}
static duk_ret_t duk__console_dir(duk_context *ctx) {
/* For now, just share the formatting of .log() */
return duk__console_log_helper(ctx, 0);
}
static void duk__console_reg_vararg_func(duk_context *ctx, duk_c_function func, const char *name, duk_uint_t flags) {
duk_push_c_function(ctx, func, DUK_VARARGS);
duk_push_string(ctx, "name");
duk_push_string(ctx, name);
duk_def_prop(ctx, -3, DUK_DEFPROP_HAVE_VALUE | DUK_DEFPROP_FORCE); /* Improve stacktraces by displaying function name */
duk_set_magic(ctx, -1, (duk_int_t) flags);
duk_put_prop_string(ctx, -2, name);
}
void duk_console_init(duk_context *ctx, duk_uint_t flags) {
duk_uint_t flags_orig;
/* If both DUK_CONSOLE_STDOUT_ONLY and DUK_CONSOLE_STDERR_ONLY where specified,
* just turn off DUK_CONSOLE_STDOUT_ONLY and keep DUK_CONSOLE_STDERR_ONLY.
*/
if ((flags & DUK_CONSOLE_STDOUT_ONLY) && (flags & DUK_CONSOLE_STDERR_ONLY)) {
flags &= ~DUK_CONSOLE_STDOUT_ONLY;
}
/* Remember the (possibly corrected) flags we received. */
flags_orig = flags;
duk_push_object(ctx);
/* Custom function to format objects; user can replace.
* For now, try JX-formatting and if that fails, fall back
* to ToString(v).
*/
duk_eval_string(ctx,
"(function (E) {"
"return function format(v){"
"try{"
"return E('jx',v);"
"}catch(e){"
"return String(v);" /* String() allows symbols, ToString() internal algorithm doesn't. */
"}"
"};"
"})(Duktape.enc)");
duk_put_prop_string(ctx, -2, "format");
flags = flags_orig;
if (!(flags & DUK_CONSOLE_STDOUT_ONLY) && !(flags & DUK_CONSOLE_STDERR_ONLY)) {
/* No output indicators were specified; these levels go to stdout. */
flags |= DUK_CONSOLE_STDOUT_ONLY;
}
duk__console_reg_vararg_func(ctx, duk__console_assert, "assert", flags);
duk__console_reg_vararg_func(ctx, duk__console_log, "log", flags);
duk__console_reg_vararg_func(ctx, duk__console_log, "debug", flags); /* alias to console.log */
duk__console_reg_vararg_func(ctx, duk__console_trace, "trace", flags);
duk__console_reg_vararg_func(ctx, duk__console_info, "info", flags);
flags = flags_orig;
if (!(flags & DUK_CONSOLE_STDOUT_ONLY) && !(flags & DUK_CONSOLE_STDERR_ONLY)) {
/* No output indicators were specified; these levels go to stderr. */
flags |= DUK_CONSOLE_STDERR_ONLY;
}
duk__console_reg_vararg_func(ctx, duk__console_warn, "warn", flags);
duk__console_reg_vararg_func(ctx, duk__console_error, "error", flags);
duk__console_reg_vararg_func(ctx, duk__console_error, "exception", flags); /* alias to console.error */
duk__console_reg_vararg_func(ctx, duk__console_dir, "dir", flags);
duk_put_global_string(ctx, "console");
/* Proxy wrapping: ensures any undefined console method calls are
* ignored silently. This was required specifically by the
* DeveloperToolsWG proposal (and was implemented also by Firefox:
* https://bugzilla.mozilla.org/show_bug.cgi?id=629607). This is
* apparently no longer the preferred way of implementing console.
* When Proxy is enabled, whitelist at least .toJSON() to avoid
* confusing JX serialization of the console object.
*/
if (flags & DUK_CONSOLE_PROXY_WRAPPER) {
/* Tolerate failure to initialize Proxy wrapper in case
* Proxy support is disabled.
*/
(void) duk_peval_string_noresult(ctx,
"(function(){"
"var D=function(){};"
"var W={toJSON:true};" /* whitelisted */
"console=new Proxy(console,{"
"get:function(t,k){"
"var v=t[k];"
"return typeof v==='function'||W[k]?v:D;"
"}"
"});"
"})();"
);
}
}