Add emscripten_console_trace and emscripten_dbg_backtrace. NFC

These are very useful for debugging.  The former simply maps directly
to `console.trace`.  The latter use `dbg()` so it writes directly to
stderr under node (better for multi-threaded apps).

ChangeLog.md

@@ -22,6 +22,10 @@ See docs/process.md for more on how version tagging works.
 -----------------------
 - Added support for WebGL extensions EXT_clip_control, EXT_depth_clamp,
   EXT_polygon_offset_clamp and WEBGL_polygon_mode (#20841)
+- New `emscripten_console_trace` and `emscripten_dbg_backtrace` APIs we were
+  added to `console.h`.  The former simply maps directly to `console.trace`.
+  The latter use `dbg()` so it writes directly to stderr under node (better for
+  multi-threaded apps).
 
 3.1.65 - 08/22/24
 -----------------

src/library.js

@@ -2062,6 +2062,10 @@ addToLibrary({
   emscripten_dbgn: (str, len) => dbg(UTF8ToString(str, len)),
 #endif
 
+  emscripten_dbg_backtrace: (str) => {
+    dbg(UTF8ToString(str) + '\n' + new Error().stack);
+  },
+
   // Use program_invocation_short_name and program_invocation_name in compiled
   // programs. This function is for implementing them.
   _emscripten_get_progname__deps: ['$getExecutableName', '$stringToUTF8'],
@@ -2090,6 +2094,13 @@ addToLibrary({
     console.error(UTF8ToString(str));
   },
 
+  emscripten_console_trace: (str) => {
+#if ASSERTIONS
+    assert(typeof str == 'number');
+#endif
+    console.trace(UTF8ToString(str));
+  },
+
   emscripten_throw_number: (number) => {
     throw number;
   },

system/include/emscripten/console.h

@@ -16,6 +16,7 @@ extern "C" {
 void emscripten_console_log(const char *utf8String __attribute__((nonnull)));
 void emscripten_console_warn(const char *utf8String __attribute__((nonnull)));
 void emscripten_console_error(const char *utf8String __attribute__((nonnull)));
+void emscripten_console_trace(const char *utf8String __attribute__((nonnull)));
 
 // Write to the out(), err() and dbg() JS functions directly.
 // These are defined an defined in shell.js and have different behavior compared
@@ -27,6 +28,7 @@ void emscripten_console_error(const char *utf8String __attribute__((nonnull)));
 void emscripten_out(const char *utf8String __attribute__((nonnull)));
 void emscripten_err(const char *utf8String __attribute__((nonnull)));
 void emscripten_dbg(const char *utf8String __attribute__((nonnull)));
+void emscripten_dbg_backtrace(const char *utf8String __attribute__((nonnull)));
 
 // Same as above but only with the length of string specified by the second
 // argument.  This allows for non-NULL-terminated strings to be passed.
@@ -43,9 +45,11 @@ void emscripten_dbgn(const char *utf8String __attribute__((nonnull)), size_t len
 void emscripten_console_logf(const char *format __attribute__((nonnull)), ...) __attribute__((__format__(printf, 1, 2)));
 void emscripten_console_warnf(const char *format __attribute__((nonnull)), ...) __attribute__((__format__(printf, 1, 2)));
 void emscripten_console_errorf(const char *format __attribute__((nonnull)), ...)__attribute__((__format__(printf, 1, 2)));
+void emscripten_console_tracef(const char *format __attribute__((nonnull)), ...)__attribute__((__format__(printf, 1, 2)));
 void emscripten_outf(const char *format __attribute__((nonnull)), ...) __attribute__((__format__(printf, 1, 2)));
 void emscripten_errf(const char *format __attribute__((nonnull)), ...) __attribute__((__format__(printf, 1, 2)));
 void emscripten_dbgf(const char *format __attribute__((nonnull)), ...) __attribute__((__format__(printf, 1, 2)));
+void emscripten_dbg_backtracef(const char *format __attribute__((nonnull)), ...) __attribute__((__format__(printf, 1, 2)));
 
 // Legacy/internal names for the above
 #define _emscripten_outf(format, ...) emscripten_outf(format, ##__VA_ARGS__)

system/lib/libc/emscripten_console.c

@@ -41,6 +41,13 @@ void emscripten_console_warnf(const char* fmt, ...) {
   va_end(ap);
 }
 
+void emscripten_console_tracef(const char* fmt, ...) {
+  va_list ap;
+  va_start(ap, fmt);
+  vlogf(fmt, ap, &emscripten_console_trace);
+  va_end(ap);
+}
+
 void emscripten_outf(const char* fmt, ...) {
   va_list ap;
   va_start(ap, fmt);
@@ -62,4 +69,11 @@ void emscripten_dbgf(const char* fmt, ...) {
   vlogf(fmt, ap, &emscripten_dbg);
   va_end(ap);
 }
+
+void emscripten_dbg_backtracef(const char* fmt, ...) {
+  va_list ap;
+  va_start(ap, fmt);
+  vlogf(fmt, ap, &emscripten_dbg_backtrace);
+  va_end(ap);
+}
 #endif

test/common.py

@@ -1480,9 +1480,9 @@ def assertContained(self, values, string, additional_info='', regex=False):
 
     if regex:
       if type(values) is str:
-        self.assertTrue(re.search(values, string), 'Expected regex "%s" to match on:\n%s' % (values, string))
+        self.assertTrue(re.search(values, string, re.DOTALL), 'Expected regex "%s" to match on:\n%s' % (values, string))
       else:
-        match_any = any(re.search(o, string) for o in values)
+        match_any = any(re.search(o, string, re.DOTALL) for o in values)
         self.assertTrue(match_any, 'Expected at least one of "%s" to match on:\n%s' % (values, string))
       return
 

test/other/test_console_out.c

@@ -5,11 +5,13 @@ int main(int argc, char** argv) {
   emscripten_err("this is err");
   emscripten_out("this is out");
   emscripten_dbg("this is dbg");
+  emscripten_dbg_backtrace("this is dbg_backtrace");
 
   // Formatting variants
   emscripten_errf("this is err: %d", argc);
   emscripten_outf("this is out: %d", argc + 1);
   emscripten_dbgf("this is dbg: %d", argc + 2);
+  emscripten_dbg_backtracef("this is dbg_backtrace: %d", argc + 3);
 
   // Length-taking variants
   emscripten_errn("hello err", 3);

test/other/test_console_out.out

@@ -1,9 +1,13 @@
 this is err
 this is out
 this is dbg
+this is dbg_backtrace
+.*
 this is err: 1
 this is out: 2
 this is dbg: 3
+this is dbg_backtrace: 4
+.*
 hel
 hell
 hello

test/test_other.py

@@ -14701,7 +14701,7 @@ def test_proxy_to_worker(self):
 
   @also_with_standalone_wasm()
   def test_console_out(self):
-    self.do_other_test('test_console_out.c')
+    self.do_other_test('test_console_out.c', regex=True)
 
   @requires_wasm64
   def test_explicit_target(self):