Remove use of demangleAll helper function (#21156)

This was used to demangle C++ symbols JS stacktraces.  However for
a long time now native symbols in JS backtraces are already demanged
because names in the name section are in demangled form.  So this
function has not done anything for a very long time.

As a followup I think we can probably completely remove the
`DEMANGLE_SUPPORT` settings.

Author: sbc100

site/source/docs/api_reference/preamble.js.rst

@@ -369,7 +369,6 @@ The :ref:`emscripten-memory-model` uses a typed array buffer (``ArrayBuffer``) t
   Module['HEAP'] = HEAP;
   Module['IHEAP'] = IHEAP;
   function demangle(func)
-  function demangleAll(text)
   function parseJSFunc(jsfunc)
   function callRuntimeCallbacks(callbacks)
   function preRun()

site/source/docs/tools_reference/settings_reference.rst

@@ -409,8 +409,7 @@ Print out exceptions in emscriptened code.
 DEMANGLE_SUPPORT
 ================
 
-If 1, build in libcxxabi's full c++ demangling code, to allow stackTrace()
-to emit fully proper demangled c++ names
+If 1, export `demangle` and `stackTrace` helper function.
 
 .. _library_debug:
 

src/library_fs.js

@@ -29,9 +29,6 @@ addToLibrary({
 #endif
 #if ASSERTIONS
     '$ERRNO_MESSAGES', '$ERRNO_CODES',
-#endif
-#if ASSERTIONS && !MINIMAL_RUNTIME
-    '$demangleAll',
 #endif
   ],
   $FS__postset: function() {
@@ -1441,7 +1438,6 @@ FS.staticInit();` +
         if (this.stack) {
           // Define the stack property for Node.js 4, which otherwise errors on the next line.
           Object.defineProperty(this, "stack", { value: (new Error).stack, writable: true });
-          this.stack = demangleAll(this.stack);
         }
 #endif // ASSERTIONS
       };

src/library_stack_trace.js

@@ -42,17 +42,6 @@ var LibraryStackTrace = {
 #endif // DEMANGLE_SUPPORT
   },
 
-  $demangleAll__deps: ['$demangle'],
-  $demangleAll: (text) => {
-    var regex =
-      /\b_Z[\w\d_]+/g;
-    return text.replace(regex,
-      function(x) {
-        var y = demangle(x);
-        return x === y ? x : (y + ' [' + x + ']');
-      });
-  },
-
   $jsStackTrace: function() {
     var error = new Error();
     if (!error.stack) {
@@ -70,11 +59,11 @@ var LibraryStackTrace = {
     return error.stack.toString();
   },
 
-  $stackTrace__deps: ['$jsStackTrace', '$demangleAll'],
+  $stackTrace__deps: ['$jsStackTrace'],
   $stackTrace: function() {
     var js = jsStackTrace();
     if (Module['extraStackTrace']) js += '\n' + Module['extraStackTrace']();
-    return demangleAll(js);
+    return js;
   }
 }
 

src/memoryprofiler.js

@@ -434,7 +434,6 @@ var emscriptenMemoryProfiler = {
   },
 
   printHeapResizeLog(heapResizes) {
-    var demangler = typeof demangleAll != 'undefined' ? demangleAll : (x) => x;
     var html = '';
     for (var i = 0; i < heapResizes.length; ++i) {
       var j = i+1;
@@ -448,7 +447,7 @@ var emscriptenMemoryProfiler = {
       var resizeFirst = heapResizes[i];
       var resizeLast = heapResizes[j-1];
       var count = j - i;
-      html += '<div style="background-color: ' + resizeFirst.color + '"><b>' + resizeFirst.begin + '-' + resizeLast.end + ' (' + count + ' times, ' + emscriptenMemoryProfiler.formatBytes(resizeLast.end-resizeFirst.begin) + ')</b>:' + demangler(resizeFirst.filteredStack || resizeFirst.stack) + '</div><br>';
+      html += '<div style="background-color: ' + resizeFirst.color + '"><b>' + resizeFirst.begin + '-' + resizeLast.end + ' (' + count + ' times, ' + emscriptenMemoryProfiler.formatBytes(resizeLast.end-resizeFirst.begin) + ')</b>:' + (resizeFirst.filteredStack || resizeFirst.stack) + '</div><br>';
       i = j-1;
     }
     return html;
@@ -599,7 +598,6 @@ var emscriptenMemoryProfiler = {
       html += self.printHeapResizeLog(self.sbrkSources);
       html += '</div>'
     } else {
-      var demangler = typeof demangleAll != 'undefined' ? demangleAll : (x) => x;
       // Print out statistics of individual allocations if they were tracked.
       if (Object.keys(self.allocationsAtLoc).length > 0) {
         var calls = [];
@@ -615,8 +613,7 @@ var emscriptenMemoryProfiler = {
           }
           html += '<h4>Allocation sites with more than ' + self.formatBytes(self.trackedCallstackMinSizeBytes) + ' of accumulated allocations, or more than ' + self.trackedCallstackMinAllocCount + ' simultaneously outstanding allocations:</h4>'
           for (var i in calls) {
-            if (calls[i].length == 3) calls[i] = [calls[i][0], calls[i][1], calls[i][2], demangler(calls[i][2])];
-            html += "<b>" + self.formatBytes(calls[i][1]) + '/' + calls[i][0] + " allocs</b>: " + calls[i][3] + "<br />";
+            html += "<b>" + self.formatBytes(calls[i][1]) + '/' + calls[i][0] + " allocs</b>: " + calls[i][2] + "<br />";
           }
         }
       }

src/settings.js

@@ -337,8 +337,7 @@ var EMULATE_FUNCTION_POINTER_CASTS = false;
 // [link]
 var EXCEPTION_DEBUG = false;
 
-// If 1, build in libcxxabi's full c++ demangling code, to allow stackTrace()
-// to emit fully proper demangled c++ names
+// If 1, export `demangle` and `stackTrace` helper function.
 // [link]
 var DEMANGLE_SUPPORT = false;
 

test/other/metadce/test_metadce_hello_O0.gzsize

@@ -1 +1 @@
-8412
+8408

test/other/metadce/test_metadce_hello_O0.jssize

@@ -1 +1 @@
-23081
+23069

test/other/metadce/test_metadce_minimal_O0.gzsize

@@ -1 +1 @@
-7242
+7238

test/other/metadce/test_metadce_minimal_O0.jssize

@@ -1 +1 @@
-19705
+19693

test/other/test_unoptimized_code_size.js.size

@@ -1 +1 @@
-58257
+58240

test/other/test_unoptimized_code_size_strict.js.size

@@ -1 +1 @@
-57099
+57082