Replace use of Emscripten's Module.postRun() with a custom callback so that we get consistent library init timing with both Emscripten 3.1.x and 4.0.x. Details and discussion are in [https://github.com/emscripten-core/emscripten/issues/23420|Emscripten ticket #23420].

FossilOrigin-Name: 4863a70ac61ff6f868429f16f0141484ea98f973fde1a9aff879252d0f1dbb6b

ext/wasm/api/extern-post-js.c-pp.js

@@ -65,15 +65,14 @@ const toExportForESM =
     return originalInit(...args).then((EmscriptenModule)=>{
       //console.warn("originalInit() then() arg =",EmscriptenModule);
       //console.warn("initModuleState =",initModuleState);
-      if( EmscriptenModule.postRun && EmscriptenModule.postRun.length ){
-        /* Emscripten 4.0.0 changes the order in which our Module.postRun handler
-           runs. In 3.x postRun would have run by now, and our code relies
-           heavily on that order, so we'll work around that difference here.
-
-           https://github.com/emscripten-core/emscripten/issues/23420 */
-        //console.warn("Emscripten did not run postRun: running them now!");
-        EmscriptenModule.postRun.shift()(EmscriptenModule);
-      }
+      EmscriptenModule.runSQLite3PostLoadInit(EmscriptenModule);
+      const s = EmscriptenModule.sqlite3;
+      s.scriptInfo = initModuleState;
+      //console.warn("sqlite3.scriptInfo =",s.scriptInfo);
+      if(ff.__isUnderTest) s.__isUnderTest = true;
+      const f = s.asyncPostInit;
+      delete s.asyncPostInit;
+      const rv = f();
 //#if wasmfs
       if('undefined'!==typeof WorkerGlobalScope &&
          EmscriptenModule['ENVIRONMENT_IS_PTHREAD']){
@@ -86,13 +85,7 @@ const toExportForESM =
         return EmscriptenModule;
       }
 //#endif
-      const s = EmscriptenModule.sqlite3;
-      s.scriptInfo = initModuleState;
-      //console.warn("sqlite3.scriptInfo =",s.scriptInfo);
-      if(ff.__isUnderTest) s.__isUnderTest = true;
-      const f = s.asyncPostInit;
-      delete s.asyncPostInit;
-      return f();
+      return rv;
     }).catch((e)=>{
       console.error("Exception loading sqlite3 module:",e);
       throw e;

ext/wasm/api/post-js-footer.js

@@ -1,6 +1,6 @@
 /* The current function scope was opened via post-js-header.js, which
    gets prepended to this at build-time. This file closes that
    scope. */
-//console.warn("This is the end of the Module.postRun handler.");
-})/*postRun.push(...)*/;
-//console.warn("This is the end of the setup of the (pending) Module.postRun");
+//console.warn("This is the end of the Module.runSQLite3PostLoadInit handler.");
+}/*Module.runSQLite3PostLoadInit()*/;
+//console.warn("This is the end of the setup of the (pending) Module.runSQLite3PostLoadInit");

ext/wasm/api/post-js-header.js

@@ -7,8 +7,12 @@
    installs will be run after the WASM module is loaded, at which
    point the sqlite3 JS API bits will get set up.
 */
-if(!Module.postRun) Module.postRun = [];
-Module.postRun.push(function(Module/*the Emscripten-style module object*/){
+Module.runSQLite3PostLoadInit = function(EmscriptenModule/*the Emscripten-style module object*/){
+  /** ^^^ As don't use Module.postRun, as that runs a different time
+      depending on whether this file is built with emcc 3.1.x or
+      4.0.x. This function name is intentionally obnoxiously verbose to
+      ensure that we don't collide with current and future Emscripten
+      symbol names. */
   'use strict';
   //console.warn("This is the start of the Module.postRun handler.");
   /* This function will contain at least the following:
@@ -16,9 +20,9 @@ Module.postRun.push(function(Module/*the Emscripten-style module object*/){
      - post-js-header.js (this file)
      - sqlite3-api-prologue.js  => Bootstrapping bits to attach the rest to
      - common/whwasmutil.js     => Replacements for much of Emscripten's glue
-     - jaccwaby/jaccwabyt.js    => Jaccwabyt (C/JS struct binding)
+     - jaccwabyt/jaccwabyt.js   => Jaccwabyt (C/JS struct binding)
      - sqlite3-api-glue.js      => glues previous parts together
-     - sqlite3-api-oo.js        => SQLite3 OO API #1
+     - sqlite3-api-oo1.js       => SQLite3 OO API #1
      - sqlite3-api-worker1.js   => Worker-based API
      - sqlite3-vfs-helper.c-pp.js  => Utilities for VFS impls
      - sqlite3-vtab-helper.c-pp.js => Utilities for virtual table impls

ext/wasm/api/sqlite3-api-prologue.js

@@ -12,12 +12,12 @@
 
   This file is intended to be combined at build-time with other
   related code, most notably a header and footer which wraps this
-  whole file into an Emscripten Module.postRun() handler. The sqlite3
-  JS API has no hard requirements on Emscripten and does not expose
-  any Emscripten APIs to clients. It is structured such that its build
-  can be tweaked to include it in arbitrary WASM environments which
-  can supply the necessary underlying features (e.g. a POSIX file I/O
-  layer).
+  whole file into an Emscripten Module.postRun()-style handler. The
+  sqlite3 JS API has no hard requirements on Emscripten and does not
+  expose any Emscripten APIs to clients. It is structured such that
+  its build can be tweaked to include it in arbitrary WASM
+  environments which can supply the necessary underlying features
+  (e.g. a POSIX file I/O layer).
 
   Main project home page: https://sqlite.org