auto-generate library stubs that abort for missing library functions, and implement DEAD_FUNCTIONS that way

4 files changed, 9 insertions, 28 deletions

diff --git a/src/compiler.js b/src/compiler.js
index d74ff7cb..313fd5f7 100644
--- a/src/compiler.js
+++ b/src/compiler.js
@@ -169,7 +169,9 @@ EXPORTED_FUNCTIONS = set(EXPORTED_FUNCTIONS);
 EXPORTED_GLOBALS = set(EXPORTED_GLOBALS);
 EXCEPTION_CATCHING_WHITELIST = set(EXCEPTION_CATCHING_WHITELIST);
 
-if (DEAD_FUNCTIONS.length && ASSERTIONS) DEFAULT_LIBRARY_FUNCS_TO_INCLUDE.push('putchar'); // for debug output
+DEAD_FUNCTIONS.forEach(function(dead) {
+  DEFAULT_LIBRARY_FUNCS_TO_INCLUDE.push(dead.substr(1));
+});
 DEAD_FUNCTIONS = numberedSet(DEAD_FUNCTIONS);
 
 RUNTIME_DEBUG = LIBRARY_DEBUG || GL_DEBUG;
diff --git a/src/jsifier.js b/src/jsifier.js
index 30a06d76..f08be1c9 100644
--- a/src/jsifier.js
+++ b/src/jsifier.js
@@ -484,17 +484,11 @@ function JSify(data, functionsOnly, givenFunctions) {
       if (BUILD_AS_SHARED_LIB) {
         // Shared libraries reuse the runtime of their parents.
         item.JS = '';
-      } else if (LibraryManager.library.hasOwnProperty(shortident)) {
-        item.JS = addFromLibrary(shortident);
-      } else if (!LibraryManager.library.hasOwnProperty(shortident + '__inline')) {
-        if (!(item.ident in DEAD_FUNCTIONS)) {
-          item.JS = 'var ' + item.ident + '; // stub for ' + item.ident;
-          if (ASM_JS) {
-            error('Unresolved symbol: ' + item.ident + ', this must be corrected for asm.js validation to succeed. Consider adding it to DEAD_FUNCTIONS.');
-          } else if (WARN_ON_UNDEFINED_SYMBOLS) {
-            warn('Unresolved symbol: ' + item.ident);
-          }
+      } else {
+        if (!LibraryManager.library.hasOwnProperty(shortident)) {
+          LibraryManager.library[shortident] = new Function("Module['printErr']('missing library function: " + shortident + "'); abort(-1);");
         }
+        item.JS = addFromLibrary(shortident);
       }
       return ret;
     }
@@ -1439,16 +1433,6 @@ function JSify(data, functionsOnly, givenFunctions) {
       returnType = getReturnType(type);
     }
 
-    if (callIdent in DEAD_FUNCTIONS) {
-      var ret = 'abort(' + DEAD_FUNCTIONS[callIdent] + ')';
-      if (ASM_JS) ret = asmCoercion(ret, returnType);
-      if (ASSERTIONS) {
-        assert(DEFAULT_LIBRARY_FUNCS_TO_INCLUDE.indexOf('putchar') >= 0, 'need putchar for DEAD_FUNCTIONS + ASSERTIONS output');
-        ret = '(' + makePrintChars('dead:' + callIdent, ',') + ',' + ret + ')';
-      }
-      return ret;
-    }
-
     if (byPointer) {
       var sig = Functions.getSignature(returnType, argsTypes, hasVarArgs);
       if (ASM_JS) {
diff --git a/src/modules.js b/src/modules.js
index 7a769846..ce162ac1 100644
--- a/src/modules.js
+++ b/src/modules.js
@@ -291,7 +291,7 @@ var Functions = {
       var sig = ASM_JS ? Functions.implementedFunctions[ident] || Functions.unimplementedFunctions[ident] || LibraryManager.library[ident.substr(1) + '__sig'] : 'x';
       assert(sig, ident);
       if (!tables[sig]) tables[sig] = emptyTable(sig); // TODO: make them compact
-      tables[sig][this.indexedFunctions[ident]] = ident in DEAD_FUNCTIONS ? '0' : ident;
+      tables[sig][this.indexedFunctions[ident]] = ident;
     }
     var generated = false;
     var wrapped = {};
diff --git a/src/settings.js b/src/settings.js
index 8c7d1f83..c878be92 100644
--- a/src/settings.js
+++ b/src/settings.js
@@ -342,12 +342,7 @@ var PGO = 0; // Enables profile-guided optimization in the form of runtime check
              // calling PGOMonitor.dump());
 var DEAD_FUNCTIONS = []; // Functions on this list are not converted to JS, and calls to
                          // them are turned into abort()s. This is potentially useful for
-                         // (1) reducing code size, if you know some function will never
-                         // be called (see PGO), and also (2) ASM.js requires all declared
-                         // functions to have a corresponding implementation (even if the
-                         // function is never called) and will emit an error during linking if no
-                         // implementation can be found; with this option, asm.js validation will
-                         // succeed for that function and calls to it.
+                         // reducing code size.
                          // If a dead function is actually called, you will get a runtime
                          // error.
                          // TODO: options to lazily load such functions