properly resolve multilevel function aliases, fixes bug with adding indexing for aliases. also optimize function indexing in compiler

4 files changed, 55 insertions, 11 deletions

diff --git a/src/jsifier.js b/src/jsifier.js
index 45177c3f..b02164f6 100644
--- a/src/jsifier.js
+++ b/src/jsifier.js
@@ -341,7 +341,7 @@ function JSify(data, functionsOnly, givenFunctions) {
       var ret = [item];
       item.JS = 'var ' + item.ident + ';';
       // Set the actual value in a postset, since it may be a global variable. We also order by dependencies there
-      var value = finalizeLLVMParameter(item.value);
+      var value = Variables.globals[item.ident].resolvedAlias = finalizeLLVMParameter(item.value);
       ret.push({
         intertype: 'GlobalVariablePostSet',
         ident: item.ident,
diff --git a/src/modules.js b/src/modules.js
index 3ce4a541..49f93e61 100644
--- a/src/modules.js
+++ b/src/modules.js
@@ -254,22 +254,37 @@ var Functions = {
   // All the function idents seen so far
   allIdents: [],
 
-  indexedFunctions: [0, 0], // Start at a non-0 (even, see below) value
+  indexedFunctions: {},
+  nextIndex: 2, // Start at a non-0 (even, see below) value
 
   // Mark a function as needing indexing, and returns the index
   getIndex: function(ident) {
-    var key = this.indexedFunctions.indexOf(ident);
-    if (key < 0) {
-      key = this.indexedFunctions.length;
-      this.indexedFunctions[key] = ident;
-      this.indexedFunctions[key+1] = 0; // Need to have keys be even numbers, see |polymorph| test
+    var ret = this.indexedFunctions[ident];
+    if (!ret) {
+      ret = this.nextIndex;
+      this.nextIndex += 2; // Need to have indexes be even numbers, see |polymorph| test
+      this.indexedFunctions[ident] = ret;
     }
-    return key.toString();
+    return ret.toString();
   },
 
   // Generate code for function indexing
   generateIndexing: function() {
-    var indices = this.indexedFunctions.toString().replace('"', '');
+    var vals = zeros(this.nextIndex);
+    for (var ident in this.indexedFunctions) {
+      vals[this.indexedFunctions[ident]] = ident;
+    }
+
+    // Resolve multi-level aliases all the way down
+    for (var i = 0; i < vals.length; i++) {
+      while (1) {
+        var varData = Variables.globals[vals[i]];
+        if (!(varData && varData.resolvedAlias)) break;
+        vals[i] = vals[varData.resolvedAlias];
+      }
+    }
+
+    var indices = vals.toString().replace('"', '');
     if (BUILD_AS_SHARED_LIB) {
       // Shared libraries reuse the parent's function table.
       return 'FUNCTION_TABLE = FUNCTION_TABLE.concat([' + indices + ']);';
diff --git a/src/parseTools.js b/src/parseTools.js
index 92a360ad..24c38296 100644
--- a/src/parseTools.js
+++ b/src/parseTools.js
@@ -951,8 +951,8 @@ function makeGetValue(ptr, pos, type, noNeedFirst, unsigned, ignore, align, noSa
 }
 
 function indexizeFunctions(value, type) {
-  assert((type && type !== '?') || (typeof value === 'string' && value.substr(0, 6) === 'CHECK_'), 'No type given for function indexizing: ' + [value, type]);
-  assert(value !== type, 'Type set to value: ' + [value, type]);
+  assert((type && type !== '?') || (typeof value === 'string' && value.substr(0, 6) === 'CHECK_'), 'No type given for function indexizing');
+  assert(value !== type, 'Type set to value');
   if (type && isFunctionType(type) && value[0] === '_') { // checking for _ differentiates from $ (local vars)
     if (BUILD_AS_SHARED_LIB) {
       return '(FUNCTION_TABLE_OFFSET + ' + Functions.getIndex(value) + ')';
diff --git a/tests/cases/aliasbitcast3.ll b/tests/cases/aliasbitcast3.ll
new file mode 100644
index 00000000..4ff969e3
--- /dev/null
+++ b/tests/cases/aliasbitcast3.ll
@@ -0,0 +1,29 @@
+; ModuleID = '/tmp/emscripten/tmp/src.cpp.o'
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32-n8:16:32"
+target triple = "i386-pc-linux-gnu"
+
+@.str = private constant [14 x i8] c"hello, world!\00", align 1 ; [#uses=1]
+
+@thriceremoved = alias bitcast (void ()* @twiceremoved to void (i32)*) ; [#uses=1]
+@othername = alias bitcast (void ()* @original to void (i32)*) ; [#uses=1]
+@twiceremoved = alias bitcast (void (i32)* @othername to void ()*) ; [#uses=1]
+
+; [#uses=2]
+define void @original() {
+entry:
+  %0 = call i32 bitcast (i32 (i8*)* @puts to i32 (i32*)*)(i8* getelementptr inbounds ([14 x i8]* @.str, i32 0, i32 0)) ; [#uses=0]
+  br label %return
+
+return:                                           ; preds = %entry
+  ret void
+}
+
+; [#uses=1]
+declare i32 @puts(i8*)
+
+; [#uses=0]
+define i32 @main() {
+entry:
+  call void @thriceremoved()
+  ret i32 0
+}