make normalizeAsm not get confused when a var later has an unneeded 'var' before it

3 files changed, 70 insertions, 3 deletions

diff --git a/tools/eliminator/asm-eliminator-test-output.js b/tools/eliminator/asm-eliminator-test-output.js
index 70eca01a..3170bd9c 100644
--- a/tools/eliminator/asm-eliminator-test-output.js
+++ b/tools/eliminator/asm-eliminator-test-output.js
@@ -74,4 +74,30 @@ function _vec2Length($this) {
   STACKTOP = __stackBase__;
   return 0;
 }
+function exc($this) {
+  $this = $this | 0;
+  var $1 = 0, $5 = 0;
+  $1 = (function() {
+    try {
+      __THREW__ = false;
+      return __ZNSt3__16locale8__globalEv();
+    } catch (e) {
+      if (typeof e != "number") throw e;
+      if (ABORT) throw e;
+      __THREW__ = true;
+      Module.print("Exception: " + e + ", currently at: " + (new Error).stack);
+      return null;
+    }
+  })();
+  if (!__THREW__) {
+    $5 = HEAP32[(($1 | 0) & 16777215) >> 2] | 0;
+    HEAP32[(($this | 0) & 16777215) >> 2] = $5;
+    __ZNSt3__114__shared_count12__add_sharedEv($5 | 0);
+    return;
+  } else {
+    $8$0 = ___cxa_find_matching_catch(HEAP32[(_llvm_eh_exception.buf & 16777215) >> 2] | 0, HEAP32[(_llvm_eh_exception.buf + 4 & 16777215) >> 2] | 0, []);
+    $8$1 = tempRet0;
+    ___cxa_call_unexpected($8$0);
+  }
+}
 
diff --git a/tools/eliminator/asm-eliminator-test.js b/tools/eliminator/asm-eliminator-test.js
index 2fcf90d4..ce34a7a6 100644
--- a/tools/eliminator/asm-eliminator-test.js
+++ b/tools/eliminator/asm-eliminator-test.js
@@ -99,5 +99,36 @@ function _vec2Length($this) {
   STACKTOP = __stackBase__;
   return 0;
 }
-// EMSCRIPTEN_GENERATED_FUNCTIONS: ["asm", "__Z11printResultPiS_j", "_segment_holding", "__ZN5identC2EiPKcPci", "_vec2Length"]
+function exc($this) {
+  $this = $this | 0;
+  var $1 = 0, $3 = 0, $4 = 0, $5 = 0, $6 = 0, $8 = +0, $9 = 0;
+  var label = 0;
+  var $1 = (function() {
+    try {
+      __THREW__ = false;
+      return __ZNSt3__16locale8__globalEv();
+    } catch (e) {
+      if (typeof e != "number") throw e;
+      if (ABORT) throw e;
+      __THREW__ = true;
+      Module.print("Exception: " + e + ", currently at: " + (new Error).stack);
+      return null;
+    }
+  })();
+  if (!__THREW__) {
+    $3 = $this | 0;
+    $4 = $1 | 0;
+    $5 = HEAP32[($4 & 16777215) >> 2] | 0;
+    HEAP32[($3 & 16777215) >> 2] = $5;
+    $6 = $5 | 0;
+    __ZNSt3__114__shared_count12__add_sharedEv($6);
+    return;
+  } else {
+    $8$0 = ___cxa_find_matching_catch(HEAP32[(_llvm_eh_exception.buf & 16777215) >> 2] | 0, HEAP32[(_llvm_eh_exception.buf + 4 & 16777215) >> 2] | 0, []);
+    $8$1 = tempRet0;
+    $9 = $8$0;
+    ___cxa_call_unexpected($9);
+  }
+}
+// EMSCRIPTEN_GENERATED_FUNCTIONS: ["asm", "__Z11printResultPiS_j", "_segment_holding", "__ZN5identC2EiPKcPci", "_vec2Length", "exc"]
 
diff --git a/tools/js-optimizer.js b/tools/js-optimizer.js
index daa08fe5..78553771 100644
--- a/tools/js-optimizer.js
+++ b/tools/js-optimizer.js
@@ -1259,8 +1259,18 @@ function normalizeAsm(func) {
     var node = stats[i];
     if (node[0] != 'var') break;
     node[1].forEach(function(v) {
-      data.vars[v[0]] = detectAsmCoercion(v[1]);
-      v.length = 1; // make an un-assigning var
+      var name = v[0];
+      var value = v[1];
+      if (!(name in data.vars)) {
+        assert(value[0] == 'num' || (value[0] == 'unary-prefix' && value[2][0] == 'num')); // must be valid coercion no-op
+        data.vars[name] = detectAsmCoercion(value);
+        v.length = 1; // make an un-assigning var
+      } else {
+        // known var, just an unneeded 'var ' that when removed leaves an assign
+        assert(node[1].length == 1);
+        node[0] = 'stat';
+        node[1] = ['assign', true, ['name', name], value];
+      }
     });
     i++;
   }