Bug 986313: Use LifoAllocPolicy for VarTypeVector and prevent a memory leak when moving it in ModuleCompiler; r=luke

js/src/ds/LifoAlloc.h

@@ -521,6 +521,36 @@ class LifoAllocScope
     }
 };
 
+class LifoAllocPolicy
+{
+    LifoAlloc &alloc_;
+
+  public:
+    LifoAllocPolicy(LifoAlloc &alloc)
+      : alloc_(alloc)
+    {}
+    void *malloc_(size_t bytes) {
+        return alloc_.alloc(bytes);
+    }
+    void *calloc_(size_t bytes) {
+        void *p = malloc_(bytes);
+        if (p)
+            memset(p, 0, bytes);
+        return p;
+    }
+    void *realloc_(void *p, size_t oldBytes, size_t bytes) {
+        void *n = malloc_(bytes);
+        if (!n)
+            return n;
+        memcpy(n, p, Min(oldBytes, bytes));
+        return n;
+    }
+    void free_(void *p) {
+    }
+    void reportAllocOverflow() const {
+    }
+};
+
 } // namespace js
 
 #endif /* ds_LifoAlloc_h */

js/src/jit/AsmJS.cpp

@@ -672,7 +672,7 @@ class ABIArgIter
 typedef js::Vector<MIRType, 8> MIRTypeVector;
 typedef ABIArgIter<MIRTypeVector> ABIArgMIRTypeIter;
 
-typedef js::Vector<VarType, 8> VarTypeVector;
+typedef js::Vector<VarType, 8, LifoAllocPolicy> VarTypeVector;
 typedef ABIArgIter<VarTypeVector> ABIArgTypeIter;
 
 class Signature
@@ -681,10 +681,10 @@ class Signature
     RetType retType_;
 
   public:
-    Signature(ExclusiveContext *cx)
-      : argTypes_(cx) {}
-    Signature(ExclusiveContext *cx, RetType retType)
-      : argTypes_(cx), retType_(retType) {}
+    Signature(LifoAlloc &alloc)
+      : argTypes_(alloc) {}
+    Signature(LifoAlloc &alloc, RetType retType)
+      : argTypes_(alloc), retType_(retType) {}
     Signature(VarTypeVector &&argTypes, RetType retType)
       : argTypes_(Move(argTypes)), retType_(Move(retType)) {}
     Signature(Signature &&rhs)
@@ -1416,6 +1416,9 @@ class MOZ_STACK_CLASS ModuleCompiler
     uint32_t minHeapLength() const {
         return module_->minHeapLength();
     }
+    LifoAlloc &lifo() {
+        return moduleLifo_;
+    }
 
     bool collectAccesses(MIRGenerator &gen) {
         if (!module_->addHeapAccesses(gen.heapAccesses()))
@@ -2281,7 +2284,7 @@ class FunctionCompiler
           : prevMaxStackBytes_(0),
             maxChildStackBytes_(0),
             spIncrement_(0),
-            sig_(f.cx(), retType),
+            sig_(f.m().lifo(), retType),
             regArgs_(f.cx()),
             stackArgs_(f.cx()),
             childClobbers_(false)
@@ -5384,7 +5387,7 @@ CheckFunction(ModuleCompiler &m, LifoAlloc &lifo, MIRGenerator **mir, ModuleComp
 
     ParseNode *stmtIter = ListHead(FunctionStatementList(fn));
 
-    VarTypeVector argTypes(m.cx());
+    VarTypeVector argTypes(m.lifo());
     if (!CheckArguments(f, &stmtIter, &argTypes))
         return false;
 
@@ -5841,7 +5844,7 @@ CheckFuncPtrTable(ModuleCompiler &m, ParseNode *var)
             return false;
     }
 
-    Signature sig(m.cx());
+    Signature sig(m.lifo());
     if (!sig.copy(*firstSig))
         return false;