[rfc][icedtea-web] C++ unit-tests for memory leak w/ simple leak-detecting operator-new, along with fix

[Pavel Tisnovsky]

Hi Adam,

this patch looks very good in overall, but I'm not sure (=I'm dumb today) why can't you
simply use ::new and ::delete operators to override them in following place:

+void* operator new(size_t size) throw (std::bad_alloc) {
+    if (!__allocations) {
+        // This uses placement-new, which calls the constructor on a specific memory location
+        // This is needed because we cannot call 'new' in this context, nor can we rely on static-initialization
+        // for the set to occur before any call to 'new'!
+        void* memory = malloc(sizeof(AllocationSet));
+        __allocations = new (memory) AllocationSet();
+    }
+
+    void* mem = malloc(size);
+    if (mem == 0) {
+        throw std::bad_alloc(); // ANSI/ISO compliant behavior
+    }
+    __allocations->insert(mem);
+    return mem;
+

Cheers,
Pavel

----- Adam Domurad <adomurad at redhat.com> wrote:
> The unit test infrastructure + tests:
> 2012-12-XX  Adam Domurad  <adomurad at redhat.com>
> 
>      * tests/cpp-unit-tests/browser_mock.cc
>      (mock_retainobject): New, mocks behaviour of NPAPI retainobject
>      (mock_releaseobject): New, mocks behaviour of NPAPI releaseobject
>      * tests/cpp-unit-tests/main.cc: Add warning of memory leak based on
>      operator-new.
>      * tests/cpp-unit-tests/IcedTeaScriptablePluginObjectTest.cc: New, tests
>      for memory leak in (IcedTeaScriptableJavaObject::deAllocate) and
>      (IcedTeaScriptableJavaPackageObject::deAllocate)
>      * tests/cpp-unit-tests/checked_allocations.h: Defines set that does not
>      use operator-new, to prevent recursion in overloaded operator-new
>      * tests/cpp-unit-tests/checked_allocations.cc: Operator new overload
>      that has allocation-set for querying live allocations.
> 
> The fix:
> 2012-12-XX  Adam Domurad  <adomurad at redhat.com>
> 
>      * plugin/icedteanp/IcedTeaScriptablePluginObject.cc
>      (IcedTeaScriptableJavaObject::deAllocate): Fix memory leak
>      (IcedTeaScriptableJavaPackageObject::deAllocate): Fix memory leak