The Tor Browser: build/clang-plugin/tests/TestNonHeapClass.cpp@ac0c01689b40

Implement a real Private Browsing Mode condition by changing the API/ABI;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

     1 #define MOZ_NONHEAP_CLASS __attribute__((annotate("moz_nonheap_class")))

     2 #define MOZ_STACK_CLASS __attribute__((annotate("moz_stack_class")))

     3 #include <stddef.h>

     5 struct MOZ_NONHEAP_CLASS NonHeap {

     6   int i;

     7   void *operator new(size_t x) { return 0; }

     8   void *operator new(size_t blah, char *buffer) { return buffer; }

     9 };

    11 template <class T>

    12 struct MOZ_NONHEAP_CLASS TemplateClass {

    13   T i;

    14 };

    16 void gobble(void *) { }

    18 void misuseNonHeapClass(int len) {

    19   NonHeap valid;

    20   NonHeap alsoValid[2];

    21   static NonHeap validStatic;

    22   static NonHeap alsoValidStatic[2];

    24   gobble(&valid);

    25   gobble(&validStatic);

    26   gobble(&alsoValid[0]);

    28   gobble(new NonHeap); // expected-error {{variable of type 'NonHeap' is not valid on the heap}}

    29   gobble(new NonHeap[10]); // expected-error {{variable of type 'NonHeap' is not valid on the heap}}

    30   gobble(new TemplateClass<int>); // expected-error {{variable of type 'TemplateClass<int>' is not valid on the heap}}

    31   gobble(len <= 5 ? &valid : new NonHeap); // expected-error {{variable of type 'NonHeap' is not valid on the heap}}

    33   char buffer[sizeof(NonHeap)];

    34   gobble(new (buffer) NonHeap);

    35 }

    37 NonHeap validStatic;

    38 struct RandomClass {

    39   NonHeap nonstaticMember; // expected-note {{'RandomClass' is a non-heap class because member 'nonstaticMember' is a non-heap class 'NonHeap'}}

    40   static NonHeap staticMember;

    41 };

    42 struct MOZ_NONHEAP_CLASS RandomNonHeapClass {

    43   NonHeap nonstaticMember;

    44   static NonHeap staticMember;

    45 };

    47 struct BadInherit : NonHeap {}; // expected-note {{'BadInherit' is a non-heap class because it inherits from a non-heap class 'NonHeap'}}

    48 struct MOZ_NONHEAP_CLASS GoodInherit : NonHeap {};

    50 void useStuffWrongly() {

    51   gobble(new BadInherit); // expected-error {{variable of type 'BadInherit' is not valid on the heap}}

    52   gobble(new RandomClass); // expected-error {{variable of type 'RandomClass' is not valid on the heap}}

    53 }

    55 // Stack class overrides non-heap classes.

    56 struct MOZ_STACK_CLASS StackClass {};

    57 struct MOZ_NONHEAP_CLASS InferredStackClass : GoodInherit {

    58   NonHeap nonstaticMember;

    59   StackClass stackClass; // expected-note {{'InferredStackClass' is a stack class because member 'stackClass' is a stack class 'StackClass'}}

    60 };

    62 InferredStackClass global; // expected-error {{variable of type 'InferredStackClass' only valid on the stack}}

The Tor Browser / file revision

build/clang-plugin/tests/TestNonHeapClass.cpp@ac0c01689b40

build/clang-plugin/tests/TestNonHeapClass.cpp