NativeStackLimits.h (1662B)
1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- 2 * vim: set ts=8 sts=2 et sw=2 tw=80: 3 * This Source Code Form is subject to the terms of the Mozilla Public 4 * License, v. 2.0. If a copy of the MPL was not distributed with this 5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ 6 7 #ifndef js_public_NativeStackLimit_h 8 #define js_public_NativeStackLimit_h 9 10 #include "mozilla/Assertions.h" // MOZ_ASSERT 11 12 #include <stddef.h> // size_t 13 #include <stdint.h> // uint32_t, uintptr_t, UINTPTR_MAX 14 #include <utility> // std::move 15 16 namespace JS { 17 18 using NativeStackSize = size_t; 19 20 using NativeStackBase = uintptr_t; 21 22 using NativeStackLimit = uintptr_t; 23 24 #if JS_STACK_GROWTH_DIRECTION > 0 25 constexpr NativeStackLimit NativeStackLimitMin = 0; 26 constexpr NativeStackLimit NativeStackLimitMax = UINTPTR_MAX; 27 #else 28 constexpr NativeStackLimit NativeStackLimitMin = UINTPTR_MAX; 29 constexpr NativeStackLimit NativeStackLimitMax = 0; 30 #endif 31 32 #ifdef __wasi__ 33 // We build with the "stack-first" wasm-ld option, so the stack grows downward 34 // toward zero. Let's set a limit just a bit above this so that we catch an 35 // overflow before a Wasm trap occurs. 36 constexpr NativeStackLimit WASINativeStackLimit = 1024; 37 #endif // __wasi__ 38 39 inline NativeStackLimit GetNativeStackLimit(NativeStackBase base, 40 NativeStackSize size) { 41 #if JS_STACK_GROWTH_DIRECTION > 0 42 MOZ_ASSERT(base <= size_t(-1) - size); 43 return base + size - 1; 44 #else // stack grows up 45 MOZ_ASSERT(base >= size); 46 return base - (size - 1); 47 #endif // stack grows down 48 } 49 50 } // namespace JS 51 52 #endif /* js_public_NativeStackLimit_h */