diff options
Diffstat (limited to 'xpcom/reflect/xptcall/md/unix/xptcinvoke_aarch64.cpp')
| -rw-r--r-- | xpcom/reflect/xptcall/md/unix/xptcinvoke_aarch64.cpp | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/xpcom/reflect/xptcall/md/unix/xptcinvoke_aarch64.cpp b/xpcom/reflect/xptcall/md/unix/xptcinvoke_aarch64.cpp new file mode 100644 index 0000000000..385cba17ad --- /dev/null +++ b/xpcom/reflect/xptcall/md/unix/xptcinvoke_aarch64.cpp @@ -0,0 +1,168 @@ +/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +/* Platform specific code to invoke XPCOM methods on native objects */ + +#include "xptcprivate.h" + +#if !defined(__aarch64__) +#error "This code is for Linux AArch64 only." +#endif + + +/* "Procedure Call Standard for the ARM 64-bit Architecture" document, sections + * "5.4 Parameter Passing" and "6.1.2 Procedure Calling" contain all the + * needed information. + * + * http://infocenter.arm.com/help/topic/com.arm.doc.ihi0042d/IHI0042D_aapcs.pdf + */ + +#ifndef __AARCH64EL__ +#error "Only little endian compatibility was tested" +#endif + +// The AAPCS doesn't require argument widening, but Apple's calling convention +// does. If we are really fortunate, the compiler will clean up all the +// copying for us. +template<typename T> +inline uint64_t normalize_arg(T value) { + return (uint64_t)value; +} + +template<> +inline uint64_t normalize_arg(float value) { + uint64_t result = 0; + memcpy(&result, &value, sizeof(value)); + return result; +} + +template<> +inline uint64_t normalize_arg(double value) { + uint64_t result = 0; + memcpy(&result, &value, sizeof(value)); + return result; +} + +/* + * Allocation of function arguments to their appropriate place in registers + * if possible and then to the stack. Handling of 'that' argument which + * goes to register r0 is handled separately and does not belong here. + * + * Note that we are handling integer arguments and floating-point arguments + * identically, depending on which register area is passed to this function. + * + * 'reg_args' - pointer to the current position in the buffer, + * corresponding to the register arguments. + * 'reg_args_end' - pointer to the end of the registers argument + * buffer. + * 'stack_args' - pointer to the current position in the buffer, + * corresponding to the arguments on stack. + * 'data' - typed data to put on the stack. + */ +template<typename T> +static inline void alloc_arg(uint64_t* ®_args, + uint64_t* reg_args_end, + void* &stack_args, + T* data) +{ + if (reg_args < reg_args_end) { + *reg_args = normalize_arg(*data); + reg_args++; + } else { + // According to the ABI, types that are smaller than 8 bytes are + // passed in registers or 8-byte stack slots. This rule is only + // partially true on Apple platforms, where types smaller than 8 + // bytes occupy only the space they require on the stack and + // their stack slot must be properly aligned. +#ifdef __APPLE__ + const size_t aligned_size = sizeof(T); +#else + const size_t aligned_size = 8; +#endif + // Ensure the pointer is aligned for the type + uintptr_t addr = (reinterpret_cast<uintptr_t>(stack_args) + aligned_size - 1) & ~(aligned_size - 1); + memcpy(reinterpret_cast<void*>(addr), data, sizeof(T)); + // Point the stack to the next slot. + stack_args = reinterpret_cast<void*>(addr + aligned_size); + } +} + +extern "C" void +invoke_copy_to_stack(uint64_t* stk, uint64_t *end, + uint32_t paramCount, nsXPTCVariant* s) +{ + uint64_t* ireg_args = stk; + uint64_t* ireg_end = ireg_args + 8; + // Pun on integer and floating-point registers being the same size. + uint64_t* freg_args = ireg_end; + uint64_t* freg_end = freg_args + 8; + void* stack_args = freg_end; + + // leave room for 'that' argument in x0 + ++ireg_args; + + for (uint32_t i = 0; i < paramCount; i++, s++) { + if (s->IsIndirect()) { + void* ptr = &s->val; + alloc_arg(ireg_args, ireg_end, stack_args, &ptr); + } else { + switch (s->type) { + case nsXPTType::T_FLOAT: + alloc_arg(freg_args, freg_end, stack_args, &s->val.f); + break; + case nsXPTType::T_DOUBLE: + alloc_arg(freg_args, freg_end, stack_args, &s->val.d); + break; + case nsXPTType::T_I8: + alloc_arg(ireg_args, ireg_end, stack_args, &s->val.i8); + break; + case nsXPTType::T_I16: + alloc_arg(ireg_args, ireg_end, stack_args, &s->val.i16); + break; + case nsXPTType::T_I32: + alloc_arg(ireg_args, ireg_end, stack_args, &s->val.i32); + break; + case nsXPTType::T_I64: + alloc_arg(ireg_args, ireg_end, stack_args, &s->val.i64); + break; + case nsXPTType::T_U8: + alloc_arg(ireg_args, ireg_end, stack_args, &s->val.u8); + break; + case nsXPTType::T_U16: + alloc_arg(ireg_args, ireg_end, stack_args, &s->val.u16); + break; + case nsXPTType::T_U32: + alloc_arg(ireg_args, ireg_end, stack_args, &s->val.u32); + break; + case nsXPTType::T_U64: + alloc_arg(ireg_args, ireg_end, stack_args, &s->val.u64); + break; + case nsXPTType::T_BOOL: + alloc_arg(ireg_args, ireg_end, stack_args, &s->val.b); + break; + case nsXPTType::T_CHAR: + alloc_arg(ireg_args, ireg_end, stack_args, &s->val.c); + break; + case nsXPTType::T_WCHAR: + alloc_arg(ireg_args, ireg_end, stack_args, &s->val.wc); + break; + default: + // all the others are plain pointer types + alloc_arg(ireg_args, ireg_end, stack_args, &s->val.p); + break; + } + } + } +} + +extern "C" nsresult _NS_InvokeByIndex(nsISupports* that, uint32_t methodIndex, + uint32_t paramCount, nsXPTCVariant* params); + +EXPORT_XPCOM_API(nsresult) +NS_InvokeByIndex(nsISupports* that, uint32_t methodIndex, + uint32_t paramCount, nsXPTCVariant* params) +{ + return _NS_InvokeByIndex(that, methodIndex, paramCount, params); +} |