| // Copyright 2020 the V8 project authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| // Push all callee-saved registers to get them on the stack for conservative |
| // stack scanning. |
| // |
| // See asm/x64/push_registers_clang.cc for why the function is not generated |
| // using clang. |
| // |
| // Do not depend on V8_TARGET_OS_* defines as some embedders may override the |
| // GN toolchain (e.g. ChromeOS) and not provide them. |
| |
| // We maintain 16-byte alignment at calls. There is an 4-byte return address |
| // on the stack and we push 28 bytes which maintains 16-byte stack alignment |
| // at the call. |
| // |
| // The following assumes cdecl calling convention. |
| // Source: https://en.wikipedia.org/wiki/X86_calling_conventions#cdecl |
| asm( |
| #ifdef _WIN32 |
| ".globl _PushAllRegistersAndIterateStack \n" |
| "_PushAllRegistersAndIterateStack: \n" |
| #else // !_WIN32 |
| ".globl PushAllRegistersAndIterateStack \n" |
| ".type PushAllRegistersAndIterateStack, %function \n" |
| ".hidden PushAllRegistersAndIterateStack \n" |
| "PushAllRegistersAndIterateStack: \n" |
| #endif // !_WIN32 |
| // [ IterateStackCallback ] |
| // [ StackVisitor* ] |
| // [ Stack* ] |
| // [ ret ] |
| // ebp is callee-saved. Maintain proper frame pointer for debugging. |
| " push %ebp \n" |
| " movl %esp, %ebp \n" |
| " push %ebx \n" |
| " push %esi \n" |
| " push %edi \n" |
| // Save 3rd parameter (IterateStackCallback). |
| " movl 28(%esp), %ecx \n" |
| // Pass 3rd parameter as esp (stack pointer). |
| " push %esp \n" |
| // Pass 2nd parameter (StackVisitor*). |
| " push 28(%esp) \n" |
| // Pass 1st parameter (Stack*). |
| " push 28(%esp) \n" |
| " call *%ecx \n" |
| // Pop the callee-saved registers. |
| " addl $24, %esp \n" |
| // Restore rbp as it was used as frame pointer. |
| " pop %ebp \n" |
| " ret \n"); |
