diff options
Diffstat (limited to 'private/crt32/misc/ppc/setjmpex.s')
| -rw-r--r-- | private/crt32/misc/ppc/setjmpex.s | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/private/crt32/misc/ppc/setjmpex.s b/private/crt32/misc/ppc/setjmpex.s new file mode 100644 index 000000000..063f8fa68 --- /dev/null +++ b/private/crt32/misc/ppc/setjmpex.s @@ -0,0 +1,194 @@ +//++ +// +// Copyright (c) 1993 IBM Corporation and Microsoft Corporation +// +// Module Name: +// +// setjmpex.s +// +// Abstract: +// +// This module implements the MIPS specific routine to provide SAFE +// handling of setjmp/longjmp with respect to structured exception +// handling. +// +// Author: +// +// Rick Simpson 13-Oct-1993 +// +// based on MIPS version by David N. Cutler (davec) 2-Apr-1993 +// +// Environment: +// +// Any mode. +// +// Revision History: +// +// Tom Wood 23-Aug-1994 +// Add stack limit parameters to RtlVirtualUnwind. +//-- + +//list(off) +#include "ksppc.h" +//list(on) + .extern ..RtlLookupFunctionEntry + .extern ..RtlVirtualUnwind + +// +// Define variable that will cause setjmp/longjmp to be safe with respect +// to structured exception handling. +// + + .globl _setjmpexused + .data +_setjmpexused: + .long .._setjmpex // set address of safe setjmp routine + +//++ +// +// int +// _setjmpex ( +// IN jmp_buf JumpBuffer +// ) +// +// Routine Description: +// +// This function transfers control to the actual setjmp routine. +// +// Arguments: +// +// JumpBuffer (r.3) - Supplies the address of a jump buffer to store the +// jump information. +// +// Return Value: +// +// A value of zero is returned. +// +//-- + +// Stack frame definition: + + .struct 0 +SjBackChain: .space 4 // chain to previous stack frame + .space 5*4 // rest of standard stack frame header + + .space 8*4 // standard outgoing arg area + + .align 3 // ensure 8-byte boundary +SjCtxt: .space ContextFrameLength // context frame + +SjFl: .space 4 // in function flag variable + + .align 3 // ensure that overall length + // will be a multiple of 8 +SjReturnAddr: .space 4 // space for saved LR (prologue will + // store it here) + .space 4 // space for saved r.31 +SetjmpFrameLength: + + + + NESTED_ENTRY (_setjmpex,SetjmpFrameLength,1,0) + + PROLOGUE_END (_setjmpex) + +// +// Save the nonvolatile machine state in the context record +// + + // skip Fprs as all we are really trying to do here is prime the + // pump for RtlVirtualUnwind. + + stw r.13, CxGpr13 + SjCtxt (r.sp) // save n-v general regs + stw r.14, CxGpr14 + SjCtxt (r.sp) + stw r.15, CxGpr15 + SjCtxt (r.sp) + stw r.16, CxGpr16 + SjCtxt (r.sp) + stw r.17, CxGpr17 + SjCtxt (r.sp) + stw r.18, CxGpr18 + SjCtxt (r.sp) + stw r.19, CxGpr19 + SjCtxt (r.sp) + stw r.20, CxGpr20 + SjCtxt (r.sp) + stw r.21, CxGpr21 + SjCtxt (r.sp) + stw r.22, CxGpr22 + SjCtxt (r.sp) + stw r.23, CxGpr23 + SjCtxt (r.sp) + stw r.24, CxGpr24 + SjCtxt (r.sp) + stw r.25, CxGpr25 + SjCtxt (r.sp) + stw r.26, CxGpr26 + SjCtxt (r.sp) + stw r.27, CxGpr27 + SjCtxt (r.sp) + stw r.28, CxGpr28 + SjCtxt (r.sp) + stw r.29, CxGpr29 + SjCtxt (r.sp) + stw r.30, CxGpr30 + SjCtxt (r.sp) + stw r.31, CxGpr31 + SjCtxt (r.sp) + + mr r.31, r.3 // save incoming jump buffer pointer + + lwz r.3, SjReturnAddr (r.sp) // pick up return addr to caller + la r.0, SetjmpFrameLength (r.sp) // save caller's stack frame pointer + stw r.0, CxGpr1 + SjCtxt (r.sp) + stw r.3, CxIar + SjCtxt (r.sp) // save resume addr in context + stw r.3, 4 (r.31) // save resume addr in 2nd word of jmpbuf + stw r.sp, JbType (r.31) // set "safe setjmp" flag in jump buffer + +// +// Perform unwind to determine the virtual frame pointer of the caller. +// + subi r.3, r.3, 4 // compute control PC address + bl ..RtlLookupFunctionEntry // lookup function table address + .znop ..RtlLookupFunctionEntry + + mr r.4, r.3 // set returned value as 2nd arg + lwz r.3, SjReturnAddr (r.sp) // pick up return address again + la r.5, SjCtxt (r.sp) // context record addr is 3rd arg + la r.6, SjFl (r.sp) // addr of in-func flag is 4th arg + subi r.3, r.3, 4 // compute control PC address as 1st arg + mr r.7, r.31 // addr of 1st word of jmpbuf is 5th arg + // (virt frame pointer will be stored here) + li r.8, 0 // ctxt pointers (NULL) is 6th arg + li r.9, 0 // low stack limit is 7th arg + li r.10, -1 // high stack limit is 8th arg + bl ..RtlVirtualUnwind // compute virtual frame pointer value + .znop ..RtlVirtualUnwind + +// +// If we were called via a thunk the Establisher Frame derived by +// RtlVirtualUnwind will be equal to the current stack frame. If +// this is the case we need to unwind one more level, also, the +// ControlPc returned by RtlVirtualUnwind (+4) should be used as +// the resume address. +// +// Note: this requirement will go away if we adopt the glue proposal +// that returns directly to the caller (caller reloades toc). +// (plj 3/26/94) + + lwz r.7, 0(r.31) // Establisher Frame + addi r.8, r.sp, SetjmpFrameLength // caller's sp + cmplw r.7, r.8 + bne SjDone + + // Save returned value (+4) as resume address in jump buffer + + addi r.8, r.3, 4 + stw r.8, 4(r.31) + + // Unwind one more level to get the "real" establisher frame. + + bl ..RtlLookupFunctionEntry // lookup function table address + .znop ..RtlLookupFunctionEntry + + mr r.4, r.3 // set returned value as 2nd arg + lwz r.3, 4(r.31) // pick up ControlPc again + la r.5, SjCtxt(r.sp) // &context record + la r.6, SjFl(r.sp) // addr of in-func flag + mr r.7, r.31 // & 1st word of jmpbuf + li r.8, 0 // ctxt pointers (NULL) + li r.9, 0 // low stack limit + li r.10, -1 // high stack limit + subi r.3, r.3, 4 // unadjust ControlPc + bl ..RtlVirtualUnwind // compute & frame pointer + .znop ..RtlVirtualUnwind +// +// Set return value, restore registers, deallocate stack frame, and return. +// + +SjDone: + li r.3, 0 // set return value of 0 + NESTED_EXIT (_setjmpex,SetjmpFrameLength,1,0) |