maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

Fix DW_CFA_GNU_args_size handling. The primary architecture using this 

opcode is VAX. A function call pushes the number of arguments given onto
the stack and "ret" will pop it automatically. The FDE of the caller
contains the amount of stack space used for arguments (and possibly
extra padding), so unwinding has to compensate for this when "returning"
from a function. This is exactly the case when step() is done. The
existing handling in unw_set_reg no longer makes sense.

llvm-svn: 204290
This commit is contained in:
Joerg Sonnenberger 2014-03-20 01:23:55 +00:00
parent fcd974a1ed
commit 1ed1a3d994
2 changed files with 2 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
libcxxabi/src/Unwind/UnwindCursor.hpp
View File

@ -1041,6 +1041,8 @@ int UnwindCursor<A, R>::step() {
this->setInfoBasedOnIPRegister(true);
if (_unwindInfoMissing)
return UNW_STEP_END;
if (_info.gp)
setReg(UNW_REG_SP, getReg(UNW_REG_SP) + _info.gp);
}
return result;

3
libcxxabi/src/Unwind/libunwind.cpp
View File

@ -174,9 +174,6 @@ _LIBUNWIND_EXPORT int unw_set_reg(unw_cursor_t *cursor, unw_regnum_t regNum,
pint_t orgArgSize = (pint_t)info.gp;
uint64_t orgFuncStart = info.start_ip;
co->setInfoBasedOnIPRegister(false);
// and adjust REG_SP if there was a DW_CFA_GNU_args_size
if ((orgFuncStart == info.start_ip) && (orgArgSize != 0))
co->setReg(UNW_REG_SP, co->getReg(UNW_REG_SP) + orgArgSize);
}
return UNW_ESUCCESS;
}