Hello, all Attached is my fix for bug #585(https://bugs.open64.net/show_bug.cgi?id=585). There are three test cases attached to the bug report. They all experience same problem: compile time segmentation fault at wgen phase. However, each of them is caused by a different problem.
pr22061-2.c
===========
The test case is shown below:
int *x;
static void bar (char a[2][(*x)++]) {}
The problem is that when generating type information for bar function,
(*x)++ needs to be expanded since `a` is a variable length array.
However, current wgen assumes that WHIRL node for current function
(`Current_Entry_Wn()`) already exists. However, this is not true at
the time of generating function type information.
crash2.C
========
The part of code causing problems is shown below:
R1::R1( const R& a ) :
m_( a.empty() ? get_empty().m_ : C() )
The gspin expression for the select is organized as follows:
COND_EXPR
|-- COND
|-- TARGET_EXPR
|-- COMPONENT_REF (S1)
|-- INDIRECT_REF
|-- ...
|-- COMPONENT_REF (S2)
|-- TARGET_REF
|-- ...
|-- ...
S1 is actually a VAR_DECL expression in gspin file. It is changed to
COMPONENT_REF when converting COND_EXPR (see wgen_expr.cxx:6056, added
for bug 15210). However, the presence of INDIRECT_REF causes target
symbol being NULL and this caused segmentation fault in WN_Lda
function.
ftp.i
=====
The following code snippet caused the problem:
struct string {
unsigned char *source;
};
struct ftp_file_info {
struct string name;
struct string symlink;
long size;
time_t mtime;
unsigned int local_time_zone:1;
mode_t permissions;
};
static int ftp_process_dirlist()
{
int ret = 0;
while (1) {
struct ftp_file_info ftp_info = { FTP_FILE_UNKNOWN, {"", 0},
{"", 0}, -1, 0, 0 };
}
}
The compiler tries to generate initialization code for each field of
`ftp_info`. For each field, `Advance_Field_Id` is called to advance to
next field after generating initialization code for current field. Due
to the presence of `struct string`, the field_id and fld is no long in
sync. For example, after generating initialization code for
ftp_info.symlink, the field_id is the for the last field of symlink
struct (ftp_info.symlink.source) while fld still points to
ftp_info.symlink field. This caused field_id being incremented
incorrectly and caused segmentation fault in `FLD_get_to_field`
function.
Thanks.
-------------------------------
Feng Zhou
bug585_v1_open64.patch
Description: Binary data
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