RE: [PATCH] Extend streamer_mode_table size to MACHINE_MODE_BITSIZE.

["Li, Pan2" <pan2.li@intel.com>]

Thanks Xu for locating this, we have one similar PATCH under reviewing/testing as below.

https://gcc.gnu.org/pipermail/gcc-patches/2023-June/622440.html

Pan

-----Original Message-----
From: Li Xu <xuli1@eswincomputing.com> 
Sent: Tuesday, June 27, 2023 2:12 PM
To: gcc-patches@gcc.gnu.org
Cc: kito.cheng@gmail.com; palmer@dabbelt.com; juzhe.zhong@rivai.ai; zhengyu@eswincomputing.com; Li, Pan2 <pan2.li@intel.com>; Li Xu <xuli1@eswincomputing.com>
Subject: [PATCH] Extend streamer_mode_table size to MACHINE_MODE_BITSIZE.

If MAX_MACHINE_MODE exceeds 8bits, a warning will appear in the following code.
waring: writing 293 bytes into a region of size 256 overflows the destination

gcc/lto-streamer-out.cc
void
lto_output_init_mode_table (void)
{
  memset (streamer_mode_table, '\0', MAX_MACHINE_MODE);
}

gcc/ChangeLog:

        * tree-streamer.cc: Extend streamer_mode_table size to MACHINE_MODE_BITSIZE.
        * tree-streamer.h: Ditto.
---
 gcc/tree-streamer.cc | 2 +-
 gcc/tree-streamer.h  | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/gcc/tree-streamer.cc b/gcc/tree-streamer.cc
index ed65a7692e3..14c222698bf 100644
--- a/gcc/tree-streamer.cc
+++ b/gcc/tree-streamer.cc
@@ -35,7 +35,7 @@ along with GCC; see the file COPYING3.  If not see
    During streaming in, we translate the on the disk mode using this
    table.  For normal LTO it is set to identity, for ACCEL_COMPILER
    depending on the mode_table content.  */
-unsigned char streamer_mode_table[1 << 8];
+unsigned char streamer_mode_table[1 << MACHINE_MODE_BITSIZE];
 
 /* Check that all the TS_* structures handled by the streamer_write_* and
    streamer_read_* routines are exactly ALL the structures defined in
diff --git a/gcc/tree-streamer.h b/gcc/tree-streamer.h
index 170d61cf20b..8bc757be189 100644
--- a/gcc/tree-streamer.h
+++ b/gcc/tree-streamer.h
@@ -75,7 +75,7 @@ void streamer_write_tree_body (struct output_block *, tree);
 void streamer_write_integer_cst (struct output_block *, tree);
 
 /* In tree-streamer.cc.  */
-extern unsigned char streamer_mode_table[1 << 8];
+extern unsigned char streamer_mode_table[1 << MACHINE_MODE_BITSIZE];
 void streamer_check_handled_ts_structures (void);
 bool streamer_tree_cache_insert (struct streamer_tree_cache_d *, tree,
 				 hashval_t, unsigned *);
-- 
2.17.1