[Bug middle-end/98373] New: [11 Repression] Bogus error: ‘symbuf’ may be used uninitialized at -O0

[hjl.tools at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98373

            Bug ID: 98373
           Summary: [11 Repression] Bogus error: ‘symbuf’ may be used
                    uninitialized at -O0
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: hjl.tools at gmail dot com
  Target Milestone: ---

Created attachment 49795
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=49795&action=edit
A testcase

[hjl@gnu-cfl-2 gold]$ /usr/gcc-11.0.0-x32/bin/g++ -S /tmp/plugin.ii -W -Wall
/export/linux/src/binutils/binutils/gold/plugin.cc: In member function ‘void
gold::Sized_pluginobj<size, big_endian>::do_add_symbols(gold::Symbol_table*,
gold::Read_symbols_data*, gold::Layout*) [with int size = 32; bool big_endian =
false]’:
/export/linux/src/binutils/binutils/gold/plugin.cc:1400:33: warning: ‘symbuf’
may be used uninitialized [-Wmaybe-uninitialized]
 1400 |   elfcpp::Sym<size, big_endian> sym(symbuf);
      |                                 ^~~
In file included from /export/linux/src/binutils/binutils/gold/script.h:37,
                 from /export/linux/src/binutils/binutils/gold/layout.h:33,
                 from /export/linux/src/binutils/binutils/gold/plugin.cc:73:
/export/linux/src/binutils/binutils/gold/../elfcpp/elfcpp.h:1532:3: note: by
argument 2 of type ‘const unsigned char*’ to ‘elfcpp::Sym<size,
big_endian>::Sym(const unsigned char*) [with int size = 32; bool big_endian =
false]’ declared here
 1532 |   Sym(const unsigned char* p)
      |   ^~~
/export/linux/src/binutils/binutils/gold/plugin.cc:1399:17: note: ‘symbuf’
declared here
 1399 |   unsigned char symbuf[sym_size];
      |                 ^~~~~~
/export/linux/src/binutils/binutils/gold/plugin.cc: In member function ‘void
gold::Sized_pluginobj<size, big_endian>::do_add_symbols(gold::Symbol_table*,
gold::Read_symbols_data*, gold::Layout*) [with int size = 64; bool big_endian =
false]’:
/export/linux/src/binutils/binutils/gold/plugin.cc:1400:33: warning: ‘symbuf’
may be used uninitialized [-Wmaybe-uninitialized]
 1400 |   elfcpp::Sym<size, big_endian> sym(symbuf);
      |                                 ^~~
In file included from /export/linux/src/binutils/binutils/gold/script.h:37,
                 from /export/linux/src/binutils/binutils/gold/layout.h:33,
                 from /export/linux/src/binutils/binutils/gold/plugin.cc:73:
/export/linux/src/binutils/binutils/gold/../elfcpp/elfcpp.h:1532:3: note: by
argument 2 of type ‘const unsigned char*’ to ‘elfcpp::Sym<size,
big_endian>::Sym(const unsigned char*) [with int size = 64; bool big_endian =
false]’ declared here
 1532 |   Sym(const unsigned char* p)
      |   ^~~
/export/linux/src/binutils/binutils/gold/plugin.cc:1399:17: note: ‘symbuf’
declared here
 1399 |   unsigned char symbuf[sym_size];
      |                 ^~~~~~
[hjl@gnu-cfl-2 gold]$ /usr/gcc-11.0.0-x32/bin/g++ -S /tmp/plugin.ii -W -Wall
-O2
[hjl@gnu-cfl-2 gold]$