https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111329
--- Comment #7 from CVS Commits ---
The master branch has been updated by Jakub Jelinek :
https://gcc.gnu.org/g:6f7f728746818062c3d6ed7ea9c7cb1562f2acb1
commit r14-3836-g6f7f728746818062c3d6ed7ea9c7cb1562f2acb1
Author: Jakub Jelinek
Date: Mon Sep 11 11:08:41 2023 +0200
pretty-print: Fix up pp_wide_int [PR111329]
The recent pp_wide_int changes for _BitInt support (because not all
wide_ints fit into the small fixed size digit_buffer anymore) apparently
broke
+FAIL: gcc.dg/analyzer/out-of-bounds-diagram-1-debug.c (test for excess
errors)
+FAIL: gcc.dg/analyzer/out-of-bounds-diagram-1-debug.c 2 blank line(s) in
output
+FAIL: gcc.dg/analyzer/out-of-bounds-diagram-1-debug.c expected multiline
pattern lines 17-39
(and I couldn't reproduce that in bisect seed (which is -O0 compiled) and
thought it would be some analyzer diagnostic bug).
The problem is that analyzer uses pp_wide_int with a function call in the
second argument. Previously, when pp_wide_int macro just did
print_dec (W, pp_buffer (PP)->digit_buffer, SGN);
pp_string (PP, pp_buffer (PP)->digit_buffer);
it worked, because the const wide_int_ref & first argument to print_dec
bound to a temporary, which was only destructed at the end of the full
statement after print_dec was called.
But with my changes where I need to first compare the precision of the
const wide_int_ref & to decide whether to use digit_buffer or XALLOCAVEC
something larger, this means that pp_wide_int_ref binds to a temporary
which is destroyed at the end of full statement which is the
const wide_int_ref _wide_int_ref = (W);
declaration, so then invokes UB accessing a destructed temporary.
The following patch fixes it by rewriting pp_wide_int into an inline
function, so that the end of the full statement is the end of the inline
function call. As functions using alloca aren't normally inlined, I've
also split that part into a separate out of line function. Putting that
into pretty-print.cc didn't work, e.g. the gm2 binary doesn't link,
because pretty-print.o is in libcommon.a, but wide-print-print.o which
defines print_dec is not. So I've put that out of line function into
wide-int-print.cc instead.
2023-09-11 Jakub Jelinek
PR middle-end/111329
* pretty-print.h (pp_wide_int): Rewrite from macro into inline
function. For printing values which don't fit into digit_buffer
use out-of-line function.
* wide-int-print.h (pp_wide_int_large): Declare.
* wide-int-print.cc: Include pretty-print.h.
(pp_wide_int_large): Define.
