https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99989
Bug ID: 99989
Summary: [11 regression] False maybe-uninitialized warning
breaks bootstrap on riscv64
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Keywords: build
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: sch...@linux-m68k.org
CC: hubicka at gcc dot gnu.org
Blocks: 24639, 98265
Target Milestone: ---
Target: riscv64-*-*
In function ‘alloca_type_and_limit alloca_call_type(range_query&, gimple*, bool
’,
inlined from ‘virtual unsigned int pass_walloca::execute(function*)’ at
../../gcc/gimple-ssa-warn-alloca.c:295:25:
../../gcc/gimple-ssa-warn-alloca.c:206:13: error: ‘*(long int*)((char*)&ret +
offsetof(alloca_type_and_limit,
alloca_type_and_limit::limit.generic_wide_int<wide_int_storage>::<unnamed>.wide_int_storage::val[0]))’
may be used uninitialized -Werror=maybe-uninitialized]
206 | ret = alloca_type_and_limit (ALLOCA_OK);
| ~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../gcc/gimple-ssa-warn-alloca.c: In member function ‘virtual unsigned int
pass_walloca::execute(function*)’:
../../gcc/gimple-ssa-warn-alloca.c:200:32: note: ‘ret’ declared here
200 | struct alloca_type_and_limit ret = alloca_type_and_limit (ALLOCA_OK);
| ^~~
In function ‘alloca_type_and_limit alloca_call_type(range_query&, gimple*, bool
’,
inlined from ‘virtual unsigned int pass_walloca::execute(function*)’ at
../../gcc/gimple-ssa-warn-alloca.c:295:25:
../../gcc/gimple-ssa-warn-alloca.c:206:13: error: ‘*(long int*)((char*)&ret +
offsetof(alloca_type_and_limit,
alloca_type_and_limit::limit.generic_wide_int<wide_int_storage>::<unnamed>.wide_int_storage::val[1]))’
may be used uninitialized -Werror=maybe-uninitialized]
206 | ret = alloca_type_and_limit (ALLOCA_OK);
| ~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../gcc/gimple-ssa-warn-alloca.c: In member function ‘virtual unsigned int
pass_walloca::execute(function*)’:
../../gcc/gimple-ssa-warn-alloca.c:200:32: note: ‘ret’ declared here
200 | struct alloca_type_and_limit ret = alloca_type_and_limit (ALLOCA_OK);
| ^~~
In function ‘alloca_type_and_limit alloca_call_type(range_query&, gimple*, bool
’,
inlined from ‘virtual unsigned int pass_walloca::execute(function*)’ at
../../gcc/gimple-ssa-warn-alloca.c:295:25:
../../gcc/gimple-ssa-warn-alloca.c:206:13: error: ‘*(long int*)((char*)&ret +
offsetof(alloca_type_and_limit,
alloca_type_and_limit::limit.generic_wide_int<wide_int_storage>::<unnamed>.wide_int_storage::val[2]))’
may be used uninitialized -Werror=maybe-uninitialized]
206 | ret = alloca_type_and_limit (ALLOCA_OK);
| ~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../gcc/gimple-ssa-warn-alloca.c: In member function ‘virtual unsigned int
pass_walloca::execute(function*)’:
../../gcc/gimple-ssa-warn-alloca.c:200:32: note: ‘ret’ declared here
200 | struct alloca_type_and_limit ret = alloca_type_and_limit (ALLOCA_OK);
| ^~~
In function ‘alloca_type_and_limit alloca_call_type(range_query&, gimple*, bool
’,
inlined from ‘virtual unsigned int pass_walloca::execute(function*)’ at
../../gcc/gimple-ssa-warn-alloca.c:295:25:
../../gcc/gimple-ssa-warn-alloca.c:206:13: error: ‘*(unsigned int*)((char*)&ret
+ offsetof(alloca_type_and_limit,
alloca_type_and_limit::limit.generic_wide_int<wide_int_storage>::<unnamed>.wide_int_storage::len))’
may be used uninitialized [-Werror=maybe-uninitialized]
206 | ret = alloca_type_and_limit (ALLOCA_OK);
| ~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../gcc/gimple-ssa-warn-alloca.c: In member function ‘virtual unsigned int
pass_walloca::execute(function*)’:
../../gcc/gimple-ssa-warn-alloca.c:200:32: note: ‘ret’ declared here
200 | struct alloca_type_and_limit ret = alloca_type_and_limit (ALLOCA_OK);
| ^~~
In function ‘alloca_type_and_limit alloca_call_type(range_query&, gimple*, bool
’,
inlined from ‘virtual unsigned int pass_walloca::execute(function*)’ at
../../gcc/gimple-ssa-warn-alloca.c:295:25:
../../gcc/gimple-ssa-warn-alloca.c:206:13: error: ‘*(unsigned int*)((char*)&ret
+ offsetof(alloca_type_and_limit,
alloca_type_and_limit::limit.generic_wide_int<wide_int_storage>::<unnamed>.wide_int_storage::precision))’
may be used uninitialized [-Werror=maybe-uninitialized]
206 | ret = alloca_type_and_limit (ALLOCA_OK);
| ~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../gcc/gimple-ssa-warn-alloca.c: In member function ‘virtual unsigned int
pass_walloca::execute(function*)’:
../../gcc/gimple-ssa-warn-alloca.c:200:32: note: ‘ret’ declared here
200 | struct alloca_type_and_limit ret = alloca_type_and_limit (ALLOCA_OK);
| ^~~
cc1plus: all warnings being treated as errors
make[3]: *** [Makefile:1142: gimple-ssa-warn-alloca.o] Error 1
Referenced Bugs:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=24639
[Bug 24639] [meta-bug] bug to track all Wuninitialized issues
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98265
[Bug 98265] [10/11 Regression] gcc-10 has significantly worse code generated
with -O2 compared to -O1 (or gcc-9 -O2) when using the Eigen C++ library
