https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65858
--- Comment #3 from prathamesh3492 at gcc dot gnu.org --- (In reply to prathamesh3492 from comment #2) > Hi, > Sorry for late response, I applied your patch and got the following ICE: > -std=gnu++11 -flto --param lto-partitions=1 > Full command line options: http://pastebin.com/6JSWH9YM > > ../../third_party/cld_2/src/internal/cld_generated_cjk_uni_prop_80.cc:7132:1: > internal compiler error: in output_constructor, at lto-streamer-out.c:2152 > } // End namespace CLD2 > ^ > 0xb25609 output_constructor > > /home/prathamesh.kulkarni/gnu-toolchain/src/gcc.git/gcc/lto-streamer-out.c: > 2152 > 0xb25609 lto_output() > > /home/prathamesh.kulkarni/gnu-toolchain/src/gcc.git/gcc/lto-streamer-out.c: > 2354 > 0xb7e6c1 write_lto > /home/prathamesh.kulkarni/gnu-toolchain/src/gcc.git/gcc/passes.c:2395 > 0xb81c0e ipa_write_summaries_1 > /home/prathamesh.kulkarni/gnu-toolchain/src/gcc.git/gcc/passes.c:2459 > 0xb81c0e ipa_write_summaries() > /home/prathamesh.kulkarni/gnu-toolchain/src/gcc.git/gcc/passes.c:2519 > 0x877dda ipa_passes > > /home/prathamesh.kulkarni/gnu-toolchain/src/gcc.git/gcc/cgraphunit.c:2216 > 0x877dda symbol_table::compile() > > /home/prathamesh.kulkarni/gnu-toolchain/src/gcc.git/gcc/cgraphunit.c:2312 > 0x879d3c symbol_table::finalize_compilation_unit() > > /home/prathamesh.kulkarni/gnu-toolchain/src/gcc.git/gcc/cgraphunit.c:2461 > 0x645c40 cp_write_global_declarations() > /home/prathamesh.kulkarni/gnu-toolchain/src/gcc.git/gcc/cp/decl2.c:4757 > > Reduced test-case: > It appears that r222249, which fixed PR65801 introduced this issue. > The following test-case also ICE's for x86. > > int x { 0.5 }; > int main() { return 0; } > > prathamesh.kulkarni@ex40-01:~$ fsf-toolchain/bin/g++ -flto braced-init.cpp > -c -Wno-narrowing -std=gnu++11 > prathamesh.kulkarni@ex40-01:~$ fsf-toolchain/bin/g++ -flto braced-init.o > lto1: internal compiler error: in get_constructor, at varpool.c:331 > 0xd22c43 varpool_node::get_constructor() > ../../src/gcc/varpool.c:331 > 0xd23af8 varpool_node::assemble_decl() > ../../src/gcc/varpool.c:602 > 0x6b8633 output_in_order > ../../src/gcc/cgraphunit.c:2137 > 0x6b8b23 symbol_table::compile() > ../../src/gcc/cgraphunit.c:2378 > 0x62b025 lto_main() > ../../src/gcc/lto/lto.c:3496 > > I think it happens because, check_narrowing() returns false and it's caller > cp/semantics.c:finish_compound_literal > returns error_mark_node, which then gets streamed into object file. > > Conside this part of check_narrowing(): > > if (!ok) > { > if (cxx_dialect == cxx98) > warning_at (EXPR_LOC_OR_LOC (init, input_location), OPT_Wnarrowing, > "narrowing conversion of %qE from %qT to %qT inside { } " > "is ill-formed in C++11", init, ftype, type); > else if (!TREE_CONSTANT (init)) > { > if (complain & tf_warning_or_error) > { > pedwarn (EXPR_LOC_OR_LOC (init, input_location), > OPT_Wnarrowing, > "narrowing conversion of %qE from %qT to %qT inside { > }", > init, ftype, type); > ok = true; > } > } > else if (complain & tf_error) > { > global_dc->pedantic_errors = 1; > pedwarn (EXPR_LOC_OR_LOC (init, input_location), OPT_Wnarrowing, > "narrowing conversion of %qE from %qT to %qT inside { }", > init, ftype, type); > global_dc->pedantic_errors = flag_pedantic_errors; > } > } > > return cxx_dialect == cxx98 || ok; > > For the above test-case ok is false and we enter the nested > else if (complain & tf_error) block. > > pedwarn() doesn't print anything here and returns 0. > That's because the following condition becomes true in > diagnostic.c:diagnostic_report_diagnostic(): > /* This tests if the user provided the appropriate -Wfoo or > -Wno-foo option. */ > if (! context->option_enabled (diagnostic->option_index, > context->option_state)) > return false; > > So diagnostic_report_diagnostic() returns false to pedwarn() > which then returns 0 to check_narrowing() and warning is not printed. > > return cxx_dialect == cxx98 || ok; > Since we are compiling with gnu++11 mode, cxx_dialect > is not cxx98 and ok is false, hence check_narrowing() returns false. > > cp/semantics.c:finish_compound_literal() calls check_narrowing(): > if (SCALAR_TYPE_P (type) > && !BRACE_ENCLOSED_INITIALIZER_P (compound_literal) > && !check_narrowing (type, compound_literal, complain)) > return error_mark_node; > > I suppose that check_narrowing() returns false here and the above if > condition becomes true and finish_compound_literal() returns > error_mark_node which is then streamed. Is that correct ? This part was wrong. For the above test-case convert_like_real() calls check_narrowing(): if (convs->check_narrowing && !check_narrowing (totype, expr, complain)) return error_mark_node; Here convert_like_real() returns error_mark_node, because check_narrowing() returns false for the above test-case. The following patch fixes the ICE. Bootstrapped and tested on x86_64-unknown-linux-gnu: Index: gcc/cp/typeck2.c =================================================================== --- gcc/cp/typeck2.c (revision 222573) +++ gcc/cp/typeck2.c (working copy) @@ -958,11 +958,17 @@ } else if (complain & tf_error) { - global_dc->pedantic_errors = 1; - pedwarn (EXPR_LOC_OR_LOC (init, input_location), OPT_Wnarrowing, - "narrowing conversion of %qE from %qT to %qT inside { }", - init, ftype, type); - global_dc->pedantic_errors = flag_pedantic_errors; + /* silence warning if -Wno-narrowing -is specified */ + if (!warn_narrowing) + ok = true; + else + { + global_dc->pedantic_errors = 1; + pedwarn (EXPR_LOC_OR_LOC (init, input_location), OPT_Wnarrowing, + "narrowing conversion of %qE from %qT to %qT inside { }", + init, ftype, type); + global_dc->pedantic_errors = flag_pedantic_errors; + } } } Thank you, Prathamesh > > I tried with the following untested patch, which prevents the ICE, > but not sure if it's the right approach: > diff --git a/gcc/cp/typeck2.c b/gcc/cp/typeck2.c > index 884957b..2a25c20 100644 > --- a/gcc/cp/typeck2.c > +++ b/gcc/cp/typeck2.c > @@ -872,8 +872,7 @@ check_narrowing (tree type, tree init, tsubst_flags_t > complain) > bool ok = true; > REAL_VALUE_TYPE d; > > - if (((!warn_narrowing || !(complain & tf_warning)) > - && cxx_dialect == cxx98) > + if ((!warn_narrowing || !(complain & tf_warning)) > || !ARITHMETIC_TYPE_P (type)) > return ok; > > Since we want -Wno-narrowing to also silence C++11 stricter > narrowing rules (PR65801), I removed condition on cxx_dialect == cxx98. > > Thank you, > Prathamesh
