[Bug preprocessor/112701] wrong type inference for ternary operator with `0/0u` in preprocessing context
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112701 Sam James changed: What|Removed |Added Target Milestone|--- |14.0
[Bug preprocessor/112701] wrong type inference for ternary operator with `0/0u` in preprocessing context
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112701 Lewis Hyatt changed: What|Removed |Added Resolution|--- |FIXED Status|NEW |RESOLVED --- Comment #8 from Lewis Hyatt --- Fixed for GCC 14.
[Bug preprocessor/112701] wrong type inference for ternary operator with `0/0u` in preprocessing context
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112701 --- Comment #7 from GCC Commits --- The master branch has been updated by Lewis Hyatt : https://gcc.gnu.org/g:ce52f1f7074d96c4d9ce63b1169c11087757e926 commit r14-5898-gce52f1f7074d96c4d9ce63b1169c11087757e926 Author: Lewis Hyatt Date: Mon Nov 27 12:08:41 2023 -0500 libcpp: Fix unsigned promotion for unevaluated divide by zero [PR112701] When libcpp encounters a divide by zero while processing a constant expression "x/y", it returns "x" as a fallback. The value of the fallback is not normally important, since an error will be generated anyway, but if the expression appears in an unevaluated context, such as "0 ? 0/0u : -1", then there will be no error, and the fallback value will be meaningful to the extent that it may cause promotion from signed to unsigned of an operand encountered later. As the PR notes, libcpp does not do the unsigned promotion correctly in this case; fix it by making the fallback return value unsigned as necessary. libcpp/ChangeLog: PR preprocessor/112701 * expr.cc (num_div_op): Set unsignedp appropriately when returning a stub value for divide by 0. gcc/testsuite/ChangeLog: PR preprocessor/112701 * gcc.dg/cpp/expr.c: Add additional tests to cover divide by 0 in an unevaluated context, where the unsignedness still matters.
[Bug preprocessor/112701] wrong type inference for ternary operator with `0/0u` in preprocessing context
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112701 Lewis Hyatt changed: What|Removed |Added Keywords||patch URL||https://gcc.gnu.org/piperma ||il/gcc-patches/2023-Novembe ||r/638346.html --- Comment #6 from Lewis Hyatt --- (In reply to Andrew Pinski from comment #5) > (In reply to Lewis Hyatt from comment #4) > > Here is the fix. Not sure if it needs to wait for GCC 15 by now, but I can > > submit it with the testcase. > > Bugs can be fixed during stage 3 (just no new __major__ features), only > during stage 4 is when regression only fixes can happen. Note this might > even be considered a regression since it worked in GCC 2.95.3. Thanks for the clarification! Patch is at: https://gcc.gnu.org/pipermail/gcc-patches/2023-November/638346.html
[Bug preprocessor/112701] wrong type inference for ternary operator with `0/0u` in preprocessing context
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112701 --- Comment #5 from Andrew Pinski --- (In reply to Lewis Hyatt from comment #4) > Here is the fix. Not sure if it needs to wait for GCC 15 by now, but I can > submit it with the testcase. Bugs can be fixed during stage 3 (just no new __major__ features), only during stage 4 is when regression only fixes can happen. Note this might even be considered a regression since it worked in GCC 2.95.3.
[Bug preprocessor/112701] wrong type inference for ternary operator with `0/0u` in preprocessing context
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112701 Lewis Hyatt changed: What|Removed |Added Status|UNCONFIRMED |NEW Last reconfirmed||2023-11-27 Ever confirmed|0 |1 CC||lhyatt at gcc dot gnu.org --- Comment #4 from Lewis Hyatt --- Here is the fix. Not sure if it needs to wait for GCC 15 by now, but I can submit it with the testcase. diff --git a/libcpp/expr.cc b/libcpp/expr.cc index 825d2c2369d..4f4a9722ac7 100644 --- a/libcpp/expr.cc +++ b/libcpp/expr.cc @@ -2216,6 +2216,7 @@ num_div_op (cpp_reader *pfile, cpp_num lhs, cpp_num rhs, enum cpp_ttype op, if (!pfile->state.skip_eval) cpp_error_with_line (pfile, CPP_DL_ERROR, location, 0, "division by zero in #if"); + lhs.unsignedp = unsignedp; return lhs; }
[Bug preprocessor/112701] wrong type inference for ternary operator with `0/0u` in preprocessing context
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112701 --- Comment #3 from Richard Biener --- Heh, I didn't know ?: is valid as preprocessor conditional.
[Bug preprocessor/112701] wrong type inference for ternary operator with `0/0u` in preprocessing context
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112701 --- Comment #2 from Mikael Pettersson --- gcc-2.95.3 generates neither, gcc-3.0.4 and up generate the bar: .long 0 (or .zero 4) one.
[Bug preprocessor/112701] wrong type inference for ternary operator with `0/0u` in preprocessing context
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112701 --- Comment #1 from Andrew Pinski --- Interesting is MSVC emits both. clang emits none.
