| Message ID | 0102019378575fe9-366c9ac9-4829-4fb2-b6d5-f34501a9df8a-000000@eu-west-1.amazonses.com |
|---|---|
| State | New |
| Headers | show |
| Series | c++: Make sure fold_sizeof_expr returns the correct type [PR117775] | expand |
Hi, On 29 Nov 2024, at 15:33, Simon Martin wrote: > We currently ICE upon the following code, that is valid under > -Wno-pointer-arith: > > === cut here === > int main() { > decltype( [](auto) { return sizeof(void); } ) x; > return x.operator()(0); > } > === cut here === > > The problem is that "fold_sizeof_expr (sizeof(void))" returns > size_one_node, that has a different TREE_TYPE from that of the sizeof > expression, which later triggers an assert in > cxx_eval_store_expression. > > This patch makes sure that fold_sizeof_expr always returns a tree with > the type requested. > > Successfully tested on x86_64-pc-linux-gnu. Ping. Thanks! Simon > > PR c++/117775 > > gcc/cp/ChangeLog: > > * decl.cc (fold_sizeof_expr): Make sure the folded result has > the requested TREE_TYPE. > > gcc/testsuite/ChangeLog: > > * g++.dg/cpp2a/constexpr-117775.C: New test. > > --- > gcc/cp/decl.cc | 1 + > gcc/testsuite/g++.dg/cpp2a/constexpr-117775.C | 13 +++++++++++++ > 2 files changed, 14 insertions(+) > create mode 100644 gcc/testsuite/g++.dg/cpp2a/constexpr-117775.C > > diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc > index 80485f0a428..fbe1407a2d2 100644 > --- a/gcc/cp/decl.cc > +++ b/gcc/cp/decl.cc > @@ -11686,6 +11686,7 @@ fold_sizeof_expr (tree t) > false, false); > if (r == error_mark_node) > r = size_one_node; > + r = cp_fold_convert (TREE_TYPE (t), r); > return r; > } > > diff --git a/gcc/testsuite/g++.dg/cpp2a/constexpr-117775.C > b/gcc/testsuite/g++.dg/cpp2a/constexpr-117775.C > new file mode 100644 > index 00000000000..59fc0d332b9 > --- /dev/null > +++ b/gcc/testsuite/g++.dg/cpp2a/constexpr-117775.C > @@ -0,0 +1,13 @@ > +// PR c++/117775 > +// Check that we don't ICE and have sizeof(void)==1 under > -Wno-pointer-arith > +// { dg-do run { target c++20 } } > +// { dg-additional-options "-Wno-pointer-arith" } > + > +int main() { > + struct why : > + decltype( [](auto) { > + return sizeof(void); > + }) > + {} x; > + return 1 - x.operator()(0); > +} > -- > 2.44.0
Hi, On 11 Dec 2024, at 22:27, Simon Martin wrote: > Hi, > > On 29 Nov 2024, at 15:33, Simon Martin wrote: > >> We currently ICE upon the following code, that is valid under >> -Wno-pointer-arith: >> >> === cut here === >> int main() { >> decltype( [](auto) { return sizeof(void); } ) x; >> return x.operator()(0); >> } >> === cut here === >> >> The problem is that "fold_sizeof_expr (sizeof(void))" returns >> size_one_node, that has a different TREE_TYPE from that of the sizeof >> expression, which later triggers an assert in >> cxx_eval_store_expression. >> >> This patch makes sure that fold_sizeof_expr always returns a tree with >> the type requested. >> >> Successfully tested on x86_64-pc-linux-gnu. > Ping. Ping. Thanks! Simon >> >> PR c++/117775 >> >> gcc/cp/ChangeLog: >> >> * decl.cc (fold_sizeof_expr): Make sure the folded result has >> the requested TREE_TYPE. >> >> gcc/testsuite/ChangeLog: >> >> * g++.dg/cpp2a/constexpr-117775.C: New test. >> >> --- >> gcc/cp/decl.cc | 1 + >> gcc/testsuite/g++.dg/cpp2a/constexpr-117775.C | 13 +++++++++++++ >> 2 files changed, 14 insertions(+) >> create mode 100644 gcc/testsuite/g++.dg/cpp2a/constexpr-117775.C >> >> diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc >> index 80485f0a428..fbe1407a2d2 100644 >> --- a/gcc/cp/decl.cc >> +++ b/gcc/cp/decl.cc >> @@ -11686,6 +11686,7 @@ fold_sizeof_expr (tree t) >> false, false); >> if (r == error_mark_node) >> r = size_one_node; >> + r = cp_fold_convert (TREE_TYPE (t), r); >> return r; >> } >> >> diff --git a/gcc/testsuite/g++.dg/cpp2a/constexpr-117775.C >> b/gcc/testsuite/g++.dg/cpp2a/constexpr-117775.C >> new file mode 100644 >> index 00000000000..59fc0d332b9 >> --- /dev/null >> +++ b/gcc/testsuite/g++.dg/cpp2a/constexpr-117775.C >> @@ -0,0 +1,13 @@ >> +// PR c++/117775 >> +// Check that we don't ICE and have sizeof(void)==1 under >> -Wno-pointer-arith >> +// { dg-do run { target c++20 } } >> +// { dg-additional-options "-Wno-pointer-arith" } >> + >> +int main() { >> + struct why : >> + decltype( [](auto) { >> + return sizeof(void); >> + }) >> + {} x; >> + return 1 - x.operator()(0); >> +} >> -- >> 2.44.0
diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc index 80485f0a428..fbe1407a2d2 100644 --- a/gcc/cp/decl.cc +++ b/gcc/cp/decl.cc @@ -11686,6 +11686,7 @@ fold_sizeof_expr (tree t) false, false); if (r == error_mark_node) r = size_one_node; + r = cp_fold_convert (TREE_TYPE (t), r); return r; } diff --git a/gcc/testsuite/g++.dg/cpp2a/constexpr-117775.C b/gcc/testsuite/g++.dg/cpp2a/constexpr-117775.C new file mode 100644 index 00000000000..59fc0d332b9 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/constexpr-117775.C @@ -0,0 +1,13 @@ +// PR c++/117775 +// Check that we don't ICE and have sizeof(void)==1 under -Wno-pointer-arith +// { dg-do run { target c++20 } } +// { dg-additional-options "-Wno-pointer-arith" } + +int main() { + struct why : + decltype( [](auto) { + return sizeof(void); + }) + {} x; + return 1 - x.operator()(0); +}
We currently ICE upon the following code, that is valid under -Wno-pointer-arith: === cut here === int main() { decltype( [](auto) { return sizeof(void); } ) x; return x.operator()(0); } === cut here === The problem is that "fold_sizeof_expr (sizeof(void))" returns size_one_node, that has a different TREE_TYPE from that of the sizeof expression, which later triggers an assert in cxx_eval_store_expression. This patch makes sure that fold_sizeof_expr always returns a tree with the type requested. Successfully tested on x86_64-pc-linux-gnu. PR c++/117775 gcc/cp/ChangeLog: * decl.cc (fold_sizeof_expr): Make sure the folded result has the requested TREE_TYPE. gcc/testsuite/ChangeLog: * g++.dg/cpp2a/constexpr-117775.C: New test. --- gcc/cp/decl.cc | 1 + gcc/testsuite/g++.dg/cpp2a/constexpr-117775.C | 13 +++++++++++++ 2 files changed, 14 insertions(+) create mode 100644 gcc/testsuite/g++.dg/cpp2a/constexpr-117775.C