| Message ID | 20231205203136.94832-1-polacek@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | c++: fix ICE with sizeof in a template [PR112869] | expand |
On 12/5/23 15:31, Marek Polacek wrote: > Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk? > > -- >8 -- > This test shows that we cannot clear *walk_subtrees in > cp_fold_immediate_r when we're in_immediate_context, because that, > as the comment says, affects cp_fold_r as well. Here we had an > expression with > > min ((long int) VIEW_CONVERT_EXPR<long unsigned int>(bytecount), (long int) <<< Unknown tree: sizeof_expr > (int) <<< error >>> >>>) > > as its sub-expression, and we never evaluated that into > > min ((long int) bytecount, 4) > > so the SIZEOF_EXPR leaked into the middle end. > > (There's still one *walk_subtrees = 0; in cp_fold_immediate_r, but that > one should be OK.) > > PR c++/112869 > > gcc/cp/ChangeLog: > > * cp-gimplify.cc (cp_fold_immediate_r): Don't clear *walk_subtrees > for unevaluated operands. I agree that we want this change for in_immediate_context (), but I don't see why we want it for TYPE_P or unevaluated_p (code) or cp_unevaluated_operand? > gcc/testsuite/ChangeLog: > > * g++.dg/template/sizeof18.C: New test. > --- > gcc/cp/cp-gimplify.cc | 8 ++------ > gcc/testsuite/g++.dg/template/sizeof18.C | 8 ++++++++ > 2 files changed, 10 insertions(+), 6 deletions(-) > create mode 100644 gcc/testsuite/g++.dg/template/sizeof18.C > > diff --git a/gcc/cp/cp-gimplify.cc b/gcc/cp/cp-gimplify.cc > index 5abb91bbdd3..46c3eb91853 100644 > --- a/gcc/cp/cp-gimplify.cc > +++ b/gcc/cp/cp-gimplify.cc > @@ -1177,13 +1177,9 @@ cp_fold_immediate_r (tree *stmt_p, int *walk_subtrees, void *data_) > ? tf_error : tf_none); > const tree_code code = TREE_CODE (stmt); > > - /* No need to look into types or unevaluated operands. > - NB: This affects cp_fold_r as well. */ > + /* No need to look into types or unevaluated operands. */ > if (TYPE_P (stmt) || unevaluated_p (code) || in_immediate_context ()) > - { > - *walk_subtrees = 0; > - return NULL_TREE; > - } > + return NULL_TREE; > > tree decl = NULL_TREE; > bool call_p = false; > diff --git a/gcc/testsuite/g++.dg/template/sizeof18.C b/gcc/testsuite/g++.dg/template/sizeof18.C > new file mode 100644 > index 00000000000..afba9946258 > --- /dev/null > +++ b/gcc/testsuite/g++.dg/template/sizeof18.C > @@ -0,0 +1,8 @@ > +// PR c++/112869 > +// { dg-do compile } > + > +void min(long, long); > +template <class T> void Binaryread(int &, T, unsigned long); > +template <> void Binaryread(int &, float, unsigned long bytecount) { > + min(bytecount, sizeof(int)); > +} > > base-commit: 9c3a880feecf81c310b4ade210fbd7004c9aece7
diff --git a/gcc/cp/cp-gimplify.cc b/gcc/cp/cp-gimplify.cc index 5abb91bbdd3..46c3eb91853 100644 --- a/gcc/cp/cp-gimplify.cc +++ b/gcc/cp/cp-gimplify.cc @@ -1177,13 +1177,9 @@ cp_fold_immediate_r (tree *stmt_p, int *walk_subtrees, void *data_) ? tf_error : tf_none); const tree_code code = TREE_CODE (stmt); - /* No need to look into types or unevaluated operands. - NB: This affects cp_fold_r as well. */ + /* No need to look into types or unevaluated operands. */ if (TYPE_P (stmt) || unevaluated_p (code) || in_immediate_context ()) - { - *walk_subtrees = 0; - return NULL_TREE; - } + return NULL_TREE; tree decl = NULL_TREE; bool call_p = false; diff --git a/gcc/testsuite/g++.dg/template/sizeof18.C b/gcc/testsuite/g++.dg/template/sizeof18.C new file mode 100644 index 00000000000..afba9946258 --- /dev/null +++ b/gcc/testsuite/g++.dg/template/sizeof18.C @@ -0,0 +1,8 @@ +// PR c++/112869 +// { dg-do compile } + +void min(long, long); +template <class T> void Binaryread(int &, T, unsigned long); +template <> void Binaryread(int &, float, unsigned long bytecount) { + min(bytecount, sizeof(int)); +}
Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk? -- >8 -- This test shows that we cannot clear *walk_subtrees in cp_fold_immediate_r when we're in_immediate_context, because that, as the comment says, affects cp_fold_r as well. Here we had an expression with min ((long int) VIEW_CONVERT_EXPR<long unsigned int>(bytecount), (long int) <<< Unknown tree: sizeof_expr (int) <<< error >>> >>>) as its sub-expression, and we never evaluated that into min ((long int) bytecount, 4) so the SIZEOF_EXPR leaked into the middle end. (There's still one *walk_subtrees = 0; in cp_fold_immediate_r, but that one should be OK.) PR c++/112869 gcc/cp/ChangeLog: * cp-gimplify.cc (cp_fold_immediate_r): Don't clear *walk_subtrees for unevaluated operands. gcc/testsuite/ChangeLog: * g++.dg/template/sizeof18.C: New test. --- gcc/cp/cp-gimplify.cc | 8 ++------ gcc/testsuite/g++.dg/template/sizeof18.C | 8 ++++++++ 2 files changed, 10 insertions(+), 6 deletions(-) create mode 100644 gcc/testsuite/g++.dg/template/sizeof18.C base-commit: 9c3a880feecf81c310b4ade210fbd7004c9aece7