| Message ID | 002f01d8271c$f6f839a0$e4e8ace0$@nextmovesoftware.com |
|---|---|
| State | New |
| Headers | show |
| Series | c++: PR c++/95999: Improved error recovery in enumeration lists. | expand |
On 2/21/22 08:17, Roger Sayle wrote: > > This patch resolves PR c++/95999 which is an ICE-after-error regression > in the g++ front-end. When parsing an enumerator list, the C++ parser > assumes that cp_parser_constant_expression always returns either an > INTEGER_CST or error_mark_node, but in testcase reported in the PR > actually returns a VAR_DECL. > > The usual (but perhaps controversial) design philosophy is that the > routine that reports the error normally has a duty to indicate this to > the rest of the compiler (via error_mark_node), but here the return > value from calling require_rvalue_constant_expression (parser.cc:10666) > is ignored. I initially experimented with setting EXPRESSION to > error_mark_node here in cp_parser_constant_expression but (perhaps > conveniently) that's insufficient to resolve the problem. The simple > fix in this patch is to tweak the two places that require INTEGER_CST > to treat all other tree types as though they are error_mark_node. > > This patch has been tested on x86_64-pc-linunx-gnu with make bootstrap > and make -k check with no new (unexpected) failures. Ok for mainline? OK. > 2022-02-21 Roger Sayle <roger@nextmovesoftware.com> > > gcc/cp/ChangeLog > PR c++/95999 > * decl.cc (finish_enum_value_list): If VALUE isn't an INTEGER_CST > consider it to be zero (i.e. treat it like error_mark_node). > (build_enumerator): Likewise, if PREV_VALUE isn't an INTEGER_CST, > set VALUE to error_mark_node. > > gcc/testsuite/ChangeLog > PR c++/95999 > * g++.dg/pr95999.c: New test case. > > > Thanks in advance, > Roger > -- >
diff --git a/gcc/cp/decl.cc b/gcc/cp/decl.cc index 7b48b56..40b8f0c 100644 --- a/gcc/cp/decl.cc +++ b/gcc/cp/decl.cc @@ -16202,7 +16202,7 @@ finish_enum_value_list (tree enumtype) /* Update the minimum and maximum values, if appropriate. */ value = DECL_INITIAL (decl); - if (value == error_mark_node) + if (TREE_CODE (value) != INTEGER_CST) value = integer_zero_node; /* Figure out what the minimum and maximum values of the enumerators are. */ @@ -16491,7 +16491,7 @@ build_enumerator (tree name, tree value, tree enumtype, tree attributes, which case the type is an unspecified integral type sufficient to contain the incremented value. */ prev_value = DECL_INITIAL (TREE_VALUE (TYPE_VALUES (enumtype))); - if (error_operand_p (prev_value)) + if (TREE_CODE (prev_value) != INTEGER_CST) value = error_mark_node; else { diff --git a/gcc/testsuite/g++.dg/pr95999.C b/gcc/testsuite/g++.dg/pr95999.C new file mode 100644 index 0000000..f399f6d --- /dev/null +++ b/gcc/testsuite/g++.dg/pr95999.C @@ -0,0 +1,9 @@ +/* { dg-do compile } */ +/* { dg-options "-O2" } */ +int a; +enum struct b; +template <typename = enum struct b { c = a d } +template <> enum struct b { e }; // { dg-error "explicit specialization" } +// { dg-excess-errors "note" } +// { dg-excess-errors "5:" } +