From 03bed1538f8c71f06dd0afa68713de019595e71e Mon Sep 17 00:00:00 2001 From: Jason Merrill Date: Wed, 27 Mar 2019 14:39:20 -0400 Subject: [PATCH] PR c++/89241 - ICE with lambda in template parameter list. We were getting confused by a lambda in template definition context that isn't actually in the scope of any templated entity. Fixed by telling type_dependent_expression_p that such a lambda is type-dependent even if we can't tell that from its closure type. I've also restored the error for defining a non-lambda class in a default template argument, and for a lambda befor C++20. * parser.c (cp_parser_lambda_expression): Also reject a lambda in a template parameter list before C++20. * pt.c (type_dependent_expression_p): True for LAMBDA_EXPR. * semantics.c (begin_class_definition): Restore error about defining non-lambda class in template parm list. From-SVN: r269972 --- gcc/cp/ChangeLog | 9 +++++++++ gcc/cp/parser.c | 2 +- gcc/cp/pt.c | 6 ++++++ gcc/cp/semantics.c | 6 ++++++ gcc/testsuite/g++.dg/cpp2a/lambda-uneval10.C | 12 ++++++++++++ gcc/testsuite/g++.dg/ext/complit16.C | 5 +++++ 6 files changed, 39 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/g++.dg/cpp2a/lambda-uneval10.C create mode 100644 gcc/testsuite/g++.dg/ext/complit16.C diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index bce9b108723..48071948f4e 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,3 +1,12 @@ +2019-03-27 Jason Merrill + + PR c++/89241 - ICE with lambda in template parameter list. + * parser.c (cp_parser_lambda_expression): Also reject a lambda in a + template parameter list before C++20. + * pt.c (type_dependent_expression_p): True for LAMBDA_EXPR. + * semantics.c (begin_class_definition): Restore error about defining + non-lambda class in template parm list. + 2019-03-26 Jason Merrill PR c++/86932 - missed SFINAE with empty pack. diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c index 4119d2a3265..348e4acf2d1 100644 --- a/gcc/cp/parser.c +++ b/gcc/cp/parser.c @@ -10397,7 +10397,7 @@ cp_parser_lambda_expression (cp_parser* parser) } ok = false; } - else if (parser->in_template_argument_list_p) + else if (parser->in_template_argument_list_p || processing_template_parmlist) { if (!token->error_reported) { diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c index dc982f3ed55..229b34a197e 100644 --- a/gcc/cp/pt.c +++ b/gcc/cp/pt.c @@ -25692,6 +25692,12 @@ type_dependent_expression_p (tree expression) || TREE_CODE (expression) == WILDCARD_DECL) return true; + /* A lambda-expression in template context is dependent. dependent_type_p is + true for a lambda in the scope of a class or function template, but that + doesn't cover all template contexts, like a default template argument. */ + if (TREE_CODE (expression) == LAMBDA_EXPR) + return true; + /* A fold expression is type-dependent. */ if (TREE_CODE (expression) == UNARY_LEFT_FOLD_EXPR || TREE_CODE (expression) == UNARY_RIGHT_FOLD_EXPR diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c index d7e97e0510d..fea269657f9 100644 --- a/gcc/cp/semantics.c +++ b/gcc/cp/semantics.c @@ -3043,6 +3043,12 @@ begin_class_definition (tree t) if (error_operand_p (t) || error_operand_p (TYPE_MAIN_DECL (t))) return error_mark_node; + if (processing_template_parmlist && !LAMBDA_TYPE_P (t)) + { + error ("definition of %q#T inside template parameter list", t); + return error_mark_node; + } + /* According to the C++ ABI, decimal classes defined in ISO/IEC TR 24733 are passed the same as decimal scalar types. */ if (TREE_CODE (t) == RECORD_TYPE diff --git a/gcc/testsuite/g++.dg/cpp2a/lambda-uneval10.C b/gcc/testsuite/g++.dg/cpp2a/lambda-uneval10.C new file mode 100644 index 00000000000..86065ebca64 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/lambda-uneval10.C @@ -0,0 +1,12 @@ +// PR c++/89421 + +template // { dg-message "lambda" "" { target c++17_down } } +struct B +{ + static const int i = I; +}; + +#if __cplusplus > 201703L +B<> b; +static_assert (b.i == 1); +#endif diff --git a/gcc/testsuite/g++.dg/ext/complit16.C b/gcc/testsuite/g++.dg/ext/complit16.C new file mode 100644 index 00000000000..5625cedd94e --- /dev/null +++ b/gcc/testsuite/g++.dg/ext/complit16.C @@ -0,0 +1,5 @@ +// { dg-options "" } + +template struct B{}; // { dg-error "" } + +B<0> b; -- 2.30.2