Hi! We ICE during error-recovery on the following testcase, compute_array_index_type checks size for error_operand_p early (and it is not error operand; it is <indirect_ref <var_decl c>> where c is of reference type with error_mark_node DECL_INITIAL), then calls mark_rvalue_use (which returns error_mark_node), but we let it go through maybe_constant_size etc. and because error_mark_node is !TREE_CONSTANT, set it back to the original size. Unfortunatley later on that results in ICE, because 9662 itype = cp_build_binary_op (input_location, 9663 MINUS_EXPR, 9664 cp_convert (ssizetype, size, complain), 9665 cp_convert (ssizetype, integer_one_node, 9666 complain), 9667 complain); errors on it the second time: error: use of local variable with automatic storage from containing function (the first error was during mark_rvalue_use) and nothing gives up anymore, so we build a domain with error_mark_node as maximum. Fixed by giving up earlier if mark_rvalue_use fails.
Initially I had the second error_operand_p check before the if (!TREE_CONSTANT (size)) check, but that unfortunately doesn't work, it broke FAIL: g++.dg/cpp0x/constexpr-47969.C -std=c++11 (test for errors, line 11) FAIL: g++.dg/cpp0x/constexpr-47969.C -std=c++14 (test for errors, line 11) FAIL: g++.dg/cpp0x/constexpr-ex2.C -std=c++11 (test for errors, line 21) FAIL: g++.dg/cpp0x/constexpr-ex2.C -std=c++14 (test for errors, line 21) FAIL: g++.dg/cpp0x/scoped_enum2.C -std=c++11 (test for errors, line 7) FAIL: g++.dg/cpp0x/scoped_enum2.C -std=c++14 (test for errors, line 7) FAIL: g++.dg/ext/stmtexpr15.C -std=gnu++11 (test for errors, line 6) FAIL: g++.dg/ext/stmtexpr15.C -std=gnu++14 (test for errors, line 6) FAIL: g++.dg/ext/stmtexpr15.C -std=gnu++98 (test for errors, line 6) FAIL: g++.dg/gomp/pr47963.C -std=gnu++11 (test for excess errors) FAIL: g++.dg/gomp/pr47963.C -std=gnu++14 (test for excess errors) FAIL: g++.dg/gomp/pr47963.C -std=gnu++98 (test for excess errors) where the errors weren't reported anymore. Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk? 2018-03-22 Jakub Jelinek <ja...@redhat.com> PR c++/85015 * decl.c (compute_array_index_type): Return error_mark_node if mark_rvalue_use or maybe_constant_value returns error_operand_p. * g++.dg/cpp0x/pr85015.C: New test. --- gcc/cp/decl.c.jj 2018-03-21 22:47:16.642996454 +0100 +++ gcc/cp/decl.c 2018-03-22 19:37:10.039385428 +0100 @@ -9522,6 +9522,9 @@ compute_array_index_type (tree name, tre { size = mark_rvalue_use (size); + if (error_operand_p (size)) + return error_mark_node; + if (cxx_dialect < cxx11 && TREE_CODE (size) == NOP_EXPR && TREE_SIDE_EFFECTS (size)) /* In C++98, we mark a non-constant array bound with a magic @@ -9534,11 +9537,10 @@ compute_array_index_type (tree name, tre if (!TREE_CONSTANT (size)) size = osize; + else if (error_operand_p (size)) + return error_mark_node; } - if (error_operand_p (size)) - return error_mark_node; - /* The array bound must be an integer type. */ tree type = TREE_TYPE (size); if (!INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type)) --- gcc/testsuite/g++.dg/cpp0x/pr85015.C.jj 2018-03-22 19:27:12.856154008 +0100 +++ gcc/testsuite/g++.dg/cpp0x/pr85015.C 2018-03-22 19:27:12.856154008 +0100 @@ -0,0 +1,12 @@ +// PR c++/85015 +// { dg-do compile { target c++11 } } +// { dg-options "" } + +void +foo () +{ + int &&c = v + 1; // { dg-error "was not declared in this scope" } + struct S { // { dg-message "declared here" "" { target *-*-* } .-1 } + void bar () { int a[c]; } // { dg-error "use of local variable with automatic storage from containing function" } + } e; +} Jakub