From 55f40d968b0bd3be4478a9481e829a99ee0fa04f Mon Sep 17 00:00:00 2001 From: Jason Merrill Date: Mon, 5 Apr 2021 22:50:44 -0400 Subject: [PATCH] c++: mangling of lambdas in default args [PR91241] In this testcase, the parms remembered in LAMBDA_EXPR_EXTRA_SCOPE are no longer the parms of the FUNCTION_DECL they have as their DECL_CONTEXT, so we were mangling both lambdas as parm #0. But since the parms are numbered from right to left we don't need to need to find them in the FUNCTION_DECL, we can measure their own DECL_CHAIN. gcc/cp/ChangeLog: PR c++/91241 * mangle.c (write_compact_number): Add sanity check. (write_local_name): Use list_length for parm number. gcc/testsuite/ChangeLog: PR c++/91241 * g++.dg/abi/lambda-defarg1.C: New test. --- gcc/cp/mangle.c | 11 ++--------- gcc/testsuite/g++.dg/abi/lambda-defarg1.C | 11 +++++++++++ 2 files changed, 13 insertions(+), 9 deletions(-) create mode 100644 gcc/testsuite/g++.dg/abi/lambda-defarg1.C --- gcc/cp/mangle.c +++ gcc/cp/mangle.c @@ -1628,6 +1628,7 @@ write_literal_operator_name (tree identifier) static void write_compact_number (int num) { + gcc_checking_assert (num >= 0); if (num > 0) write_unsigned_number (num - 1); write_char ('_'); @@ -2027,15 +2028,7 @@ write_local_name (tree function, const tree local_entity, /* For this purpose, parameters are numbered from right-to-left. */ if (parm) { - tree t; - int i = 0; - for (t = DECL_ARGUMENTS (function); t; t = DECL_CHAIN (t)) - { - if (t == parm) - i = 1; - else if (i) - ++i; - } + int i = list_length (parm); write_char ('d'); write_compact_number (i - 1); } --- /dev/null +++ gcc/testsuite/g++.dg/abi/lambda-defarg1.C @@ -0,0 +1,11 @@ +// PR c++/91241 +// { dg-do compile { target c++11 } } + +struct A { + int *b(const int & = []() -> int { return 0; }(), + const int & = []() -> int { return 0; }()); +}; +int *A::b(const int &, const int &) { b(); return 0; } +// { dg-final { scan-assembler "_ZN1A1bERKiS1_" } } +// { dg-final { scan-assembler "_ZZN1A1bERKiS1_Ed_NKUlvE_clEv" } } +// { dg-final { scan-assembler "_ZZN1A1bERKiS1_Ed0_NKUlvE_clEv" } } -- 2.27.0