Hi, This is the patch to fix this issue based on our discussion.
I have tested it on aarch64 with bootstrap and regtests. X86 bootstrap was done, regtests is ongoing. Okay for trunk? Thanks. Qing ====================== >From d349ef0145512efe7f9af2c6bbd01f636475bce3 Mon Sep 17 00:00:00 2001 From: qing zhao <qing.z...@oracle.com> Date: Mon, 4 Oct 2021 15:26:03 -0700 Subject: [PATCH] middle-end/102359 Not add initialization for variables that have been initialized by FEs. C++ FE creates proxy variables, which have associated DECL_VALUE_EXPR and have been initialized by FE. For such auto variable, we should not add initialization when -ftrivial-auto-var-init presents. gcc/ChangeLog: 2021-10-04 qing zhao <qing.z...@oracle.com> * gimplify.c (is_decl_init_by_fe): New function. (gimplify_decl_expr): Not add initialization for an auto variable when it has been initialized by frontend. gcc/testsuite/ChangeLog: 2021-10-04 qing zhao <qing.z...@oracle.com> * g++.dg/pr102359_1.C: New test. * g++.dg/pr102359_2.C: New test. --- gcc/gimplify.c | 21 ++++++++++++++++++++- gcc/testsuite/g++.dg/pr102359_1.C | 13 +++++++++++++ gcc/testsuite/g++.dg/pr102359_2.C | 13 +++++++++++++ 3 files changed, 46 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/g++.dg/pr102359_1.C create mode 100644 gcc/testsuite/g++.dg/pr102359_2.C diff --git a/gcc/gimplify.c b/gcc/gimplify.c index b27776a..d6865ad 100644 --- a/gcc/gimplify.c +++ b/gcc/gimplify.c @@ -1819,6 +1819,19 @@ gimple_add_padding_init_for_auto_var (tree decl, bool is_vla, gimplify_seq_add_stmt (seq_p, call); } +/* Return true if the DECL is initialized by FE. + If the VAR_DECL has DECL_VALUE_EXPR that was created by FE (usually C++FE), + it's a proxy varaible, and FE already initializd the DECL_VALUE_EXPR of it. +*/ +static bool +is_decl_init_by_fe (tree decl, bool is_created_by_fe) +{ + if (DECL_HAS_VALUE_EXPR_P (decl) + && is_created_by_fe) + return true; + return false; +} + /* Return true if the DECL need to be automaticly initialized by the compiler. */ static bool @@ -1871,8 +1884,13 @@ gimplify_decl_expr (tree *stmt_p, gimple_seq *seq_p) if (VAR_P (decl) && !DECL_EXTERNAL (decl)) { tree init = DECL_INITIAL (decl); + bool is_value_expr_created_by_fe = false; bool is_vla = false; + /* Check whether a decl has FE created VALUE_EXPR here BEFORE + gimplify_vla_decl creates VALUE_EXPR for vla decl. */ + is_value_expr_created_by_fe = DECL_HAS_VALUE_EXPR_P (decl); + poly_uint64 size; if (!poly_int_tree_p (DECL_SIZE_UNIT (decl), &size) || (!TREE_STATIC (decl) @@ -1934,7 +1952,8 @@ gimplify_decl_expr (tree *stmt_p, gimple_seq *seq_p) /* When there is no explicit initializer, if the user requested, We should insert an artifical initializer for this automatic variable. */ - else if (is_var_need_auto_init (decl)) + else if (is_var_need_auto_init (decl) + && !is_decl_init_by_fe (decl, is_value_expr_created_by_fe)) { gimple_add_init_for_auto_var (decl, flag_auto_var_init, diff --git a/gcc/testsuite/g++.dg/pr102359_1.C b/gcc/testsuite/g++.dg/pr102359_1.C new file mode 100644 index 0000000..da643cd --- /dev/null +++ b/gcc/testsuite/g++.dg/pr102359_1.C @@ -0,0 +1,13 @@ +/* PR middle-end/102359 ICE gimplification failed since + r12-3433-ga25e0b5e6ac8a77a. */ +/* { dg-do compile } */ +/* { dg-options "-ftrivial-auto-var-init=zero" } */ +/* { dg-require-effective-target c++17 } */ + +struct A { + double a = 111; + auto foo() { + return [*this] { return a; }; + } +}; +int X = A{}.foo()(); diff --git a/gcc/testsuite/g++.dg/pr102359_2.C b/gcc/testsuite/g++.dg/pr102359_2.C new file mode 100644 index 0000000..d026d72 --- /dev/null +++ b/gcc/testsuite/g++.dg/pr102359_2.C @@ -0,0 +1,13 @@ +/* PR middle-end/102359 ICE gimplification failed since + r12-3433-ga25e0b5e6ac8a77a. */ +/* { dg-do run} */ +/* { dg-options "-ftrivial-auto-var-init=zero" } */ +/* { dg-require-effective-target c++17 } */ + +int main() +{ + int i = 42; + auto l = [=]() mutable { return i; }; + if (l() != i) + __builtin_abort (); +} -- 1.9.1