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author | Ng YongXiang <yongxiangng@gmail.com> | 2023-07-27 08:06:14 +0800 |
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committer | Jason Merrill <jason@redhat.com> | 2023-07-28 08:40:02 -0700 |
commit | a47e615fbf9c6f4b24e5032df5d720b6bf9b63b5 (patch) | |
tree | 7005a6811bb4f9b5a1ecbb75bf1c3806f1af31d2 | |
parent | f5fb9ff2396fd41fdd2e6d35a412e936d2d42f75 (diff) | |
download | gcc-a47e615fbf9c6f4b24e5032df5d720b6bf9b63b5.zip gcc-a47e615fbf9c6f4b24e5032df5d720b6bf9b63b5.tar.gz gcc-a47e615fbf9c6f4b24e5032df5d720b6bf9b63b5.tar.bz2 |
c++: devirtualization of array destruction [PR110057]
PR c++/110057
PR ipa/83054
gcc/cp/ChangeLog:
* init.cc (build_vec_delete_1): Devirtualize array destruction.
gcc/testsuite/ChangeLog:
* g++.dg/warn/pr83054.C: Remove devirtualization warning.
* g++.dg/lto/pr89335_0.C: Likewise.
* g++.dg/tree-ssa/devirt-array-destructor-1.C: New test.
* g++.dg/tree-ssa/devirt-array-destructor-2.C: New test.
* g++.dg/warn/pr83054-2.C: New test.
Signed-off-by: Ng Yong Xiang <yongxiangng@gmail.com>
-rw-r--r-- | gcc/cp/init.cc | 11 | ||||
-rw-r--r-- | gcc/testsuite/g++.dg/lto/pr89335_0.C | 2 | ||||
-rw-r--r-- | gcc/testsuite/g++.dg/tree-ssa/devirt-array-destructor-1.C | 28 | ||||
-rw-r--r-- | gcc/testsuite/g++.dg/tree-ssa/devirt-array-destructor-2.C | 29 | ||||
-rw-r--r-- | gcc/testsuite/g++.dg/warn/pr83054-2.C | 44 | ||||
-rw-r--r-- | gcc/testsuite/g++.dg/warn/pr83054.C | 2 |
6 files changed, 110 insertions, 6 deletions
diff --git a/gcc/cp/init.cc b/gcc/cp/init.cc index ff5014c..3b9a778 100644 --- a/gcc/cp/init.cc +++ b/gcc/cp/init.cc @@ -4116,8 +4116,8 @@ build_vec_delete_1 (location_t loc, tree base, tree maxindex, tree type, if (type_build_dtor_call (type)) { tmp = build_delete (loc, ptype, base, sfk_complete_destructor, - LOOKUP_NORMAL|LOOKUP_DESTRUCTOR, 1, - complain); + LOOKUP_NORMAL|LOOKUP_DESTRUCTOR|LOOKUP_NONVIRTUAL, + 1, complain); if (tmp == error_mark_node) return error_mark_node; } @@ -4146,9 +4146,12 @@ build_vec_delete_1 (location_t loc, tree base, tree maxindex, tree type, if (tmp == error_mark_node) return error_mark_node; body = build_compound_expr (loc, body, tmp); + /* [expr.delete]/3: "In an array delete expression, if the dynamic type of + the object to be deleted is not similar to its static type, the behavior + is undefined." So we can set LOOKUP_NONVIRTUAL. */ tmp = build_delete (loc, ptype, tbase, sfk_complete_destructor, - LOOKUP_NORMAL|LOOKUP_DESTRUCTOR, 1, - complain); + LOOKUP_NORMAL|LOOKUP_DESTRUCTOR|LOOKUP_NONVIRTUAL, + 1, complain); if (tmp == error_mark_node) return error_mark_node; body = build_compound_expr (loc, body, tmp); diff --git a/gcc/testsuite/g++.dg/lto/pr89335_0.C b/gcc/testsuite/g++.dg/lto/pr89335_0.C index 95bf4b3..76382f8 100644 --- a/gcc/testsuite/g++.dg/lto/pr89335_0.C +++ b/gcc/testsuite/g++.dg/lto/pr89335_0.C @@ -9,7 +9,7 @@ public: virtual ~Container (); }; -class List : public Container // { dg-lto-message "final would enable devirtualization" } +class List : public Container { }; diff --git a/gcc/testsuite/g++.dg/tree-ssa/devirt-array-destructor-1.C b/gcc/testsuite/g++.dg/tree-ssa/devirt-array-destructor-1.C new file mode 100644 index 0000000..ce8dc2a --- /dev/null +++ b/gcc/testsuite/g++.dg/tree-ssa/devirt-array-destructor-1.C @@ -0,0 +1,28 @@ +// PR c++/110057 +/* { dg-do-compile } */ +/* Virtual calls should be devirtualized because we know dynamic type of object in array at compile time */ +/* { dg-options "-O3 -fdump-tree-optimized -fno-inline" } */ + +class A +{ +public: + virtual ~A() + { + } +}; + +class B : public A +{ +public: + virtual ~B() + { + } +}; + +int main() +{ + B b[10]; + return 0; +} + +/* { dg-final { scan-tree-dump-times "OBJ_TYPE_REF" 0 "optimized"} } */ diff --git a/gcc/testsuite/g++.dg/tree-ssa/devirt-array-destructor-2.C b/gcc/testsuite/g++.dg/tree-ssa/devirt-array-destructor-2.C new file mode 100644 index 0000000..6b44dc1 --- /dev/null +++ b/gcc/testsuite/g++.dg/tree-ssa/devirt-array-destructor-2.C @@ -0,0 +1,29 @@ +// PR c++/110057 +/* { dg-do-compile } */ +/* Virtual calls should be devirtualized because we know dynamic type of object in array at compile time */ +/* { dg-options "-O3 -fdump-tree-optimized -fno-inline" } */ + +class A +{ +public: + virtual ~A() + { + } +}; + +class B : public A +{ +public: + virtual ~B() + { + } +}; + +int main() +{ + B* ptr = new B[10]; + delete[] ptr; + return 0; +} + +/* { dg-final { scan-tree-dump-times "OBJ_TYPE_REF" 0 "optimized"} } */ diff --git a/gcc/testsuite/g++.dg/warn/pr83054-2.C b/gcc/testsuite/g++.dg/warn/pr83054-2.C new file mode 100644 index 0000000..6d8216d --- /dev/null +++ b/gcc/testsuite/g++.dg/warn/pr83054-2.C @@ -0,0 +1,44 @@ +// PR ipa/83054 +// { dg-options "-O3 -Wsuggest-final-types" } +// { dg-do compile } + +// A throwing dtor in C++98 mode changes the warning. +#if __cplusplus < 201100L +#define NOTHROW throw() +#else +#define NOTHROW noexcept +#endif + +extern "C" int printf (const char *, ...); +struct foo // { dg-warning "final would enable devirtualization of 1 call" } +{ + static int count; + void print (int i, int j) { printf ("foo[%d][%d] = %d\n", i, j, x); } + int x; + foo () { + x = count++; + printf("this %d = %x\n", x, (void *)this); + } + virtual ~foo () NOTHROW { + printf("this %d = %x\n", x, (void *)this); + --count; + } +}; +int foo::count; + + +int main () +{ + foo *arr[9]; + for (int i = 0; i < 9; ++i) + arr[i] = new foo(); + if (foo::count != 9) + return 1; + for (int i = 0; i < 9; ++i) + arr[i]->print(i / 3, i % 3); + for (int i = 0; i < 9; ++i) + delete arr[i]; + if (foo::count != 0) + return 1; + return 0; +} diff --git a/gcc/testsuite/g++.dg/warn/pr83054.C b/gcc/testsuite/g++.dg/warn/pr83054.C index 5285f94..5a4a6ab 100644 --- a/gcc/testsuite/g++.dg/warn/pr83054.C +++ b/gcc/testsuite/g++.dg/warn/pr83054.C @@ -10,7 +10,7 @@ #endif extern "C" int printf (const char *, ...); -struct foo // { dg-warning "final would enable devirtualization of 5 calls" } +struct foo { static int count; void print (int i, int j) { printf ("foo[%d][%d] = %d\n", i, j, x); } |