From 16ff70ddd430b63ca4dd68bf1d52828f2ed4f030 Mon Sep 17 00:00:00 2001 From: Sergio Durigan Junior Date: Sat, 7 Jul 2018 17:16:55 -0400 Subject: [PATCH] Fix PR c++/23373: GDB hangs when printing a struct with a static member of itself This patch fixes a failure that happens when a structure has a static member whose type is the same as itself. From the bug report: Example code: struct A { static A Empty; int a; }; int main(void) { A a; return 0; } Output: (gdb) ptype/o A /* offset | size */ type = struct A { static struct A { static struct A { static struct A { static struct A { static struct A { static struct A { ... # infinite loop The problem here is that GDB is not taking into account the fact that static members inside a class/struct are not stored in the class/struct, and therefore they should not be accounted for during the display of the offsets/sizes. The fix is simple: we just check if the field we're dealing with (on c-typeprint.c:c_type_print_base_struct_union) is static, and if it is then we don't iterate over it. This patch also adds a new test for this case, and doesn't introduce any regressions. I believe it is important enough to be included in the 8.2 branch. OK? gdb/ChangeLog: 2018-07-11 Sergio Durigan Junior PR c++/23373 * c-typeprint.c (c_type_print_base_struct_union): Don't print offsets/sizes for static members of a class/struct. gdb/testsuite/ChangeLog: 2018-07-11 Sergio Durigan Junior PR c++/23373 * gdb.base/ptype-offsets.cc (struct static_member): New struct. (main) : New variable. * gdb.base/ptype-offsets.exp: Add test for printing a struct with a static member in it. --- gdb/ChangeLog | 6 ++++++ gdb/c-typeprint.c | 2 +- gdb/testsuite/ChangeLog | 9 +++++++++ gdb/testsuite/gdb.base/ptype-offsets.cc | 8 ++++++++ gdb/testsuite/gdb.base/ptype-offsets.exp | 11 +++++++++++ 5 files changed, 35 insertions(+), 1 deletion(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 7c74c87d8c5..5ac6c604f6a 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,9 @@ +2018-07-11 Sergio Durigan Junior + + PR c++/23373 + * c-typeprint.c (c_type_print_base_struct_union): Don't print + offsets/sizes for static members of a class/struct. + 2018-07-11 Alan Hayward * target-descriptions.c (tdesc_register_bitsize): Rename. diff --git a/gdb/c-typeprint.c b/gdb/c-typeprint.c index c167e212ded..eccb972f245 100644 --- a/gdb/c-typeprint.c +++ b/gdb/c-typeprint.c @@ -1168,7 +1168,7 @@ c_type_print_base_struct_union (struct type *type, struct ui_file *stream, int newshow = show - 1; - if (flags->print_offsets + if (!is_static && flags->print_offsets && (TYPE_CODE (TYPE_FIELD_TYPE (type, i)) == TYPE_CODE_STRUCT || TYPE_CODE (TYPE_FIELD_TYPE (type, i)) == TYPE_CODE_UNION)) { diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog index d073eda401a..f1b2a70379b 100644 --- a/gdb/testsuite/ChangeLog +++ b/gdb/testsuite/ChangeLog @@ -1,3 +1,12 @@ +2018-07-11 Sergio Durigan Junior + + PR c++/23373 + * gdb.base/ptype-offsets.cc (struct static_member): New + struct. + (main) : New variable. + * gdb.base/ptype-offsets.exp: Add test for printing a struct + with a static member in it. + 2018-07-10 Andrew Burgess * gdb.base/watchpoint-reuse-slot.exp: Test with hardware diff --git a/gdb/testsuite/gdb.base/ptype-offsets.cc b/gdb/testsuite/gdb.base/ptype-offsets.cc index 7b01dbc5fb4..e1aefe5bb3f 100644 --- a/gdb/testsuite/gdb.base/ptype-offsets.cc +++ b/gdb/testsuite/gdb.base/ptype-offsets.cc @@ -177,6 +177,13 @@ struct asd void *f16; }; +/* See PR c++/23373. */ + +struct static_member +{ + static static_member Empty; + int abc; +}; int main (int argc, char *argv[]) @@ -188,6 +195,7 @@ main (int argc, char *argv[]) struct tyu e; struct asd f; uint8_t i; + static_member stmember; return 0; } diff --git a/gdb/testsuite/gdb.base/ptype-offsets.exp b/gdb/testsuite/gdb.base/ptype-offsets.exp index d8718d581b1..ca0c5de7eea 100644 --- a/gdb/testsuite/gdb.base/ptype-offsets.exp +++ b/gdb/testsuite/gdb.base/ptype-offsets.exp @@ -328,3 +328,14 @@ gdb_test_multiple "$test" "$test" { pass $test } } + +# Test that printing a struct with a static member of itself doesn't +# get us into an infinite loop. +gdb_test "ptype/o static_member" \ + [multi_line \ +{/\* offset | size \*/ type = struct static_member \{} \ +{ static static_member Empty;} \ +{\/* 0 | 4 \*/ int abc;} \ +{} \ +{ /\* total size \(bytes\): 4 \*/} \ +{ \}}] -- 2.30.2