From 4e1d2f5814b29048d1dd1cea2cb50570e6c8f1f8 Mon Sep 17 00:00:00 2001 From: Tom Tromey Date: Wed, 7 Sep 2022 08:39:52 -0600 Subject: Add new overload of gdbarch_return_value The gdbarch "return_value" can't correctly handle variably-sized types. The problem here is that the TYPE_LENGTH of such a type is 0, until the type is resolved, which requires reading memory. However, gdbarch_return_value only accepts a buffer as an out parameter. Fixing this requires letting the implementation of the gdbarch method resolve the type and return a value -- that is, both the contents and the new type. After an attempt at this, I realized I wouldn't be able to correctly update all implementations (there are ~80) of this method. So, instead, this patch adds a new method that falls back to the current method, and it updates gdb to only call the new method. This way it's possible to incrementally convert the architectures that I am able to test. --- gdb/arch-utils.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'gdb/arch-utils.c') diff --git a/gdb/arch-utils.c b/gdb/arch-utils.c index a6d0035..3ca1930 100644 --- a/gdb/arch-utils.c +++ b/gdb/arch-utils.c @@ -1098,6 +1098,24 @@ default_get_return_buf_addr (struct type *val_type, frame_info_ptr cur_frame) return 0; } +enum return_value_convention +default_gdbarch_return_value + (struct gdbarch *gdbarch, struct value *function, struct type *valtype, + struct regcache *regcache, struct value **read_value, + const gdb_byte *writebuf) +{ + gdb_byte *readbuf = nullptr; + + if (read_value != nullptr) + { + *read_value = allocate_value (valtype); + readbuf = value_contents_raw (*read_value).data (); + } + + return gdbarch_return_value (gdbarch, function, valtype, regcache, + readbuf, writebuf); +} + /* Non-zero if we want to trace architecture code. */ #ifndef GDBARCH_DEBUG -- cgit v1.1