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On openSUSE Tumbleweed ppc64le-linux using gcc 14.3.0, with a gdb 16.3 based package and test-case gdb.ada/finish-var-size.exp, I run into: ... (gdb) finish^M Run till exit from #0 pck.get (value=true) at pck.adb:19^M 0x0000000100004a20 in p () at finish-var-size/p.adb:18^M 18 V : Result_T := Get (True);^M Value returned is $1 = <error reading variable: \ Cannot access memory at address 0x0>^M (gdb) FAIL: gdb.ada/finish-var-size.exp: finish ... Function pck.get returns type Result_T: ... type Array_Type is array (1 .. 64) of Integer; type Maybe_Array (Defined : Boolean := False) is record Arr : Array_Type; Arr2 : Array_Type; end record; type Result_T (Defined : Boolean := False) is record case Defined is when False => Arr : Maybe_Array; when True => Payload : Boolean; end case; end record; ... and uses r3 as address of the return value, which means RETURN_VALUE_STRUCT_CONVENTION, but while executing finish_command we do: ... return_value = gdbarch_return_value_as_value (gdbarch, read_var_value (sm->function, nullptr, callee_frame), val_type, nullptr, nullptr, nullptr); ... and get: ... (gdb) p return_value $1 = RETURN_VALUE_REGISTER_CONVENTION ... This is caused by this check in ppc64_sysv_abi_return_value: ... /* In the ELFv2 ABI, aggregate types of up to 16 bytes are returned in registers r3:r4. */ if (tdep->elf_abi == POWERPC_ELF_V2 && valtype->length () <= 16 ... which succeeds because valtype->length () == 0. Fix this by also checking for !TYPE_HAS_DYNAMIC_LENGTH (valtype). [ I also tested a version of this patch using "!is_dynamic_type (valtype)" instead, but ran into a regression in test-case gdb.ada/variant-record.exp, because type T: ... Length : constant Positive := 8; subtype Name_T is String (1 .. Length); type A_Record_T is record X1 : Natural; X2 : Natural; end record; type Yes_No_T is (Yes, No); type T (Well : Yes_No_T := Yes) is record case Well is when Yes => Name : Name_T; when No => Unique_Name : A_Record_T; end case; end record; ... while being dynamic, also has a non-zero size, and is small enough to be returned in registers r3:r4. ] Fixing this causes the test-case to fail with the familiar: ... warning: Cannot determine the function return value. Try compiling with -fvar-tracking. ... and indeed using -fvar-tracking makes the test-case pass. Tested on ppc64le-linux. PR tdep/33000 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=33000
README for GNU development tools This directory contains various GNU compilers, assemblers, linkers, debuggers, etc., plus their support routines, definitions, and documentation. If you are receiving this as part of a GDB release, see the file gdb/README. If with a binutils release, see binutils/README; if with a libg++ release, see libg++/README, etc. That'll give you info about this package -- supported targets, how to use it, how to report bugs, etc. It is now possible to automatically configure and build a variety of tools with one command. To build all of the tools contained herein, run the ``configure'' script here, e.g.: ./configure make To install them (by default in /usr/local/bin, /usr/local/lib, etc), then do: make install (If the configure script can't determine your type of computer, give it the name as an argument, for instance ``./configure sun4''. You can use the script ``config.sub'' to test whether a name is recognized; if it is, config.sub translates it to a triplet specifying CPU, vendor, and OS.) If you have more than one compiler on your system, it is often best to explicitly set CC in the environment before running configure, and to also set CC when running make. For example (assuming sh/bash/ksh): CC=gcc ./configure make A similar example using csh: setenv CC gcc ./configure make Much of the code and documentation enclosed is copyright by the Free Software Foundation, Inc. See the file COPYING or COPYING.LIB in the various directories, for a description of the GNU General Public License terms under which you can copy the files. REPORTING BUGS: Again, see gdb/README, binutils/README, etc., for info on where and how to report problems.