From: Tom de Vries Date: Fri, 8 Aug 2025 05:19:50 +0000 (+0200) Subject: [gdb/tdep] Fix inferior call return of small char array for ppc64 v1 abi X-Git-Tag: gdb-17-branchpoint~366 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=13f1820106cf8888d8df5fcc0f01e55ed1a10db4;p=thirdparty%2Fbinutils-gdb.git [gdb/tdep] Fix inferior call return of small char array for ppc64 v1 abi In ppc64_sysv_abi_return_value I came across this if clause: ... /* Small character arrays are returned, right justified, in r3. */ if (valtype->code () == TYPE_CODE_ARRAY && !valtype->is_vector () && valtype->length () <= 8 && valtype->target_type ()->code () == TYPE_CODE_INT && valtype->target_type ()->length () == 1) ... I decided to write a test-case to try and trigger this. AFAIU, in C/C++, we're not allowed to return an array, so I wrote an Ada test-case instead, with a function returning this type: ... type T is new String (1 .. 4); ... After doing so I realized that the clause above is not triggering because valtype->target_type ()->code () == TYPE_CODE_CHAR. Fix this by allowing both TYPE_CODE_INT and TYPE_CODE_CHAR. Then I realized that the specific "small character array" handling comes from the v1 abi. Add a check for this as well. Tested on ppc64le-linux, with v2 abi. Approved-By: Simon Marchi --- diff --git a/gdb/ppc-sysv-tdep.c b/gdb/ppc-sysv-tdep.c index cae5aa62572..f872f73e414 100644 --- a/gdb/ppc-sysv-tdep.c +++ b/gdb/ppc-sysv-tdep.c @@ -2060,10 +2060,12 @@ ppc64_sysv_abi_return_value (struct gdbarch *gdbarch, struct value *function, } /* Small character arrays are returned, right justified, in r3. */ - if (valtype->code () == TYPE_CODE_ARRAY + if (tdep->elf_abi == POWERPC_ELF_V1 + && valtype->code () == TYPE_CODE_ARRAY && !valtype->is_vector () && valtype->length () <= 8 - && valtype->target_type ()->code () == TYPE_CODE_INT + && (valtype->target_type ()->code () == TYPE_CODE_INT + || valtype->target_type ()->code () == TYPE_CODE_CHAR) && valtype->target_type ()->length () == 1) { int regnum = tdep->ppc_gp0_regnum + 3; diff --git a/gdb/testsuite/gdb.ada/return-small-char-array.exp b/gdb/testsuite/gdb.ada/return-small-char-array.exp new file mode 100644 index 00000000000..75c781e9a0e --- /dev/null +++ b/gdb/testsuite/gdb.ada/return-small-char-array.exp @@ -0,0 +1,40 @@ +# Copyright 2025 Free Software Foundation, Inc. +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 3 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see . + +load_lib "ada.exp" + +require allow_ada_tests + +standard_ada_testfile proc + +if { [gdb_compile_ada $srcfile $binfile executable debug] != "" } { + return -1 +} + +clean_restart $testfile + +set bp_location [gdb_get_line_number "STOP" $testdir/proc.adb] +runto "proc.adb:$bp_location" + +gdb_test "print Value.Name(My_Value)" \ + { = "abcd"} + +# Step into the function. +gdb_test "step 2" \ + "return Of_Value;" + +# and finish. +gdb_test "finish" \ + { = "abcd"} diff --git a/gdb/testsuite/gdb.ada/return-small-char-array/proc.adb b/gdb/testsuite/gdb.ada/return-small-char-array/proc.adb new file mode 100644 index 00000000000..b18d9fe1fe0 --- /dev/null +++ b/gdb/testsuite/gdb.ada/return-small-char-array/proc.adb @@ -0,0 +1,22 @@ +-- Copyright 2025 Free Software Foundation, Inc. +-- +-- This program is free software; you can redistribute it and/or modify +-- it under the terms of the GNU General Public License as published by +-- the Free Software Foundation; either version 3 of the License, or +-- (at your option) any later version. +-- +-- This program is distributed in the hope that it will be useful, +-- but WITHOUT ANY WARRANTY; without even the implied warranty of +-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +-- GNU General Public License for more details. +-- +-- You should have received a copy of the GNU General Public License +-- along with this program. If not, see . + +with Value; +procedure Proc is + My_Value : Value.T := "abcd"; +begin + null; -- STOP + My_Value := Value.Name(My_Value); +end; diff --git a/gdb/testsuite/gdb.ada/return-small-char-array/value.adb b/gdb/testsuite/gdb.ada/return-small-char-array/value.adb new file mode 100644 index 00000000000..2dd9faacc1b --- /dev/null +++ b/gdb/testsuite/gdb.ada/return-small-char-array/value.adb @@ -0,0 +1,21 @@ +-- Copyright 2025 Free Software Foundation, Inc. +-- +-- This program is free software; you can redistribute it and/or modify +-- it under the terms of the GNU General Public License as published by +-- the Free Software Foundation; either version 3 of the License, or +-- (at your option) any later version. +-- +-- This program is distributed in the hope that it will be useful, +-- but WITHOUT ANY WARRANTY; without even the implied warranty of +-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +-- GNU General Public License for more details. +-- +-- You should have received a copy of the GNU General Public License +-- along with this program. If not, see . + +package body Value is + function Name (Of_Value : T) return T is + begin + return Of_Value; + end Name; +end Value; diff --git a/gdb/testsuite/gdb.ada/return-small-char-array/value.ads b/gdb/testsuite/gdb.ada/return-small-char-array/value.ads new file mode 100644 index 00000000000..16b171e9422 --- /dev/null +++ b/gdb/testsuite/gdb.ada/return-small-char-array/value.ads @@ -0,0 +1,20 @@ +-- Copyright 2025 Free Software Foundation, Inc. +-- +-- This program is free software; you can redistribute it and/or modify +-- it under the terms of the GNU General Public License as published by +-- the Free Software Foundation; either version 3 of the License, or +-- (at your option) any later version. +-- +-- This program is distributed in the hope that it will be useful, +-- but WITHOUT ANY WARRANTY; without even the implied warranty of +-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +-- GNU General Public License for more details. +-- +-- You should have received a copy of the GNU General Public License +-- along with this program. If not, see . + +package Value is + type T is new String (1 .. 4); + + function Name (Of_Value : T) return T; +end;