From 5f6ec13ffe8ae4db04419bf66868e082df73634d Mon Sep 17 00:00:00 2001 From: Tom de Vries Date: Wed, 25 Jan 2023 13:27:03 +0100 Subject: [gdb/testsuite] Improve leaf fn in gdb.base/unwind-on-each-insn.exp In test-case gdb.base/unwind-on-each-insn.exp, we stepi through function foo to check various invariants at each insn, in particular hoping to excercise insns that modify stack and frame pointers. For x86_64-linux, we have a reasonably complex foo (and similar for -m32): ... 4004bc: 55 push %rbp 4004bd: 48 89 e5 mov %rsp,%rbp 4004c0: 90 nop 4004c1: 5d pop %rbp 4004c2: c3 ret ... Both stack pointer (%rsp) and frame pointer (%rbp) are modified. Also for s390x-linux (and similar for -m31): ... 0000000001000668 : 1000668: e3 b0 f0 58 00 24 stg %r11,88(%r15) 100066e: b9 04 00 bf lgr %r11,%r15 1000672: e3 b0 b0 58 00 04 lg %r11,88(%r11) 1000678: 07 fe br %r14 ... Frame pointer (%r11) is modified. Likewise for powerpc64le-linux: ... 00000000100006c8 : 100006c8: f8 ff e1 fb std r31,-8(r1) 100006cc: d1 ff 21 f8 stdu r1,-48(r1) 100006d0: 78 0b 3f 7c mr r31,r1 100006d4: 00 00 00 60 nop 100006d8: 30 00 3f 38 addi r1,r31,48 100006dc: f8 ff e1 eb ld r31,-8(r1) 100006e0: 20 00 80 4e blr ... Both stack pointer (r1) and frame pointer (r31) are modified. But for aarch64-linux, we have: ... 00000000004005fc : 4005fc: d503201f nop 400600: d65f03c0 ret ... There's no insn that modifies stack or frame pointer. Fix this by making foo more complex, adding an (unused) argument: ... 0000000000400604 : 400604: d10043ff sub sp, sp, #0x10 400608: f90007e0 str x0, [sp, #8] 40060c: d503201f nop 400610: 910043ff add sp, sp, #0x10 400614: d65f03c0 ret ... such that the stack pointer (sp) is modified. [ Note btw that we're seeing the effects of -momit-leaf-frame-pointer, with -mno-omit-leaf-frame-pointer we have instead: ... 0000000000400604 : 400604: a9be7bfd stp x29, x30, [sp, #-32]! 400608: 910003fd mov x29, sp 40060c: f9000fa0 str x0, [x29, #24] 400610: d503201f nop 400614: a8c27bfd ldp x29, x30, [sp], #32 400618: d65f03c0 ret ... such that also the frame pointer (x29) is modified. ] Having made foo more complex, we now run into the following fail on x86_64/-m32: ... FAIL: gdb.base/unwind-on-each-insn.exp: instruction 1: $sp_value == $main_sp .... The problem is that the stack pointer has changed inbetween the sampling of main_sp and *foo, in particular by the push insn: ... 804841a: 68 c0 84 04 08 push $0x80484c0 804841f: e8 10 00 00 00 call 8048434 ... Fix this by updating main_sp. On powerpc64le-linux, with gcc 7.5.0 I now run into PR tdep/30021: ... FAIL: gdb.base/unwind-on-each-insn.exp: insn 7: $fba_value == $main_fba FAIL: gdb.base/unwind-on-each-insn.exp: insn 7: [string equal $fid $main_fid] ... but I saw the same failure before this commit with gcc 4.8.5. Tested on: - x86_64-linux (-m64 and -m32) - s390x-linux (-m64 and -m31) - powerpc64le-linux - aarch64-linux Also I've checked that the test-case still functions as regression test for PR record/16678 on x86_64. --- gdb/testsuite/gdb.base/unwind-on-each-insn-foo.c | 2 +- gdb/testsuite/gdb.base/unwind-on-each-insn.c | 4 ++-- gdb/testsuite/gdb.base/unwind-on-each-insn.exp | 7 ++++++- 3 files changed, 9 insertions(+), 4 deletions(-) (limited to 'gdb/testsuite') diff --git a/gdb/testsuite/gdb.base/unwind-on-each-insn-foo.c b/gdb/testsuite/gdb.base/unwind-on-each-insn-foo.c index af9fc11..635aa44 100644 --- a/gdb/testsuite/gdb.base/unwind-on-each-insn-foo.c +++ b/gdb/testsuite/gdb.base/unwind-on-each-insn-foo.c @@ -16,7 +16,7 @@ along with this program. If not, see . */ void -foo () +foo (const char *s) { /* Nothing. */ } diff --git a/gdb/testsuite/gdb.base/unwind-on-each-insn.c b/gdb/testsuite/gdb.base/unwind-on-each-insn.c index 60bc83a..821df37 100644 --- a/gdb/testsuite/gdb.base/unwind-on-each-insn.c +++ b/gdb/testsuite/gdb.base/unwind-on-each-insn.c @@ -15,11 +15,11 @@ You should have received a copy of the GNU General Public License along with this program. If not, see . */ -extern void foo (); +extern void foo (const char *); int main () { - foo (); + foo ("foo"); return 0; } diff --git a/gdb/testsuite/gdb.base/unwind-on-each-insn.exp b/gdb/testsuite/gdb.base/unwind-on-each-insn.exp index fc48bf5..6e68b24 100644 --- a/gdb/testsuite/gdb.base/unwind-on-each-insn.exp +++ b/gdb/testsuite/gdb.base/unwind-on-each-insn.exp @@ -113,7 +113,12 @@ for { set i_count 1 } { true } { incr i_count } { # Check we can unwind the stack-pointer and the frame base # address correctly. lassign [get_sp_and_fba "for main"] sp_value fba_value - gdb_assert { $sp_value == $main_sp } + if { $i_count == 1 } { + # The stack-pointer may have changed while running to *foo. + set main_sp $sp_value + } else { + gdb_assert { $sp_value == $main_sp } + } gdb_assert { $fba_value == $main_fba } # Check we have a consistent value for main's frame-id. -- cgit v1.1