diff mbox series

[PATCHv2] gdb/riscv: add systemtap support

Message ID 87v8ivcclt.fsf@redhat.com
State New
Headers
Series [PATCHv2] gdb/riscv: add systemtap support |

Commit Message

Andrew Burgess March 20, 2023, 9:54 p.m. UTC 
  Here's a V2 with the changes in riscv-tdep.c rather than
riscv-linux-tdep.c.  Nothing else has changed.

Thanks,
Andrew

---

commit f0288ff3d6468fb6c42c69a027f391d3460f790b
Author: Andrew Burgess <aburgess@redhat.com>
Date:   Sat Mar 18 15:15:49 2023 +0000

    gdb/riscv: add systemtap support
    
    This commit is initial support for SystemTap for RISC-V Linux.  The
    following two tests exercise SystemTap functionality, and are showing
    many failures, which are all fixed by this commit:
    
      gdb.cp/exceptprint.exp
      gdb.base/stap-probe.exp
    
    One thing I wasn't sure about is if the SystemTap support should be
    Linux specific, or architecture specific.  For aarch64, arm, ia64, and
    ppc, the SystemTap support seems to libe in the ARCH-linux-tdep.c
    file, while for amd64, i386, and s390 the implementation lives in
    ARCH-tdep.c.  I have no idea which of these is the better choice -- or
    maybe both choices are correct in the right circumstances, and I'm
    just not aware of how to choose between them.
    
    Anyway, for this patch I selected riscv-tdep.c (though clearly, moving
    the changes to riscv-linux-tdep.c is trivial if anyone thinks that's a
    more appropriate location).
    
    The stap-probe.exp file tests immediate, register, and register
    indirect operands, all of which appear to be working fine with this
    commit.  The generic expression support doesn't appear to be
    architecture specific, so I'd expect that to work fine too.

Comments

Tom Tromey March 21, 2023, 2:15 p.m. UTC | #1 
>>>>> "Andrew" == Andrew Burgess via Gdb-patches <gdb-patches@sourceware.org> writes:

Andrew> Here's a V2 with the changes in riscv-tdep.c rather than
Andrew> riscv-linux-tdep.c.  Nothing else has changed.

Thanks, it looks good to me.
Reviewed-By: Tom Tromey <tom@tromey.com>

Tom
Andrew Burgess March 23, 2023, 7:20 a.m. UTC | #2 
Tom Tromey <tom@tromey.com> writes:

>>>>>> "Andrew" == Andrew Burgess via Gdb-patches <gdb-patches@sourceware.org> writes:
>
> Andrew> Here's a V2 with the changes in riscv-tdep.c rather than
> Andrew> riscv-linux-tdep.c.  Nothing else has changed.
>
> Thanks, it looks good to me.
> Reviewed-By: Tom Tromey <tom@tromey.com>

I pushed this patch.

Thanks,
Andrew
diff mbox series

Patch

diff --git a/gdb/riscv-tdep.c b/gdb/riscv-tdep.c
index 771d892df26..d01ba9bfa6a 100644
--- a/gdb/riscv-tdep.c
+++ b/gdb/riscv-tdep.c
@@ -56,6 +56,7 @@ 
 #include "prologue-value.h"
 #include "arch/riscv.h"
 #include "riscv-ravenscar-thread.h"
+#include "safe-ctype.h"
 
 /* The stack must be 16-byte aligned.  */
 #define SP_ALIGNMENT 16
@@ -4039,6 +4040,33 @@  riscv_gnu_triplet_regexp (struct gdbarch *gdbarch)
   return "riscv(32|64)?";
 }
 
+/* Implementation of `gdbarch_stap_is_single_operand', as defined in
+   gdbarch.h.  */
+
+static int
+riscv_stap_is_single_operand (struct gdbarch *gdbarch, const char *s)
+{
+  return (ISDIGIT (*s) /* Literal number.  */
+	  || *s == '(' /* Register indirection.  */
+	  || ISALPHA (*s)); /* Register value.  */
+}
+
+/* String that appears before a register name in a SystemTap register
+   indirect expression.  */
+
+static const char *const stap_register_indirection_prefixes[] =
+{
+  "(", nullptr
+};
+
+/* String that appears after a register name in a SystemTap register
+   indirect expression.  */
+
+static const char *const stap_register_indirection_suffixes[] =
+{
+  ")", nullptr
+};
+
 /* Initialize the current architecture based on INFO.  If possible,
    re-use an architecture from ARCHES, which is a list of
    architectures already created during this debugging session.
@@ -4277,6 +4305,13 @@  riscv_gdbarch_init (struct gdbarch_info info,
 					  disassembler_options_riscv ());
   set_gdbarch_disassembler_options (gdbarch, &riscv_disassembler_options);
 
+  /* SystemTap Support.  */
+  set_gdbarch_stap_is_single_operand (gdbarch, riscv_stap_is_single_operand);
+  set_gdbarch_stap_register_indirection_prefixes
+    (gdbarch, stap_register_indirection_prefixes);
+  set_gdbarch_stap_register_indirection_suffixes
+    (gdbarch, stap_register_indirection_suffixes);
+
   /* Hook in OS ABI-specific overrides, if they have been registered.  */
   gdbarch_init_osabi (info, gdbarch);