[gdb] Fix warning in foreach_arch selftests

When running the selftests, I run into:
...
$ gdb -q -batch -ex "maint selftest"
  ...
Running selftest execute_cfa_program::aarch64:ilp32.
warning: A handler for the OS ABI "GNU/Linux" is not built into this
configuration of GDB.  Attempting to continue with the default aarch64:ilp32
settings.
...
and likewise for execute_cfa_program::i8086 and
execute_cfa_program::ia64-elf32.

The warning can easily be reproduced outside the selftests by doing:
...
$ gdb -q -batch -ex "set arch aarch64:ilp32"
...
and can be prevented by first doing "set osabi none".

Fix the warning by setting osabi to none while doing selftests that iterate
over all architectures.

This causes a regression in the print_one_insn selftests for the ARC
architecture.

The problem is pre-existing, and can be demonstrated (already without this
patch) using:
...
$ gdb -q -batch -ex "set osabi none" -ex "maint selftest print_one_insn::A6"
Running selftest print_one_insn::A6.
Self test failed: Cannot access memory at address 0x0
Ran 1 unit tests, 1 failed
$
...

For ARC, we use the generic case in print_one_insn_test, containing this code:
...
       int kind = gdbarch_breakpoint_kind_from_pc (gdbarch, &pc);
       ...
       insn = gdbarch_sw_breakpoint_from_kind (gdbarch, kind, &bplen);
...

The problem is that with osabi linux we trigger:
...
static int
arc_linux_breakpoint_kind_from_pc (struct gdbarch *gdbarch, CORE_ADDR *pcptr)
{
  return trap_size;
}
...
but with osabi none:
...
arc_breakpoint_kind_from_pc (struct gdbarch *gdbarch, CORE_ADDR *pcptr)
{
  size_t length_with_limm = gdb_insn_length (gdbarch, *pcptr);
...
which needs access to memory, and will consequently fail.

Fix this in print_one_insn_test, in the default case, by iterating over
supported osabi's to makes sure we trigger arc_linux_breakpoint_kind_from_pc
which will give us a usable instruction to disassemble.

Tested on x86_64-linux.

diff --git a/gdb/disasm-selftests.c b/gdb/disasm-selftests.c
index 928d26f7018e49906d5572eae8cf3dd1a916f466..7daa0138f6f97ea3b35b0f96becea80c14c5fbd9 100644 (file)
--- a/gdb/disasm-selftests.c
+++ b/gdb/disasm-selftests.c
@@ -101,12 +101,52 @@ print_one_insn_test (struct gdbarch *gdbarch)
       {
        /* Test disassemble breakpoint instruction.  */
        CORE_ADDR pc = 0;
-       int kind = gdbarch_breakpoint_kind_from_pc (gdbarch, &pc);
+       int kind;
        int bplen;
 
-       insn = gdbarch_sw_breakpoint_from_kind (gdbarch, kind, &bplen);
-       len = bplen;
+       struct gdbarch_info info;
+       info.bfd_arch_info = gdbarch_bfd_arch_info (gdbarch);
+
+       enum gdb_osabi it;
+       bool found = false;
+       for (it = GDB_OSABI_UNKNOWN; it != GDB_OSABI_INVALID;
+            it = static_cast<enum gdb_osabi>(static_cast<int>(it) + 1))
+         {
+           if (it == GDB_OSABI_UNKNOWN)
+             continue;
+
+           info.osabi = it;
+
+           if (it != GDB_OSABI_NONE)
+             {
+               if (!has_gdb_osabi_handler (info))
+                 /* Unsupported.  Skip to prevent warnings like:
+                    A handler for the OS ABI <x> is not built into this
+                    configuration of GDB.  Attempting to continue with the
+                    default <y> settings.  */
+                 continue;
+             }
+
+           gdbarch = gdbarch_find_by_info (info);
+           SELF_CHECK (gdbarch != NULL);
+
+           try
+             {
+               kind = gdbarch_breakpoint_kind_from_pc (gdbarch, &pc);
+               insn = gdbarch_sw_breakpoint_from_kind (gdbarch, kind, &bplen);
+             }
+           catch (...)
+             {
+               continue;
+             }
+           found = true;
+           break;
+         }
+
+       /* Assert that we have found an instruction to disassemble.  */
+       SELF_CHECK (found);
 
+       len = bplen;
        break;
       }
     }

diff --git a/gdb/osabi.c b/gdb/osabi.c
index bbd7635532fb93111c1cebeac048e33ad184fe46..f1b7f227b87773228e98a0d22b6d70a946506cee 100644 (file)
--- a/gdb/osabi.c
+++ b/gdb/osabi.c
@@ -332,9 +332,10 @@ can_run_code_for (const struct bfd_arch_info *a, const struct bfd_arch_info *b)
   return (a == b || a->compatible (a, b) == a);
 }
 
+/* Return OS ABI handler for INFO.  */
 
-void
-gdbarch_init_osabi (struct gdbarch_info info, struct gdbarch *gdbarch)
+static struct gdb_osabi_handler *
+gdbarch_osabi_handler (struct gdbarch_info info)
 {
   struct gdb_osabi_handler *handler;
 
@@ -367,10 +368,32 @@ gdbarch_init_osabi (struct gdbarch_info info, struct gdbarch *gdbarch)
         ISA").  BFD doesn't normally consider 32-bit and 64-bit
         "compatible" so it doesn't succeed.  */
       if (can_run_code_for (info.bfd_arch_info, handler->arch_info))
-       {
-         (*handler->init_osabi) (info, gdbarch);
-         return;
-       }
+       return handler;
+    }
+
+  return nullptr;
+}
+
+/* See osabi.h.  */
+
+bool
+has_gdb_osabi_handler (struct gdbarch_info info)
+{
+  return gdbarch_osabi_handler (info) != nullptr;
+}
+
+void
+gdbarch_init_osabi (struct gdbarch_info info, struct gdbarch *gdbarch)
+{
+  struct gdb_osabi_handler *handler;
+
+  gdb_assert (info.osabi != GDB_OSABI_UNKNOWN);
+  handler = gdbarch_osabi_handler (info);
+
+  if (handler != nullptr)
+    {
+      (*handler->init_osabi) (info, gdbarch);
+      return;
     }
 
   if (info.osabi == GDB_OSABI_NONE)

diff --git a/gdb/osabi.h b/gdb/osabi.h
index be016732cbcf3b9c53e7506a708fcc01c1740400..478a418aac235b30e29093e399b82fdabcacdc56 100644 (file)
--- a/gdb/osabi.h
+++ b/gdb/osabi.h
@@ -74,6 +74,9 @@ enum gdb_osabi gdbarch_lookup_osabi (bfd *);
    string.  */
 enum gdb_osabi osabi_from_tdesc_string (const char *text);
 
+/* Return true if there's an OS ABI handler for INFO.  */
+bool has_gdb_osabi_handler (struct gdbarch_info info);
+
 /* Initialize the gdbarch for the specified OS ABI variant.  */
 void gdbarch_init_osabi (struct gdbarch_info, struct gdbarch *);
 

diff --git a/gdb/selftest-arch.c b/gdb/selftest-arch.c
index f434da718d518da5cc7cfccfdf2cf6da088c9daa..1fe0b2d59b432ba583cad049697f5f83d1d35fe4 100644 (file)
--- a/gdb/selftest-arch.c
+++ b/gdb/selftest-arch.c
@@ -68,6 +68,7 @@ foreach_arch_test_generator (const std::string &name,
           {
             struct gdbarch_info info;
             info.bfd_arch_info = bfd_scan_arch (arch);
+            info.osabi = GDB_OSABI_NONE;
             struct gdbarch *gdbarch = gdbarch_find_by_info (info);
             SELF_CHECK (gdbarch != NULL);
             function (gdbarch);