commit 08248ca9fe11040e9a4126cefebc5023d1d67222

Author: Sergio Durigan Junior <sergiodj@redhat.com>

Date:   Sat Dec 28 14:14:11 2013 -0200

    Implement SystemTap SDT probe support for AArch64

    This commit implements the needed bits for SystemTap SDT probe support

    on AArch64 architectures.

    First, I started by looking at AArch64 assembly specification and

    filling the necessary options on gdbarch's stap machinery in order to

    make the generic asm parser (implemented in stap-probe.c) recognize

    AArch64's asm.

    After my last patch for the SystemTap SDT API, which extends it in order

    to accept multiple prefixes and suffixes, this patch became simpler.  I

    also followed Marcus suggestion and did not shared code between 32- and

    64-bit ARM.

    Tom asked me in a previous message how I did my tests.  I believe I

    replied that, but just in case: I ran the tests on

    gdb.base/stap-probe.exp by hand.  I also managed to run the tests on

    real hardware, and they pass without regressions.

    2013-12-28  Sergio Durigan Junior  <sergiodj@redhat.com>

    	PR tdep/15653

    	* NEWS: Mention SystemTap SDT probe support for AArch64 GNU/Linux.

    	* aarch64-linux-tdep.c: Include necessary headers for parsing of

    	SystemTap SDT probes.

    	(aarch64_stap_is_single_operand): New function.

    	(aarch64_stap_parse_special_token): Likewise.

    	(aarch64_linux_init_abi): Declare SystemTap SDT probe argument

    	prefixes and suffixes.  Initialize gdbarch with them.

Index: gdb-7.6.1/gdb/NEWS

===================================================================

--- gdb-7.6.1.orig/gdb/NEWS

+++ gdb-7.6.1/gdb/NEWS

@@ -30,6 +30,8 @@ qXfer:libraries-svr4:read's annex

 *** Changes in GDB 7.6

+* GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.

+

 * Target record has been renamed to record-full.

   Record/replay is now enabled with the "record full" command.

   This also affects settings that are associated with full record/replay

Index: gdb-7.6.1/gdb/aarch64-linux-tdep.c

===================================================================

--- gdb-7.6.1.orig/gdb/aarch64-linux-tdep.c

+++ gdb-7.6.1/gdb/aarch64-linux-tdep.c

@@ -35,6 +35,12 @@

 #include "regcache.h"

 #include "regset.h"

+#include "cli/cli-utils.h"

+#include "stap-probe.h"

+#include "parser-defs.h"

+#include "user-regs.h"

+#include <ctype.h>

+

 /* The general-purpose regset consists of 31 X registers, plus SP, PC,

    and PSTATE registers, as defined in the AArch64 port of the Linux

    kernel.  */

@@ -268,9 +274,129 @@ aarch64_linux_regset_from_core_section (

   return NULL;

 }

+/* Implementation of `gdbarch_stap_is_single_operand', as defined in

+   gdbarch.h.  */

+

+static int

+aarch64_stap_is_single_operand (struct gdbarch *gdbarch, const char *s)

+{

+  return (*s == '#' || isdigit (*s) /* Literal number.  */

+	  || *s == '[' /* Register indirection.  */

+	  || isalpha (*s)); /* Register value.  */

+}

+

+/* This routine is used to parse a special token in AArch64's assembly.

+

+   The special tokens parsed by it are:

+

+      - Register displacement (e.g, [fp, #-8])

+

+   It returns one if the special token has been parsed successfully,

+   or zero if the current token is not considered special.  */

+

+static int

+aarch64_stap_parse_special_token (struct gdbarch *gdbarch,

+				  struct stap_parse_info *p)

+{

+  if (*p->arg == '[')

+    {

+      /* Temporary holder for lookahead.  */

+      const char *tmp = p->arg;

+      char *endp;

+      /* Used to save the register name.  */

+      const char *start;

+      char *regname;

+      int len;

+      int got_minus = 0;

+      long displacement;

+      struct stoken str;

+

+      ++tmp;

+      start = tmp;

+

+      /* Register name.  */

+      while (isalnum (*tmp))

+	++tmp;

+

+      if (*tmp != ',')

+	return 0;

+

+      len = tmp - start;

+      regname = alloca (len + 2);

+

+      strncpy (regname, start, len);

+      regname[len] = '\0';

+

+      if (user_reg_map_name_to_regnum (gdbarch, regname, len) == -1)

+	error (_("Invalid register name `%s' on expression `%s'."),

+	       regname, p->saved_arg);

+

+      ++tmp;

+      tmp = skip_spaces_const (tmp);

+      /* Now we expect a number.  It can begin with '#' or simply

+	 a digit.  */

+      if (*tmp == '#')

+	++tmp;

+

+      if (*tmp == '-')

+	{

+	  ++tmp;

+	  got_minus = 1;

+	}

+      else if (*tmp == '+')

+	++tmp;

+

+      if (!isdigit (*tmp))

+	return 0;

+

+      displacement = strtol (tmp, &endp, 10);

+      tmp = endp;

+

+      /* Skipping last `]'.  */

+      if (*tmp++ != ']')

+	return 0;

+

+      /* The displacement.  */

+      write_exp_elt_opcode (OP_LONG);

+      write_exp_elt_type (builtin_type (gdbarch)->builtin_long);

+      write_exp_elt_longcst (displacement);

+      write_exp_elt_opcode (OP_LONG);

+      if (got_minus)

+	write_exp_elt_opcode (UNOP_NEG);

+

+      /* The register name.  */

+      write_exp_elt_opcode (OP_REGISTER);

+      str.ptr = regname;

+      str.length = len;

+      write_exp_string (str);

+      write_exp_elt_opcode (OP_REGISTER);

+

+      write_exp_elt_opcode (BINOP_ADD);

+

+      /* Casting to the expected type.  */

+      write_exp_elt_opcode (UNOP_CAST);

+      write_exp_elt_type (lookup_pointer_type (p->arg_type));

+      write_exp_elt_opcode (UNOP_CAST);

+

+      write_exp_elt_opcode (UNOP_IND);

+

+      p->arg = tmp;

+    }

+  else

+    return 0;

+

+  return 1;

+}

+

 static void

 aarch64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)

 {

+  static const char *const stap_integer_prefixes[] = { "#", "", NULL };

+  static const char *const stap_register_prefixes[] = { "", NULL };

+  static const char *const stap_register_indirection_prefixes[] = { "[",

+								    NULL };

+  static const char *const stap_register_indirection_suffixes[] = { "]",

+								    NULL };

   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

   tdep->lowest_pc = 0x8000;

@@ -295,6 +421,17 @@ aarch64_linux_init_abi (struct gdbarch_i

   set_gdbarch_regset_from_core_section (gdbarch,

 					aarch64_linux_regset_from_core_section);

+

+  /* SystemTap related.  */

+  set_gdbarch_stap_integer_prefixes (gdbarch, stap_integer_prefixes);

+  set_gdbarch_stap_register_prefixes (gdbarch, stap_register_prefixes);

+  set_gdbarch_stap_register_indirection_prefixes (gdbarch,

+					    stap_register_indirection_prefixes);

+  set_gdbarch_stap_register_indirection_suffixes (gdbarch,

+					    stap_register_indirection_suffixes);

+  set_gdbarch_stap_is_single_operand (gdbarch, aarch64_stap_is_single_operand);

+  set_gdbarch_stap_parse_special_token (gdbarch,

+					aarch64_stap_parse_special_token);

 }

 /* Provide a prototype to silence -Wmissing-prototypes.  */