Re: [PATCH 2/2] Extend recognized types of SDT probe's arguments

[Sergio Durigan Junior <sergiodj@redhat.com>]

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On Friday, May 02 2014, Pedro Alves wrote:

> On 05/01/2014 10:52 PM, Sergio Durigan Junior wrote:
>> This commit is actually an update to make the parser in
>> gdb/stap-probe.c be aware of all the possible prefixes that a probe
>> argument can have.  According to the section "Argument Format" in:
>> 
>>   <https://sourceware.org/systemtap/wiki/UserSpaceProbeImplementation>
>> 
>> The bitness of the arguments can be 8, 16, 32 or 64 bits, signed or
>> unsigned.  Currently GDB recognizes only 32 and 64-bit arguments.
>
> Looks good.

Thanks.

>> This commit extends this.  Since this is a straightforward extension,
>> I am not submitting a testcase; I can do that if anybody wants.
>
> I think it'd be good to have a test -- the code that triggered the other
> bug was also supposedly straightforward.  :-)  Can we do this in C ?
> Ideally we'd also test that we don't crash with an invalid bitness
> (the complaint path).

Hm, OK, here is the testcase then.

>> 
>> gdb/
>> 2014-05-01  Sergio Durigan Junior  <sergiodj@redhat.com>
>> 
>> 	stap-probe.c (enum stap_arg_bitness): New enums to represent 8
>
> Missing '*'-

Writing ChangeLog entries while at "git commit" buffer is tricky...
Second mistake in a row!  Thanks.

>> 	and 16-bit signed and unsigned arguments.
>> 	(stap_parse_probe_arguments): Extend code to handle such
>> 	arguments.
>
> -- 
> Pedro Alves

Here is what I will push if there are no other comments.

Thanks,

-- 
Sergio


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commit 4fdce9c1c58588209e26cd690e7e653b6056d458
Author: Sergio Durigan Junior <sergiodj@redhat.com>
Date:   Thu May 1 18:39:28 2014 -0300

    Extend recognized types of SDT probe's arguments
    
    This commit is actually an update to make the parser in
    gdb/stap-probe.c be aware of all the possible prefixes that a probe
    argument can have.  According to the section "Argument Format" in:
    
      <https://sourceware.org/systemtap/wiki/UserSpaceProbeImplementation>
    
    The bitness of the arguments can be 8, 16, 32 or 64 bits, signed or
    unsigned.  Currently GDB recognizes only 32 and 64-bit arguments.
    This commit extends this.  Since this is a straightforward extension,
    I am not submitting a testcase; I can do that if anybody wants.
    
    gdb/
    2014-05-02  Sergio Durigan Junior  <sergiodj@redhat.com>
    
    	* stap-probe.c (enum stap_arg_bitness): New enums to represent 8
    	and 16-bit signed and unsigned arguments.  Update comment.
    	(stap_parse_probe_arguments): Extend code to handle such
    	arguments.  Use warning instead of complaint to notify about
    	unrecognized bitness.
    
    gdb/testsuite/
    2014-05-02  Sergio Durigan Junior  <sergiodj@redhat.com>
    
    	* gdb.arch/amd64-stap-optional-prefix.S (main): Add several
    	probes to test for bitness recognition.
    	* gdb.arch/amd64-stap-optional-prefix.exp
    	(test_probe_value_without_reg): New procedure.
    	Add code to test for different kinds of bitness.

diff --git a/gdb/stap-probe.c b/gdb/stap-probe.c
index ef45495..84714b5 100644
--- a/gdb/stap-probe.c
+++ b/gdb/stap-probe.c
@@ -60,6 +60,10 @@ static unsigned int stap_expression_debug = 0;
    The relationship is:
 
    - STAP_ARG_BITNESS_UNDEFINED:  The user hasn't specified the bitness.
+   - STAP_ARG_BITNESS_8BIT_UNSIGNED:  argument string starts with `1@'.
+   - STAP_ARG_BITNESS_8BIT_SIGNED:  argument string starts with `-1@'.
+   - STAP_ARG_BITNESS_16BIT_UNSIGNED:  argument string starts with `2@'.
+   - STAP_ARG_BITNESS_16BIT_SIGNED:  argument string starts with `-2@'.
    - STAP_ARG_BITNESS_32BIT_UNSIGNED:  argument string starts with `4@'.
    - STAP_ARG_BITNESS_32BIT_SIGNED:  argument string starts with `-4@'.
    - STAP_ARG_BITNESS_64BIT_UNSIGNED:  argument string starts with `8@'.
@@ -68,6 +72,10 @@ static unsigned int stap_expression_debug = 0;
 enum stap_arg_bitness
 {
   STAP_ARG_BITNESS_UNDEFINED,
+  STAP_ARG_BITNESS_8BIT_UNSIGNED,
+  STAP_ARG_BITNESS_8BIT_SIGNED,
+  STAP_ARG_BITNESS_16BIT_UNSIGNED,
+  STAP_ARG_BITNESS_16BIT_SIGNED,
   STAP_ARG_BITNESS_32BIT_UNSIGNED,
   STAP_ARG_BITNESS_32BIT_SIGNED,
   STAP_ARG_BITNESS_64BIT_UNSIGNED,
@@ -329,6 +337,18 @@ stap_get_expected_argument_type (struct gdbarch *gdbarch,
       else
 	return builtin_type (gdbarch)->builtin_uint64;
 
+    case STAP_ARG_BITNESS_8BIT_UNSIGNED:
+      return builtin_type (gdbarch)->builtin_uint8;
+
+    case STAP_ARG_BITNESS_8BIT_SIGNED:
+      return builtin_type (gdbarch)->builtin_int8;
+
+    case STAP_ARG_BITNESS_16BIT_UNSIGNED:
+      return builtin_type (gdbarch)->builtin_uint16;
+
+    case STAP_ARG_BITNESS_16BIT_SIGNED:
+      return builtin_type (gdbarch)->builtin_int16;
+
     case STAP_ARG_BITNESS_32BIT_SIGNED:
       return builtin_type (gdbarch)->builtin_int32;
 
@@ -1095,7 +1115,7 @@ stap_parse_probe_arguments (struct stap_probe *probe, struct gdbarch *gdbarch)
 
 	 N@OP
 
-	 Where `N' can be [+,-][4,8].  This is not mandatory, so
+	 Where `N' can be [+,-][1,2,4,8].  This is not mandatory, so
 	 we check it here.  If we don't find it, go to the next
 	 state.  */
       if ((cur[0] == '-' && isdigit (cur[1]) && cur[2] == '@')
@@ -1108,20 +1128,37 @@ stap_parse_probe_arguments (struct stap_probe *probe, struct gdbarch *gdbarch)
 	      got_minus = 1;
 	    }
 
-	  if (*cur == '4')
-	    b = (got_minus ? STAP_ARG_BITNESS_32BIT_SIGNED
-		 : STAP_ARG_BITNESS_32BIT_UNSIGNED);
-	  else if (*cur == '8')
-	    b = (got_minus ? STAP_ARG_BITNESS_64BIT_SIGNED
-		 : STAP_ARG_BITNESS_64BIT_UNSIGNED);
-	  else
+	  /* Defining the bitness.  */
+	  switch (*cur)
 	    {
-	      /* We have an error, because we don't expect anything
-		 except 4 and 8.  */
-	      complaint (&symfile_complaints,
-			 _("unrecognized bitness `%c' for probe `%s'"),
-			 *cur, probe->p.name);
-	      return;
+	    case '1':
+	      b = (got_minus ? STAP_ARG_BITNESS_8BIT_SIGNED
+		   : STAP_ARG_BITNESS_8BIT_UNSIGNED);
+	      break;
+
+	    case '2':
+	      b = (got_minus ? STAP_ARG_BITNESS_16BIT_SIGNED
+		   : STAP_ARG_BITNESS_16BIT_UNSIGNED);
+	      break;
+
+	    case '4':
+	      b = (got_minus ? STAP_ARG_BITNESS_32BIT_SIGNED
+		   : STAP_ARG_BITNESS_32BIT_UNSIGNED);
+	      break;
+
+	    case '8':
+	      b = (got_minus ? STAP_ARG_BITNESS_64BIT_SIGNED
+		   : STAP_ARG_BITNESS_64BIT_UNSIGNED);
+	      break;
+
+	    default:
+	      {
+		/* We have an error, because we don't expect anything
+		   except 1, 2, 4 and 8.  */
+		warning (_("unrecognized bitness %s%c' for probe `%s'"),
+			 got_minus ? "`-" : "`", *cur, probe->p.name);
+		return;
+	      }
 	    }
 
 	  arg.bitness = b;
diff --git a/gdb/testsuite/gdb.arch/amd64-stap-optional-prefix.S b/gdb/testsuite/gdb.arch/amd64-stap-optional-prefix.S
index 66689cb..3cdb4c2 100644
--- a/gdb/testsuite/gdb.arch/amd64-stap-optional-prefix.S
+++ b/gdb/testsuite/gdb.arch/amd64-stap-optional-prefix.S
@@ -28,5 +28,15 @@ main:
 	STAP_PROBE1(probe, foo_prefix, 8@(%rsp))
 	STAP_PROBE1(probe, bar_prefix, 8@-8(%rbp))
 	mov	%rbp,%rsp
+	STAP_PROBE1(probe, uint8_probe, 1@$8)
+	STAP_PROBE1(probe, int8_probe, -1@$-8)
+	STAP_PROBE1(probe, uint16_probe, 2@$16)
+	STAP_PROBE1(probe, int16_probe, -2@$-16)
+	STAP_PROBE1(probe, uint32_probe, 4@$32)
+	STAP_PROBE1(probe, int32_probe, -4@$-32)
+	STAP_PROBE1(probe, uint64_probe, 8@$64)
+	STAP_PROBE1(probe, int64_probe, -8@$-64)
+	STAP_PROBE1(probe, fail_probe, -7@$16)
+	STAP_PROBE1(probe, fail2_probe, 23-@$16)
 	xor	%rax,%rax
 	ret
diff --git a/gdb/testsuite/gdb.arch/amd64-stap-optional-prefix.exp b/gdb/testsuite/gdb.arch/amd64-stap-optional-prefix.exp
index cc9d6c3..b7f1505 100644
--- a/gdb/testsuite/gdb.arch/amd64-stap-optional-prefix.exp
+++ b/gdb/testsuite/gdb.arch/amd64-stap-optional-prefix.exp
@@ -43,6 +43,11 @@ proc test_probe_value { value reg_val } {
     gdb_test "print \$_probe_arg0 == *((unsigned int *) (${reg_val}))" "= 1"
 }
 
+proc test_probe_value_without_reg { value } {
+    gdb_test "print \$_probe_argc" "= 1"
+    gdb_test "print \$_probe_arg0" "= $value"
+}
+
 if { ![runto_main] } {
     return -1
 }
@@ -55,3 +60,32 @@ foreach probe_name [list "foo" "bar" "foo_prefix" "bar_prefix"] \
 	test_probe_value $probe_val $probe_reg_val
     }
 }
+
+# Testing normal probes, with several prefixes.
+
+set normal_probes_names { }
+
+foreach bit [list 8 16 32 64] {
+    lappend normal_probes_names "uint${bit}_probe"
+    lappend normal_probes_names "int${bit}_probe"
+}
+
+foreach probe_name $normal_probes_names \
+    probe_val [list 8 -8 16 -16 32 -32 64 -64] {
+    with_test_prefix $probe_name {
+	goto_probe $probe_name
+	test_probe_value_without_reg $probe_val
+    }
+}
+
+# Testing the fail probes.
+
+with_test_prefix "fail_probe" {
+    goto_probe "fail_probe"
+    gdb_test "print \$_probe_arg0" "warning: unrecognized bitness `-7' for probe `fail_probe'\r\nInvalid probe argument 0 -- probe has 0 arguments available"
+}
+
+with_test_prefix "fail2_probe" {
+    goto_probe "fail2_probe"
+    gdb_test "print \$_probe_arg0" "Unknown numeric token on expression `23-@\\\$16'."
+}