[PATCH] Allow osabi to be optional in target descriptors

[PATCH] Allow osabi to be optional in target descriptors

[Alan Hayward]

Osabi is an option field in target descriptors, according to:
https://sourceware.org/gdb/current/onlinedocs/gdb/Target-Description-Format.html

However, removing the osabi field from the i386 and amd64 target descriptors
will cause gdbserver to assert. This is code I used to test (not for
committing!) :

diff --git a/gdb/arch/amd64.c b/gdb/arch/amd64.c
index 30c73e642f..5c63a6c223 100644
--- a/gdb/arch/amd64.c
+++ b/gdb/arch/amd64.c
@@ -41,9 +41,6 @@ amd64_create_target_description (uint64_t xcr0, bool is_x32, bool is_linux)

 #ifndef IN_PROCESS_AGENT
   set_tdesc_architecture (tdesc, is_x32 ? "i386:x64-32" : "i386:x86-64");
-
-  if (is_linux)
-    set_tdesc_osabi (tdesc, "GNU/Linux");
 #endif

   long regnum = 0;
diff --git a/gdb/arch/i386.c b/gdb/arch/i386.c
index 7d71506a7b..112c0a89e6 100644
--- a/gdb/arch/i386.c
+++ b/gdb/arch/i386.c
@@ -37,8 +37,6 @@ i386_create_target_description (uint64_t xcr0, bool is_linux)

 #ifndef IN_PROCESS_AGENT
   set_tdesc_architecture (tdesc, "i386");
-  if (is_linux)
-    set_tdesc_osabi (tdesc, "GNU/Linux");
 #endif

   long regnum = 0;


The following patch fixes this error.

Tested with gdbserver on x86 and also on aarch64 with my target descriptor patch.
Also ran make check on x86 with unix and native-gdbserver.


2017-11-16  Alan Hayward  <alan.hayward@arm.com>

gdbserver
	* tdesc.c (tdesc_get_features_xml): Allow null osabi.


diff --git a/gdb/gdbserver/tdesc.c b/gdb/gdbserver/tdesc.c
index 63d6467d56d168777f4fa39b56495dd5649c046b..72603d626f005821a8b866d60cfdfca112c1395c 100644
--- a/gdb/gdbserver/tdesc.c
+++ b/gdb/gdbserver/tdesc.c
@@ -92,8 +92,7 @@ tdesc_get_features_xml (target_desc *tdesc)
   /* Either .xmltarget or .features is not NULL.  */
   gdb_assert (tdesc->xmltarget != NULL
 	      || (tdesc->features != NULL
-		  && tdesc->arch != NULL
-		  && tdesc->osabi != NULL));
+		  && tdesc->arch != NULL));

   if (tdesc->xmltarget == NULL)
     {
@@ -105,9 +104,12 @@ tdesc_get_features_xml (target_desc *tdesc)
       buffer += tdesc->arch;
       buffer += "</architecture>";

-      buffer += "<osabi>";
-      buffer += tdesc->osabi;
-      buffer += "</osabi>";
+      if (tdesc->osabi != NULL)
+	{
+	  buffer += "<osabi>";
+	  buffer += tdesc->osabi;
+	  buffer += "</osabi>";
+	}

       char *xml;

Re: [PATCH] Allow osabi to be optional in target descriptors

[Yao Qi]

Alan Hayward <Alan.Hayward@arm.com> writes:

Patch is good to me, some nits on commit log and code,

> Osabi is an option field in target descriptors, according to:

s/target descriptors/target descriptions/

> https://sourceware.org/gdb/current/onlinedocs/gdb/Target-Description-Format.html
>
> However, removing the osabi field from the i386 and amd64 target descriptors

Likewise.

>
> The following patch fixes this error.
>
> Tested with gdbserver on x86 and also on aarch64 with my target descriptor patch.

Likewise.

> @@ -105,9 +104,12 @@ tdesc_get_features_xml (target_desc *tdesc)
>        buffer += tdesc->arch;
>        buffer += "</architecture>";
>
> -      buffer += "<osabi>";
> -      buffer += tdesc->osabi;
> -      buffer += "</osabi>";
> +      if (tdesc->osabi != NULL)

As we are in C++, I prefer nullptr.

s/NULL/nullptr/

-- 
Yao (齐尧)

Re: [PATCH] Allow osabi to be optional in target descriptors

[Alan Hayward]

> On 16 Nov 2017, at 09:17, Yao Qi <qiyaoltc@gmail.com> wrote:
> 
> Alan Hayward <Alan.Hayward@arm.com> writes:
> 
> Patch is good to me, some nits on commit log and code,
> 
>> Osabi is an option field in target descriptors, according to:
> 
> s/target descriptors/target descriptions/
> 
>> https://sourceware.org/gdb/current/onlinedocs/gdb/Target-Description-Format.html
>> 
>> However, removing the osabi field from the i386 and amd64 target descriptors
> 
> Likewise.
> 
>> 
>> The following patch fixes this error.
>> 
>> Tested with gdbserver on x86 and also on aarch64 with my target descriptor patch.
> 
> Likewise.
> 
>> @@ -105,9 +104,12 @@ tdesc_get_features_xml (target_desc *tdesc)
>>       buffer += tdesc->arch;
>>       buffer += "</architecture>";
>> 
>> -      buffer += "<osabi>";
>> -      buffer += tdesc->osabi;
>> -      buffer += "</osabi>";
>> +      if (tdesc->osabi != NULL)
> 
> As we are in C++, I prefer nullptr.
> 
> s/NULL/nullptr/
> 

Thanks.

Pushed with changes as above.


diff --git a/gdb/gdbserver/tdesc.c b/gdb/gdbserver/tdesc.c
index 63d6467d56d168777f4fa39b56495dd5649c046b..e2c4288efba1546247a3b376da3c573c223b6eef 100644
--- a/gdb/gdbserver/tdesc.c
+++ b/gdb/gdbserver/tdesc.c
@@ -92,8 +92,7 @@ tdesc_get_features_xml (target_desc *tdesc)
   /* Either .xmltarget or .features is not NULL.  */
   gdb_assert (tdesc->xmltarget != NULL
 	      || (tdesc->features != NULL
-		  && tdesc->arch != NULL
-		  && tdesc->osabi != NULL));
+		  && tdesc->arch != NULL));

   if (tdesc->xmltarget == NULL)
     {
@@ -105,9 +104,12 @@ tdesc_get_features_xml (target_desc *tdesc)
       buffer += tdesc->arch;
       buffer += "</architecture>";

-      buffer += "<osabi>";
-      buffer += tdesc->osabi;
-      buffer += "</osabi>";
+      if (tdesc->osabi != nullptr)
+	{
+	  buffer += "<osabi>";
+	  buffer += tdesc->osabi;
+	  buffer += "</osabi>";
+	}

       char *xml;