Re: [PATCH] Explicitly put registers in the general group for ARM

["Christian Biesinger via gdb-patches" <gdb-patches at sourceware dot org>]

On Mon, Mar 2, 2020 at 1:07 PM Luis Machado <luis.machado@linaro.org> wrote:
>
> Hi,
>
> On 3/2/20 2:59 PM, Christian Biesinger via gdb-patches wrote:
> > This seems like the right thing per the documentation:
> > https://sourceware.org/gdb/current/onlinedocs/gdb/Target-Description-Format.html#Target-Description-Format
> > "If no group is specified, GDB will not display the register in
> > info registers."
> > but should also help with this issue:
> > https://sourceware.org/ml/gdb-patches/2020-02/msg01038.html]
>
> I don't have a problem with the patch, but i think this should be done
> for all the targets that currently do not explicitly set the group name
> and fall into the "general" category based on the previous heuristic. Of
> course, this is if we want to honor the existing documentation.

Yeah, I agree. But I don't have the bandwidth to do this all targets,
it is a good amount of manual work.

> There are also other target description producers out there that will
> keep generating wrong group information, and there is little we can do
> about it. So it makes me wonder if it is worth honoring the
> documentation or if we should just update the documentation with the
> existing behavior, since we'll have to keep it for a while.

Yeah, but I still think it is good to be explicit about which
registers are in the general group? If y'all disagree, I can drop this
patch.

> Users can always define some arbitrary group name that will not get
> displayed by "info registers" anyway, right?

That is true.

> I'm thinking the offending patch will still need to be reverted or fixed
> up to bring back the old behavior.
>
> Shahab was working on an alternative patch, but it hasn't been submitted
> yet.

Yeah, I think this is independent of that.

Christian

> > Note that "set tdesc filename features/arm/arm-core.xml; maint print c-tdesc"
> > prints an empty target description both before and after this change,
> > so I just manually edited the .c file to specify the group.
> >
> > gdb/ChangeLog:
> >
> > 2020-03-02  Christian Biesinger  <cbiesinger@google.com>
> >
> >       * features/aarch64-core.c (create_feature_aarch64_core): Put all
> >       registers in the "general" group.
> >       * features/aarch64-core.xml: Likewise.
> >       * features/arm/arm-core.c (create_feature_arm_arm_core): Likewise.
> >       * features/arm/arm-core.xml: Likewise.
> > ---
> >   gdb/features/aarch64-core.c   | 68 +++++++++++++++++------------------
> >   gdb/features/aarch64-core.xml | 68 +++++++++++++++++------------------
> >   gdb/features/arm/arm-core.c   | 34 +++++++++---------
> >   gdb/features/arm/arm-core.xml | 34 +++++++++---------
> >   4 files changed, 102 insertions(+), 102 deletions(-)
> >
> > diff --git a/gdb/features/aarch64-core.c b/gdb/features/aarch64-core.c
> > index a080a641c4..f929b2cbf9 100644
> > --- a/gdb/features/aarch64-core.c
> > +++ b/gdb/features/aarch64-core.c
> > @@ -30,39 +30,39 @@ create_feature_aarch64_core (struct target_desc *result, long regnum)
> >     tdesc_add_flag (type_with_fields, 30, "Z");
> >     tdesc_add_flag (type_with_fields, 31, "N");
> >
> > -  tdesc_create_reg (feature, "x0", regnum++, 1, NULL, 64, "int");
> > -  tdesc_create_reg (feature, "x1", regnum++, 1, NULL, 64, "int");
> > -  tdesc_create_reg (feature, "x2", regnum++, 1, NULL, 64, "int");
> > -  tdesc_create_reg (feature, "x3", regnum++, 1, NULL, 64, "int");
> > -  tdesc_create_reg (feature, "x4", regnum++, 1, NULL, 64, "int");
> > -  tdesc_create_reg (feature, "x5", regnum++, 1, NULL, 64, "int");
> > -  tdesc_create_reg (feature, "x6", regnum++, 1, NULL, 64, "int");
> > -  tdesc_create_reg (feature, "x7", regnum++, 1, NULL, 64, "int");
> > -  tdesc_create_reg (feature, "x8", regnum++, 1, NULL, 64, "int");
> > -  tdesc_create_reg (feature, "x9", regnum++, 1, NULL, 64, "int");
> > -  tdesc_create_reg (feature, "x10", regnum++, 1, NULL, 64, "int");
> > -  tdesc_create_reg (feature, "x11", regnum++, 1, NULL, 64, "int");
> > -  tdesc_create_reg (feature, "x12", regnum++, 1, NULL, 64, "int");
> > -  tdesc_create_reg (feature, "x13", regnum++, 1, NULL, 64, "int");
> > -  tdesc_create_reg (feature, "x14", regnum++, 1, NULL, 64, "int");
> > -  tdesc_create_reg (feature, "x15", regnum++, 1, NULL, 64, "int");
> > -  tdesc_create_reg (feature, "x16", regnum++, 1, NULL, 64, "int");
> > -  tdesc_create_reg (feature, "x17", regnum++, 1, NULL, 64, "int");
> > -  tdesc_create_reg (feature, "x18", regnum++, 1, NULL, 64, "int");
> > -  tdesc_create_reg (feature, "x19", regnum++, 1, NULL, 64, "int");
> > -  tdesc_create_reg (feature, "x20", regnum++, 1, NULL, 64, "int");
> > -  tdesc_create_reg (feature, "x21", regnum++, 1, NULL, 64, "int");
> > -  tdesc_create_reg (feature, "x22", regnum++, 1, NULL, 64, "int");
> > -  tdesc_create_reg (feature, "x23", regnum++, 1, NULL, 64, "int");
> > -  tdesc_create_reg (feature, "x24", regnum++, 1, NULL, 64, "int");
> > -  tdesc_create_reg (feature, "x25", regnum++, 1, NULL, 64, "int");
> > -  tdesc_create_reg (feature, "x26", regnum++, 1, NULL, 64, "int");
> > -  tdesc_create_reg (feature, "x27", regnum++, 1, NULL, 64, "int");
> > -  tdesc_create_reg (feature, "x28", regnum++, 1, NULL, 64, "int");
> > -  tdesc_create_reg (feature, "x29", regnum++, 1, NULL, 64, "int");
> > -  tdesc_create_reg (feature, "x30", regnum++, 1, NULL, 64, "int");
> > -  tdesc_create_reg (feature, "sp", regnum++, 1, NULL, 64, "data_ptr");
> > -  tdesc_create_reg (feature, "pc", regnum++, 1, NULL, 64, "code_ptr");
> > -  tdesc_create_reg (feature, "cpsr", regnum++, 1, NULL, 32, "cpsr_flags");
> > +  tdesc_create_reg (feature, "x0", regnum++, 1, "general", 64, "int");
> > +  tdesc_create_reg (feature, "x1", regnum++, 1, "general", 64, "int");
> > +  tdesc_create_reg (feature, "x2", regnum++, 1, "general", 64, "int");
> > +  tdesc_create_reg (feature, "x3", regnum++, 1, "general", 64, "int");
> > +  tdesc_create_reg (feature, "x4", regnum++, 1, "general", 64, "int");
> > +  tdesc_create_reg (feature, "x5", regnum++, 1, "general", 64, "int");
> > +  tdesc_create_reg (feature, "x6", regnum++, 1, "general", 64, "int");
> > +  tdesc_create_reg (feature, "x7", regnum++, 1, "general", 64, "int");
> > +  tdesc_create_reg (feature, "x8", regnum++, 1, "general", 64, "int");
> > +  tdesc_create_reg (feature, "x9", regnum++, 1, "general", 64, "int");
> > +  tdesc_create_reg (feature, "x10", regnum++, 1, "general", 64, "int");
> > +  tdesc_create_reg (feature, "x11", regnum++, 1, "general", 64, "int");
> > +  tdesc_create_reg (feature, "x12", regnum++, 1, "general", 64, "int");
> > +  tdesc_create_reg (feature, "x13", regnum++, 1, "general", 64, "int");
> > +  tdesc_create_reg (feature, "x14", regnum++, 1, "general", 64, "int");
> > +  tdesc_create_reg (feature, "x15", regnum++, 1, "general", 64, "int");
> > +  tdesc_create_reg (feature, "x16", regnum++, 1, "general", 64, "int");
> > +  tdesc_create_reg (feature, "x17", regnum++, 1, "general", 64, "int");
> > +  tdesc_create_reg (feature, "x18", regnum++, 1, "general", 64, "int");
> > +  tdesc_create_reg (feature, "x19", regnum++, 1, "general", 64, "int");
> > +  tdesc_create_reg (feature, "x20", regnum++, 1, "general", 64, "int");
> > +  tdesc_create_reg (feature, "x21", regnum++, 1, "general", 64, "int");
> > +  tdesc_create_reg (feature, "x22", regnum++, 1, "general", 64, "int");
> > +  tdesc_create_reg (feature, "x23", regnum++, 1, "general", 64, "int");
> > +  tdesc_create_reg (feature, "x24", regnum++, 1, "general", 64, "int");
> > +  tdesc_create_reg (feature, "x25", regnum++, 1, "general", 64, "int");
> > +  tdesc_create_reg (feature, "x26", regnum++, 1, "general", 64, "int");
> > +  tdesc_create_reg (feature, "x27", regnum++, 1, "general", 64, "int");
> > +  tdesc_create_reg (feature, "x28", regnum++, 1, "general", 64, "int");
> > +  tdesc_create_reg (feature, "x29", regnum++, 1, "general", 64, "int");
> > +  tdesc_create_reg (feature, "x30", regnum++, 1, "general", 64, "int");
> > +  tdesc_create_reg (feature, "sp", regnum++, 1, "general", 64, "data_ptr");
> > +  tdesc_create_reg (feature, "pc", regnum++, 1, "general", 64, "code_ptr");
> > +  tdesc_create_reg (feature, "cpsr", regnum++, 1, "general", 32, "cpsr_flags");
> >     return regnum;
> >   }
> > diff --git a/gdb/features/aarch64-core.xml b/gdb/features/aarch64-core.xml
> > index ee6a3a6dfa..2f66088c6d 100644
> > --- a/gdb/features/aarch64-core.xml
> > +++ b/gdb/features/aarch64-core.xml
> > @@ -8,40 +8,40 @@
> >
> >   <!DOCTYPE feature SYSTEM "gdb-target.dtd">
> >   <feature name="org.gnu.gdb.aarch64.core">
> > -  <reg name="x0" bitsize="64"/>
> > -  <reg name="x1" bitsize="64"/>
> > -  <reg name="x2" bitsize="64"/>
> > -  <reg name="x3" bitsize="64"/>
> > -  <reg name="x4" bitsize="64"/>
> > -  <reg name="x5" bitsize="64"/>
> > -  <reg name="x6" bitsize="64"/>
> > -  <reg name="x7" bitsize="64"/>
> > -  <reg name="x8" bitsize="64"/>
> > -  <reg name="x9" bitsize="64"/>
> > -  <reg name="x10" bitsize="64"/>
> > -  <reg name="x11" bitsize="64"/>
> > -  <reg name="x12" bitsize="64"/>
> > -  <reg name="x13" bitsize="64"/>
> > -  <reg name="x14" bitsize="64"/>
> > -  <reg name="x15" bitsize="64"/>
> > -  <reg name="x16" bitsize="64"/>
> > -  <reg name="x17" bitsize="64"/>
> > -  <reg name="x18" bitsize="64"/>
> > -  <reg name="x19" bitsize="64"/>
> > -  <reg name="x20" bitsize="64"/>
> > -  <reg name="x21" bitsize="64"/>
> > -  <reg name="x22" bitsize="64"/>
> > -  <reg name="x23" bitsize="64"/>
> > -  <reg name="x24" bitsize="64"/>
> > -  <reg name="x25" bitsize="64"/>
> > -  <reg name="x26" bitsize="64"/>
> > -  <reg name="x27" bitsize="64"/>
> > -  <reg name="x28" bitsize="64"/>
> > -  <reg name="x29" bitsize="64"/>
> > -  <reg name="x30" bitsize="64"/>
> > -  <reg name="sp" bitsize="64" type="data_ptr"/>
> > +  <reg name="x0" bitsize="64" group="general"/>
> > +  <reg name="x1" bitsize="64" group="general"/>
> > +  <reg name="x2" bitsize="64" group="general"/>
> > +  <reg name="x3" bitsize="64" group="general"/>
> > +  <reg name="x4" bitsize="64" group="general"/>
> > +  <reg name="x5" bitsize="64" group="general"/>
> > +  <reg name="x6" bitsize="64" group="general"/>
> > +  <reg name="x7" bitsize="64" group="general"/>
> > +  <reg name="x8" bitsize="64" group="general"/>
> > +  <reg name="x9" bitsize="64" group="general"/>
> > +  <reg name="x10" bitsize="64" group="general"/>
> > +  <reg name="x11" bitsize="64" group="general"/>
> > +  <reg name="x12" bitsize="64" group="general"/>
> > +  <reg name="x13" bitsize="64" group="general"/>
> > +  <reg name="x14" bitsize="64" group="general"/>
> > +  <reg name="x15" bitsize="64" group="general"/>
> > +  <reg name="x16" bitsize="64" group="general"/>
> > +  <reg name="x17" bitsize="64" group="general"/>
> > +  <reg name="x18" bitsize="64" group="general"/>
> > +  <reg name="x19" bitsize="64" group="general"/>
> > +  <reg name="x20" bitsize="64" group="general"/>
> > +  <reg name="x21" bitsize="64" group="general"/>
> > +  <reg name="x22" bitsize="64" group="general"/>
> > +  <reg name="x23" bitsize="64" group="general"/>
> > +  <reg name="x24" bitsize="64" group="general"/>
> > +  <reg name="x25" bitsize="64" group="general"/>
> > +  <reg name="x26" bitsize="64" group="general"/>
> > +  <reg name="x27" bitsize="64" group="general"/>
> > +  <reg name="x28" bitsize="64" group="general"/>
> > +  <reg name="x29" bitsize="64" group="general"/>
> > +  <reg name="x30" bitsize="64" group="general"/>
> > +  <reg name="sp" bitsize="64" type="data_ptr" group="general"/>
> >
> > -  <reg name="pc" bitsize="64" type="code_ptr"/>
> > +  <reg name="pc" bitsize="64" type="code_ptr" group="general"/>
> >
> >     <flags id="cpsr_flags" size="4">
> >       <!-- Stack Pointer.  -->
> > @@ -86,6 +86,6 @@
> >       <!-- Negative Condition flag.  -->
> >       <field name="N" start="31" end="31"/>
> >     </flags>
> > -  <reg name="cpsr" bitsize="32" type="cpsr_flags"/>
> > +  <reg name="cpsr" bitsize="32" type="cpsr_flags" group="general"/>
> >
> >   </feature>
> > diff --git a/gdb/features/arm/arm-core.c b/gdb/features/arm/arm-core.c
> > index e401411fc5..4519752975 100644
> > --- a/gdb/features/arm/arm-core.c
> > +++ b/gdb/features/arm/arm-core.c
> > @@ -9,23 +9,23 @@ create_feature_arm_arm_core (struct target_desc *result, long regnum)
> >     struct tdesc_feature *feature;
> >
> >     feature = tdesc_create_feature (result, "org.gnu.gdb.arm.core");
> > -  tdesc_create_reg (feature, "r0", regnum++, 1, NULL, 32, "uint32");
> > -  tdesc_create_reg (feature, "r1", regnum++, 1, NULL, 32, "uint32");
> > -  tdesc_create_reg (feature, "r2", regnum++, 1, NULL, 32, "uint32");
> > -  tdesc_create_reg (feature, "r3", regnum++, 1, NULL, 32, "uint32");
> > -  tdesc_create_reg (feature, "r4", regnum++, 1, NULL, 32, "uint32");
> > -  tdesc_create_reg (feature, "r5", regnum++, 1, NULL, 32, "uint32");
> > -  tdesc_create_reg (feature, "r6", regnum++, 1, NULL, 32, "uint32");
> > -  tdesc_create_reg (feature, "r7", regnum++, 1, NULL, 32, "uint32");
> > -  tdesc_create_reg (feature, "r8", regnum++, 1, NULL, 32, "uint32");
> > -  tdesc_create_reg (feature, "r9", regnum++, 1, NULL, 32, "uint32");
> > -  tdesc_create_reg (feature, "r10", regnum++, 1, NULL, 32, "uint32");
> > -  tdesc_create_reg (feature, "r11", regnum++, 1, NULL, 32, "uint32");
> > -  tdesc_create_reg (feature, "r12", regnum++, 1, NULL, 32, "uint32");
> > -  tdesc_create_reg (feature, "sp", regnum++, 1, NULL, 32, "data_ptr");
> > -  tdesc_create_reg (feature, "lr", regnum++, 1, NULL, 32, "int");
> > -  tdesc_create_reg (feature, "pc", regnum++, 1, NULL, 32, "code_ptr");
> > +  tdesc_create_reg (feature, "r0", regnum++, 1, "general", 32, "uint32");
> > +  tdesc_create_reg (feature, "r1", regnum++, 1, "general", 32, "uint32");
> > +  tdesc_create_reg (feature, "r2", regnum++, 1, "general", 32, "uint32");
> > +  tdesc_create_reg (feature, "r3", regnum++, 1, "general", 32, "uint32");
> > +  tdesc_create_reg (feature, "r4", regnum++, 1, "general", 32, "uint32");
> > +  tdesc_create_reg (feature, "r5", regnum++, 1, "general", 32, "uint32");
> > +  tdesc_create_reg (feature, "r6", regnum++, 1, "general", 32, "uint32");
> > +  tdesc_create_reg (feature, "r7", regnum++, 1, "general", 32, "uint32");
> > +  tdesc_create_reg (feature, "r8", regnum++, 1, "general", 32, "uint32");
> > +  tdesc_create_reg (feature, "r9", regnum++, 1, "general", 32, "uint32");
> > +  tdesc_create_reg (feature, "r10", regnum++, 1, "general", 32, "uint32");
> > +  tdesc_create_reg (feature, "r11", regnum++, 1, "general", 32, "uint32");
> > +  tdesc_create_reg (feature, "r12", regnum++, 1, "general", 32, "uint32");
> > +  tdesc_create_reg (feature, "sp", regnum++, 1, "general", 32, "data_ptr");
> > +  tdesc_create_reg (feature, "lr", regnum++, 1, "general", 32, "int");
> > +  tdesc_create_reg (feature, "pc", regnum++, 1, "general", 32, "code_ptr");
> >     regnum = 25;
> > -  tdesc_create_reg (feature, "cpsr", regnum++, 1, NULL, 32, "int");
> > +  tdesc_create_reg (feature, "cpsr", regnum++, 1, "general", 32, "int");
> >     return regnum;
> >   }
> > diff --git a/gdb/features/arm/arm-core.xml b/gdb/features/arm/arm-core.xml
> > index 144fc4638a..d506004fe1 100644
> > --- a/gdb/features/arm/arm-core.xml
> > +++ b/gdb/features/arm/arm-core.xml
> > @@ -7,25 +7,25 @@
> >
> >   <!DOCTYPE feature SYSTEM "gdb-target.dtd">
> >   <feature name="org.gnu.gdb.arm.core">
> > -  <reg name="r0" bitsize="32" type="uint32"/>
> > -  <reg name="r1" bitsize="32" type="uint32"/>
> > -  <reg name="r2" bitsize="32" type="uint32"/>
> > -  <reg name="r3" bitsize="32" type="uint32"/>
> > -  <reg name="r4" bitsize="32" type="uint32"/>
> > -  <reg name="r5" bitsize="32" type="uint32"/>
> > -  <reg name="r6" bitsize="32" type="uint32"/>
> > -  <reg name="r7" bitsize="32" type="uint32"/>
> > -  <reg name="r8" bitsize="32" type="uint32"/>
> > -  <reg name="r9" bitsize="32" type="uint32"/>
> > -  <reg name="r10" bitsize="32" type="uint32"/>
> > -  <reg name="r11" bitsize="32" type="uint32"/>
> > -  <reg name="r12" bitsize="32" type="uint32"/>
> > -  <reg name="sp" bitsize="32" type="data_ptr"/>
> > -  <reg name="lr" bitsize="32"/>
> > -  <reg name="pc" bitsize="32" type="code_ptr"/>
> > +  <reg name="r0" bitsize="32" type="uint32" group="general"/>
> > +  <reg name="r1" bitsize="32" type="uint32" group="general"/>
> > +  <reg name="r2" bitsize="32" type="uint32" group="general"/>
> > +  <reg name="r3" bitsize="32" type="uint32" group="general"/>
> > +  <reg name="r4" bitsize="32" type="uint32" group="general"/>
> > +  <reg name="r5" bitsize="32" type="uint32" group="general"/>
> > +  <reg name="r6" bitsize="32" type="uint32" group="general"/>
> > +  <reg name="r7" bitsize="32" type="uint32" group="general"/>
> > +  <reg name="r8" bitsize="32" type="uint32" group="general"/>
> > +  <reg name="r9" bitsize="32" type="uint32" group="general"/>
> > +  <reg name="r10" bitsize="32" type="uint32" group="general"/>
> > +  <reg name="r11" bitsize="32" type="uint32" group="general"/>
> > +  <reg name="r12" bitsize="32" type="uint32" group="general"/>
> > +  <reg name="sp" bitsize="32" type="data_ptr" group="general"/>
> > +  <reg name="lr" bitsize="32" group="general"/>
> > +  <reg name="pc" bitsize="32" type="code_ptr"/ group="general">
> >
> >     <!-- The CPSR is register 25, rather than register 16, because
> >          the FPA registers historically were placed between the PC
> >          and the CPSR in the "g" packet.  -->
> > -  <reg name="cpsr" bitsize="32" regnum="25"/>
> > +  <reg name="cpsr" bitsize="32" regnum="25" group="general"/>
> >   </feature>
> >