[llvm-project] Fix typos mutli and mutliple. NFC. (#122880)

[lldb] Add register field enum class (#90063)

This represents the enum type that can be assigned to a field using the
`<enum>` element in the target XML.

https://sourceware.org/gdb/current/onlin

[lldb] Add register field enum class (#90063)

This represents the enum type that can be assigned to a field using the
`<enum>` element in the target XML.

https://sourceware.org/gdb/current/onlinedocs/gdb.html/Enum-Target-Types.html

Each enumerator has:
* A non-empty name
* A value that is within the range of the field it's applied to

The XML includes a "size" but we don't need that for anything and it's a
pain to verify so I've left it out of our internal structures. When
emitting XML we'll set size to the size of the register using the enum.

An Enumerator class is added to RegisterFlags and hooked up to the
existing ToXML so lldb-server can use it to emit enums as well.

As enums are elements on the same level as flags, when emitting XML
we'll do so via the registers. Before emitting a flags element we look
at all the fields and see what enums they reference. Then print all of
those if we haven't already done so.

Functions are added to dump enum information for `register info` to use
to show the enum information.

show more ...

[lldb][lldb-server] Enable sending RegisterFlags as XML (#69951)

This adds ToXML methods to encode RegisterFlags and its fields into XML
according to GDB's target XML format:

https://sourceware.

[lldb][lldb-server] Enable sending RegisterFlags as XML (#69951)

This adds ToXML methods to encode RegisterFlags and its fields into XML
according to GDB's target XML format:

https://sourceware.org/gdb/onlinedocs/gdb/Target-Description-Format.html#Target-Description-Format

lldb-server does not use libXML to build XML, so this follows the
existing code that uses strings. Indentation is used so the result is
still human readable.

```
<flags id=\"Foo\" size=\"4\">
<field name=\"abc\" start=\"0\" end=\"0\"/>
</flags>
```

This is used by lldb-server when building target XML, though no one sets
any fields yet. That'll come in a later commit.

show more ...

[lldb] Add a single bit constructor for RegisterFlags::Field (#69315)

This means you don't have to do RegisterField("", 0, 0), you can do
RegisterField("", 0).

Which is useful for testing and ev

[lldb] Add a single bit constructor for RegisterFlags::Field (#69315)

This means you don't have to do RegisterField("", 0, 0), you can do
RegisterField("", 0).

Which is useful for testing and even more useful when we are writing
definitions of real registers which have 10s of single bit fields.

show more ...

[LLDB] Add table formatting for register fields

This will be used by the "register info" command to show
the layout of register contents. For example if we have
these fields coming in from XML:
```

[LLDB] Add table formatting for register fields

This will be used by the "register info" command to show
the layout of register contents. For example if we have
these fields coming in from XML:
```
<field name="D" start="0" end="7"/>
<field name="C" start="8" end="15"/>
<field name="B" start="16" end="23"/>
<field name="A" start="24" end="31"/>
```
We get:
```
| 31-24 | 23-16 | 15-8 | 7-0 |
|-------|-------|------|-----|
| A | B | C | D |
```
Note that this is only the layout, not the values.
For values, use "register read".

The tables' columns are center padded (left bias
if there's an odd padding) and will wrap if the terminal width
is too low.

```
| 31-24 | 23-16 |
|-------|-------|
| A | B |

| 15-8 | 7-0 |
|------|-----|
| C | D |
```

This means we match the horizontal format seen in many architecture
manuals but don't spam the user with lots of misaligned text when the
output gets very long.

Reviewed By: jasonmolenda

Differential Revision: https://reviews.llvm.org/D152917

show more ...

[lldb][test] Fix -Wsign-compare in RegisterFlagsTest.cpp (NFC)

/data/llvm-project/third-party/unittest/googletest/include/gtest/gtest.h:1526:11: error: comparison of integers of different signs: 'co

[lldb][test] Fix -Wsign-compare in RegisterFlagsTest.cpp (NFC)

/data/llvm-project/third-party/unittest/googletest/include/gtest/gtest.h:1526:11: error: comparison of integers of different signs: 'const unsigned long long' and 'const int' [-Werror,-Wsign-compare]
if (lhs == rhs) {
~~~ ^ ~~~
/data/llvm-project/third-party/unittest/googletest/include/gtest/gtest.h:1553:12: note: in instantiation of function template specialization 'testing::internal::CmpHelperEQ<unsigned long long, int>' requested here
return CmpHelperEQ(lhs_expression, rhs_expression, lhs, rhs);
^
/data/llvm-project/lldb/unittests/Target/RegisterFlagsTest.cpp:128:3: note: in instantiation of function template specialization 'testing::internal::EqHelper::Compare<unsigned long long, int, nullptr>' requested here
ASSERT_EQ(0x12345678ULL, rf.ReverseFieldOrder(0x12345678));
^
/data/llvm-project/third-party/unittest/googletest/include/gtest/gtest.h:2056:32: note: expanded from macro 'ASSERT_EQ'
^
/data/llvm-project/third-party/unittest/googletest/include/gtest/gtest.h:2040:54: note: expanded from macro 'GTEST_ASSERT_EQ'
ASSERT_PRED_FORMAT2(::testing::internal::EqHelper::Compare, val1, val2)
^
1 error generated.

show more ...

[lldb] Show register fields using bitfield struct types

This change uses the information from target.xml sent by
the GDB stub to produce C types that we can use to print
register fields.

lldb-serve

[lldb] Show register fields using bitfield struct types

This change uses the information from target.xml sent by
the GDB stub to produce C types that we can use to print
register fields.

lldb-server *does not* produce this information yet. This will
only work with GDB stubs that do. gdbserver or qemu
are 2 I know of. Testing is added that uses a mocked lldb-server.
```
(lldb) register read cpsr x0 fpcr fpsr x1
cpsr = 0x60001000
= (N = 0, Z = 1, C = 1, V = 0, TCO = 0, DIT = 0, UAO = 0, PAN = 0, SS = 0, IL = 0, SSBS = 1, BTYPE = 0, D = 0, A = 0, I = 0, F = 0, nRW = 0, EL = 0, SP = 0)
```

Only "register read" will display fields, and only when
we are not printing a register block.

For example, cpsr is a 32 bit register. Using the target's scratch type
system we construct a type:
```
struct __attribute__((__packed__)) cpsr {
uint32_t N : 1;
uint32_t Z : 1;
...
uint32_t EL : 2;
uint32_t SP : 1;
};
```

If this register had unallocated bits in it, those would
have been filled in by RegisterFlags as anonymous fields.
A new option "SetChildPrintingDecider" is added so we
can disable printing those.

Important things about this type:
* It is packed so that sizeof(struct cpsr) == sizeof(the real register).
(this will hold for all flags types we create)
* Each field has the same storage type, which is the same as the type
of the raw register value. This prevents fields being spilt over
into more storage units, as is allowed by most ABIs.
* Each bitfield size matches that of its register field.
* The most significant field is first.

The last point is required because the most significant bit (MSB)
being on the left/top of a print out matches what you'd expect to
see in an architecture manual. In addition, having lldb print a
different field order on big/little endian hosts is not acceptable.

As a consequence, if the target is little endian we have to
reverse the order of the fields in the value. The value of each field
remains the same. For example 0b01 doesn't become 0b10, it just shifts
up or down.

This is needed because clang's type system assumes that for a struct
like the one above, the least significant bit (LSB) will be first
for a little endian target. We need the MSB to be first.

Finally, if lldb's host is a different endian to the target we have
to byte swap the host endian value to match the endian of the target's
typesystem.

| Host Endian | Target Endian | Field Order Swap | Byte Order Swap |
|-------------|---------------|------------------|-----------------|
| Little | Little | Yes | No |
| Big | Little | Yes | Yes |
| Little | Big | No | Yes |
| Big | Big | No | No |

Testing was done as follows:
* Little -> Little
* LE AArch64 native debug.
* Big -> Little
* s390x lldb running under QEMU, connected to LE AArch64 target.
* Little -> Big
* LE AArch64 lldb connected to QEMU's GDB stub, which is running
an s390x program.
* Big -> Big
* s390x lldb running under QEMU, connected to another QEMU's GDB
stub, which is running an s390x program.

As we are not allowed to link core code to plugins directly,
I have added a new plugin RegisterTypeBuilder. There is one implementation
of this, RegisterTypeBuilderClang, which uses TypeSystemClang to build
the CompilerType from the register fields.

Reviewed By: jasonmolenda

Differential Revision: https://reviews.llvm.org/D145580

show more ...

[lldb] Add RegisterFlags class

This models the "flags" node from GDB's target XML:
https://sourceware.org/gdb/onlinedocs/gdb/Target-Description-Format.html

This node is used to describe the fields

[lldb] Add RegisterFlags class

This models the "flags" node from GDB's target XML:
https://sourceware.org/gdb/onlinedocs/gdb/Target-Description-Format.html

This node is used to describe the fields of registers like cpsr on AArch64.

RegisterFlags is a class that contains a list of register fields.
These fields will be extracted from the XML sent by the remote.

We assume that there is at least one field, that the fields are
sorted in descending order and do not overlap. That will be
enforced by the XML processor (the GDB client code in our case).

The fields may not cover the whole register. To account for this
RegisterFields will add anonymous padding fields so that
sizeof(all fields) == sizeof(register). This will save a lot
of hasssle later.

Reviewed By: jasonmolenda, JDevlieghere

Differential Revision: https://reviews.llvm.org/D145566

show more ...