RISC-V: List all integer registers for lldb compatibility (#149)

* lldb/risc-v: Add all integer registers

lldb requires a full list of registers in the target_description_xml (gdb
on the other hand seems to ignore the list completely).

The gdb manual sounds like these registers should exist anyway:
> The ‘org.gnu.gdb.riscv.cpu’ feature is required for RISC-V targets. It should contain the registers ‘x0’ through ‘x31’, and ‘pc’.

Therefore it seems reasonable that the RISC-V arch returns the full list.

* Include original files via include_str! instead

gdbstub_arch/src/riscv/mod.rs

@@ -15,21 +15,21 @@ pub enum Riscv64 {}
 impl Arch for Riscv32 {
     type Usize = u32;
     type Registers = reg::RiscvCoreRegs<u32>;
-    type RegId = reg::id::RiscvRegId<u32>;
     type BreakpointKind = usize;
+    type RegId = reg::id::RiscvRegId<u32>;
 
     fn target_description_xml() -> Option<&'static str> {
-        Some(r#"<target version="1.0"><architecture>riscv:rv32</architecture></target>"#)
+        Some(include_str!("rv32i.xml"))
     }
 }
 
 impl Arch for Riscv64 {
     type Usize = u64;
     type Registers = reg::RiscvCoreRegs<u64>;
-    type RegId = reg::id::RiscvRegId<u64>;
     type BreakpointKind = usize;
+    type RegId = reg::id::RiscvRegId<u64>;
 
     fn target_description_xml() -> Option<&'static str> {
-        Some(r#"<target version="1.0"><architecture>riscv:rv64</architecture></target>"#)
+        Some(include_str!("rv64i.xml"))
     }
 }

gdbstub_arch/src/riscv/rv32i.xml

@@ -0,0 +1,47 @@
+<?xml version="1.0"?>
+<!-- Copyright (C) 2018-2024 Free Software Foundation, Inc.
+
+     Copying and distribution of this file, with or without modification,
+     are permitted in any medium without royalty provided the copyright
+     notice and this notice are preserved.  -->
+
+<!-- Register numbers are hard-coded in order to maintain backward
+     compatibility with older versions of tools that didn't use xml
+     register descriptions.  -->
+
+<!DOCTYPE feature SYSTEM "gdb-target.dtd">
+<feature name="org.gnu.gdb.riscv.cpu">
+  <reg name="zero" bitsize="32" type="int" regnum="0"/>
+  <reg name="ra" bitsize="32" type="code_ptr"/>
+  <reg name="sp" bitsize="32" type="data_ptr"/>
+  <reg name="gp" bitsize="32" type="data_ptr"/>
+  <reg name="tp" bitsize="32" type="data_ptr"/>
+  <reg name="t0" bitsize="32" type="int"/>
+  <reg name="t1" bitsize="32" type="int"/>
+  <reg name="t2" bitsize="32" type="int"/>
+  <reg name="fp" bitsize="32" type="data_ptr"/>
+  <reg name="s1" bitsize="32" type="int"/>
+  <reg name="a0" bitsize="32" type="int"/>
+  <reg name="a1" bitsize="32" type="int"/>
+  <reg name="a2" bitsize="32" type="int"/>
+  <reg name="a3" bitsize="32" type="int"/>
+  <reg name="a4" bitsize="32" type="int"/>
+  <reg name="a5" bitsize="32" type="int"/>
+  <reg name="a6" bitsize="32" type="int"/>
+  <reg name="a7" bitsize="32" type="int"/>
+  <reg name="s2" bitsize="32" type="int"/>
+  <reg name="s3" bitsize="32" type="int"/>
+  <reg name="s4" bitsize="32" type="int"/>
+  <reg name="s5" bitsize="32" type="int"/>
+  <reg name="s6" bitsize="32" type="int"/>
+  <reg name="s7" bitsize="32" type="int"/>
+  <reg name="s8" bitsize="32" type="int"/>
+  <reg name="s9" bitsize="32" type="int"/>
+  <reg name="s10" bitsize="32" type="int"/>
+  <reg name="s11" bitsize="32" type="int"/>
+  <reg name="t3" bitsize="32" type="int"/>
+  <reg name="t4" bitsize="32" type="int"/>
+  <reg name="t5" bitsize="32" type="int"/>
+  <reg name="t6" bitsize="32" type="int"/>
+  <reg name="pc" bitsize="32" type="code_ptr"/>
+</feature>

gdbstub_arch/src/riscv/rv64i.xml

@@ -0,0 +1,47 @@
+<?xml version="1.0"?>
+<!-- Copyright (C) 2018-2024 Free Software Foundation, Inc.
+
+     Copying and distribution of this file, with or without modification,
+     are permitted in any medium without royalty provided the copyright
+     notice and this notice are preserved.  -->
+
+<!-- Register numbers are hard-coded in order to maintain backward
+     compatibility with older versions of tools that didn't use xml
+     register descriptions.  -->
+
+<!DOCTYPE feature SYSTEM "gdb-target.dtd">
+<feature name="org.gnu.gdb.riscv.cpu">
+  <reg name="zero" bitsize="64" type="int" regnum="0"/>
+  <reg name="ra" bitsize="64" type="code_ptr"/>
+  <reg name="sp" bitsize="64" type="data_ptr"/>
+  <reg name="gp" bitsize="64" type="data_ptr"/>
+  <reg name="tp" bitsize="64" type="data_ptr"/>
+  <reg name="t0" bitsize="64" type="int"/>
+  <reg name="t1" bitsize="64" type="int"/>
+  <reg name="t2" bitsize="64" type="int"/>
+  <reg name="fp" bitsize="64" type="data_ptr"/>
+  <reg name="s1" bitsize="64" type="int"/>
+  <reg name="a0" bitsize="64" type="int"/>
+  <reg name="a1" bitsize="64" type="int"/>
+  <reg name="a2" bitsize="64" type="int"/>
+  <reg name="a3" bitsize="64" type="int"/>
+  <reg name="a4" bitsize="64" type="int"/>
+  <reg name="a5" bitsize="64" type="int"/>
+  <reg name="a6" bitsize="64" type="int"/>
+  <reg name="a7" bitsize="64" type="int"/>
+  <reg name="s2" bitsize="64" type="int"/>
+  <reg name="s3" bitsize="64" type="int"/>
+  <reg name="s4" bitsize="64" type="int"/>
+  <reg name="s5" bitsize="64" type="int"/>
+  <reg name="s6" bitsize="64" type="int"/>
+  <reg name="s7" bitsize="64" type="int"/>
+  <reg name="s8" bitsize="64" type="int"/>
+  <reg name="s9" bitsize="64" type="int"/>
+  <reg name="s10" bitsize="64" type="int"/>
+  <reg name="s11" bitsize="64" type="int"/>
+  <reg name="t3" bitsize="64" type="int"/>
+  <reg name="t4" bitsize="64" type="int"/>
+  <reg name="t5" bitsize="64" type="int"/>
+  <reg name="t6" bitsize="64" type="int"/>
+  <reg name="pc" bitsize="64" type="code_ptr"/>
+</feature>