[Lldb-commits] [lldb] b1f4f06 - [LLDB][LoongArch] Delete the s9 register alias definition

[Weining Lu via lldb-commits]

Author: Hui Li
Date: 2023-01-14T09:22:14+08:00
New Revision: b1f4f06dede54627c546d0e7f21e7e72295f280b

URL: https://github.com/llvm/llvm-project/commit/b1f4f06dede54627c546d0e7f21e7e72295f280b
DIFF: https://github.com/llvm/llvm-project/commit/b1f4f06dede54627c546d0e7f21e7e72295f280b.diff

LOG: [LLDB][LoongArch] Delete the s9 register alias definition

In RegisterInfos_loongarch64.h, r22 is defined twice. Having an extra array
member causes problems reading and writing registers defined after r22. So,
for r22, keep the alias fp, delete the s9 alias.

The PC register is incorrectly accessed when the step command is executed.
The step command behavior is incorrect.

This test reflects this problem:

```
loongson at linux:~$ cat test.c

 #include <stdio.h>

int func(int a) {
  return a + 1;
}

int main(int argc, char const *argv[]) {
  func(10);
  return 0;
}

loongson at linux:~$ clang -g test.c  -o test

```

Without this patch:
```
loongson at linux:~$ llvm-project/llvm/build/bin/lldb test
(lldb) target create "test"
Current executable set to '/home/loongson/test' (loongarch64).
(lldb) b main
Breakpoint 1: where = test`main + 40 at test.c:8:3, address = 0x0000000120000668
(lldb) r
Process 278049 launched: '/home/loongson/test' (loongarch64)
Process 278049 stopped
* thread #1, name = 'test', stop reason = breakpoint 1.1
    frame #0: 0x0000000120000668 test`main(argc=1, argv=0x00007fffffff72a8) at test.c:8:3
   5   	}
   6
   7   	int main(int argc, char const *argv[]) {
-> 8   	  func(10);
   9   	  return 0;
   10  	}
   11
(lldb) s
Process 278049 stopped
* thread #1, name = 'test', stop reason = step in
    frame #0: 0x0000000120000670 test`main(argc=1, argv=0x00007fffffff72a8) at test.c:9:3
   6
   7   	int main(int argc, char const *argv[]) {
   8   	  func(10);
-> 9   	  return 0;
   10  	}

```

With this patch:

```
loongson at linux:~$ llvm-project/llvm/build/bin/lldb test
(lldb) target create "test"
Current executable set to '/home/loongson/test' (loongarch64).
(lldb) b main
Breakpoint 1: where = test`main + 40 at test.c:8:3, address = 0x0000000120000668
(lldb) r
Process 278632 launched: '/home/loongson/test' (loongarch64)
Process 278632 stopped
* thread #1, name = 'test', stop reason = breakpoint 1.1
    frame #0: 0x0000000120000668 test`main(argc=1, argv=0x00007fffffff72a8) at test.c:8:3
   5   	}
   6
   7   	int main(int argc, char const *argv[]) {
-> 8   	  func(10);
   9   	  return 0;
   10  	}
   11
(lldb) s
Process 278632 stopped
* thread #1, name = 'test', stop reason = step in
    frame #0: 0x0000000120000624 test`func(a=10) at test.c:4:10
   1   	 #include <stdio.h>
   2
   3   	int func(int a) {
-> 4   	  return a + 1;
   5   	}

```

Reviewed By: SixWeining, DavidSpickett

Differential Revision: https://reviews.llvm.org/D140615

Added: 
    

Modified: 
    lldb/source/Plugins/Process/Utility/RegisterInfos_loongarch64.h
    lldb/source/Plugins/Process/Utility/lldb-loongarch-register-enums.h
    lldb/source/Utility/LoongArch_DWARF_Registers.h

Removed: 
    


################################################################################
diff  --git a/lldb/source/Plugins/Process/Utility/RegisterInfos_loongarch64.h b/lldb/source/Plugins/Process/Utility/RegisterInfos_loongarch64.h
index 723881bb92750..27f2bac22dd51 100644
--- a/lldb/source/Plugins/Process/Utility/RegisterInfos_loongarch64.h
+++ b/lldb/source/Plugins/Process/Utility/RegisterInfos_loongarch64.h
@@ -100,7 +100,6 @@ static lldb_private::RegisterInfo g_register_infos_loongarch64[] = {
     DEFINE_GPR64_ALT(r20, t8, LLDB_INVALID_REGNUM),
     DEFINE_GPR64(r21, LLDB_INVALID_REGNUM),
     DEFINE_GPR64_ALT(r22, fp, LLDB_REGNUM_GENERIC_FP),
-    DEFINE_GPR64_ALT(r22, s9, LLDB_REGNUM_GENERIC_FP),
     DEFINE_GPR64_ALT(r23, s0, LLDB_INVALID_REGNUM),
     DEFINE_GPR64_ALT(r24, s1, LLDB_INVALID_REGNUM),
     DEFINE_GPR64_ALT(r25, s2, LLDB_INVALID_REGNUM),

diff  --git a/lldb/source/Plugins/Process/Utility/lldb-loongarch-register-enums.h b/lldb/source/Plugins/Process/Utility/lldb-loongarch-register-enums.h
index d53e8ce1b3f7d..f55c807f86c00 100644
--- a/lldb/source/Plugins/Process/Utility/lldb-loongarch-register-enums.h
+++ b/lldb/source/Plugins/Process/Utility/lldb-loongarch-register-enums.h
@@ -85,7 +85,6 @@ enum {
   gpr_t7_loongarch = gpr_r19_loongarch,
   gpr_t8_loongarch = gpr_r20_loongarch,
   gpr_fp_loongarch = gpr_r22_loongarch,
-  gpr_s9_loongarch = gpr_r22_loongarch,
   gpr_s0_loongarch = gpr_r23_loongarch,
   gpr_s1_loongarch = gpr_r24_loongarch,
   gpr_s2_loongarch = gpr_r25_loongarch,

diff  --git a/lldb/source/Utility/LoongArch_DWARF_Registers.h b/lldb/source/Utility/LoongArch_DWARF_Registers.h
index b9c1928531442..34e40a066051e 100644
--- a/lldb/source/Utility/LoongArch_DWARF_Registers.h
+++ b/lldb/source/Utility/LoongArch_DWARF_Registers.h
@@ -128,7 +128,6 @@ enum {
   dwarf_gpr_t7 = dwarf_gpr_r19,
   dwarf_gpr_t8 = dwarf_gpr_r20,
   dwarf_gpr_fp = dwarf_gpr_r22,
-  dwarf_gpr_s9 = dwarf_gpr_r22,
   dwarf_gpr_s0 = dwarf_gpr_r23,
   dwarf_gpr_s1 = dwarf_gpr_r24,
   dwarf_gpr_s2 = dwarf_gpr_r25,