[lldb][test][FreeBSD] Account for spsr being 8 bytes in newer versions

[DavidSpickett]

Since https://reviews.freebsd.org/D38983, spsr (aka cpsr) is stored as an 8 byte value. However in lldb's structures it is a 32 bit value still.

The version number comes from
https://cgit.freebsd.org/src/commit/?id=ea3061526e9ce5d3b65932c1d3e4437abd556d65.

[llvmbot]

@llvm/pr-subscribers-lldb

Author: David Spickett (DavidSpickett)

Changes

Since https://reviews.freebsd.org/D38983, spsr (aka cpsr) is stored as an 8 byte value. However in lldb's structures it is a 32 bit value still.

The version number comes from
https://cgit.freebsd.org/src/commit/?id=ea3061526e9ce5d3b65932c1d3e4437abd556d65.

---

Full diff: https://github.com/llvm/llvm-project/pull/84032.diff

1 Files Affected:

• (modified) lldb/unittests/Process/Utility/RegisterContextFreeBSDTest.cpp (+9)

diff --git a/lldb/unittests/Process/Utility/RegisterContextFreeBSDTest.cpp b/lldb/unittests/Process/Utility/RegisterContextFreeBSDTest.cpp
index e541a34e6e22a0..70697766dd82ba 100644
--- a/lldb/unittests/Process/Utility/RegisterContextFreeBSDTest.cpp
+++ b/lldb/unittests/Process/Utility/RegisterContextFreeBSDTest.cpp
@@ -7,6 +7,7 @@
 //===----------------------------------------------------------------------===//
 
 // clang-format off
+#include <sys/param.h>
 #include <sys/types.h>
 #include <machine/reg.h>
 #if defined(__arm__)
@@ -362,7 +363,15 @@ TEST(RegisterContextFreeBSDTest, arm64) {
   EXPECT_GPR_ARM64(lr, lr);
   EXPECT_GPR_ARM64(sp, sp);
   EXPECT_GPR_ARM64(pc, elr);
+#if __FreeBSD_version >= 1400084
+  // LLDB assumes that cpsr is 32 bit but the kernel stores it as a 64 bit
+  // value.
+  EXPECT_THAT(GetRegParams(reg_ctx, gpr_cpsr_arm64),
+              ::testing::Pair(offsetof(reg, spsr), 4));
+#else
+  // Older kernels stored spsr as a 32 bit value.
   EXPECT_GPR_ARM64(cpsr, spsr);
+#endif
 
   size_t base_offset = reg_ctx.GetRegisterInfo()[fpu_v0_arm64].byte_offset;
 

[DavidSpickett]

This may also imply there is work to be done to make lldb show the upper 32 bits, but I'll leave that to the FreeBSD experts to decide.

[emaste]

CC @zxombie

[emaste]

This will be correct when the host running the debugger is the same as the target (or at least the same version) but we should handle this based on target version

[DavidSpickett]

Good point. Though these tests are likely only run on the machine that built them, but if lldb is loading a FreeBSD corefile it would need to know there was a difference. That at least needs checking, even if it may appear to "just work".

Making cross version core files work is more than I have time for here, so if any FreeBSD person wants to do a proper version of this fix, feel free.

(I did look for a runtime way to get __FreeBSD_version but none of the version strings I found contained the final part of the macro's value)

[DavidSpickett]

Fixing the general issue needs more attention, so I am abandoning this fix.