gdb-helpers/libcr.py: Fixes for running on actual ARM

1 files changed, 23 insertions, 3 deletions

diff --git a/gdb-helpers/libcr.py b/gdb-helpers/libcr.py
index e2e24a8..0509387 100644
--- a/gdb-helpers/libcr.py
+++ b/gdb-helpers/libcr.py
@@ -39,6 +39,19 @@ def gdb_setjmp() -> GdbJmpBuf:
 
 def gdb_longjmp(buf: GdbJmpBuf) -> None:
     """Our own in-Python GDB-specific implementation of `longjmp()`"""
+    if (
+        ("sp" in buf.registers)
+        and ("msp" in buf.registers)
+        and ("psp" in buf.registers)
+        and ("control" in buf.registers)
+    ):
+        # On ARM, 'sp' is an alias for either 'msp' or 'psp'
+        # (depending on 'control'&(1<<1)).  We must set all 3 before
+        # fussing with 'xPSR' or frames, or GDB will get upset at us
+        # about "Invalid state".
+        gdb.execute(f"set $sp = {buf.registers['sp']}", to_string=True)
+        gdb.execute(f"set $msp = {buf.registers['msp']}")
+        gdb.execute(f"set $psp = {buf.registers['psp']}")
     for reg, val in buf.registers.items():
         gdb.execute(f"set ${reg} = {val}")
     buf.frame.select()
@@ -101,7 +114,11 @@ class CrCoroutine:
         cr_env = self.env
         if self.cid == self.cr_globals.coroutine_running:
             cr_env = saved_env
-        assert cr_env
+        if not cr_env:
+            raise gdb.GdbError(
+                f"GDB does not have a saved execution environment for coroutine {self.id}.  "
+                + "This can happen if the coroutine has not run for as long as GDB has been attached."
+            )
 
         gdb_longjmp(cr_env)
         try:
@@ -179,8 +196,11 @@ class CrListCommand(gdb.Command):
             )
 
     def _pretty_frame(self, cr: CrCoroutine, from_tty: bool) -> str:
-        with cr.active():
-            full = gdb.execute("frame", from_tty=from_tty, to_string=True)
+        try:
+            with cr.active():
+                full = gdb.execute("frame", from_tty=from_tty, to_string=True)
+        except Exception as e:
+            full = "#1 err: " + str(e)
         line = full.split("\n", maxsplit=1)[0]
         return line.split(maxsplit=1)[1]