Add pystack definition to Misc/gdbinit with some explanation of its behavior
and add flag comments to ceval.c and main.c alerting people to the coupling
between pystack and the layout of those files.
diff --git a/Misc/gdbinit b/Misc/gdbinit
index 05f6a91..4790ada 100644
--- a/Misc/gdbinit
+++ b/Misc/gdbinit
@@ -34,3 +34,26 @@
x/s ((PyStringObject*)f->f_code->co_name)->ob_sval
p f->f_lineno
end
+
+# Here's a somewhat fragile way to print the entire Python stack from gdb.
+# It's fragile because the tests for the value of $pc depend on the layout
+# of specific functions in the C source code.
+
+# Explanation of while and if tests: We want to pop up the stack until we
+# land in Py_Main (this is probably an incorrect assumption in an embedded
+# interpreter, but the test can be extended by an interested party). If
+# Py_Main <= $pc <= Py_GetArgcArv is true $pc is in Py_Main(), so the while
+# tests succeeds as long as it's not true. In a similar fashion the if
+# statement tests to see if we are in eval_frame().
+
+define pystack
+ while $pc < Py_Main || $pc > Py_GetArgcArgv
+ if $pc > eval_frame && $pc < PyEval_EvalCodeEx
+ set $__fn = PyString_AsString(co->co_filename)
+ set $__n = PyString_AsString(co->co_name)
+ printf "%s (%d): %s\n", $__fn, f->f_lineno, $__n
+ end
+ up-silently 1
+ end
+ select-frame 0
+end