checkstack: Handle conditional checks at start of functions

Recent versions of gcc will sometimes place conditional checks in the
code prior to setting up the function's stack frame.  Handle this case
correctly.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

1 files changed, 5 insertions, 0 deletions

diff --git a/scripts/checkstack.py b/scripts/checkstack.py
index 5d9b0bfa..255768ae 100755
--- a/scripts/checkstack.py
+++ b/scripts/checkstack.py
@@ -153,6 +153,11 @@ def main():
             if '%esp' in insn or insn.startswith('leal'):
                 # Still part of initial header
                 continue
+            if not stackusage and (
+                    insn.startswith('test') or insn.startswith('cmp')
+                    or insn.startswith('j')):
+                # There may be conditional checks prior to stack frame
+                continue
             cur.basic_stack_usage = stackusage
             atstart = 0