tests: Add loop and AnnAssign xfail tests (#103)

- process_stmt now raises NotImplementedError on an unsupported statement
  instead of warning: a dropped statement silently changes what the
  program means (a for/while loop compiled to nothing).
- failing_tests/loops/: 8 xfail tests for for/while/break/continue/nested
  loops and map iteration
- failing_tests/assign/annotated_assign.py: xfail for `x: c_int64 = 0`
  (ast.AnnAssign is not handled)

Author: varun-r-mallya

pythonbpf/functions/functions_pass.py

@@ -401,11 +401,11 @@ def process_stmt(
             builder, stmt, local_sym_tab, ret_type, compilation_context
         )
     else:
-        # Silently dropping a statement makes the program mean something other
-        # than what it says, so say so.
-        logger.warning(
-            f"Unsupported statement on line {getattr(stmt, 'lineno', '?')}, "
-            f"ignored: {type(stmt).__name__}"
+        # Dropping a statement makes the program mean something other than what
+        # it says (a loop compiles to nothing), so refuse rather than warn.
+        raise NotImplementedError(
+            f"Unsupported statement on line {getattr(stmt, 'lineno', '?')}: "
+            f"{type(stmt).__name__}"
         )
     return did_return
 

tests/failing_tests/assign/annotated_assign.py

@@ -0,0 +1,18 @@
+from pythonbpf import bpf, section, bpfglobal, compile
+from ctypes import c_void_p, c_int64
+
+
+@bpf
+@section("tracepoint/syscalls/sys_enter_execve")
+def hello(ctx: c_void_p) -> c_int64:
+    total: c_int64 = 0
+    return total
+
+
+@bpf
+@bpfglobal
+def LICENSE() -> str:
+    return "GPL"
+
+
+compile()

tests/failing_tests/loops/for_break.py

@@ -0,0 +1,22 @@
+from pythonbpf import bpf, section, bpfglobal, compile
+from ctypes import c_void_p, c_int64
+
+
+@bpf
+@section("tracepoint/syscalls/sys_enter_execve")
+def hello(ctx: c_void_p) -> c_int64:
+    total: c_int64 = 0
+    for i in range(10):
+        if i == 5:
+            break
+        total = total + 1
+    return total
+
+
+@bpf
+@bpfglobal
+def LICENSE() -> str:
+    return "GPL"
+
+
+compile()

tests/failing_tests/loops/for_continue.py

@@ -0,0 +1,22 @@
+from pythonbpf import bpf, section, bpfglobal, compile
+from ctypes import c_void_p, c_int64
+
+
+@bpf
+@section("tracepoint/syscalls/sys_enter_execve")
+def hello(ctx: c_void_p) -> c_int64:
+    total: c_int64 = 0
+    for i in range(10):
+        if i % 2 == 0:
+            continue
+        total = total + i
+    return total
+
+
+@bpf
+@bpfglobal
+def LICENSE() -> str:
+    return "GPL"
+
+
+compile()

tests/failing_tests/loops/for_map_items.py

@@ -0,0 +1,29 @@
+from pythonbpf import bpf, map, bpfglobal, section, compile
+from pythonbpf.maps import HashMap
+from ctypes import c_void_p, c_int64, c_int32, c_uint64
+
+
+@bpf
+@map
+def mymap() -> HashMap:
+    return HashMap(key=c_int32, value=c_uint64, max_entries=16)
+
+
+# Imagined sugar over the kernel's bpf_for_each_map_elem() callback helper:
+# iterating a map's entries directly from a `for` statement.
+@bpf
+@section("tracepoint/syscalls/sys_enter_execve")
+def hello(ctx: c_void_p) -> c_int64:
+    total: c_int64 = 0
+    for k, v in mymap.items():
+        total = total + 1
+    return total
+
+
+@bpf
+@bpfglobal
+def LICENSE() -> str:
+    return "GPL"
+
+
+compile()

tests/failing_tests/loops/for_range_start_stop_step.py

@@ -0,0 +1,20 @@
+from pythonbpf import bpf, section, bpfglobal, compile
+from ctypes import c_void_p, c_int64
+
+
+@bpf
+@section("tracepoint/syscalls/sys_enter_execve")
+def hello(ctx: c_void_p) -> c_int64:
+    total: c_int64 = 0
+    for i in range(0, 10, 2):
+        total = total + i
+    return total
+
+
+@bpf
+@bpfglobal
+def LICENSE() -> str:
+    return "GPL"
+
+
+compile()

tests/failing_tests/loops/for_range_sum.py

@@ -0,0 +1,20 @@
+from pythonbpf import bpf, section, bpfglobal, compile
+from ctypes import c_void_p, c_int64
+
+
+@bpf
+@section("tracepoint/syscalls/sys_enter_execve")
+def hello(ctx: c_void_p) -> c_int64:
+    total: c_int64 = 0
+    for i in range(10):
+        total = total + 1
+    return total
+
+
+@bpf
+@bpfglobal
+def LICENSE() -> str:
+    return "GPL"
+
+
+compile()

tests/failing_tests/loops/nested_for.py

@@ -0,0 +1,21 @@
+from pythonbpf import bpf, section, bpfglobal, compile
+from ctypes import c_void_p, c_int64
+
+
+@bpf
+@section("tracepoint/syscalls/sys_enter_execve")
+def hello(ctx: c_void_p) -> c_int64:
+    total: c_int64 = 0
+    for i in range(3):
+        for j in range(3):
+            total = total + 1
+    return total
+
+
+@bpf
+@bpfglobal
+def LICENSE() -> str:
+    return "GPL"
+
+
+compile()

tests/failing_tests/loops/while_basic.py

@@ -0,0 +1,20 @@
+from pythonbpf import bpf, section, bpfglobal, compile
+from ctypes import c_void_p, c_int64
+
+
+@bpf
+@section("tracepoint/syscalls/sys_enter_execve")
+def hello(ctx: c_void_p) -> c_int64:
+    i: c_int64 = 0
+    while i < 10:
+        i = i + 1
+    return i
+
+
+@bpf
+@bpfglobal
+def LICENSE() -> str:
+    return "GPL"
+
+
+compile()

tests/failing_tests/loops/while_true_break.py

@@ -0,0 +1,22 @@
+from pythonbpf import bpf, section, bpfglobal, compile
+from ctypes import c_void_p, c_int64
+
+
+@bpf
+@section("tracepoint/syscalls/sys_enter_execve")
+def hello(ctx: c_void_p) -> c_int64:
+    total: c_int64 = 0
+    while True:
+        total = total + 1
+        if total == 10:
+            break
+    return total
+
+
+@bpf
+@bpfglobal
+def LICENSE() -> str:
+    return "GPL"
+
+
+compile()