From d0b412518401cc4c9958926af006f83af17e69fc Mon Sep 17 00:00:00 2001 From: Brandon Maier Date: Sun, 24 Nov 2024 15:48:04 -0600 Subject: [PATCH] pylibfdt/libfdt.i: fix backwards compatibility of return values When our Python functions wrap `fdt_getprop()` they return a list containing `[*data, length]`. In SWIG v4.2 and earlier SWIG would discard `*data` if it is NULL/None. Causing the return value to just be `length`. But starting in SWIG v4.3 it no longer discards `*data`. So the return value is now `[None, length]`. Handle this compatibility issue in libfdt.i by checking if the return value looks like the older 4.2 return value, and casting it to the newer style. See https://github.com/swig/swig/pull/2907 Signed-off-by: Brandon Maier --- pylibfdt/libfdt.i | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-) diff --git a/pylibfdt/libfdt.i b/pylibfdt/libfdt.i index 9f5b6a9c..bb9985c3 100644 --- a/pylibfdt/libfdt.i +++ b/pylibfdt/libfdt.i @@ -114,11 +114,14 @@ def check_err_null(val, quiet=()): FdtException if val indicates an error was reported and the error is not in @quiet. """ - # Normally a list is returned which contains the data and its length. - # If we get just an integer error code, it means the function failed. + # Compatibility for SWIG v4.2 and earlier. SWIG 4.2 would drop the first + # item from the list if it was None, returning only the second item. if not isinstance(val, list): - if -val not in quiet: - raise FdtException(val) + val = [None, val] + + if val[0] is None: + if -val[1] not in quiet: + raise FdtException(val[1]) return val class FdtRo(object): @@ -395,8 +398,8 @@ class FdtRo(object): """ pdata = check_err_null( fdt_get_property_by_offset(self._fdt, prop_offset), quiet) - if isinstance(pdata, (int)): - return pdata + if pdata[0] is None: + return pdata[1] return Property(pdata[0], pdata[1]) def getprop(self, nodeoffset, prop_name, quiet=()): @@ -417,8 +420,8 @@ class FdtRo(object): """ pdata = check_err_null(fdt_getprop(self._fdt, nodeoffset, prop_name), quiet) - if isinstance(pdata, (int)): - return pdata + if pdata[0] is None: + return pdata[1] return Property(prop_name, bytearray(pdata[0])) def hasprop(self, nodeoffset, prop_name, quiet=()): @@ -444,10 +447,10 @@ class FdtRo(object): """ pdata = check_err_null(fdt_getprop(self._fdt, nodeoffset, prop_name), quiet + (NOTFOUND,)) - if isinstance(pdata, (int)): - if pdata == -NOTFOUND: + if pdata[0] is None: + if pdata[1] == -NOTFOUND: return False - return pdata + return pdata[1] return True def get_phandle(self, nodeoffset):