From ae2a15bc14bc448e625ad93fd044bc077ede4b3f Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Thu, 22 Mar 2018 16:53:26 +0100 Subject: macro: introduce TAKE_PTR() macro This macro will read a pointer of any type, return it, and set the pointer to NULL. This is useful as an explicit concept of passing ownership of a memory area between pointers. This takes inspiration from Rust: https://doc.rust-lang.org/std/option/enum.Option.html#method.take and was suggested by Alan Jenkins (@sourcejedi). It drops ~160 lines of code from our codebase, which makes me like it. Also, I think it clarifies passing of ownership, and thus helps readability a bit (at least for the initiated who know the new macro) --- src/shared/efivars.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'src/shared/efivars.c') diff --git a/src/shared/efivars.c b/src/shared/efivars.c index 9ca51cf750..d31cf2d860 100644 --- a/src/shared/efivars.c +++ b/src/shared/efivars.c @@ -249,8 +249,7 @@ int efi_get_variable( ((char*) buf)[st.st_size - 4] = 0; ((char*) buf)[st.st_size - 4 + 1] = 0; - *value = buf; - buf = NULL; + *value = TAKE_PTR(buf); *size = (size_t) st.st_size - 4; if (attribute) @@ -563,8 +562,7 @@ int efi_get_boot_order(uint16_t **order) { l / sizeof(uint16_t) > INT_MAX) return -EINVAL; - *order = buf; - buf = NULL; + *order = TAKE_PTR(buf); return (int) (l / sizeof(uint16_t)); } -- cgit v1.2.1