OPENSSL_FILE(3SSL)

💖 OPENSSL_FILE — the manual, but make it cute 💖

okay bestie, so this is OPENSSL_FILE(3SSL) from the OpenSSL manual set, and it's genuinely just a lil grab-bag of generic C programming utility macros that live in <openssl/macros.h>. no scary crypto math here, just some preprocessor besties. let's get into it 🫶

The whole girl squad is: OPENSSL_FILE, OPENSSL_LINE, OPENSSL_FUNC, OSSL_BEGIN_ALLOW_DEPRECATED, OSSL_END_ALLOW_DEPRECATED, OPENSSL_MSTR, and OPENSSL_MSTR_HELPER. seven macros, one file to include, zero drama. ✨

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🌸 SYNOPSIS 🌸

like, this is literally how you summon them:

#include <openssl/macros.h>

#define OPENSSL_FILE /* typically: __FILE__ */
#define OPENSSL_LINE /* typically: __LINE__ */
#define OPENSSL_FUNC /* typically: __func__ */

#define OPENSSL_MSTR_HELPER(x) #x
#define OPENSSL_MSTR(x) OPENSSL_MSTR_HELPER(x)

#define OSSL_BEGIN_ALLOW_DEPRECATED /* compiler specific */
#define OSSL_END_ALLOW_DEPRECATED /* compiler specific */

see? iconic. no notes. 💅

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✨ DESCRIPTION ✨

okay so OPENSSL_FILE and OPENSSL_LINE — they're giving "where am i right now" energy. OPENSSL_FILE typically hands you the current filename and OPENSSL_LINE typically hands you the current line number, all while your C code is getting compiled. 🦋

but wait — plot twist 🫢 — if OPENSSL_NO_FILENAMES is defined, they don't do that anymore. OPENSSL_FILE yields "" and OPENSSL_LINE yields 0. literally empty string and a zero. that's it, that's the whole vibe change.

then there's OPENSSL_FUNC, our main character 😌. it attempts to yield the name of the C function currently being compiled — as far as language and compiler versions allow. "as far as... allow" is doing a LOT of heavy lifting there, ngl. and if it can't? it yields "(unknown function)". respectfully. 🙈

next up, OPENSSL_MSTR — it yields the expansion of the macro you hand it as an argument, which is highkey useful for concatenation with string constants. and OPENSSL_MSTR_HELPER? that one's just the auxiliary macro that makes the whole thing work behind the scenes. the supportive bestie of the group, we love her 🎀

and finally, the deprecation duo: OSSL_BEGIN_ALLOW_DEPRECATED and OSSL_END_ALLOW_DEPRECATED. they respectively disable and then re-enable compiler warnings for deprecated functions within a source file, for compilers which OpenSSL supports. so like, they do the same thing as disabling the warnings with compiler-specific options — but they're convenient when you wanna use deprecated OpenSSL functions temporarily in limited areas of code without turning off warnings more globally. small controlled chaos, basically. 💀

⚠️ BUT. listen. it is nevertheless important to remember to eventually transition such code to replacement functions, because deprecated functions may be removed in later major OpenSSL releases. don't get comfy in there, bestie. that room is getting renovated. 😭

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👑 RETURN VALUES 👑

see above. (yes really, that's the whole section. it's giving "scroll up". i respect the laziness fr fr 🌈)

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⭐ SEE ALSO ⭐

• crypto(7)

go read that one too, it's the whole extended universe iykyk 💜

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🦋 HISTORY 🦋

• OPENSSL_FUNC, OPENSSL_MSTR, and OPENSSL_MSTR_HELPER were added in OpenSSL 3.0.
• OSSL_BEGIN_ALLOW_DEPRECATED and OSSL_END_ALLOW_DEPRECATED were added in OpenSSL 4.0, inspired by BoringSSL.

glow-up timeline fr 🧚

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🎀 COPYRIGHT 🎀

Copyright 2018-2026 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the Apache License 2.0 (the "License"). You may not use this file except in compliance with the License. You can obtain a copy in the file LICENSE in the source distribution or at <https://www.openssl.org/source/license.html>.

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and that's the whole page, bestie!! 🌸 this was OpenSSL 4.0.3, dated 2026-09-29, and yeah, it's the OPENSSL_FILE(3SSL) page. slay, stay compiling, and go fix that deprecated code. mwah 💖✨