blob: efc4add7954268c3b037bb5199f6aac5aa9c3121 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
|
From baa3a54e019b8ba6161fe20943c897490f4bcde8 Mon Sep 17 00:00:00 2001
From: Fangrui Song <i@maskray.me>
Date: Sat, 27 Nov 2021 18:19:46 +0100
Subject: [PATCH basu] LLD 13 and GNU ld 2.37 support -z start-stop-gc which
allows garbage collection of C identifier name sections despite the
__start_/__stop_ references. Simply set the retain attribute so that GCC 11
(if configure-time binutils is 2.36 or newer)/Clang 13 will set the
SHF_GNU_RETAIN section attribute to prevent garbage collection.
Without the patch, there are linker errors like the following with -z
start-stop-gc.
```
ld: error: undefined symbol: __start_SYSTEMD_BUS_ERROR_MAP
>>> referenced by bus-error.c:93 (../src/libsystemd/sd-bus/bus-error.c:93)
>>> sd-bus_bus-error.c.o:(bus_error_name_to_errno) in archive src/libsystemd/libsystemd_static.a
```
Co-authored-by: Evgeniy Khramtsov <evgeniy@khramtsov.org>
---
Upstream: https://git.sr.ht/~emersion/basu/commit/5fa970e868f25ebc79ccca9b1d9df4c030d97661
Gentoo bug: https://bugs.gentoo.org/832045
src/libsystemd/sd-bus/bus-error.h | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/src/libsystemd/sd-bus/bus-error.h b/src/libsystemd/sd-bus/bus-error.h
index 06c478a..883213f 100644
--- a/src/libsystemd/sd-bus/bus-error.h
+++ b/src/libsystemd/sd-bus/bus-error.h
@@ -28,11 +28,17 @@ int bus_error_set_errnofv(sd_bus_error *e, int error, const char *format, va_lis
* the bus error table, and BUS_ERROR_MAP_ELF_USE has to be used at
* least once per compilation unit (i.e. per library), to ensure that
* the error map is really added to the final binary.
+ *
+ * In addition, set the retain attribute so that the section cannot be
+ * discarded by ld --gc-sections -z start-stop-gc. Older compilers would
+ * warn for the unknown attribute, so just disable -Wattributes.
*/
#define BUS_ERROR_MAP_ELF_REGISTER \
+ _Pragma("GCC diagnostic ignored \"-Wattributes\"") \
__attribute__ ((__section__("BUS_ERROR_MAP"))) \
__attribute__ ((__used__)) \
+ __attribute__ ((retain)) \
__attribute__ ((aligned(8)))
#define BUS_ERROR_MAP_ELF_USE(errors) \
--
2.34.1
|
GitWeb
