9.67 __attribute__((used)) variable attribute

This variable attribute informs the compiler that a static variable is to be retained in the object file, even if it is unreferenced.


Static variables marked as used are emitted to a single section, in the order they are declared. You can specify the section that variables are placed in using __attribute__((section("name"))).
Data marked with __attribute__((used)) is tagged in the object file to avoid removal by linker unused section removal.


This variable attribute is a GNU compiler extension that the ARM compiler supports.


Static functions can also be marked as used using __attribute__((used)).
You can use __attribute__((used)) to build tables in the object.


static int lose_this = 1;
static int keep_this __attribute__((used)) = 2;     // retained in object file
static int keep_this_too __attribute__((used)) = 3; // retained in object file
Related reference
9.49 __attribute__((used)) function attribute
9.46 __attribute__((section("name"))) function attribute
Related information
Elimination of unused sections
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