__attribute__((???)) ignored

[Kent-Dorfman]

whiskey tango, guys

I've always tried to avoid coding where I need to play with compiler directives but I've got some stuff where I need to mark functions as "unused". The offending function is a private static helper function in a compilation unit. It's not activated until I get other parts of the project completed and the warnings annoy my sensibilities.

Anyway, gnu/c++ is "suppose" to support

static void helper() __attribute__((unused));

but regardless of what I try it continues to be flagged as an "unused function" warnign with -Wall during compilation.

I also tried

static void helper()  [[unused]];

with equally undesirable results.

my compilation options show "under eclipse IDE" as:

g++ -std=c++17 -I"/home/me/eclipse-2403/farm" -O0 -g3 -Wall -c -fmessage-length=0

What gives, with gnu not accepting function attributes?

[SGaist]

Hi,

Which version of g++ are you using ?
With which distribution ?

[Kent-Dorfman]

@SGaist

gcc/g++ 10.2
on Debian 10

[jeremy_k]

@Kent-Dorfman said in __attribute__((???)) ignored:

static void helper()  [[unused]];

Perhaps [[maybe_unused]]?

The function example also places the attribute before the function signature.

[Kent-Dorfman]

@jeremy_k

that is weird. some examples place the directive after the declaration and others before like it shouldn't matter...but you are right. It did make a different. Placing it before the declation cause the warning to be igrnored.

looks like gcc documention is wrong...go figure. LOL

wrong in TWO PLACES...First, they say "unused" is a valid attribute, and second, internal examples sometimes place the attribute after the decl.

Hmmm.