Bug #21496: Fix for gcc-15 `-flto` option

• Status: Closed
• Assignee: -
• Target version: -
• Backport: 3.2: DONE, 3.3: DONE, 3.4: DONE

[nobu (Nobuyoshi Nakada)]

Even no prototype information is available, gcc-15 seems retrieve something when LTO is enabled.
As the result, have_func method may fail due to the inconsistency between the info and the default old-style declaration.

Possible fixes are:

• Specify the header file providing its proper prototype.
• Add the argument list to the first argument.

By the following commits, the extconf.h files generated with -flto option became same as without the option.

11fe8b26c14 [ruby/etc] Run have_func with the header providing the declarations
134bdf2d34a [ruby/io-console] Run have_func with the header providing the declarations
ac72a25a578 [ruby/io-nonblock] Run have_func with the header providing the declarations
89031666487 [ruby/io-wait] Run have_func with the header providing the declarations
5277ca1431a [ruby/openssl] Run have_func with the header providing the declarations
94803fe9e7b [ruby/strscan] Run have_func with the header providing the declarations
9d080765cc3 [ruby/json] Run have_func with the header providing the declarations

[nobu (Nobuyoshi Nakada)]

• Is duplicate of Bug #21497: building issue when using gcc15, because C23 is default added

[hsbt (Hiroshi SHIBATA)]

I created https://github.com/ruby/ruby/pull/13892 for Ruby 3.4.

[hsbt (Hiroshi SHIBATA)]

• Backport changed from 3.2: REQUIRED, 3.3: REQUIRED, 3.4: REQUIRED to 3.2: REQUIRED, 3.3: REQUIRED, 3.4: DONE

[nagachika (Tomoyuki Chikanaga)]

I have created a backporting pull request along with [Bug #21500].
https://github.com/ruby/ruby/pull/13962

[nagachika (Tomoyuki Chikanaga)]

• Backport changed from 3.2: REQUIRED, 3.3: REQUIRED, 3.4: DONE to 3.2: REQUIRED, 3.3: DONE, 3.4: DONE

[hsbt (Hiroshi SHIBATA)]

• Backport changed from 3.2: REQUIRED, 3.3: DONE, 3.4: DONE to 3.2: DONE, 3.3: DONE, 3.4: DONE

I merged them at https://github.com/ruby/ruby/pull/14001

I only merged strscan, json and io-wait because other libraries didn't declare affected have_func.