Fix unused-but-set-global warnings in clang-23

Merged: https://github.com/ruby/ruby/pull/17475

complex.c

@@ -40,7 +40,6 @@ static VALUE RFLOAT_0;
 VALUE rb_cComplex;
 
 static ID id_abs, id_arg,
-    id_denominator, id_numerator,
     id_real_p, id_i_real, id_i_imag,
     id_finite_p, id_infinite_p, id_rationalize,
     id_PI;
@@ -2696,8 +2695,6 @@ Init_Complex(void)
     VALUE compat;
     id_abs = rb_intern_const("abs");
     id_arg = rb_intern_const("arg");
-    id_denominator = rb_intern_const("denominator");
-    id_numerator = rb_intern_const("numerator");
     id_real_p = rb_intern_const("real?");
     id_i_real = rb_intern_const("@real");
     id_i_imag = rb_intern_const("@image"); /* @image, not @imag */

hash.c

@@ -5138,7 +5138,11 @@ rb_hash_new_with_bulk_insert(long argc, const VALUE *argv)
     return val;
 }
 
+#undef USE_ORIGENVIRON
+#if !defined(_WIN32) && !(defined(HAVE_SETENV) && defined(HAVE_UNSETENV))
+# define USE_ORIGENVIRON 1
 static char **origenviron;
+#endif
 #ifdef _WIN32
 #define GET_ENVIRON(e) ((e) = rb_w32_get_environ())
 #define FREE_ENVIRON(e) rb_w32_free_environ(e)
@@ -7678,7 +7682,9 @@ Init_Hash(void)
      * Hack to get RDoc to regard ENV as a class:
      * envtbl = rb_define_class("ENV", rb_cObject);
      */
+#ifdef USE_ORIGENVIRON
     origenviron = environ;
+#endif
     envtbl = TypedData_Wrap_Struct(rb_cObject, &env_data_type, NULL);
     rb_extend_object(envtbl, rb_mEnumerable);
     RB_OBJ_SET_SHAREABLE(envtbl);

io.c

@@ -193,8 +193,10 @@ VALUE rb_mWaitWritable;
 
 static VALUE rb_eEAGAINWaitReadable;
 static VALUE rb_eEAGAINWaitWritable;
+#if EAGAIN != EWOULDBLOCK
 static VALUE rb_eEWOULDBLOCKWaitReadable;
 static VALUE rb_eEWOULDBLOCKWaitWritable;
+#endif
 static VALUE rb_eEINPROGRESSWaitWritable;
 static VALUE rb_eEINPROGRESSWaitReadable;
 
@@ -208,7 +210,7 @@ VALUE rb_default_rs;
 
 static VALUE argf;
 
-static ID id_write, id_read, id_getc, id_flush, id_readpartial, id_set_encoding, id_fileno;
+static ID id_write, id_read, id_flush, id_readpartial, id_set_encoding, id_fileno;
 static VALUE sym_mode, sym_perm, sym_flags, sym_extenc, sym_intenc, sym_encoding, sym_open_args;
 static VALUE sym_textmode, sym_binmode, sym_autoclose;
 static VALUE sym_SET, sym_CUR, sym_END;
@@ -15698,7 +15700,6 @@ Init_IO(void)
 
     id_write = rb_intern_const("write");
     id_read = rb_intern_const("read");
-    id_getc = rb_intern_const("getc");
     id_flush = rb_intern_const("flush");
     id_readpartial = rb_intern_const("readpartial");
     id_set_encoding = rb_intern_const("set_encoding");
@@ -15746,10 +15747,8 @@ Init_IO(void)
     rb_eEAGAINWaitWritable = rb_define_class_under(rb_cIO, "EAGAINWaitWritable", rb_eEAGAIN);
     rb_include_module(rb_eEAGAINWaitWritable, rb_mWaitWritable);
 #if EAGAIN == EWOULDBLOCK
-    rb_eEWOULDBLOCKWaitReadable = rb_eEAGAINWaitReadable;
     /* same as IO::EAGAINWaitReadable */
     rb_define_const(rb_cIO, "EWOULDBLOCKWaitReadable", rb_eEAGAINWaitReadable);
-    rb_eEWOULDBLOCKWaitWritable = rb_eEAGAINWaitWritable;
     /* same as IO::EAGAINWaitWritable */
     rb_define_const(rb_cIO, "EWOULDBLOCKWaitWritable", rb_eEAGAINWaitWritable);
 #else

marshal.c

@@ -99,7 +99,7 @@ shortlen(size_t len, BDIGIT *ds)
 #define TYPE_LINK	'@'
 
 static ID s_dump, s_load, s_mdump, s_mload;
-static ID s_dump_data, s_load_data, s_alloc, s_call;
+static ID s_dump_data, s_load_data, s_call;
 static ID s_getbyte, s_read, s_write, s_binmode;
 static ID s_encoding_short, s_ruby2_keywords_flag;
 #define s_encoding_long rb_id_encoding()
@@ -110,7 +110,6 @@ static ID s_encoding_short, s_ruby2_keywords_flag;
 #define name_s_mload	"marshal_load"
 #define name_s_dump_data "_dump_data"
 #define name_s_load_data "_load_data"
-#define name_s_alloc	"_alloc"
 #define name_s_call	"call"
 #define name_s_getbyte	"getbyte"
 #define name_s_read	"read"
@@ -2577,7 +2576,6 @@ Init_marshal(void)
     set_id(s_mload);
     set_id(s_dump_data);
     set_id(s_load_data);
-    set_id(s_alloc);
     set_id(s_call);
     set_id(s_getbyte);
     set_id(s_read);

rational.c

@@ -53,8 +53,7 @@ RBIMPL_WARNING_POP()
 
 VALUE rb_cRational;
 
-static ID id_abs, id_integer_p,
-    id_i_num, id_i_den;
+static ID id_abs, id_i_num, id_i_den;
 
 #define id_idiv idDiv
 #define id_to_i idTo_i
@@ -2769,7 +2768,6 @@ Init_Rational(void)
 {
     VALUE compat;
     id_abs = rb_intern_const("abs");
-    id_integer_p = rb_intern_const("integer?");
     id_i_num = rb_intern_const("@numerator");
     id_i_den = rb_intern_const("@denominator");
 

regparse.c

@@ -114,6 +114,7 @@ extern void onig_set_warn_func(OnigWarnFunc f)
 extern void onig_set_verb_warn_func(OnigWarnFunc f)
 {
   onig_verb_warn = f;
+  (void)onig_verb_warn;
 }
 
 static void CC_DUP_WARN(ScanEnv *env, OnigCodePoint from, OnigCodePoint to);

scheduler.c

@@ -30,7 +30,9 @@ static ID id_unblock;
 
 static ID id_yield;
 
+#ifdef FIBER_SCHEDULER_CALL_TIMEOUT_AFTER
 static ID id_timeout_after;
+#endif
 static ID id_kernel_sleep;
 static ID id_process_wait;
 
@@ -314,7 +316,9 @@ Init_Fiber_Scheduler(void)
     id_unblock = rb_intern_const("unblock");
     id_yield = rb_intern_const("yield");
 
+#ifdef FIBER_SCHEDULER_CALL_TIMEOUT_AFTER
     id_timeout_after = rb_intern_const("timeout_after");
+#endif
     id_kernel_sleep = rb_intern_const("kernel_sleep");
     id_process_wait = rb_intern_const("process_wait");
 
@@ -555,7 +559,7 @@ rb_fiber_scheduler_yield(VALUE scheduler)
     return rb_fiber_scheduler_kernel_sleep(scheduler, RB_INT2NUM(0));
 }
 
-#if 0
+#ifdef FIBER_SCHEDULER_CALL_TIMEOUT_AFTER
 /*
  *  Document-method: Fiber::Scheduler#timeout_after
  *  call-seq: timeout_after(duration, exception_class, *exception_arguments, &block) -> result of block