package configuration for libffi
cflags:  
ldflags: 
libs: -lffi  

have_library: checking for ffi_call() in -lffi... -------------------- yes

"gcc -o conftest -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1/x86_64-linux -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1/ruby/backward -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1 -I.     -O3 -ggdb -Wall -Wextra -Wno-unused-parameter -Wno-parentheses -Wno-long-long -Wno-missing-field-initializers -Wpointer-arith -Wwrite-strings -Wdeclaration-after-statement -Wimplicit-function-declaration  -fPIC   conftest.c  -L. -L/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -Wl,-R/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -L.  -rdynamic -Wl,-export-dynamic      -lffi   -Wl,-R -Wl,/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -L/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -lruby  -lpthread -lrt -ldl -lcrypt -lm   -lc"
checked program was:
/* begin */
1: #include "ruby.h"
2: 
3: int main(int argc, char **argv)
4: {
5:   return 0;
6: }
/* end */

"gcc -o conftest -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1/x86_64-linux -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1/ruby/backward -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1 -I.     -O3 -ggdb -Wall -Wextra -Wno-unused-parameter -Wno-parentheses -Wno-long-long -Wno-missing-field-initializers -Wpointer-arith -Wwrite-strings -Wdeclaration-after-statement -Wimplicit-function-declaration  -fPIC   conftest.c  -L. -L/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -Wl,-R/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -L.  -rdynamic -Wl,-export-dynamic      -lffi   -Wl,-R -Wl,/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -L/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -lruby -lffi  -lffi   -lpthread -lrt -ldl -lcrypt -lm   -lc"
conftest.c: In function ‘t’:
conftest.c:6:28: warning: variable ‘p’ set but not used [-Wunused-but-set-variable]
checked program was:
/* begin */
 1: #include "ruby.h"
 2: 
 3: #include <ffi.h>
 4: 
 5: /*top*/
 6: int t() { void ((*volatile p)()); p = (void ((*)()))ffi_call; return 0; }
 7: int main(int argc, char **argv)
 8: {
 9:   if (argc > 1000000) {
10:     printf("%p", &t);
11:   }
12: 
13:   return 0;
14: }
/* end */

--------------------

have_func: checking for ffi_prep_closure()... -------------------- yes

"gcc -o conftest -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1/x86_64-linux -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1/ruby/backward -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1 -I.     -O3 -ggdb -Wall -Wextra -Wno-unused-parameter -Wno-parentheses -Wno-long-long -Wno-missing-field-initializers -Wpointer-arith -Wwrite-strings -Wdeclaration-after-statement -Wimplicit-function-declaration  -fPIC   conftest.c  -L. -L/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -Wl,-R/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -L.  -rdynamic -Wl,-export-dynamic     -lffi  -lffi   -Wl,-R -Wl,/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -L/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -lruby -lffi  -lffi   -lpthread -lrt -ldl -lcrypt -lm   -lc"
conftest.c: In function ‘t’:
conftest.c:4:53: error: ‘ffi_prep_closure’ undeclared (first use in this function)
conftest.c:4:53: note: each undeclared identifier is reported only once for each function it appears in
conftest.c:4:28: warning: variable ‘p’ set but not used [-Wunused-but-set-variable]
checked program was:
/* begin */
 1: #include "ruby.h"
 2: 
 3: /*top*/
 4: int t() { void ((*volatile p)()); p = (void ((*)()))ffi_prep_closure; return 0; }
 5: int main(int argc, char **argv)
 6: {
 7:   if (argc > 1000000) {
 8:     printf("%p", &t);
 9:   }
10: 
11:   return 0;
12: }
/* end */

"gcc -o conftest -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1/x86_64-linux -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1/ruby/backward -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1 -I.     -O3 -ggdb -Wall -Wextra -Wno-unused-parameter -Wno-parentheses -Wno-long-long -Wno-missing-field-initializers -Wpointer-arith -Wwrite-strings -Wdeclaration-after-statement -Wimplicit-function-declaration  -fPIC   conftest.c  -L. -L/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -Wl,-R/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -L.  -rdynamic -Wl,-export-dynamic     -lffi  -lffi   -Wl,-R -Wl,/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -L/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -lruby -lffi  -lffi   -lpthread -lrt -ldl -lcrypt -lm   -lc"
conftest.c: In function ‘t’:
conftest.c:4:1: warning: implicit declaration of function ‘ffi_prep_closure’ [-Wimplicit-function-declaration]
checked program was:
/* begin */
 1: #include "ruby.h"
 2: 
 3: /*top*/
 4: int t() { ffi_prep_closure(); return 0; }
 5: int main(int argc, char **argv)
 6: {
 7:   if (argc > 1000000) {
 8:     printf("%p", &t);
 9:   }
10: 
11:   return 0;
12: }
/* end */

--------------------

have_func: checking for ffi_raw_call()... -------------------- yes

"gcc -o conftest -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1/x86_64-linux -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1/ruby/backward -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1 -I.     -O3 -ggdb -Wall -Wextra -Wno-unused-parameter -Wno-parentheses -Wno-long-long -Wno-missing-field-initializers -Wpointer-arith -Wwrite-strings -Wdeclaration-after-statement -Wimplicit-function-declaration  -fPIC   conftest.c  -L. -L/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -Wl,-R/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -L.  -rdynamic -Wl,-export-dynamic     -lffi  -lffi   -Wl,-R -Wl,/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -L/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -lruby -lffi  -lffi   -lpthread -lrt -ldl -lcrypt -lm   -lc"
conftest.c: In function ‘t’:
conftest.c:4:53: error: ‘ffi_raw_call’ undeclared (first use in this function)
conftest.c:4:53: note: each undeclared identifier is reported only once for each function it appears in
conftest.c:4:28: warning: variable ‘p’ set but not used [-Wunused-but-set-variable]
checked program was:
/* begin */
 1: #include "ruby.h"
 2: 
 3: /*top*/
 4: int t() { void ((*volatile p)()); p = (void ((*)()))ffi_raw_call; return 0; }
 5: int main(int argc, char **argv)
 6: {
 7:   if (argc > 1000000) {
 8:     printf("%p", &t);
 9:   }
10: 
11:   return 0;
12: }
/* end */

"gcc -o conftest -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1/x86_64-linux -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1/ruby/backward -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1 -I.     -O3 -ggdb -Wall -Wextra -Wno-unused-parameter -Wno-parentheses -Wno-long-long -Wno-missing-field-initializers -Wpointer-arith -Wwrite-strings -Wdeclaration-after-statement -Wimplicit-function-declaration  -fPIC   conftest.c  -L. -L/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -Wl,-R/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -L.  -rdynamic -Wl,-export-dynamic     -lffi  -lffi   -Wl,-R -Wl,/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -L/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -lruby -lffi  -lffi   -lpthread -lrt -ldl -lcrypt -lm   -lc"
conftest.c: In function ‘t’:
conftest.c:4:1: warning: implicit declaration of function ‘ffi_raw_call’ [-Wimplicit-function-declaration]
checked program was:
/* begin */
 1: #include "ruby.h"
 2: 
 3: /*top*/
 4: int t() { ffi_raw_call(); return 0; }
 5: int main(int argc, char **argv)
 6: {
 7:   if (argc > 1000000) {
 8:     printf("%p", &t);
 9:   }
10: 
11:   return 0;
12: }
/* end */

--------------------

have_func: checking for ffi_prep_raw_closure()... -------------------- yes

"gcc -o conftest -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1/x86_64-linux -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1/ruby/backward -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1 -I.     -O3 -ggdb -Wall -Wextra -Wno-unused-parameter -Wno-parentheses -Wno-long-long -Wno-missing-field-initializers -Wpointer-arith -Wwrite-strings -Wdeclaration-after-statement -Wimplicit-function-declaration  -fPIC   conftest.c  -L. -L/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -Wl,-R/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -L.  -rdynamic -Wl,-export-dynamic     -lffi  -lffi   -Wl,-R -Wl,/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -L/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -lruby -lffi  -lffi   -lpthread -lrt -ldl -lcrypt -lm   -lc"
conftest.c: In function ‘t’:
conftest.c:4:53: error: ‘ffi_prep_raw_closure’ undeclared (first use in this function)
conftest.c:4:53: note: each undeclared identifier is reported only once for each function it appears in
conftest.c:4:28: warning: variable ‘p’ set but not used [-Wunused-but-set-variable]
checked program was:
/* begin */
 1: #include "ruby.h"
 2: 
 3: /*top*/
 4: int t() { void ((*volatile p)()); p = (void ((*)()))ffi_prep_raw_closure; return 0; }
 5: int main(int argc, char **argv)
 6: {
 7:   if (argc > 1000000) {
 8:     printf("%p", &t);
 9:   }
10: 
11:   return 0;
12: }
/* end */

"gcc -o conftest -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1/x86_64-linux -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1/ruby/backward -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1 -I.     -O3 -ggdb -Wall -Wextra -Wno-unused-parameter -Wno-parentheses -Wno-long-long -Wno-missing-field-initializers -Wpointer-arith -Wwrite-strings -Wdeclaration-after-statement -Wimplicit-function-declaration  -fPIC   conftest.c  -L. -L/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -Wl,-R/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -L.  -rdynamic -Wl,-export-dynamic     -lffi  -lffi   -Wl,-R -Wl,/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -L/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -lruby -lffi  -lffi   -lpthread -lrt -ldl -lcrypt -lm   -lc"
conftest.c: In function ‘t’:
conftest.c:4:1: warning: implicit declaration of function ‘ffi_prep_raw_closure’ [-Wimplicit-function-declaration]
checked program was:
/* begin */
 1: #include "ruby.h"
 2: 
 3: /*top*/
 4: int t() { ffi_prep_raw_closure(); return 0; }
 5: int main(int argc, char **argv)
 6: {
 7:   if (argc > 1000000) {
 8:     printf("%p", &t);
 9:   }
10: 
11:   return 0;
12: }
/* end */

--------------------

have_func: checking for rb_thread_blocking_region()... -------------------- yes

"gcc -o conftest -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1/x86_64-linux -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1/ruby/backward -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1 -I.     -O3 -ggdb -Wall -Wextra -Wno-unused-parameter -Wno-parentheses -Wno-long-long -Wno-missing-field-initializers -Wpointer-arith -Wwrite-strings -Wdeclaration-after-statement -Wimplicit-function-declaration  -fPIC   conftest.c  -L. -L/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -Wl,-R/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -L.  -rdynamic -Wl,-export-dynamic     -lffi  -lffi   -Wl,-R -Wl,/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -L/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -lruby -lffi  -lffi   -lpthread -lrt -ldl -lcrypt -lm   -lc"
conftest.c: In function ‘t’:
conftest.c:4:28: warning: variable ‘p’ set but not used [-Wunused-but-set-variable]
checked program was:
/* begin */
 1: #include "ruby.h"
 2: 
 3: /*top*/
 4: int t() { void ((*volatile p)()); p = (void ((*)()))rb_thread_blocking_region; return 0; }
 5: int main(int argc, char **argv)
 6: {
 7:   if (argc > 1000000) {
 8:     printf("%p", &t);
 9:   }
10: 
11:   return 0;
12: }
/* end */

--------------------

have_func: checking for rb_thread_call_with_gvl()... -------------------- yes

"gcc -o conftest -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1/x86_64-linux -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1/ruby/backward -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1 -I.     -O3 -ggdb -Wall -Wextra -Wno-unused-parameter -Wno-parentheses -Wno-long-long -Wno-missing-field-initializers -Wpointer-arith -Wwrite-strings -Wdeclaration-after-statement -Wimplicit-function-declaration  -fPIC   conftest.c  -L. -L/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -Wl,-R/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -L.  -rdynamic -Wl,-export-dynamic     -lffi  -lffi   -Wl,-R -Wl,/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -L/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -lruby -lffi  -lffi   -lpthread -lrt -ldl -lcrypt -lm   -lc"
conftest.c: In function ‘t’:
conftest.c:4:53: error: ‘rb_thread_call_with_gvl’ undeclared (first use in this function)
conftest.c:4:53: note: each undeclared identifier is reported only once for each function it appears in
conftest.c:4:28: warning: variable ‘p’ set but not used [-Wunused-but-set-variable]
checked program was:
/* begin */
 1: #include "ruby.h"
 2: 
 3: /*top*/
 4: int t() { void ((*volatile p)()); p = (void ((*)()))rb_thread_call_with_gvl; return 0; }
 5: int main(int argc, char **argv)
 6: {
 7:   if (argc > 1000000) {
 8:     printf("%p", &t);
 9:   }
10: 
11:   return 0;
12: }
/* end */

"gcc -o conftest -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1/x86_64-linux -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1/ruby/backward -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1 -I.     -O3 -ggdb -Wall -Wextra -Wno-unused-parameter -Wno-parentheses -Wno-long-long -Wno-missing-field-initializers -Wpointer-arith -Wwrite-strings -Wdeclaration-after-statement -Wimplicit-function-declaration  -fPIC   conftest.c  -L. -L/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -Wl,-R/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -L.  -rdynamic -Wl,-export-dynamic     -lffi  -lffi   -Wl,-R -Wl,/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -L/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -lruby -lffi  -lffi   -lpthread -lrt -ldl -lcrypt -lm   -lc"
conftest.c: In function ‘t’:
conftest.c:4:1: warning: implicit declaration of function ‘rb_thread_call_with_gvl’ [-Wimplicit-function-declaration]
checked program was:
/* begin */
 1: #include "ruby.h"
 2: 
 3: /*top*/
 4: int t() { rb_thread_call_with_gvl(); return 0; }
 5: int main(int argc, char **argv)
 6: {
 7:   if (argc > 1000000) {
 8:     printf("%p", &t);
 9:   }
10: 
11:   return 0;
12: }
/* end */

--------------------

have_func: checking for rb_thread_call_without_gvl()... -------------------- yes

"gcc -o conftest -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1/x86_64-linux -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1/ruby/backward -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1 -I.     -O3 -ggdb -Wall -Wextra -Wno-unused-parameter -Wno-parentheses -Wno-long-long -Wno-missing-field-initializers -Wpointer-arith -Wwrite-strings -Wdeclaration-after-statement -Wimplicit-function-declaration  -fPIC   conftest.c  -L. -L/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -Wl,-R/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -L.  -rdynamic -Wl,-export-dynamic     -lffi  -lffi   -Wl,-R -Wl,/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -L/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -lruby -lffi  -lffi   -lpthread -lrt -ldl -lcrypt -lm   -lc"
conftest.c: In function ‘t’:
conftest.c:4:53: error: ‘rb_thread_call_without_gvl’ undeclared (first use in this function)
conftest.c:4:53: note: each undeclared identifier is reported only once for each function it appears in
conftest.c:4:28: warning: variable ‘p’ set but not used [-Wunused-but-set-variable]
checked program was:
/* begin */
 1: #include "ruby.h"
 2: 
 3: /*top*/
 4: int t() { void ((*volatile p)()); p = (void ((*)()))rb_thread_call_without_gvl; return 0; }
 5: int main(int argc, char **argv)
 6: {
 7:   if (argc > 1000000) {
 8:     printf("%p", &t);
 9:   }
10: 
11:   return 0;
12: }
/* end */

"gcc -o conftest -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1/x86_64-linux -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1/ruby/backward -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1 -I.     -O3 -ggdb -Wall -Wextra -Wno-unused-parameter -Wno-parentheses -Wno-long-long -Wno-missing-field-initializers -Wpointer-arith -Wwrite-strings -Wdeclaration-after-statement -Wimplicit-function-declaration  -fPIC   conftest.c  -L. -L/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -Wl,-R/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -L.  -rdynamic -Wl,-export-dynamic     -lffi  -lffi   -Wl,-R -Wl,/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -L/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -lruby -lffi  -lffi   -lpthread -lrt -ldl -lcrypt -lm   -lc"
conftest.c: In function ‘t’:
conftest.c:4:1: warning: implicit declaration of function ‘rb_thread_call_without_gvl’ [-Wimplicit-function-declaration]
checked program was:
/* begin */
 1: #include "ruby.h"
 2: 
 3: /*top*/
 4: int t() { rb_thread_call_without_gvl(); return 0; }
 5: int main(int argc, char **argv)
 6: {
 7:   if (argc > 1000000) {
 8:     printf("%p", &t);
 9:   }
10: 
11:   return 0;
12: }
/* end */

--------------------

have_func: checking for ffi_prep_cif_var()... -------------------- yes

"gcc -o conftest -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1/x86_64-linux -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1/ruby/backward -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1 -I.     -O3 -ggdb -Wall -Wextra -Wno-unused-parameter -Wno-parentheses -Wno-long-long -Wno-missing-field-initializers -Wpointer-arith -Wwrite-strings -Wdeclaration-after-statement -Wimplicit-function-declaration  -fPIC   conftest.c  -L. -L/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -Wl,-R/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -L.  -rdynamic -Wl,-export-dynamic     -lffi  -lffi   -Wl,-R -Wl,/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -L/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -lruby -lffi  -lffi   -lpthread -lrt -ldl -lcrypt -lm   -lc"
conftest.c: In function ‘t’:
conftest.c:4:53: error: ‘ffi_prep_cif_var’ undeclared (first use in this function)
conftest.c:4:53: note: each undeclared identifier is reported only once for each function it appears in
conftest.c:4:28: warning: variable ‘p’ set but not used [-Wunused-but-set-variable]
checked program was:
/* begin */
 1: #include "ruby.h"
 2: 
 3: /*top*/
 4: int t() { void ((*volatile p)()); p = (void ((*)()))ffi_prep_cif_var; return 0; }
 5: int main(int argc, char **argv)
 6: {
 7:   if (argc > 1000000) {
 8:     printf("%p", &t);
 9:   }
10: 
11:   return 0;
12: }
/* end */

"gcc -o conftest -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1/x86_64-linux -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1/ruby/backward -I/usr/local/rvm/rubies/ruby-1.9.3-p429/include/ruby-1.9.1 -I.     -O3 -ggdb -Wall -Wextra -Wno-unused-parameter -Wno-parentheses -Wno-long-long -Wno-missing-field-initializers -Wpointer-arith -Wwrite-strings -Wdeclaration-after-statement -Wimplicit-function-declaration  -fPIC   conftest.c  -L. -L/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -Wl,-R/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -L.  -rdynamic -Wl,-export-dynamic     -lffi  -lffi   -Wl,-R -Wl,/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -L/usr/local/rvm/rubies/ruby-1.9.3-p429/lib -lruby -lffi  -lffi   -lpthread -lrt -ldl -lcrypt -lm   -lc"
conftest.c: In function ‘t’:
conftest.c:4:1: warning: implicit declaration of function ‘ffi_prep_cif_var’ [-Wimplicit-function-declaration]
checked program was:
/* begin */
 1: #include "ruby.h"
 2: 
 3: /*top*/
 4: int t() { ffi_prep_cif_var(); return 0; }
 5: int main(int argc, char **argv)
 6: {
 7:   if (argc > 1000000) {
 8:     printf("%p", &t);
 9:   }
10: 
11:   return 0;
12: }
/* end */

--------------------

extconf.h is:
/* begin */
 1: #ifndef EXTCONF_H
 2: #define EXTCONF_H
 3: #define HAVE_FFI_PREP_CLOSURE 1
 4: #define HAVE_FFI_RAW_CALL 1
 5: #define HAVE_FFI_PREP_RAW_CLOSURE 1
 6: #define HAVE_RAW_API 1
 7: #define HAVE_RB_THREAD_BLOCKING_REGION 1
 8: #define HAVE_RB_THREAD_CALL_WITH_GVL 1
 9: #define HAVE_RB_THREAD_CALL_WITHOUT_GVL 1
10: #define HAVE_FFI_PREP_CIF_VAR 1
11: #define RUBY_1_9 1
12: #endif
/* end */