Issue #24543: Use AC_LINK instead of AC_COMPILE in order to prevent false

Stefan Krah · Stefan Krah · commit e31db2a8214e · 2015-07-02T20:27:56.000+02:00
positives with the -flto option (gcc &gt;= 4.9.0 and clang).
diff --git a/configure b/configure
@@ -13397,12 +13397,13 @@ main ()
   return 0;
 }
 _ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
+if ac_fn_c_try_link "$LINENO"; then :
   have_gcc_asm_for_x64=yes
 else
   have_gcc_asm_for_x64=no
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $have_gcc_asm_for_x64" >&5
 $as_echo "$have_gcc_asm_for_x64" >&6; }
 if test "$have_gcc_asm_for_x64" = yes
@@ -13573,12 +13574,13 @@ main ()
   return 0;
 }
 _ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
+if ac_fn_c_try_link "$LINENO"; then :
   have_gcc_asm_for_x87=yes
 else
   have_gcc_asm_for_x87=no
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $have_gcc_asm_for_x87" >&5
 $as_echo "$have_gcc_asm_for_x87" >&6; }
 if test "$have_gcc_asm_for_x87" = yes
@@ -13605,12 +13607,13 @@ main ()
   return 0;
 }
 _ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
+if ac_fn_c_try_link "$LINENO"; then :
   have_gcc_asm_for_mc68881=yes
 else
   have_gcc_asm_for_mc68881=no
 fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $have_gcc_asm_for_mc68881" >&5
 $as_echo "$have_gcc_asm_for_mc68881" >&6; }
 if test "$have_gcc_asm_for_mc68881" = yes
diff --git a/configure.ac b/configure.ac
@@ -3910,7 +3910,7 @@ fi],
 # **************************************
 
 AC_MSG_CHECKING(for x64 gcc inline assembler)
-AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[
+AC_LINK_IFELSE(   [AC_LANG_PROGRAM([[]], [[
   __asm__ __volatile__ ("movq %rcx, %rax");
 ]])],[have_gcc_asm_for_x64=yes],[have_gcc_asm_for_x64=no])
 AC_MSG_RESULT($have_gcc_asm_for_x64)
@@ -4008,7 +4008,7 @@ fi
 # so we try it on all platforms.
 
 AC_MSG_CHECKING(whether we can use gcc inline assembler to get and set x87 control word)
-AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[
+AC_LINK_IFELSE(   [AC_LANG_PROGRAM([[]], [[
   unsigned short cw;
   __asm__ __volatile__ ("fnstcw %0" : "=m" (cw));
   __asm__ __volatile__ ("fldcw %0" : : "m" (cw));
@@ -4021,7 +4021,7 @@ then
 fi
 
 AC_MSG_CHECKING(whether we can use gcc inline assembler to get and set mc68881 fpcr)
-AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]], [[
+AC_LINK_IFELSE(   [AC_LANG_PROGRAM([[]], [[
   unsigned int fpcr;
   __asm__ __volatile__ ("fmove.l %%fpcr,%0" : "=g" (fpcr));
   __asm__ __volatile__ ("fmove.l %0,%%fpcr" : : "g" (fpcr));
