aclocal.m4

   1 dnl grub_ASM_USCORE checks if C symbols get an underscore after
   2 dnl compiling to assembler.
   3 dnl Written by Pavel Roskin. Based on grub_ASM_EXT_C written by
   4 dnl Erich Boleyn and modified by Yoshinori K. Okuji.
   5 AC_DEFUN(grub_ASM_USCORE,
   6 [AC_REQUIRE([AC_PROG_CC])
   7 AC_MSG_CHECKING([if C symbols get an underscore after compilation])
   8 AC_CACHE_VAL(grub_cv_asm_uscore,
   9 [cat > conftest.c <<\EOF
  10 int
  11 func (int *list)
  12 {
  13   *list = 0;
  14   return *list;
  15 }
  16 EOF
  17
  18 if AC_TRY_COMMAND([${CC-cc} ${CFLAGS} -S conftest.c]) && test -s conftest.s; then
  19   true
  20 else
  21   AC_MSG_ERROR([${CC-cc} failed to produce assembly code])
  22 fi
  23
  24 if grep _func conftest.s >/dev/null 2>&1; then
  25   grub_cv_asm_uscore=yes
  26 else
  27   grub_cv_asm_uscore=no
  28 fi
  29
  30 rm -f conftest*])
  31
  32 if test "x$grub_cv_asm_uscore" = xyes; then
  33   AC_DEFINE_UNQUOTED([HAVE_ASM_USCORE], $grub_cv_asm_uscore,
  34     [Define if C symbols get an underscore after compilation])
  35 fi
  36
  37 AC_MSG_RESULT([$grub_cv_asm_uscore])
  38 ])
  39
  40
  41 dnl Some versions of `objcopy -O binary' vary their output depending
  42 dnl on the link address.
  43 AC_DEFUN(grub_PROG_OBJCOPY_ABSOLUTE,
  44 [AC_MSG_CHECKING([whether ${OBJCOPY} works for absolute addresses])
  45 AC_CACHE_VAL(grub_cv_prog_objcopy_absolute,
  46 [cat > conftest.c <<\EOF
  47 void
  48 cmain (void)
  49 {
  50    *((int *) 0x1000) = 2;
  51 }
  52 EOF
  53
  54 if AC_TRY_EVAL(ac_compile) && test -s conftest.o; then :
  55 else
  56   AC_MSG_ERROR([${CC-cc} cannot compile C source code])
  57 fi
  58 grub_cv_prog_objcopy_absolute=yes
  59 for link_addr in 2000 8000 7C00; do
  60   if AC_TRY_COMMAND([${CC-cc} ${CFLAGS} -nostdlib -Wl,-N -Wl,-Ttext -Wl,$link_addr conftest.o -o conftest.exec]); then :
  61   else
  62     AC_MSG_ERROR([${CC-cc} cannot link at address $link_addr])
  63   fi
  64   if AC_TRY_COMMAND([${OBJCOPY-objcopy} -O binary conftest.exec conftest]); then :
  65   else
  66     AC_MSG_ERROR([${OBJCOPY-objcopy} cannot create binary files])
  67   fi
  68   if test ! -f conftest.old || AC_TRY_COMMAND([cmp -s conftest.old conftest]); then
  69     mv -f conftest conftest.old
  70   else
  71     grub_cv_prog_objcopy_absolute=no
  72     break
  73   fi
  74 done
  75 rm -f conftest*])
  76 AC_MSG_RESULT([$grub_cv_prog_objcopy_absolute])
  77
  78 if test "x$grub_cv_prog_objcopy_absolute" = xno; then
  79   AC_MSG_ERROR([GRUB requires a working absolute objcopy; upgrade your binutils])
  80 fi
  81 ])
  82
  83
  84 dnl Mass confusion!
  85 dnl Older versions of GAS interpret `.code16' to mean ``generate 32-bit
  86 dnl instructions, but implicitly insert addr32 and data32 bytes so
  87 dnl that the code works in real mode''.
  88 dnl
  89 dnl Newer versions of GAS interpret `.code16' to mean ``generate 16-bit
  90 dnl instructions,'' which seems right.  This requires the programmer
  91 dnl to explicitly insert addr32 and data32 instructions when they want
  92 dnl them.
  93 dnl
  94 dnl We only support the newer versions, because the old versions cause
  95 dnl major pain, by requiring manual assembly to get 16-bit instructions into
  96 dnl asm files.
  97 AC_DEFUN(grub_I386_ASM_ADDR32,
  98 [AC_REQUIRE([AC_PROG_CC])
  99 AC_REQUIRE([grub_I386_ASM_PREFIX_REQUIREMENT])
 100 AC_MSG_CHECKING([for .code16 addr32 assembler support])
 101 AC_CACHE_VAL(grub_cv_i386_asm_addr32,
 102 [cat > conftest.s.in <<\EOF
 103         .code16
 104 l1:     @ADDR32@        movb    %al, l1
 105 EOF
 106
 107 if test "x$grub_cv_i386_asm_prefix_requirement" = xyes; then
 108   sed -e s/@ADDR32@/addr32/ < conftest.s.in > conftest.s
 109 else
 110   sed -e s/@ADDR32@/addr32\;/ < conftest.s.in > conftest.s
 111 fi
 112
 113 if AC_TRY_COMMAND([${CC-cc} ${CFLAGS} -c conftest.s]) && test -s conftest.o; then
 114   grub_cv_i386_asm_addr32=yes
 115 else
 116   grub_cv_i386_asm_addr32=no
 117 fi
 118
 119 rm -f conftest*])
 120
 121 AC_MSG_RESULT([$grub_cv_i386_asm_addr32])])
 122
 123
 124 dnl Later versions of GAS requires that addr32 and data32 prefixes
 125 dnl appear in the same lines as the instructions they modify, while
 126 dnl earlier versions requires that they appear in separate lines.
 127 AC_DEFUN(grub_I386_ASM_PREFIX_REQUIREMENT,
 128 [AC_REQUIRE([AC_PROG_CC])
 129 AC_MSG_CHECKING(dnl
 130 [whether addr32 must be in the same line as the instruction])
 131 AC_CACHE_VAL(grub_cv_i386_asm_prefix_requirement,
 132 [cat > conftest.s <<\EOF
 133         .code16
 134 l1:     addr32  movb    %al, l1
 135 EOF
 136
 137 if AC_TRY_COMMAND([${CC-cc} ${CFLAGS} -c conftest.s]) && test -s conftest.o; then
 138   grub_cv_i386_asm_prefix_requirement=yes
 139 else
 140   grub_cv_i386_asm_prefix_requirement=no
 141 fi
 142
 143 rm -f conftest*])
 144
 145 if test "x$grub_cv_i386_asm_prefix_requirement" = xyes; then
 146   grub_tmp_addr32="addr32"
 147   grub_tmp_data32="data32"
 148 else
 149   grub_tmp_addr32="addr32;"
 150   grub_tmp_data32="data32;"
 151 fi
 152
 153 AC_DEFINE_UNQUOTED([ADDR32], $grub_tmp_addr32,
 154   [Define it to \"addr32\" or \"addr32;\" to make GAS happy])
 155 AC_DEFINE_UNQUOTED([DATA32], $grub_tmp_data32,
 156   [Define it to \"data32\" or \"data32;\" to make GAS happy])
 157
 158 AC_MSG_RESULT([$grub_cv_i386_asm_prefix_requirement])])
 159
 160
 161 dnl Older versions of GAS require that absolute indirect calls/jumps are
 162 dnl not prefixed with `*', while later versions warn if not prefixed.
 163 AC_DEFUN(grub_I386_ASM_ABSOLUTE_WITHOUT_ASTERISK,
 164 [AC_REQUIRE([AC_PROG_CC])
 165 AC_MSG_CHECKING(dnl
 166 [whether an absolute indirect call/jump must not be prefixed with an asterisk])
 167 AC_CACHE_VAL(grub_cv_i386_asm_absolute_without_asterisk,
 168 [cat > conftest.s <<\EOF
 169         lcall   *(offset)
 170 offset:
 171         .long   0
 172         .word   0
 173 EOF
 174
 175 if AC_TRY_COMMAND([${CC-cc} ${CFLAGS} -c conftest.s]) && test -s conftest.o; then
 176   grub_cv_i386_asm_absolute_without_asterisk=no
 177 else
 178   grub_cv_i386_asm_absolute_without_asterisk=yes
 179 fi
 180
 181 rm -f conftest*])
 182
 183 if test "x$grub_cv_i386_asm_absolute_without_asterisk" = xyes; then
 184   AC_DEFINE([ABSOLUTE_WITHOUT_ASTERISK], 1,
 185             [Define it if GAS requires that absolute indirect calls/jumps are not prefixed with an asterisk])
 186 fi
 187
 188 AC_MSG_RESULT([$grub_cv_i386_asm_absolute_without_asterisk])])
 189
 190
 191 dnl Check what symbol is defined as a start symbol.
 192 dnl Written by Yoshinori K. Okuji.
 193 AC_DEFUN(grub_CHECK_START_SYMBOL,
 194 [AC_REQUIRE([AC_PROG_CC])
 195 AC_MSG_CHECKING([if start is defined by the compiler])
 196 AC_CACHE_VAL(grub_cv_check_start_symbol,
 197 [AC_TRY_LINK([], [asm ("incl start")],
 198    grub_cv_check_start_symbol=yes,
 199    grub_cv_check_start_symbol=no)])
 200
 201 AC_MSG_RESULT([$grub_cv_check_start_symbol])
 202
 203 AC_MSG_CHECKING([if _start is defined by the compiler])
 204 AC_CACHE_VAL(grub_cv_check_uscore_start_symbol,
 205 [AC_TRY_LINK([], [asm ("incl _start")],
 206    grub_cv_check_uscore_start_symbol=yes,
 207    grub_cv_check_uscore_start_symbol=no)])
 208
 209 AC_MSG_RESULT([$grub_cv_check_uscore_start_symbol])
 210
 211 AH_TEMPLATE([START_SYMBOL], [Define it to either start or _start])
 212
 213 if test "x$grub_cv_check_start_symbol" = xyes; then
 214   AC_DEFINE([START_SYMBOL], [start])
 215 elif test "x$grub_cv_check_uscore_start_symbol" = xyes; then
 216   AC_DEFINE([START_SYMBOL], [_start])
 217 else
 218   AC_MSG_ERROR([neither start nor _start is defined])
 219 fi
 220 ])
 221
 222 dnl Check what symbol is defined as a bss start symbol.
 223 dnl Written by Michael Hohmoth and Yoshinori K. Okuji.
 224 AC_DEFUN(grub_CHECK_BSS_START_SYMBOL,
 225 [AC_REQUIRE([AC_PROG_CC])
 226 AC_MSG_CHECKING([if __bss_start is defined by the compiler])
 227 AC_CACHE_VAL(grub_cv_check_uscore_uscore_bss_start_symbol,
 228 [AC_TRY_LINK([], [asm ("incl __bss_start")],
 229    grub_cv_check_uscore_uscore_bss_start_symbol=yes,
 230    grub_cv_check_uscore_uscore_bss_start_symbol=no)])
 231
 232 AC_MSG_RESULT([$grub_cv_check_uscore_uscore_bss_start_symbol])
 233
 234 AC_MSG_CHECKING([if edata is defined by the compiler])
 235 AC_CACHE_VAL(grub_cv_check_edata_symbol,
 236 [AC_TRY_LINK([], [asm ("incl edata")],
 237    grub_cv_check_edata_symbol=yes,
 238    grub_cv_check_edata_symbol=no)])
 239
 240 AC_MSG_RESULT([$grub_cv_check_edata_symbol])
 241
 242 AC_MSG_CHECKING([if _edata is defined by the compiler])
 243 AC_CACHE_VAL(grub_cv_check_uscore_edata_symbol,
 244 [AC_TRY_LINK([], [asm ("incl _edata")],
 245    grub_cv_check_uscore_edata_symbol=yes,
 246    grub_cv_check_uscore_edata_symbol=no)])
 247
 248 AC_MSG_RESULT([$grub_cv_check_uscore_edata_symbol])
 249
 250 AH_TEMPLATE([BSS_START_SYMBOL], [Define it to one of __bss_start, edata and _edata])
 251
 252 if test "x$grub_cv_check_uscore_uscore_bss_start_symbol" = xyes; then
 253   AC_DEFINE([BSS_START_SYMBOL], [__bss_start])
 254 elif test "x$grub_cv_check_edata_symbol" = xyes; then
 255   AC_DEFINE([BSS_START_SYMBOL], [edata])
 256 elif test "x$grub_cv_check_uscore_edata_symbol" = xyes; then
 257   AC_DEFINE([BSS_START_SYMBOL], [_edata])
 258 else
 259   AC_MSG_ERROR([none of __bss_start, edata or _edata is defined])
 260 fi
 261 ])
 262
 263 dnl Check what symbol is defined as an end symbol.
 264 dnl Written by Yoshinori K. Okuji.
 265 AC_DEFUN(grub_CHECK_END_SYMBOL,
 266 [AC_REQUIRE([AC_PROG_CC])
 267 AC_MSG_CHECKING([if end is defined by the compiler])
 268 AC_CACHE_VAL(grub_cv_check_end_symbol,
 269 [AC_TRY_LINK([], [asm ("incl end")],
 270    grub_cv_check_end_symbol=yes,
 271    grub_cv_check_end_symbol=no)])
 272
 273 AC_MSG_RESULT([$grub_cv_check_end_symbol])
 274
 275 AC_MSG_CHECKING([if _end is defined by the compiler])
 276 AC_CACHE_VAL(grub_cv_check_uscore_end_symbol,
 277 [AC_TRY_LINK([], [asm ("incl _end")],
 278    grub_cv_check_uscore_end_symbol=yes,
 279    grub_cv_check_uscore_end_symbol=no)])
 280
 281 AC_MSG_RESULT([$grub_cv_check_uscore_end_symbol])
 282
 283 AH_TEMPLATE([END_SYMBOL], [Define it to either end or _end])
 284
 285 if test "x$grub_cv_check_end_symbol" = xyes; then
 286   AC_DEFINE([END_SYMBOL], [end])
 287 elif test "x$grub_cv_check_uscore_end_symbol" = xyes; then
 288   AC_DEFINE([END_SYMBOL], [_end])
 289 else
 290   AC_MSG_ERROR([neither end nor _end is defined])
 291 fi
 292 ])
 293
 294 dnl Check if the C compiler has a bug while using nested functions when
 295 dnl mregparm is used on the i386.  Some gcc versions do not pass the third
 296 dnl parameter correctly to the nested function.
 297 dnl Written by Marco Gerards.
 298 AC_DEFUN(grub_I386_CHECK_REGPARM_BUG,
 299 [AC_REQUIRE([AC_PROG_CC])
 300 AC_MSG_CHECKING([if GCC has the regparm=3 bug])
 301 AC_CACHE_VAL(grub_cv_i386_check_nested_functions,
 302 [AC_RUN_IFELSE([AC_LANG_SOURCE(
 303 [[
 304 static int
 305 test (int *n)
 306 {
 307   return *n == -1;
 308 }
 309
 310 static int
 311 testfunc (int __attribute__ ((__regparm__ (3))) (*hook) (int a, int b, int *c))
 312 {
 313   int a = 0;
 314   int b = 0;
 315   int c = -1;
 316   return hook (a, b, &c);
 317 }
 318
 319 int
 320 main (void)
 321 {
 322   int __attribute__ ((__regparm__ (3))) nestedfunc (int a, int b, int *c)
 323     {
 324       return a == b && test (c);
 325     }
 326   return testfunc (nestedfunc) ? 0 : 1;
 327 }
 328 ]])],
 329         [grub_cv_i386_check_nested_functions=no],
 330         [grub_cv_i386_check_nested_functions=yes])])
 331
 332 AC_MSG_RESULT([$grub_cv_i386_check_nested_functions])
 333
 334 if test "x$grub_cv_i386_check_nested_functions" = xyes; then
 335   AC_DEFINE([NESTED_FUNC_ATTR],
 336         [__attribute__ ((__regparm__ (2)))],
 337         [Catch gcc bug])
 338 else
 339 dnl Unfortunately, the above test does not detect a bug in gcc-4.0.
 340 dnl So use regparm 2 until a better test is found.
 341   AC_DEFINE([NESTED_FUNC_ATTR],
 342         [__attribute__ ((__regparm__ (2)))],
 343         [Catch gcc bug])
 344 fi
 345 ])