Re: error linking lto1 for target avr

[Georg-Johann Lay <avr at gjlay dot de>]

Sean D'Epagnier schrieb:
> I have the latest gcc from svn, and with "configure --target=avr --enable-languages=c":
>
> When building with "make" eventually I get:
>
> gcc   -g -O2 -DIN_GCC -DCROSS_DIRECTORY_STRUCTURE  -W -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual -Wstrict-prototypes -Wmissing-prototypes -Wmissing-format-attribute -pedantic -Wno-long-long -Wno-variadic-macros -Wno-overlength-strings -Wold-style-definition -Wc++-compat -fno-common  -DHAVE_CONFIG_H  -o lto1 \
> 		lto/lto-lang.o lto/lto.o lto/lto-object.o attribs.o main.o tree-browser.o libbackend.a libcommon-target.a libcommon.a ../libcpp/libcpp.a ../libdecnumber/libdecnumber.a   -lmpc -lmpfr -lgmp -rdynamic -ldl  -L../zlib -lz libcommon.a ../libcpp/libcpp.a   ../libiberty/libiberty.a ../libdecnumber/libdecnumber.a 
> libbackend.a(avr.o): In function `avr_pgm_check_var_decl':
> /home/sean/build/gcc-svn/build-avr-nofixed/gcc/../../gcc/config/avr/avr.c:6652: undefined reference to `c_addr_space_name'
> /home/sean/build/gcc-svn/build-avr-nofixed/gcc/../../gcc/config/avr/avr.c:6649: undefined reference to `c_addr_space_name'
> libbackend.a(avr.o): In function `avr_insert_attributes':
> /home/sean/build/gcc-svn/build-avr-nofixed/gcc/../../gcc/config/avr/avr.c:6690: undefined reference to `c_addr_space_name'
> libbackend.a(avr.o): In function `avr_out_lpm':
> /home/sean/build/gcc-svn/build-avr-nofixed/gcc/../../gcc/config/avr/avr.c:2352: undefined reference to `c_addr_space_name'
> collect2: ld returned 1 exit status
>
> avr.c uses c_addr_space_name to get the names of address spaces for 
> diagnostics.  GCC's build machinery does not arrange for this symbol
> to be available when linking lto1.  If configured with --disable-lto,
> the compiler builds, but lto is unavailable.
>
> This issue is causing trouble for people building the avr toolchain,
> and will likely affect other targets as they adopt the use of
> c_addr_space_name.  Please suggest a fix.
>
> Sean

In avr.c there is:

...
#include "c-family/c-common.h"
...

/* Sanity check NODE so that all pointers targeting address space
   go along with CONST qualifier.  Writing to this address spaces should
   be detected and complained about as early as possible.  */

static bool
avr_pgm_check_var_decl (tree node)
{
  const char *reason = NULL;

  addr_space_t as = ADDR_SPACE_GENERIC;

  gcc_assert (as == 0);

  if (avr_log.progmem)
    avr_edump ("%?: %t\n", node);

  switch (TREE_CODE (node))
    {
    default:
      break;

    case VAR_DECL:
      if (as = avr_nonconst_pointer_addrspace (TREE_TYPE (node)), as)
        reason = "variable";
      break;

    case PARM_DECL:
      if (as = avr_nonconst_pointer_addrspace (TREE_TYPE (node)), as)
        reason = "function parameter";
      break;

    case FIELD_DECL:
      if (as = avr_nonconst_pointer_addrspace (TREE_TYPE (node)), as)
        reason = "structure field";
      break;

    case FUNCTION_DECL:
      if (as = avr_nonconst_pointer_addrspace (TREE_TYPE (TREE_TYPE 
(node))),
          as)
        reason = "return type of function";
      break;

    case POINTER_TYPE:
      if (as = avr_nonconst_pointer_addrspace (node), as)
        reason = "pointer";
      break;
    }

  if (reason)
    {
      if (TYPE_P (node))
        error ("pointer targeting address space %qs must be const in %qT",
               c_addr_space_name (as), node);
      else
        error ("pointer targeting address space %qs must be const in %s 
%q+D",
               c_addr_space_name (as), reason, node);
    }

  return reason == NULL;
}

Is the problem some missing dependencies in the build machinery for LTO? 
Or must target.c not call functions from c-family/c-common.h?

I configure with --disable-lto because LTO fails in canadian cross 
builds, see http://sourceware.org/PR12742

Johann