[Bug other/109522] New: Spurious "cc1: error: no include path in which to search for stdc-predef.h" building a cross compiler

[Bug other/109522] New: Spurious "cc1: error: no include path in which to search for stdc-predef.h" building a cross compiler

[xry111 at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109522

            Bug ID: 109522
           Summary: Spurious "cc1: error: no include path in which to
                    search for stdc-predef.h" building a cross compiler
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: other
          Assignee: unassigned at gcc dot gnu.org
          Reporter: xry111 at gcc dot gnu.org
  Target Milestone: ---

Build a cross compiler (with target libc not installed yet):

../gcc/configure --target=loongarch64-linux-gnu --disable-multilib
--with-system-zlib && make gcc

Then a spurious message is outputted for macro_list:

echo | /home/xry111/git-repos/gcc-la/./gcc/xgcc
-B/home/xry111/git-repos/gcc-la/./gcc/  -E -dM - | \
  sed -n -e 's/^#define \([^_][a-zA-Z0-9_]*\).*/\1/p' \
         -e 's/^#define \(_[^_A-Z][a-zA-Z0-9_]*\).*/\1/p' | \
  sort -u > tmp-macro_list
cc1: error: no include path in which to search for stdc-predef.h
/bin/sh ../../gcc/gcc/../move-if-change tmp-macro_list macro_list

Though the macro_list file is created successfully, the message can lead people
to think something is wrong.

[Bug other/109522] Spurious "cc1: error: no include path in which to search for stdc-predef.h" building a cross compiler

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109522

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu.org

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
I bet we really don't need the macros from stdc-predef.h, so perhaps we could
use -nostdinc.
stdc-predef.h currently (sometimes) predefines
__STDC_IEC_559__
__STDC_IEC_60559_BFP__
__STDC_IEC_559_COMPLEX__
__STDC_IEC_60559_COMPLEX__
__STDC_ISO_10646__
and grep doesn't find any STDC_IEC nor STDC_ISO occurrences in fixincl.

[Bug other/109522] Spurious "cc1: error: no include path in which to search for stdc-predef.h" building a cross compiler

[xry111 at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109522

--- Comment #2 from Xi Ruoyao <xry111 at gcc dot gnu.org> ---
(In reply to Jakub Jelinek from comment #1)
> I bet we really don't need the macros from stdc-predef.h, so perhaps we
> could use -nostdinc.
> stdc-predef.h currently (sometimes) predefines
> __STDC_IEC_559__
> __STDC_IEC_60559_BFP__
> __STDC_IEC_559_COMPLEX__
> __STDC_IEC_60559_COMPLEX__
> __STDC_ISO_10646__
> and grep doesn't find any STDC_IEC nor STDC_ISO occurrences in fixincl.

Yes, these macros are some sort of "modern" (stdc-predef.h was firstly added to
Glibc in 2012), and it's unlikely anyone has ever used them in a broken way
(without "__").

[Bug other/109522] Spurious "cc1: error: no include path in which to search for stdc-predef.h" building a cross compiler

[xry111 at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109522

Xi Ruoyao <xry111 at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                URL|                            |https://gcc.gnu.org/piperma
                   |                            |il/gcc-patches/2023-April/6
                   |                            |15791.html

--- Comment #3 from Xi Ruoyao <xry111 at gcc dot gnu.org> ---
Posted the patch adding -nostdinc for review.

[Bug other/109522] Spurious "cc1: error: no include path in which to search for stdc-predef.h" building a cross compiler

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109522

--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Xi Ruoyao <xry111@gcc.gnu.org>:

https://gcc.gnu.org/g:be6c13d5cef6fd9ca97dea7a6f5fbf93c51235b5

commit r14-544-gbe6c13d5cef6fd9ca97dea7a6f5fbf93c51235b5
Author: Xi Ruoyao <xry111@xry111.site>
Date:   Sat Apr 15 19:55:50 2023 +0800

    build: Use -nostdinc generating macro_list [PR109522]

    This prevents a spurious message building a cross-compiler when target
    libc is not installed yet:

        cc1: error: no include path in which to search for stdc-predef.h

    As stdc-predef.h was added to define __STDC_* macros by libc, it's
    unlikely the header will ever contain some bad definitions w/o "__"
    prefix so it should be safe.

    gcc/ChangeLog:

            PR other/109522
            * Makefile.in (s-macro_list): Pass -nostdinc to
            $(GCC_FOR_TARGET).

[Bug other/109522] Spurious "cc1: error: no include path in which to search for stdc-predef.h" building a cross compiler

[xry111 at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109522

Xi Ruoyao <xry111 at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |14.0
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |FIXED
      Known to fail|                            |13.1.0
      Known to work|                            |14.0

--- Comment #5 from Xi Ruoyao <xry111 at gcc dot gnu.org> ---
Fixed for 14.