Before the build system used something like
echo "int main(){} void _exit(int n) {(void)n;while(1);}" | LC_ALL=C $(LINK) -xc - -o /dev/null -lc -Wall -Wextra -pedantic <FLAGS_TO_TEST>
to check for flags supported by the compiler (used as linker frontend).
This however no longer works with newlib 4.3.0, which requires the
symbols `_sbrk_r`, `_close_r`, `_lseek_r`, `_read_r`, and `_write_r` to
be present. Instead, now a new file `minimal_linkable.c` was added that
adds all the missing symbols and is used in the linker feature tests
instead.
Modern binutils complain about segments with RWX permissions. While
this is indeed a bad habit, RIOT ignores segments permissions anyway.
(We do have a `mpu_noexec_ram` module to disable execution of all of
RAM, which would do so regardless of the segment permission.) So for
now, we can safely just disable the warning.
This fixes:
/usr/lib/gcc/arm-none-eabi/12.2.0/../../../../arm-none-eabi/bin/ld: warning: /home/maribu/Repos/software/RIOT/examples/default/bin/nucleo-f767zi/default.elf has a LOAD segment with RWX permissions
collect2: error: ld returned 1 exit status
The test for the requirement of disabling wchar_t size warnings assumed
that $(CC) is used for linking, instead of $(LINK). With GCC $(LINK)
and $(CC) happen to be (in most cases) identical, but with LLVM they
are not. This results in issues with compiling with LLVM.
This is a regression which was introduced in #16114, without resetting
the color the red color will be used for all following text written to
the terminal and will also cause the shell prompt etc. pp. to be colored
in red which is undesirable. This commit fixes this regression by using
the ANSI escape sequences to reset the color after the error message has
been written.
This makes RIOT use the integer-only printf/scanf code by default and
includes a new make parameter to select the full floating point
version. This saves about 6kB of text space when building hello-world
for the microbit board.
Signed-off-by: Keith Packard <keithp@keithp.com>
----
v2:
Use USEMODULE=printf_float instead of separate parameter
Support for picolibc as alternative libc implementation is added with
this commit. For now only cortex-m CPU's are supported.
Enable via PICOLIBC=1
---
v2:
squash fixes in
v3:
Remove picolibc integer printf/scanf stuff from sys/Makefile.include,
it gets set in makefiles/libc/picolibc.mk
fixup for dependency
