linux-bl808/scripts
Masahiro Yamada 6f9ac9f442 fixdep: check return value of printf() and putchar()
When there is not enough space on your storage device, the build will
fail with 'No space left on device' error message.

The reason is obvious from the message, so you will free up some disk
space, then you will resume the build.

However, sometimes you may still see a mysterious error message:

  unterminated call to function 'wildcard': missing ')'.

If you run out of the disk space, fixdep may end up with generating
incomplete .*.cmd files.

For example, if the disk-full error occurs while fixdep is running
print_dep(), the .*.cmd might be truncated like this:

   $(wildcard include/config/

When you run 'make' next time, this broken .*.cmd will be included,
then Make will terminate parsing since it is a wrong syntax.

Once this happens, you need to run 'make clean' or delete the broken
.*.cmd file manually.

Even if you do not see any error message, the .*.cmd files after any
error could be potentially incomplete, and unreliable. You may miss
the re-compilation due to missing header dependency.

If printf() cannot output the string for disk shortage or whatever
reason, it returns a negative value, but currently fixdep does not
check it at all. Consequently, fixdep *successfully* generates a
broken .*.cmd file. Make never notices that since fixdep exits with 0,
which means success.

Given the intended usage of fixdep, it must respect the return value
of not only malloc(), but also printf() and putchar().

This seems a long-standing issue since the introduction of fixdep.

In old days, Kbuild tried to provide an extra safety by letting fixdep
output to a temporary file and renaming it after everything is done:

  scripts/basic/fixdep $(depfile) $@ '$(make-cmd)' > $(dot-target).tmp;\
  rm -f $(depfile);                                                    \
  mv -f $(dot-target).tmp $(dot-target).cmd)

It was no help to avoid the current issue; fixdep successfully created
a truncated tmp file, which would be renamed to a .*.cmd file.

This problem should be fixed by propagating the error status to the
build system because:

[1] Since commit 9c2af1c737 ("kbuild: add .DELETE_ON_ERROR special
    target"), Make will delete the target automatically on any failure
    in the recipe.

[2] Since commit 392885ee82 ("kbuild: let fixdep directly write to
    .*.cmd files"), .*.cmd file is included only when the corresponding
    target already exists.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-07-01 10:30:39 +09:00
..
atomic
basic fixdep: check return value of printf() and putchar() 2019-07-01 10:30:39 +09:00
coccinelle
dtc
gcc-plugins
gdb
genksyms genksyms: Teach parser about 128-bit built-in types 2019-06-24 03:43:03 +09:00
kconfig
ksymoops
mod
package kbuild: deb-pkg: do not run headers_check 2019-06-15 19:57:02 +09:00
selinux
tracing
.gitignore
adjust_autoksyms.sh
asn1_compiler.c
bin2c.c
bloat-o-meter
bootgraph.pl
bpf_helpers_doc.py
cc-can-link.sh
check_extable.sh
checkincludes.pl
checkkconfigsymbols.py
checkpatch.pl
checkstack.pl
checksyscalls.sh
checkversion.pl
clang-version.sh
cleanfile
cleanpatch
coccicheck
config
conmakehash.c
const_structs.checkpatch
decode_stacktrace.sh
decodecode
depmod.sh
diffconfig
documentation-file-ref-check
export_report.pl
extract-cert.c
extract-ikconfig
extract-module-sig.pl
extract-sys-certs.pl
extract-vmlinux
extract_xc3028.pl
faddr2line
file-size.sh
find-unused-docs.sh
gcc-goto.sh
gcc-ld
gcc-plugin.sh
gcc-version.sh
gcc-x86_32-has-stack-protector.sh
gcc-x86_64-has-stack-protector.sh
gen_compile_commands.py
gen_ksymdeps.sh
get_dvb_firmware
get_maintainer.pl
gfp-translate
headerdep.pl
headers_check.pl
headers_install.sh kbuild: simplify scripts/headers_install.sh 2019-06-15 19:57:02 +09:00
insert-sys-cert.c
kallsyms.c
Kbuild.include kbuild: save $(strip ...) for calling if_changed and friends 2019-07-01 10:03:40 +09:00
Kconfig.include
kernel-doc
ld-version.sh
leaking_addresses.pl
Lindent
link-vmlinux.sh
Makefile kbuild: remove build_unifdef target in scripts/Makefile 2019-06-15 19:57:01 +09:00
Makefile.asm-generic
Makefile.build kbuild: add support for ensuring headers are self-contained 2019-06-15 19:57:02 +09:00
Makefile.clean
Makefile.dtbinst
Makefile.extrawarn kbuild: Remove unnecessary -Wno-unused-value 2019-06-24 03:43:03 +09:00
Makefile.gcc-plugins
Makefile.headersinst kbuild: fix 'No such file or directory' warning for headers_install 2019-06-24 03:43:03 +09:00
Makefile.host
Makefile.kasan
Makefile.kcov
Makefile.lib kbuild: add support for ensuring headers are self-contained 2019-06-15 19:57:02 +09:00
Makefile.modbuiltin
Makefile.modinst
Makefile.modpost
Makefile.modsign
Makefile.ubsan
makelst
markup_oops.pl
mkcompile_h
mkmakefile
mksysmap
mkuboot.sh
module-common.lds
modules-check.sh
namespace.pl
objdiff
parse-maintainers.pl
patch-kernel
pnmtologo.c
profile2linkerlist.pl
prune-kernel
recordmcount.c
recordmcount.h
recordmcount.pl
setlocalversion
show_delta
sign-file.c
sortextable.c
sortextable.h
spdxcheck-test.sh
spdxcheck.py
spelling.txt
sphinx-pre-install
split-man.pl
stackdelta
stackusage
subarch.include
tags.sh
unifdef.c
ver_linux
xen-hypercalls.sh
xz_wrap.sh