[Bug]: tcc unhappy about system headers

[Randrianasulu]

Problem description

installed tcc from repo, tried to change CC to it.

got:

tcc -O1 -Wall -Wextra -pedantic -Wno-unused-parameter -Wno-unused-variable -std=c99 -DNDEBUG -DINLINE=inline -DAugmentation_7ch -march=native   -Wall -c common.c -o common.o
In file included from common.c:1:                                                                  In file included from common.h:10:
In file included from /data/data/com.termux/files/usr/include/stdio.h:47:                       
   /data/data/com.termux/files/usr/include/string.h:177: error: ',' expected (got "__dst")           
 make: *** [Makefile:61: common.o] Error 1

What steps will reproduce the bug?

pkg in tcc get some simple project, try to replace cc=gcc in Makefile with cc=tcc

try make

What is the expected behavior?

tcc works

System information

termux-info:

Termux Variables:
TERMUX_API_VERSION=0.50.1
TERMUX_APK_RELEASE=F_DROID
TERMUX_APP_PACKAGE_MANAGER=apt
TERMUX_APP_PID=881
TERMUX_IS_DEBUGGABLE_BUILD=0
TERMUX_MAIN_PACKAGE_FORMAT=debian
TERMUX_VERSION=0.118.0
TERMUX__USER_ID=0
Packages CPU architecture:
aarch64
Subscribed repositories:
# sources.list
deb https://mirrors.zju.edu.cn/termux/apt/termux-main stable main
# x11-repo (sources.list.d/x11.list)
deb https://mirrors.zju.edu.cn/termux/apt/termux-x11 x11 main
# tur-repo (sources.list.d/tur.list)
deb https://tur.kcubeterm.com tur-packages tur tur-on-device tur-continuous
Updatable packages:
liborc/stable 0.4.35 aarch64 [upgradable from: 0.4.34]
termux-tools version:
1.40.5
Android version:
11
Kernel build information:
Linux localhost 4.14.193 #1 SMP PREEMPT Thu Jul 8 13:58:00 CST 2021 aarch64 Android
Device manufacturer:
DEXP
Device model:
K38
LD Variables:
LD_LIBRARY_PATH=
LD_PRELOAD=/data/data/com.termux/files/usr/lib/libtermux-exec.so
Installed termux plugins:
com.termux.api versionCode:51

[Biswa96]

This seems an issue with tcc. The following line shows where that error happened.

$ sed -n 177p /data/data/com.termux/files/usr/include/string.h
size_t strxfrm(char* __BIONIC_COMPLICATED_NULLNESS __dst, const char* _Nonnull __src, size_t __n);

And __BIONIC_COMPLICATED_NULLNESS macro is defined as

$ grep -ir "define __BIONIC_COMPLICATED_NULLNESS" /data/data/com.termux/files/usr/include/
/data/data/com.termux/files/usr/include/sys/cdefs.h:#define __BIONIC_COMPLICATED_NULLNESS _Null_unspecified

So, tcc could not recognize _Null_unspecified attribute.

[Biswa96]

Or, could you try with newer C standard. The clang docs suggests that _Null_unspecified attribute is available for c23 https://clang.llvm.org/docs/AttributeReference.html#null-unspecified

[Randrianasulu]

@Biswa96 I do not think tcc understands anything beyound c11 (but it IS small). Wil try to raise issue upstream (tinycc git also fails for me on termux)

[licy183]

This is because the headers in ndk-sysroot is only tested with clang. _Nonnull, _Nullable and _Null_unspecified are keywords that only exist in clang. You can define them manually in $PREFIX/include/sys/cdefs.h.

#if !defined(__clang__)
#define _Nonnull
#define _Nullable
#define _Null_unspecified
#endif

[Randrianasulu]

@licy183 thanks, manually editing this file and adding those defines fixes tcc! but I guess this will be overwritten by update at some point ...

[licy183]

I have no idea whether this issue should be fixed or not. Actually ndk-sysroot is only designed for clang because NDK has dropped support for GCC.

Maybe other maintainers have something to say?

[truboxl]

Ask tcc to add the missing defines. It already got _Nonnull and _Nullable.

~/bin $ grep "define _Nonnull" -nHR $PREFIX/include
~/bin $ grep "define _Nullable" -nHR $PREFIX/include
~/bin $ echo | tcc -E -dM - | sort | grep "define _N"
#define _Nonnull
#define _Nullable

https://repo.or.cz/tinycc.git/blob/HEAD:/include/tccdefs.h#l129

#elif defined __ANDROID__
    #define  BIONIC_IOCTL_NO_SIGNEDNESS_OVERLOAD
    #define  __PRETTY_FUNCTION__ __FUNCTION__
    #define __has_builtin(x) 0
    #define __has_feature(x) 0
    #define _Nonnull
    #define _Nullable