tinycc/TODO

TODO list:

Bugs:

- i386 fastcall is mostly wrong
- FPU st(0) is left unclean (kwisatz haderach). Incompatible with
  optimized gcc/msc code
- see transparent union pb in /urs/include/sys/socket.h
- precise behaviour of typeof with arrays ? (__put_user macro)
  but should suffice for most cases)
- handle '? x, y : z' in unsized variable initialization (',' is
  considered incorrectly as separator in preparser)
- transform functions to function pointers in function parameters
  (net/ipv4/ip_output.c)
- fix function pointer type display
- check section alignment in C
- fix invalid cast in comparison 'if (v == (int8_t)v)'
- finish varargs.h support (gcc 3.2 testsuite issue)
- fix static functions declared inside block
- fix multiple unions init
- make libtcc fully reentrant (except for the compilation stage itself).
- struct/union/enum definitions in nested scopes (see also Debian bug #770657)
- __STDC_IEC_559__: float f(void) { static float x = 0.0 / 0.0; return x; }
- memory may be leaked after errors (longjmp).

Portability:

- it is assumed that int is 32-bit and sizeof(int) == 4
- int is used when host or target size_t would make more sense
- TCC handles target floating-point (fp) values using the host's fp
  arithmetic, which is simple and fast but may lead to exceptions
  and inaccuracy and wrong representations when cross-compiling

Linking:

- static linking (-static) does not work

Bound checking:

- fix bound exit on RedHat 7.3
- setjmp is not supported properly in bound checking.
- fix bound check code with '&' on local variables (currently done
  only for local arrays).
- bound checking and float/long long/struct copy code. bound
  checking and symbol + offset optimization

Missing features:

- disable-asm and disable-bcheck options
- __builtin_expect()
- atexit (Nigel Horne)
- C99: add complex types (gcc 3.2 testsuite issue)
- postfix compound literals (see 20010124-1.c)
- interactive mode / integrated debugger

Optimizations:

- suppress specific anonymous symbol handling
- more parse optimizations (=even faster compilation)
- memory alloc optimizations (=even faster compilation)
- optimize VT_LOCAL + const
- better local variables handling (needed for other targets)

Not critical:

- C99: fix multiple compound literals inits in blocks (ISOC99
  normative example - only relevant when using gotos! -> must add
  boolean variable to tell if compound literal was already
  initialized).
- add PowerPC generator and improve codegen for RISC (need
  to suppress VT_LOCAL and use a base register instead).
- fix preprocessor symbol redefinition
- add portable byte code generator and interpreter for other
  unsupported architectures.
- C++: variable declaration in for, minimal 'class' support.
- win32: __intxx. use resolve for bchecked malloc et al.
  check exception code (exception filter func).
- handle void (__attribute__() *ptr)()
- VLAs are implemented in a way that is not compatible with signals:
  http://lists.gnu.org/archive/html/tinycc-devel/2015-11/msg00018.html

Fixed (probably):

- bug with defines:
    #define spin_lock(lock) do { } while (0)
    #define wq_spin_lock spin_lock
    #define TEST() wq_spin_lock(a)
- typedefs can be structure fields
- see bugfixes.diff + improvement.diff from Daniel Glockner
- long long constant evaluation
- add alloca()
- gcc '-E' option.
- #include_next support for /usr/include/limits ?
- function pointers/lvalues in ? : (linux kernel net/core/dev.c)
- win32: add __stdcall, check GetModuleHandle for dlls.
- macro substitution with nested definitions (ShangHongzhang)
- with "-run" and libtcc, a PLT is now built.
- '-E' option was improved
- packed attribute is now supported
- ARM and ARM64 code generators have been added.