We need to preserve the type of the pointer to the structure, f.ex.
when a global structure is returned.
This is not a perfect solution. Registers loaded in the first iteration
might be overwritten in a following iteration as the register is no
longer on vtop. This is not a problem for ARM32 as gfunc_sret returns
a maximum of 1 in the integer case.
TinyCC miscompiled
void g(int,...);
void f(void)
{
char b[4000];
g(1, 2, 3, 4, b);
}
in two ways:
1. It didn't align the stack to 8 bytes before the call
2. It added sizeof(b) to the stack pointer after the call
TinyCC fails to link correctly to libraries when both R_ARM_PLT32 and
R_ARM_GOT32 relocation to a same symbol exist (see
http://lists.nongnu.org/archive/html/tinycc-devel/2010-05/msg00032.html
for more details).
The patch marks all undefined weak symbols found in external libraries
as strong. The value of all remaining weak symbols is set to zero just
before the section is output.
Note by Thomas Preud'homme: it's been 2 months in Debian without any new
bug report, hence commiting.
The loop constructs to iterate over the non-overlapping, even
positions of two or three bytes in a word were broken.
This patch fixes the loops. It has been verified to generate the
72 combinations for two and the 80 combinations for three bytes.
nocode_wanted can't be used to enforce constant expressions, as it is
set f.ex. by __builtin_constant_p.
A null pointer is unequal to a pointer to any object or function.
Assuming symbols always point to memory, a symbol+constant cast to bool
is always true.
Casting of constants was done only inside functions.
I restructured the code and used intermediate types (long double/long long)
for most conversions to have less ifs.
Please review.
There are lots of cases to take care of and lots of mistakes to make.
The return type of a statement expression (a GCC extention) may
involve elements on the symbol stack that have been put there by
the expression. These will be freed at the end of the expression
so that the calling block can not use them.
Contrary to the comment (written in 2003), this bug no longer shows
up in Valgrind, as freed symbols are now put onto a stack for later
reuse.
The ISO C draft allow only signed/unsigned int and _Bool as base type
for bitfields. TinyCC ever since allowed a wider range of types, but
there were many bugs that shifted values when they shouldn't, etc..
The patch introduces a restriction to the layout of bitfields with
mixed types that makes it incompatible with GCC. In
struct {
typeA x:1;
typeB y:1;
};
y is combined with x in the same byte iff typeA is typeB (neglecting
signedness). This is done to avoid alignment issues and exceeding the
width of typeA.
TinyCC sometimes has problems to evaluate constant expressions at
compile time. This leads to code being generated outside of functions.
Without this patch some of these bugs are not caught, because
cur_text_section still points to the section of the last function.
Before the first function cur_text_section is uninitialized.
Setting cur_text_section to a null pointer should make TinyCC die in
all cases.
long long a();
long long b() {
return a();
}
At the end of b there will be some useless register shuffling.
This is because return wants to have the result of a in REG_IRET.
gv checks if this is the case for BOTH registers of the long long.
After this test it uses REG_LRET for the second register if the
first is supposed to be REG_IRET. In other cases it uses RC_INT.
The patch compares the second register against the class it will
have in the end instead of the register class the first register
will have.
At this point I would like to remind those who pick up the patches
that there are two other mails by me with uncommitted fixes:
http://lists.gnu.org/archive/html/tinycc-devel/2003-10/msg00044.htmlhttp://lists.gnu.org/archive/html/tinycc-devel/2008-08/msg00007.html
Daniel
This patch adds a switch --with-libgcc to configure.
When passed it prevents libtcc1.a from being built and links to
/lib/libgcc_s.so.1 instead of PREFIX/lib/tcc/libtcc1.a.
It will work on ARM when using libgcc from GCC >= 4.2.0.
Prior versions don't have the __floatun[sd]i[sdx]f functions.
It won't work on i386 because of two missing symbols emitted when
floats are cast to integers, but users can provide those symbols
(global short constants) in their code if needed.
Daniel
This patch is useful for cross compilers. Without this patch tcc
tries to use the host's libraries, crt*.o and include files.
The patch prepends a string to all default paths. The string can
be passed to configure with --sysroot=string.
Daniel
- Builds all four possible ARM targets when cross compiling
- Adds some auto detection to select the target for native ARM builds
The auto detection will select EABI if it finds /lib/ld-linux.so.3.
It will select VFP floating point support when /proc/cpuinfo lists
a VFP or iWMMXt coprocessor. Intel Wireless MMX does not imply VFP,
but it conflicts with FPA, so VFP is the only choice (apart from
yet unsupported soft-float).
Daniel
Yesterday I felt the urge to change a few things in TinyCC.
This is the first and biggest change of all of them.
- use __aeabi_*divmod functions in ARM EABI to make binaries depend
solely on standardized library functions
- refactor ARM floating point <-> integer conversion a bit
- rename long long->float and shift library functions to correspond to
the names used by GCC
- compile more tokens conditionally to reduce the size of TinyCC
The intention is primarily to allow users of the ARM target to use
libgcc (which is usually available as a shared library) instead of
libtcc1 (which can't be compiled for ARM due to lack of an inline
assembler).
Changing the EABI target to use the divmod functions in theory allows
to use it without libtcc1 on any (not necessarily GCC based) ARM EABI
system.
Daniel
Daniel Glöckner