this is a bit complicated: for i386 and x86-64 we really need to
extend return values ourself, as the common code now does. For arm64
this at least preserves old behaviour. For riscv64 we don't have to
extend ourself but can expect things to be extended up to int (this
matters for var-args tests, when the sign-extension to int64 needs to
happen explicitely). As the extensions are useless, don't do them.
And for arm32 we actually can't express GCC behaviour: the callee side
expects the return value to be correctly extended to int32, but
remembers the original type. In case the ultimate target type for the
call result is only int, no further extension is done. But in case
the target type is e.g. int64 an extension happens, but not from int32
but from the original type. We don't know the ultimate target type,
so we have to choose a type to put into vtop:
* original type (plus VT_MUSTCAST) - this looses when the ultimate
target is int (GCC: no cast, TCC: a cast)
* int (without MUSTCAST) - this looses when the ultimate target is
int64 (GCC: cast from original type, TCC: cast from int)
This difference can only be seen with undefined sources, like the
testcases, so it doesn't seem worthwhile to try an make it work, just
disable the test on arm and choose the second variant as that generates
less code.
This allows adding files or libraries from
#pragma comment(option, ...)
Also, {f}/file.c will be expanded with the directory of
the current source, that is the file that has the #pragma
this is enough to let me link a tcctest.c compiled by GCC
using some current debian sid riscv64 system. It needs
linking against libgcc.a for various floating point TFmode
routines. The result runs.
- libtcc.c/tccpp.c: fix -U option for multiple input files
- libtcc: remove decl of tcc_add_crt() for PE
- tcc.h: define __i386__ and __x86_64__ for msvc
- tcc.h: undef __attribute__ for __TINYC__ on gnu/linux platforms
- tccelf.c: disable prepare_dynamic_rel unless x86/x64
- tccpe.c: construct rather than predefine PE section flags
- tccpp.c: (alt.) fix access of dead stack variable after error/longjmp
- x86_64-gen.c: fix func_alloca chain for nocode_wanted
- tccpp.c/tccgen.c: improve file:line info for inline functions
- winapi/winnt.h: correct position for DECLSPEC_ALIGN attribute
- win32/lib/crt: simplify top exception handler (needed for signal)
- arm64-gen.c: remove dprintf left from VT_CMP commit
- tccgen.c: limit binary scan with gcase to > 8 (= smaller code)
- tccgen.c: call save_regs(4) in gen_opl for cmp-ops (see test in tcctest.c)
A more automatic approach to code suppression (aka. nocode_wanted)
The simple rules are:
- Clear 'nocode_wanted' at (im/explicit) label IF it was used
- Set 'nocode_wanted' after unconditional jumps
Also in order to test this then I did add the "function might
return no value" warning, and then to make that work again I
did add the __attribute__((noreturn)).
Also moved the look ahead label check into the type parser
to gain a little speed.
there's no need for two new flags in type.t . We just can't use
VT_EXTERN as marker if functions are defined or not (like we can
for objects), and then can simply implement the rules of C99/C11
by not overwriting VT_STATIC/VT_EXTERN at all but rather only
look at them. A function already on the inline list can be
forced by removing the VT_INLINE flag, and then linkage
follows from some combination of VT_STATIC, VT_EXTERN and VT_INLINE.
GCC wouldn't be able to implement this either (due to the separate
phases of compilation and assembly). We could allow it but it
makes not much sense and actively can confuse broken code into
segfaulting TCC. At least we can warn.
Warning exposes a problem in tcctest, and fixing that gives us
an opportunity to also test .pushsection/.popsection and .previous
directive support.
see testcases. A local 'extern int i' declaration needs to
refer to the global declaration, not to a local one it might
be shadowing. Doesn't seem to happen in the wild very often as
this was broken forever.
Also added a test yielding a failure with the previous definition,
i.e. when using: (va_end(ap));
The test also checks potentially incorrect va_start() definition.
which requires being able to emit an arbitrary number of NOP
instructions, which is also implemented here. For x86 we
could emit other sequences but these are the easiest.
the rules for constant expressions in static initializers are more
relaxed than for integer constant expressions. We need to accept
0.0/0.0 in static initializers (in non-static initializers the potential
exceptions need to be raised though, so no translation-time calculation
then).
tccgen.c:
- fix ldouble asm hack
- fix a VLA problem on Win64 (also x86_64-gen.c)
- patch_type(): make sure that no symbol ever changes
from global to static
tcc.c:
- tcc -vv: print libtcc1.a path also on win32
tccpe.c, tcctools.c:
- use unix LF mode to for .def output files (that is for
creating reproducible output trees)
Makefile:
- suppress some warnings when makeinfo is missing
- call 'which install' only on win32
tests/Makefile:
- change PATH only on WINNT systems (i.e. not if cross-compiling
on linux for win32)
- asm-c-connect.test: slim output and do diff
tccrun.c tccpe.c *-link.c:
- integrate former 'pe_relocate_rva()' into normal relocation
This also fixes linkage of the unwind data on WIN64 for -run
(reported by Janus Lynggaard Thorborg)
tccasm.c, tests/tcctest.c:
- fix dot (sym_index of -1 crashed in put_elf_reloc)
- massage .set a bit (see test)
other:
- #define SECTION_ABS removed
- ST_DATA Section *strtab_section: removed
- put_extern_sym2(): take int section number
Conflicts:
tccelf.c
tccpe.c
Conflicts:
tccelf.c
one some systems GCC defaults to PIC/PIE code which is incompatible
with a unannotated asm call to a function (getenv here). TCC doesn't
support these PIC annotations (yet), so play some pre-processor games.
fixes the problem in the testcase. A symbolic reference
from asm, which remains undefined at the end of processing is
always a global reference, not a static (STB_LOCAL) one.
This also affected the linux kernel.
win32/Makefile ("for cygwin") removed
- On cygwin, the normal ./configure && make can be used with either
cygwin's "GCC for Win32 Toolchain"
./configure --cross-prefix=i686-w64-mingw32-
or with an existing tcc:
./configure --cc=<old-tccdir>/tcc.exe
tcctest.c:
- exclude test_high_clobbers() on _WIN64 (does not work)
tests2/95_bitfield.c:
- use 'signed char' for ARM (where default 'char' is unsigned)
tests:
- remove -I "expr" diff option to allow tests with
busybox-diff.
libtcc.c, tcc.c:
- removed -iwithprefix option. It is supposed to be
combined with -iprefix which we don't have either.
tccgen.c:
- fix assignments and return of 'void', as in
void f() {
void *p, *q;
*p = *q:
return *p;
}
This appears to be allowed but should do nothing.
tcc.h, libtcc.c, tccpp.c:
- Revert "Introduce VIP sysinclude paths which are always searched first"
This reverts commit 1d5e386b0a.
The patch was giving tcc's system includes priority over -I which
is not how it should be.
tccelf.c:
- add DT_TEXTREL tag only if text relocations are actually
used (which is likely not the case on x86_64)
- prepare_dynamic_rel(): avoid relocation of unresolved
(weak) symbols
tccrun.c:
- for HAVE_SELINUX, use two mappings to the same (real) file.
(it was so once except the RX mapping wasn't used at all).
tccpe.c:
- fix relocation constant used for x86_64 (by Andrei E. Warentin)
- #ifndef _WIN32 do "chmod 755 ..." to get runnable exes on cygwin.
tccasm.c:
- keep forward asm labels static, otherwise they will endup
in dynsym eventually.
configure, Makefile:
- mingw32: respect ./configure options --bindir --docdir --libdir
- allow overriding tcc when building libtcc1.a and libtcc.def with
make XTCC=<tcc program to use>
- use $(wildcard ...) for install to allow installing just
a cross compiler for example
make cross-arm
make install
- use name <target>-libtcc1.a
build-tcc.bat:
- add options: -clean, -b bindir
The assembler uses the ->sym_scope member to walk up the symbols
until finding a non-automatic symbol. Since reordering the
members of Sym the sym_scope member contains a scope even for local
statics. Formerly the use of asm_label for statics was implicitely
clearing sym_scope, now we have to do that explicitely.
Add a testcase for that, and one I encountered when moving the
clearing of sym_scope too deep into the call chain (into put_extern_sym).
Like returned local variables also labels local to a statement expression
can be returned, and so their symbols must not be immediately freed
(though they need to be removed from the symbol table).
Use 2 level strategy to access packed bitfields cleanly:
1) Allow to override the original declaration type with
an auxilary "access type". This solves cases such as
struct {
...
unsigned f1:1;
};
by using VT_BYTE to access f1.
2) Allow byte-wise split accesses using two new functions
load/store_packed_bf. This solves any cases, also ones
such as
struct __attribute((packed)) _s {
unsigned x : 12;
unsigned char y : 7;
unsigned z : 28;
unsigned a: 3;
unsigned b: 3;
unsigned c: 3;
};
where for field 'z':
- VT_INT access from offset 2 would be unaligned
- VT_LLONG from offset 0 would go past the total
struct size (7)
and for field 'a' because it is in two bytes and
aligned access with VT_SHORT/INT is not possible.
Also, static bitfield initializers are stored byte-wise always.
Also, cleanup the struct_layout function a bit.
* tccgen: re-allow long double constants for x87 cross
sizeof (long double) may be 12 or 16 depending on host platform
(i386/x86_64 on unix/windows).
Except that it's 8 if the host is on windows and not gcc
was used to compile tcc.
* win64: fix builtin_va_start after VT_REF removal
See also a8b83ce43a
* tcctest.c: remove outdated limitation for ll-bitfield test
It always worked, there is no reason why it should not work
in future.
* libtcc1.c: exclude long double conversion on ARM
* Makefile: remove CFLAGS from link recipes
* lib/Makefile: use target DEFINES as passed from main Makefile
* lib/armflush.c lib/va_list.c: factor out from libtcc1.c
* arm-gen.c: disable "depreciated" warnings for now
'extern int i = 42;' at file scope (but not in function scope!) is
allowed and is a proper definition, even though questionable style;
some compilers warn about this.
This invalid function definition:
int f()[] {}
was tried to be handled but there was no testcase if it actually worked.
This fixes it and adds a TCC only testcase.
factor code a bit for transforming tokens into SValues. This revealed
a bug in TOK_GET (see testcase), which happened to be harmless before.
So fix that as well.
Our code generation assumes that it can load/store with the
bit-fields base type, so bit_pos/bit_size must be in range for this.
We could change the fields type or adjust offset/bit_pos; we do the
latter.
Checked the lcc testsuite for bitfield stuff (in cq.c and fields.c),
fixed one more error in initializing unnamed members (which have
to be skipped), removed the TODO.
usage:
tcc -ar [rcsv] lib files...
tcc -impdef lib.dll [-v] [-o lib.def]
also:
- support more files with -c: tcc -c f1.c f2.c ...
- fix a bug which caused tcc f1.c f2.S to produce no asm
- allow tcc -ar @listfile too
- change prototype: _void_ tcc_set_options(...)
- apply -Wl,-whole-archive when a librariy is given
as libxxx.a also (not just for -lxxx)
tests/Makefile: fix out-of-tree build issues
Also:
- win64: align(16) MEM_DEBUG user memory
on win64 the struct jmp_buf in the TCCState structure which we
allocate by tcc_malloc needs alignment 16 because the msvcrt
setjmp uses MMX instructions.
- libtcc_test.c: win32/64 need __attribute__((dllimport)) for
extern data objects
- tcctest.c: exclude stuff that gcc does not compile
except for relocation_test() the other issues are mostly ASM
related. We should probably check GCC versions but I have
no idea which mingw/gcc versions support what and which don't.
- lib/Makefile: use tcc to compile libtcc1.a (except on arm
which needs arm-asm
Some more subtle issues with code suppression:
- outputting asms but not their operand setup is broken
- but global asms must always be output
- statement expressions are transparent to code suppression
- vtop can't be transformed from VT_CMP/VT_JMP when nocode_wanted
Also remove .exe files from tests2 if they don't fail.
Also ...
tcctest.c:
- exclude stuff that gcc doesn't compile on windows.
libtcc.c/tccpp.c:
- use unsigned for memory sizes to avoid printf format warnings
- use "file:line: message" to make IDE error parsers happy.
tccgen.c: fix typo
on 32bit long long support was sometimes broken. This fixes
code-gen for long long values in switches, disables a x86-64 specific
testcase and avoid an undefined shift amount. It comments out
a bitfield test involving long long bitfields > 32 bit; with GCC layout
they can straddle multiple words and code generation isn't prepared
for this.
when an alignment is explicitely given on the member itself,
or on its types attributes then respect it always. Was only
allowed to increase before, but GCC is allowing it.
The linux kernel has some structures that are page aligned,
i.e. 4096. Instead of enlarging the bit fields to specify this,
use the fact that alignment is always power of two, and store only
the log2 minus 1 of it. The 5 bits are enough to specify an alignment
of 1 << 30.
Such struct decl:
struct S { char a; int i;} __attribute__((packed));
should be accepted and cause S to be five bytes long (i.e.
the packed attribute should matter). So we can't layout
the members during parsing already. Split off the offset
and alignment calculation for this.
See testcases. We now support 64bit case constants. At the same time
also 64bit enum constants on L64 platforms (otherwise the Sym struct
isn't large enough for now). The testcase also checks for various
cases where sign/zero extension was confused.
In certain very specific situations (involving switches
with asms inside dead statement expressions) we could generate
invalid code (clobbering the buffer so much that we generated
invalid instructions). Don't emit the decision table if the
switch itself is dead.
The callee saved registers (among them r12-r15) really need
saving/restoring if mentioned in asm clobbers, even if TCC
itself doesn't use them. E.g. the linux kernel relies on that
in its switch_to() implementation.
Similar to GCC a local asm register variable enforces the use of a
specified register in asm operands (and doesn't otherwise
matter). Works only if the variable is directly mentioned as
operand. For that we now generally store a backpointer from
an SValue to a Sym when the SValue was the result of unary()
parsing a symbol identifier.
If the destination is an indirect pointer access (which ends up
as VT_LLOCAL) the intermediate pointer must be loaded as VT_PTR,
not as whatever the pointed to type is.
If a condition is always zero/non-zero we can omit the
then or else code. This is complicated a bit by having to
deal with labels that might make such code reachable without
us yet knowing during parsing.
This happens when e.g. string constants (or other static data)
are passed as operands to inline asm as immediates. The produced
symbol ref wouldn't be found. So tighten the connection between
C and asm-local symbol table even more.
The return value of statement expressions might refer to local
symbols, so those can't be popped. The old error message always
was just a band-aid, and since disabling it for pointer types it
wasn't effective anyway. It also never considered that also the
vtop->sym member might have referred to such symbols (see the
testcase with the local static, that used to segfault).
For fixing this (can be seen better with valgrind and SYM_DEBUG)
simply leave local symbols of stmt exprs on the stack.
The include directive needs to be parsed as pp-tokens, not
as token (i.e. no conversion to TOK_STR or TOK_NUM). Also fix
parsing computed includes using quoted strings.
But like GCC do warn about changes in signedness. The latter
leads to some changes in gen_assign_cast to not also warn about
unsigned* = int*
(where GCC warns, but only with extra warnings).
This snippet is valid:
void foo(void);
... foo + 42 ...
the function designator is converted to pointer to function
implicitely. gen_op didn't do that and bailed out.
This must compile:
typedef int arrtype1[];
arrtype1 sinit19 = {1};
arrtype1 sinit20 = {2,3};
and generate two arrays of one resp. two elements. Before the fix
the determined size of the first array was encoded in the type
directly, so sinit20 couldn't be parsed anymore (because arrtype1
was thought to be only one element long).
Given this code:
struct __attribute__((...)) Name {...};
TCC was eating "Name", hence generating an anonymous struct.
It also didn't apply any packed attributes to the parsed
members. Both fixed. The testcase also contains a case
that isn't yet handled by TCC (under a BROKEN #define).
The problem was with tcctest.c:
unsigned set;
__asm__("btsl %1,%0" : "=m"(set) : "Ir"(20) : "cc");
when with tcc compiled with the HAVE_SELINUX option, run with
tcc -run, it would use large addresses far beyond the 32bits
range when tcc did not use the pc-relative mode for accessing
'set' in global data memory. In fact the assembler did not
know about %rip at all.
Changes:
- memory operands use (%rax) not (%eax)
- conversion from VT_LLOCAL: use type VT_PTR
- support 'k' modifier
- support %rip register
- support X(%rip) pc-relative addresses
The test in tcctest.c is from Michael Matz.
Also:
- regenerate all tests/pp/*.expect with gcc
- test "insert one space" feature
- test "0x1E-1" in asm mode case
- PARSE_FLAG_SPACES: ignore \f\v\r better
- tcc.h: move some things
tccgen.c:gv() when loading long long from lvalue, before
was saving all registers which caused problems in the arm
function call register parameter preparation, as with
void foo(long long y, int x);
int main(void)
{
unsigned int *xx[1], x;
unsigned long long *yy[1], y;
foo(**yy, **xx);
return 0;
}
Now only the modified register is saved if necessary,
as in this case where it is used to store the result
of the post-inc:
long long *p, v, **pp;
v = 1;
p = &v;
p[0]++;
printf("another long long spill test : %lld\n", *p);
i386-gen.c :
- found a similar problem with TOK_UMULL caused by the
vstack juggle in tccgen:gen_opl()
(bug seen only when using EBX as 4th register)
On 2016-08-11 09:24 +0100, Balazs Kezes wrote:
> I think it's just that that copy_params() never restores the spilled
> registers. Maybe it needs some extra code at the end to see if any
> parameters have been spilled to stack and then restore them?
I've spent some time on this and I've found an alternative solution.
Although I'm not entirely sure about it but I've attached a patch
nevertheless.
And while poking at that I've found another problem affecting the
unsigned long long division on arm and I've attached a patch for that
too.
More details in the patches themselves. Please review and consider them
for merging! Thank you!
--
Balazs
[PATCH 1/2] Fix slow unsigned long long division on ARM
The macro AEABI_UXDIVMOD expands to this bit:
#define AEABI_UXDIVMOD(name,type, rettype, typemacro) \
...
while (num >= den) { \
...
while ((q << 1) * den <= num && q * den <= typemacro ## _MAX / 2) \
q <<= 1; \
...
With the current ULONG_MAX version the inner loop goes only until 4
billion so the outer loop will progress very slowly if num is large.
With ULLONG_MAX the inner loop works as expected. The current version is
probably a result of a typo.
The following bash snippet demonstrates the bug:
$ uname -a
Linux eper 4.4.16-2-ARCH #1 Wed Aug 10 20:03:13 MDT 2016 armv6l GNU/Linux
$ cat div.c
int printf(const char *, ...);
int main(void) {
unsigned long long num, denom;
num = 12345678901234567ULL;
denom = 7;
printf("%lld\n", num / denom);
return 0;
}
$ time tcc -run div.c
1763668414462081
real 0m16.291s
user 0m15.860s
sys 0m0.020s
[PATCH 2/2] Fix long long dereference during argument passing on ARMv6
For some reason the code spills the register to the stack. copy_params
in arm-gen.c doesn't expect this so bad code is generated. It's not
entirely clear why the saving part is necessary. It was added in commit
59c35638 with the comment "fixed long long code gen bug" with no further
clarification. Given that tcctest.c passes without this, maybe it's no
longer needed? Let's remove it.
Also add a new testcase just for this. After I've managed to make the
tests compile on a raspberry pi, I get the following diff without this
patch:
--- test.ref 2016-08-22 22:12:43.380000000 +0100
+++ test.out3 2016-08-22 22:12:49.990000000 +0100
@@ -499,7 +499,7 @@
2
1 0 1 0
4886718345
-shift: 9 9 9312
+shift: 291 291 291
shiftc: 36 36 2328
shiftc: 0 0 9998683865088
manyarg_test:
More discussion on this thread:
https://lists.nongnu.org/archive/html/tinycc-devel/2016-08/msg00004.html
fixes 5c35ba66c5
Implementation was consistent within tcc but incompatible
with the ABI (for example library functions vprintf etc)
Also:
- tccpp.c/get_tok_str() : avoid "unknown format "%llu" warning
- x86_64_gen.c/gen_vla_alloc() : fix vstack leak
