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
* fix some macro expansion issues
* add some pp tests in tests/pp
* improved tcc -E output for better diff'ability
* remove -dD feature (quirky code, exotic feature,
didn't work well)
Based partially on ideas / researches from PipCet
Some issues remain with VA_ARGS macros (if used in a
rather tricky way).
Also, to keep it simple, the pp doesn't automtically
add any extra spaces to separate tokens which otherwise
would form wrong tokens if re-read from tcc -E output
(such as '+' '=') GCC does that, other compilers don't.
* cleanups
- #line 01 "file" / # 01 "file" processing
- #pragma comment(lib,"foo")
- tcc -E: forward some pragmas to output (pack, comment(lib))
- fix macro parameter list parsing mess from
a3fc543459a715d7143d
(some coffee might help, next time ;)
- introduce TOK_PPSTR - to have character constants as
written in the file (similar to TOK_PPNUM)
- allow '\' appear in macros
- new functions begin/end_macro to:
- fix switching macro levels during expansion
- allow unget_tok to unget more than one tok
- slight speedup by using bitflags in isidnum_table
Also:
- x86_64.c : fix decl after statements
- i386-gen,c : fix a vstack leak with VLA on windows
- configure/Makefile : build on windows (MSYS) was broken
- tcc_warning: fflush stderr to keep output order (win32)
From: Matteo Cypriani <mcy@lm7.fr>
Date: Fri, 5 Sep 2014 23:22:56 -0400
Subject: Disable floating-point test for ARM soft-float
tcc is not yet capable of doing softfloat floating-point operations on
ARM, therefore we disable this test for these platforms. Note that tcc
displays a warning to warn ARM users about this limitation
(debian)
This provides a simple implementation of alloca for ARM (and enables
the associated testcase). As tcc for ARM doesn't contain an assembler,
we'll have to resort using gcc for compiling it.
Result of float to unsigned integer conversion is undefined if float is
negative. This commit take the absolute value of the float before doing
the conversion to unsigned integer and add more float to integer
conversion test.
negate(x) is subtract(-0,x), not subtract(+0,x), which makes
a difference with signed zeros. Also +x was expressed as x+0,
in order for the integer promotions to happen, but also mangles signed
zeros, so just don't do that with floating types.
I really should do this when less tired; I keep breaking one platform
while fixing another. I've also fixed some Windows issues with tcctest
since Windows printf() uses different format flags to those on Linux,
and removed some conditional compilation tests in tcctest since they
now should work.
Modified tcctest.c so that it uses 'double' in place of 'long double'
with MinGW since this is what TCC does, and what Visual C++ does. Added
an option -norunsrc to tcc to allow argv[0] to be set independently of
the compiled source when using tcc -run, which allows tests that rely on
the value of argv[0] to work in out-of-tree builds.
Also added Makefile rules to automatically update out-of-tree build
Makefiles when in-tree Makefiles have changed.
Michael Matz