This does not have any adverse effect, since yylex never calls mpatov
with a string with leading 0 (and not 0x) that contains non-octal
digits, but the condition was wrong regardless.
It is a bit of a annoyance that kenc will try to expand
function like macros on any symbol with the same name
and then complain when it doesnt see the '(' in the
invocation.
test case below:
void
foo(int)
{
}
struct Bar
{
int baz; /* <- should not conflict */
};
void
main(void)
{
baz(123);
}
This prevents an incorrect warning for a comparison such as `0 < x`,
where x is an unsigned type. Previously, this would get normalized as
`x >= 0` rather than `x > 0` when checking the comparison.
C99 integer constants with no type suffix promote differently
depending on the way that they're written: hex and oct consts
promote as int => uint => long => ulong => vlong => uvlong.
Decimal constants are always signed.
We used to promote all values to uint on overflow, and never
went wider. This change fixes that, and adds a warning when
a decimal constant that would have been promoted to uint in
the past gets promoted to int.
the caller of macexpand() needs one more byte in
the buffer to append peekc.
make macexpand() actually check for buffer overflow.
just use strdup() to duplicate include file name
instead of the hunk dance.
move GETC() macro in cc.h
slookup() copies to symb, so use the symb[NSYMB] buffer directly
to declare type conversion functions and get rid of the arbitrary
sized local buffer. replace sprint() with snprint().
mysbrk() was only used in gethunk() and should not be
called by anyone, so dont export the symbol.
simplify gethunk() using brk().
double allocation size on each call until we reach
1000*NHUNK.
use signed long for nhunk as alignment rountin might
make it negative and handle that case.
for gethunk() to work, all allocators have to use it,
including allocations done by libc thru malloc(),
so the fake allocation functions are mandatory for
everyone.
to avoid duplication the code is moved to cc/compat
and prototypes provided in new cc/compat.h header.
the assemblers share gethunk() cc/macbody but are compiled
without compat.c, so calls such as getenv() trigger malloc()
which does its own sbrk() calls, breaking the continuity
of the hunk.
so this change needs another revision. until then, this is
backed out.
the compilers and linkers use ther own memory allocator.
free memory is between hunk and hunk+nhunk. allocation
works by checking if nhunk is bigger or equal to the
amount needed, and if not, repeatedly call gethunk()
until there is. after that, the allocated amount is added
from hunk and subtracted from nhunk by the user.
the problem was when the needed amount was bigger than
the default NHUNK size gethunk() allocates per call.
gethunk() would not actually grow nhunk, but instead
just set hunk and nhunk variables to the last allocated
block. this resulted in a infinite loop of calls to
gethunk() until sbrk() would hit the maximum size for
the BSS segment.
this change makes gethunk() actually grow the hunk space,
increasing nhunk, and only updating hunk when nhunk was
previously zero. we assume that mysbrk() retuns increasing
addresses and that the space between the previous hunk+nhunk
and the new block base returned by mysbrk() is usable.
the real problem is that gethunk() does not grow the allocation
but just allocates a new hunk, so repeated calls to gethunk()
wont make nhunk grow to satisfy the allocation.
this will be fixed in a upcoming commit.
ccom may be called multiple times on the same
node, via 'goto loop' calls from the commute
label, OADD, and a few other places.
Casts to void could null out the LHS of the
node, which would cause the compiler to crash
if the cast was revisited due to one of these
cases, because we tried frobbing n->left.
Now, if n->left is nil, we just return.w
Section 6.5.15 of the C99 spec requires that if
one argument of a ?: expression is a null pointer
constant, and the other has a pointer type T*, then
the type of the expression is T*.
We were attempting to follow this rule, however,
we only handled literal expressions when checking
for null pointers.
This change looks through casts, so 'nil' and 'NULL',
and their expansion '(void*)0' are all detected as
null pointer constants.
This fixes ocaml on non-x86 architectures, where we have code
that looks like:
#define Fl_head ((uintptr_t)(&sentinel.first_field))
Without this change, we get an error about a non-constant
initializer. This change takes the checks for pointers and
makes them apply to all expressions. It also makes the checks
stricter, preventing the following from compiling to junk:
int x;
int y = 42;
int *p = &x + y
the following code reproduces the crash:
void
foo(void)
{
}
void
main(int argc, char **argv)
{
(void)(1 ? (void)0 : foo());
}
the problem is that side() gives a false positive on the OCOND
with later constant folding eleminating the acutal side effect
and OCAST ending up with two nested OCATS with the nested one
being zapped (type == T).
implicit casts would cause spurious "result of operation not used"
warnings such as ape's stdio putc() macro.
make (void) casts non-ops when the casted expression has no
side effects. this avoid spurious warning with ape's assert()
macro.
This change imports a few warnings and minor fixes from Charles branch
here: https://bitbucket.org/plan9-from-bell-labs/plan9.
The changes included here:
changeset: 1374:9185dc017be0
summary: declare castucom; move a declaration into order;
use cast instead of ULL suffix
changeset: 1353:5fe8380b1818
summary: supporting functions:
1. castucom to match unlikely mask operation;
2. be sure to snap both sides of pointer subtraction completely;
3. add extra operators as side-effect free
changeset: 1352:90058c092d66
summary: 1. correct result type for mixed-mode assignment operators
2. detect divide by zero (erik);
3. detect masks misformed by sign-extension;
4. diagnose mixed old/new prototypes
to reproduce:
u8int x, y;
x = 0xff;
y = 0xc0;
if((s8int)(x & y) >= 0)
print("help\n");
compiles correctly but prints a warning
warning: test.c:11 useless or misleading comparison: UINT >= 0
the issue is that compar() unconditionally skipped over
all left casts ignoring the case when a cast would sign
extend the value.
the new code only skips over the cast when the original
type with is smaller than the cast result or when they
are equal width and types have same signedness. so the
effective left hand side type is the last truncation
or sign extension.
The Plan 9 assemblers use strtoll to parse the integer literals
in their input. It turns out that this is almost correct, but
VLONG_MIN is clamped. This patch changes to use strtoull
in order to allow the full range of integers.
introduce rolor() function to subsitute (a << c) | (a >> (bits(a) - c))
with (a <<< c) where <<< is cyclic rotation and c is constant.
this almost doubles the speed of chacha encryption of 386 and amd64.
the peephole optimizer used to stop when it hit a shift or rol
instruction when attempting to eleminate moves by register
substitution. but we do not have to as long as the shift count
operand is not CX (which cannot be substituted) and CX is not
a subject for substitution.
from charles forsuth:
because the previous version thought OINDEX might have a side effect, it
stopped it building a tower of them.
probably the best thing is to limit that anyway, since each one consumes
2-3 registers, so towering them can
keep even more active, and the x86 hasn't got that many.
the quick hack is to return that case to the earlier state by treating
OINDEX as a side-effect in side().
it's not a bad thing to do in the OSTRUCT case, for similar reasons: it's
better to collapse the indexed pointer
into a direct register, instead of repeating the indexing operation through
the copying of the value.
OINDEX isn't a machine-independent operation, so it doesn't affect the uses
in ../cc
