re2c version 4 enabled some warnings by default. This fixes re2c code
for the `-Wuseless-escape` warnings.
There are two same issues reported.
Issue: GH-17523
Closes: GH-17204
This hack not only breaks the handling of custom allocators, but also
breaks if zend_alloc is compiled with USE_CUSTOM_MM.
This hack is just no good, if you want leak information then use ASAN.
Closes GH-18813.
It's possible to return a reference from __toString(), but this is not
handled and results in a (confusing) error telling that the return value
must be a string.
Properly handle this by unwrapping the reference.
Closes GH-18810.
This changes the signature of opcode handlers in the CALL VM so that the opline
is passed directly via arguments. This reduces the number of memory operations
on EX(opline), and makes the CALL VM considerably faster.
Additionally, this unifies the CALL and HYBRID VMs a bit, as EX(opline) is now
handled in the same way in both VMs.
This is a part of GH-17849.
Currently we have two VMs:
* HYBRID: Used when compiling with GCC. execute_data and opline are global
register variables
* CALL: Used when compiling with something else. execute_data is passed as
opcode handler arg, but opline is passed via execute_data->opline
(EX(opline)).
The Call VM looks like this:
while (1) {
ret = execute_data->opline->handler(execute_data);
if (UNEXPECTED(ret != 0)) {
if (ret > 0) { // returned by ZEND_VM_ENTER() / ZEND_VM_LEAVE()
execute_data = EG(current_execute_data);
} else { // returned by ZEND_VM_RETURN()
return;
}
}
}
// example op handler
int ZEND_INIT_FCALL_SPEC_CONST_HANDLER(zend_execute_data *execute_data) {
// load opline
const zend_op *opline = execute_data->opline;
// instruction execution
// dispatch
// ZEND_VM_NEXT_OPCODE():
execute_data->opline++;
return 0; // ZEND_VM_CONTINUE()
}
Opcode handlers return a positive value to signal that the loop must load a
new execute_data from EG(current_execute_data), typically when entering
or leaving a function.
Here I make the following changes:
* Pass opline as opcode handler argument
* Return next opline from opcode handlers
* ZEND_VM_ENTER / ZEND_VM_LEAVE return opline|(1<<0) to signal that
execute_data must be reloaded from EG(current_execute_data)
This gives us:
while (1) {
opline = opline->handler(execute_data, opline);
if (UNEXPECTED((uintptr_t) opline & ZEND_VM_ENTER_BIT) {
opline = opline & ~ZEND_VM_ENTER_BIT;
if (opline != 0) { // ZEND_VM_ENTER() / ZEND_VM_LEAVE()
execute_data = EG(current_execute_data);
} else { // ZEND_VM_RETURN()
return;
}
}
}
// example op handler
const zend_op * ZEND_INIT_FCALL_SPEC_CONST_HANDLER(zend_execute_data *execute_data, const zend_op *opline) {
// opline already loaded
// instruction execution
// dispatch
// ZEND_VM_NEXT_OPCODE():
return ++opline;
}
bench.php is 23% faster on Linux / x86_64, 18% faster on MacOS / M1.
Symfony Demo is 2.8% faster.
When using the HYBRID VM, JIT'ed code stores execute_data/opline in two fixed
callee-saved registers and rarely touches EX(opline), just like the VM.
Since the registers are callee-saved, the JIT'ed code doesn't have to
save them before calling other functions, and can assume they always
contain execute_data/opline. The code also avoids saving/restoring them in
prologue/epilogue, as execute_ex takes care of that (JIT'ed code is called
exclusively from there).
The CALL VM can now use a fixed register for execute_data/opline as well, but
we can't rely on execute_ex to save the registers for us as it may use these
registers itself. So we have to save/restore the two registers in JIT'ed code
prologue/epilogue.
Closes GH-17952
On Windows, the cli and phpdbg SAPIs have variants (cli-win32 and
phpdbgs, respectively) which are build by default. However, the
variants share some files, what leads to duplicate build rules in the
generated Makefile. NMake throws warning U4004[1], but proceeds
happily, ignoring the second build rule. That means that different
flags for duplicate rules are ignored, hinting at a potential problem.
We solve this by introducing an additional (optional) argument to
`SAPI()` and `ADD_SOURCES()` which can be used to avoid such duplicate
build rules. It's left to the SAPI maintainers to make sure that
appropriate rules are created. We fix this for phpdbgs right away,
which currently couldn't be build without phpdbg due to the missing
define; we remove the unused `PHP_PHPDBG_EXPORTS` flag altogether.
[1] <https://learn.microsoft.com/en-us/cpp/error-messages/tool-errors/nmake-warning-u4004>
Closes GH-17545.
The phpdbg issue is a real issue, although it's unlikely that harm can
be done due to stack alignment and little-endianess. The others seem
to be more cosmetic.
Internal function won't need their refcount increased as they outlive
the debugger session, and userland functions won't be unloaded either.
So no refcount management is necessary for registered functions.
Internal function won't need their refcount increased as they outlive
the debugger session, and userland functions won't be unloaded either.
So no refcount management is necessary for registered functions.
It crashes because it's gonna try accessing the breakpoint which was cleared
by user code in `phpdbg_clear();`. Not all breakpoint data was properly
cleaned.
Closes GH-16953.
With 04a67cd86c the list of source files
are now added alphabetically. Previously the phpdbg_parser.c was added
before the phpdbg_lexer.c. Which caused the
"sapi/phpdbg/phpdbg_lexer.l:8:10: fatal error: 'phpdbg_parser.h' file
not found" error.
To make the order of source files irrelevant, the Makefile substitutions
needs to be fixed - the 3rd argument of PHP_ADD_MAKEFILE_FRAGMENT macro,
which is the substitution of the $(builddir) Make variable. The
$(builddir)/phpdbg_lexer.lo was previously substituted to an absolute
path. And the relative should be used, for Make to be able to find the
dependent target.
