Fix a problem at the boundary of DWARF-driven backtrace
and frame-driver backtrace, as well as handling of the
JIT's different internal calling conventions.
Also, allow crossing back from frame-driven to DWARF-driven.
... when PWD is defined and when it refers to the same directory
as the result of getcwd().
A shell sets PWD before starting Racket to communicate a preferred
way of referring to the current directory, which may involve soft
links that are not reflected in getpwd().
With this patch racket will never grow beyond of the defaults limits of
the OS and also it doesn't limit the stack size to a fixed value.
Merge to v5.3.4
The output of "/proc/cpuinfo" seems wrong for a Raspberry Pi running
the latest Raspian, because it claims ARMv6-compatible but also claims
"thumb" as a feature and 7 as the CPU architecture. Use the C compiler's
configuraton, instead, which is relatively straightforward and drops
code that will turn out to be dead.
In a minor collection, old-generation pages can be ignored for
the fixup pass. Also, the "moved" bit implies the "marked" bit.
Also, move the mark bits to low and the hash bits to high,
which leads to slightly better generated code for the GC.
The validator was not as smart as the compiler in determining
that a `let' expression could be relied on to produce a
constant-shaped function (without side effect or error) in the case
that a right-hand side expression is a call to a known structure
constructor or predicate.
Closes PR 13679
Merge to v5.3.4
Swap order of argument for `environment-variables-get'
and `environment-variables-set!', so that the environment
variables come first --- which follows the usual order.
This change means that the parameter isn't used to get
the default environment variables, but that seems ok; the
convenient interface is `getenv' and `putenv'.
On Windows, case-normalized environment variable names.
Also, change the implementation to use an immutable hash
internally.
Fix ephemeral-port support in `udp-bind!', and
change `udp-bind!' and `udp-connect!' to try address
resolutions in order to find one that works (which is
typically needed to auto-select an IPv4 or IPv6 variant
of an address).
The `current-environment-variables' parameter determines the current
mutable "environment variable set". If that set is the initial one for
a Racket process, then using the set corresponds to working with OS
environment variables. Otherwise, it's really just a hash table that
is packaged up as OS environment variables if a subprocess is created.
The new environment-variable interface works in terms of bytes, instead
of assuming that environment variable names and values fit in a string
encoding.
The string-based `getenv' and `putenv' are still available as
convenience wrappers. The checking on environment-variable names
for those wrappers is a little tighter, preventing any attempt to use a
name that contains "=".
On OpenBSD, for example, the libffi link test doesn't work until
"-pthread" is in $LIBS.
Also, make `configure' complain if `--enable-libffi' is specified
and linking to libffi fails.
Allow a thread to be GCed when it is blocked on a place
channel for reading and the place channel's write end
is inaccessible.
GC is limited to threads that do not participate in cycles
of such threads, where the otherwise unerachable threads
are blocked on place channels that are reachable among the
set of threads. In other words, the GC finds the greatest
fix point (as measured by the threads to retain) instead of
least fix point --- which isn't what you want, but finding
the least fix point seems to require significant extra GC
machinery across places.
This improvement was intended to solve the same problem as
commit 7b0608c, but that case seems to run into the limitation
on cycles.
A tail call with certain kinds of primitives would fail to
clear local bindings in a detectable way. For example, a
tail call to `sync' that blocks could retain references
to unreachable data in the context of the `sync' call.
Primitives that can cause problems in the run-time system
are already identified as "imemdiate" primitives. The
safe-for-space pass now inserts clearing actions before a tail
call, unless the call it to a known immediate primitive or a
Racket-implemented function.
Clearing operations are now omitted before non-tail calls
to immediate operations like structure predicates.
The newly added clearing operations could affect performance,
but they probably won't, since the clear operations are still
avoided in tail-call cases that are otherwise fast. The newly
omitted clearing operations may improve performance.
The shortcut could be triggered in a bad case (first
argument as `#f' in non-timeout mode) and returned the
wrong result (void instead of the semaphore).
