This implementation relies on arithmetic conversion, let's see what
happens when we do
std::size_t length{std::strlen(string)};
if (length <= std::numeric_limits<std::int64_t>::max())
return static_cast<std::int64_t>(length);
1) if size_t == uint32_t (or lower), then the comparison operator
invokes integral promotion to uint64_t, the comparison happens, it's
fine.
2) if size_t == uint64_t, then the comparison is done between unsigned
types, which implies a conversion of
std::numeric_limits<std::int64_t>::max() to uint64_t, which happens
without accuracy loss, fine
3) if size_t == uint128_t (or higher), then we invoke integral promotion
of std::int64_t, it's also fine.
So this snippet has the same behavior as the existing one, while being
easier to read.
This patch add support of intrinsics GNU extension GETCWD
https://github.com/llvm/llvm-project/issues/84203. Some usage info and
example has been added to `flang/docs/Intrinsics.md`. The patch contains
both the lowering and the runtime code and works on both Windows and
Linux.
| System | Implmentation |
|-----------|--------------------|
| Windows | _getcwd |
| Linux |getcwd |
This patch add support of intrinsics Fortran 2008 EXECUTE_COMMAND_LINE.
The patch contains both the lowering and the runtime code and works on
both Windows and Linux. The patch contains a list of commits, to convey
the authorship and the history of changes. Some implementation specifics
or status has been added to `flang/docs/Intrinsics.md`.
I have provided a summary of the usage and the options required for the
`EXECUTE_COMMAND_LINE intrinsic`. The intrinsic supports both a
synchronous
(by default) and an asynchronous option.
| System | Mode | Implemention |
|---------|-------|---------------------------|
| Linux | Sync | std::system() |
| Windows | Sync | std::system() |
| Linux | Async | fork() |
| Windows | Async | CreateProcess |
Support for the SYSTEM GNU extension will be added in a separate PR.
Co-authored with @jeffhammond
---------
Signed-off-by: Jeff Hammond <jeff.science@gmail.com>
Co-authored-by: Jeff Hammond <jeff.science@gmail.com>
Co-authored-by: Yi Wu <yiwu02@wdev-yiwu02.arm.com>
This patch enables the Fortran runtime support library to be
built without native 128-bit integer support in the C++ compiler.
Experimental: do not merge yet.
Differential Revision: https://reviews.llvm.org/D154660
This patch refactors the runtime support for GET_ENVIRONMENT_VARIABLE
to have a single entry point instead of 2. It also updates lowering
accordingly.
This makes it easier to handle dynamically optional arguments.
See also https://reviews.llvm.org/D118777
Reviewed By: jeanPerier
Differential Revision: https://reviews.llvm.org/D142489
This patch refactors the runtime support for GET_COMMAND_ARGUMENT to
have a single entry point instead of 2. It also updates lowering
accordingly.
This makes it easier to handle dynamically optional arguments. See also
https://reviews.llvm.org/D118777
Differential Revision: https://reviews.llvm.org/D130475
Statically checking for overflow with
if constexpr (sizeof(std::size_t) <= sizeof(std::int64_t)) {
return static_cast<std::int64_t>(length);
}
Doesn't work if `sizeof(std::size_t) == sizeof(std::int64_t)` because std::size_t
is unsigned.
if `length == std::numeric_limits<size_t>` casting it to `int64_t` is going to overflow.
This code would be much simpler if returning a `uint64_t` instead of a signed
value...
Differential Revision: https://reviews.llvm.org/D122705
Implement the GET_COMMAND intrinsic.
Add 2 new parameters (sourceFile and line) so we can create a terminator
for RUNTIME_CHECKs.
Differential Revision: https://reviews.llvm.org/D118777
Implement the second entry point for GET_ENVIRONMENT_VARIABLE. Reuse
existing bits and pieces wherever possible.
This patch also increases CFI_* error codes in order to avoid conflicts.
GET_ENVIRONMENT_VARIABLE is required to return a status of 1 if an
environment variable does not exist and 2 if environment variables are
not supported. However, if we add status codes for that they will
conflict with CFI_ERROR_BASE_ADDR_NULL and CFI_ERROR_BASE_ADDR_NOT_NULL,
which are also 1 and 2 at the moment. We therefore move all CFI error
codes up (an arbitrary) 10 spots to make room. Hopefully this isn't
a problem, since we weren't matching the CFI error codes that gfortran
uses anyway. It may still be an issue if any other runtime functions
will need to return a status of 1 or 2, but we should probably deal with
that when/if it occurs.
Differential Revision: https://reviews.llvm.org/D112698
Add support for reading environment variables directly, via std::getenv.
This needs to allocate a C-style string to pass into std::getenv. If the
memory allocation for that fails, we terminate.
This also changes the interface for EnvVariableLength to receive the
source file and line so we can crash gracefully.
Note that we are now completely ignoring the envp pointer passed into
ProgramStart, since that could go stale if the environment is modified
during execution.
Differential Revision: https://reviews.llvm.org/D111785
Search for the environment variable in the envp string passed to
ProgramStart. This doesn't work if the main program isn't Fortran.
Differential Revision: https://reviews.llvm.org/D111394
Recommit https://reviews.llvm.org/D109813 and
https://reviews.llvm.org/D109814.
This implements the second and final entry point for GET_COMMAND_ARGUMENT,
handling the VALUE, STATUS and ERRMSG parameters.
It has a small fix in that we're now using memcpy instead of strncpy
(which was a bad idea to begin with, since we're not actually interested
in a string copy).
This reverts commit 0446f1299f6be9fd35bc5f458c78b34dca3105f6 and
df6302311f88d0fbc666b6277d029aa371039945.
There's a warning on flang-aarch64-latest-gcc related to strncpy using
the result of strlen as a bound. I'll recommit with a fix.
Implement the final part of GET_COMMAND_ARGUMENT, i.e. the handling of
ERRMSG. This uses some of the infrastructure in stat.h and gets rid of
the magic numbers that we were using for return codes.
Differential Revision: https://reviews.llvm.org/D109814
Partial implementation for the second entry point for
GET_COMMAND_ARGUMENT. It handles the VALUE and STATUS arguments, and
doesn't touch ERRMSG.
Differential Revision: https://reviews.llvm.org/D109813
Implement the ArgumentLength entry point of GET_COMMAND_ARGUMENT. Also
introduce a fixture for the tests.
Note that this also changes the interface for ArgumentLength from
returning a 4-byte integer to returning an 8-byte integer.
Differential Revision: https://reviews.llvm.org/D109227
Move the closure of the subset of flang/runtime/*.h header files that
are referenced by source files outside flang/runtime (apart from unit tests)
into a new directory (flang/include/flang/Runtime) so that relative
include paths into ../runtime need not be used.
flang/runtime/pgmath.h.inc is moved to flang/include/flang/Evaluate;
it's not used by the runtime.
Differential Revision: https://reviews.llvm.org/D109107
Grab whatever ProgramStart has stored in executionEnvironment.argc and
subtract 1 (based on the assumption that ProgramStart is called with
a C-style argc that counts the command name as an argument).
Spoiler alert: The tests will evolve into fixtures when we implement
GET_COMMAND_ARGUMENT etc.
Differential Revision: https://reviews.llvm.org/D109048
