de8939ffca
With HLFIR the lbounds for the ALLOCATABLE result are taken from the
mutable box created for the result, so the non-default lbounds might be
propagated further causing incorrect result, e.g.:
```
program p
real, allocatable :: p5(:)
allocate(p5, source=real_init())
print *, lbound(p5, 1) ! must print 1, but prints 7
contains
function real_init()
real, allocatable :: real_init(:)
allocate(real_init(7:8))
end function real_init
end program p
```
With FIR lowering the box passed for `source` has explicit lower bound 1
at the call site, but the runtime box initialized by `real_init` call
still has lower bound 7. I am not sure if the runtime box initialized by
`real_init` will ever be accessed in a debugger via Fortran variable
names, but I think that having the right runtime bounds that can be
accessible via examining registers/stack might be good in general. So I
decided to update the runtime bounds at the point of return.
This change fixes the test above for HLFIR.
Reviewed By: jeanPerier
Differential Revision: https://reviews.llvm.org/D156187
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| cmake/modules | ||
| docs | ||
| examples | ||
| include | ||
| lib | ||
| module | ||
| runtime | ||
| test | ||
| tools | ||
| unittests | ||
| .clang-format | ||
| .clang-tidy | ||
| .drone.star | ||
| .gitignore | ||
| CMakeLists.txt | ||
| CODE_OWNERS.TXT | ||
| LICENSE.TXT | ||
| README.md | ||
Flang
Flang is a ground-up implementation of a Fortran front end written in modern C++. It started off as the f18 project (https://github.com/flang-compiler/f18) with an aim to replace the previous flang project (https://github.com/flang-compiler/flang) and address its various deficiencies. F18 was subsequently accepted into the LLVM project and rechristened as Flang.
Please note that flang is not ready yet for production usage.
Getting Started
Read more about flang in the docs directory. Start with the compiler overview.
To better understand Fortran as a language and the specific grammar accepted by flang, read Fortran For C Programmers and flang's specifications of the Fortran grammar and the OpenMP grammar.
Treatment of language extensions is covered in this document.
To understand the compilers handling of intrinsics, see the discussion of intrinsics.
To understand how a flang program communicates with libraries at runtime, see the discussion of runtime descriptors.
If you're interested in contributing to the compiler, read the style guide and also review how flang uses modern C++ features.
If you are interested in writing new documentation, follow LLVM's Markdown style guide.
Consult the Getting Started with Flang for information on building and running flang.