Backport operator precedence algorithm from here:
397b96f6d7
This eliminates unnecessary parentheses from our unparsed output and makes Spack's unparser
consistent with the one in upstream Python 3.9+, with one exception.
Our parser normalizes argument order when `py_ver_consistent` is set, so that star arguments
in function calls come last. We have to do this because Python 2's AST doesn't have information
about their actual order.
If we ever support only Python 3.9 and higher, we can easily switch over to `ast.unparse`, as
the unparsing is consistent except for this detail (modulo future changes to `ast.unparse`)
Previously, there were differences in the unparsed code for Python 2.7 and for 3.5-3.10.
This makes unparsed code the same across these Python versions by:
1. Ensuring there are no spaces between unary operators and
their operands.
2. Ensuring that *args and **kwargs are always the last arguments,
regardless of the python version.
3. Always unparsing print as a function.
4. Not putting an extra comma after Python 2 class definitions.
Without these changes, the same source can generate different code for different
Python versions, depending on subtle AST differences.
One place where single source will generate an inconsistent AST is with
multi-argument print statements, e.g.:
```
print("foo", "bar", "baz")
```
In Python 2, this prints a tuple; in Python 3, it is the print function with
multiple arguments. Use `from __future__ import print_function` to avoid
this inconsistency.
Add `astunparse` as `spack_astunparse`. This library unparses Python ASTs and we're
adding it under our own name so that we can make modifications to it.
Ultimately this will be used to make `package_hash` consistent across Python versions.
Add an abstraction around libllvm to allow libllvm
providers to be specified for all packages.
This is targeting allowing mesa to build against
llvm-amdgpu or intel-llvm or llvm or any other
custom llvm variant that arises for specific GPU
toolchains
* Python: set default config_vars
* Add missing commas
* dso_suffix not present for some reason
* Remove use of default_site_packages_dir
* Use config_vars during bootstrapping too
* Catch more errors
* Fix unit tests
* Catch more errors
* Update docstring
* Update existing 2020.0 version to use tag
* Add versions 2018.2 and master
* Add patches for GCC/Intel
* Use MPI compiler wrappers when +mpi
* Constrain CMake build dependency (need >= 3.1)
* Add variants for optional components (e.g QFIT library)
./configure tries to execute an MPI test, which is not possible on
most HPC platforms (if you don't build on a compute node), so this
check is disabled to allow the build to proceed. Ideally we could
check this by placing constraints on the MPI that Spack builds (e.g.
require building a version that is guaranteed to have threading
support).
