llvm-project/compiler-rt
Zachary Turner a0e55b6403 [lit] Force site configs to be run before source-tree configs
This patch simplifies LLVM's lit infrastructure by enforcing an ordering
that a site config is always run before a source-tree config.

A significant amount of the complexity from lit config files arises from
the fact that inside of a source-tree config file, we don't yet know if
the site config has been run.  However it is *always* required to run
a site config first, because it passes various variables down through
CMake that the main config depends on.  As a result, every config
file has to do a bunch of magic to try to reverse-engineer the location
of the site config file if they detect (heuristically) that the site
config file has not yet been run.

This patch solves the problem by emitting a mapping from source tree
config file to binary tree site config file in llvm-lit.py. Then, during
discovery when we find a config file, we check to see if we have a
target mapping for it, and if so we use that instead.

This mechanism is generic enough that it does not affect external users
of lit. They will just not have a config mapping defined, and everything
will work as normal.

On the other hand, for us it allows us to make many simplifications:

* We are guaranteed that a site config will be executed first
* Inside of a main config, we no longer have to assume that attributes
  might not be present and use getattr everywhere.
* We no longer have to pass parameters such as --param llvm_site_config=<path>
  on the command line.
* It is future-proof, meaning you don't have to edit llvm-lit.in to add
  support for new projects.
* All of the duplicated logic of trying various fallback mechanisms of
  finding a site config from the main config are now gone.

One potentially noteworthy thing that was required to implement this
change is that whereas the ninja check targets previously used the first
method to spawn lit, they now use the second. In particular, you can no
longer run lit.py against the source tree while specifying the various
`foo_site_config=<path>` parameters.  Instead, you need to run
llvm-lit.py.

Differential Revision: https://reviews.llvm.org/D37756

llvm-svn: 313270
2017-09-14 16:47:58 +00:00
..
cmake [ubsan-minimal] Enable on Darwin 2017-09-11 21:37:53 +00:00
docs [sanitizers] Make it possible to XFAIL on the effective target, not just the default. 2016-08-09 11:50:53 +00:00
include Prevent DCE on __lsan_is_turned_off and re-enable test case 2017-09-08 19:43:53 +00:00
lib [sanitizer] Add empty Fuchsia and Win versions of StartReportDeadlySignal 2017-09-14 08:14:56 +00:00
test [lit] Force site configs to be run before source-tree configs 2017-09-14 16:47:58 +00:00
unittests [lit] Force site configs to be run before source-tree configs 2017-09-14 16:47:58 +00:00
www Update references to new lists.llvm.org mailing lists. 2015-08-05 03:58:00 +00:00
.arcconfig Upgrade all the .arcconfigs to https. 2016-07-14 13:15:37 +00:00
.gitignore Add .pyc files to .gitignore to compiler-rt 2017-07-24 21:51:12 +00:00
CMakeLists.txt Revert "Determine up front which projects are enabled." 2017-09-13 20:49:25 +00:00
CODE_OWNERS.TXT [sanitizers] remove earthdok@ from owners 2016-05-18 18:52:18 +00:00
CREDITS.TXT
LICENSE.TXT Update copyright year to 2016. 2016-03-30 22:38:50 +00:00
README.txt

README.txt

Compiler-RT
================================

This directory and its subdirectories contain source code for the compiler
support routines.

Compiler-RT is open source software. You may freely distribute it under the
terms of the license agreement found in LICENSE.txt.

================================