5d671952ee
This PR fixes #4066: it modifies the Cranelift `build.rs` workflow to invoke the ISLE DSL compiler on every compilation, rather than only when the user specifies a special "rebuild ISLE" feature. The main benefit of this change is that it vastly simplifies the mental model required of developers, and removes a bunch of failure modes we have tried to work around in other ways. There is now just one "source of truth", the ISLE source itself, in the repository, and so there is no need to understand a special "rebuild" step and how to handle merge errors. There is no special process needed to develop the compiler when modifying the DSL. And there is no "noise" in the git history produced by constantly-regenerated files. The two main downsides we discussed in #4066 are: - Compile time could increase, by adding more to the "meta" step before the main build; - It becomes less obvious where the source definitions are (everything becomes more "magic"), which makes exploration and debugging harder. This PR addresses each of these concerns: 1. To maintain reasonable compile time, it includes work to cut down the dependencies of the `cranelift-isle` crate to *nothing* (only the Rust stdlib), in the default build. It does this by putting the error-reporting bits (`miette` crate) under an optional feature, and the logging (`log` crate) under a feature-controlled macro, and manually writing an `Error` impl rather than using `thiserror`. This completely avoids proc macros and the `syn` build slowness. The user can still get nice errors out of `miette`: this is enabled by specifying a Cargo feature `--features isle-errors`. 2. To allow the user to optionally inspect the generated source, which nominally lives in a hard-to-find path inside `target/` now, this PR adds a feature `isle-in-source-tree` that, as implied by the name, moves the target for ISLE generated source into the source tree, at `cranelift/codegen/isle_generated_source/`. It seems reasonable to do this when an explicit feature (opt-in) is specified because this is how ISLE regeneration currently works as well. To prevent surprises, if the feature is *not* specified, the build fails if this directory exists.
46 lines
1.5 KiB
Bash
Executable File
46 lines
1.5 KiB
Bash
Executable File
#!/bin/bash
|
|
|
|
# This script makes sure that the meta crate deterministically generate files
|
|
# with a high probability.
|
|
# The current directory must be set to the repository's root.
|
|
#
|
|
# We set SKIP_ISLE=1 to skip ISLE generation, because it depends on files
|
|
# in-tree (cranelift/codegen/.../*.isle) but these are not available when we
|
|
# switch to different working directories during this test.
|
|
|
|
set -e
|
|
|
|
BUILD_SCRIPT=$(find -wholename "./target/debug/build/cranelift-codegen-*/build-script-build")
|
|
|
|
# First, run the script to generate a reference comparison.
|
|
rm -rf /tmp/reference
|
|
mkdir /tmp/reference
|
|
SKIP_ISLE=1 OUT_DIR=/tmp/reference TARGET=x86_64 CARGO_PKG_VERSION=0.1.0 CARGO_MANIFEST_DIR=/tmp $BUILD_SCRIPT
|
|
|
|
# To make sure the build script doesn't depend on the current directory, we'll
|
|
# change the current working directory on every iteration. Make this easy to
|
|
# reproduce this locally by first copying the target/ directory into an initial
|
|
# temporary directory (and not move and lose the local clone's content).
|
|
rm -rf /tmp/src0
|
|
mkdir /tmp/src0
|
|
|
|
echo Copying target directory...
|
|
cp -r ./target /tmp/src0/target
|
|
cd /tmp/src0
|
|
echo "Done, starting loop."
|
|
|
|
# Then, repeatedly make sure that the output is the same.
|
|
for i in {1..20}
|
|
do
|
|
# Move to a different directory, as explained above.
|
|
rm -rf /tmp/src$i
|
|
mkdir /tmp/src$i
|
|
mv ./* /tmp/src$i
|
|
cd /tmp/src$i
|
|
|
|
rm -rf /tmp/try
|
|
mkdir /tmp/try
|
|
SKIP_ISLE=1 OUT_DIR=/tmp/try TARGET=x86_64 CARGO_PKG_VERSION=0.1.0 CARGO_MANIFEST_DIR=/tmp/src$i $BUILD_SCRIPT
|
|
diff -qr /tmp/reference /tmp/try
|
|
done
|