Distributed minimal source archives -- take 2 (#135)

* Add export ignores to produce small tarballs
* Do not add benchmarks subdirectory
* Include benchmarks directory if present
* Use checkout@v1 action

The v2 action seems to ignore files marked with `export-ignore` in the .gitattributes file.

See https://github.community/t/using-container-checkout-doesnt-checkout-hidden-files/18429

* fix the CI apocalypse
* [CMAKE] fix EXISTS test

Co-authored-by: Noah D. Brenowitz <nbren12@gmail.com>

.gitattributes

@@ -0,0 +1,17 @@
+/LICENSE export-ignore
+/Readme.md export-ignore
+/clang export-ignore
+/clang-tools-extra export-ignore
+/compiler-rt export-ignore
+/contrib export-ignore
+/debuginfo-tests export-ignore
+/libcxx export-ignore
+/libcxxabi export-ignore
+/libunwind export-ignore
+/lld export-ignore
+/lldb export-ignore
+/llvm export-ignore
+/openmp export-ignore
+/polly export-ignore
+/tests export-ignore
+/enzyme/benchmarks export-ignore

.github/workflows/benchmark.yml

@@ -3,10 +3,10 @@ name: Benchmarking
 on: 
   push:
     branches:
-    - master
+    - main
   pull_request:
     branches:
-    - master
+    - main
 
 jobs:
   build:
@@ -28,7 +28,7 @@ jobs:
           sudo apt-get install -y python-pip autoconf cmake gcc g++ libtool gfortran libblas-dev llvm-${{ matrix.llvm }}-dev clang-${{ matrix.llvm }} libeigen3-dev libboost-dev
           sudo pip install lit
           sudo touch /usr/lib/llvm-${{ matrix.llvm }}/bin/yaml-bench
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v1
       with:
           fetch-depth: 1
     - name: mkdir

.github/workflows/ccpp.yml

@@ -3,10 +3,10 @@ name: C/C++ CI
 on: 
   push:
     branches:
-    - master
+    - main
   pull_request:
     branches:
-    - master
+    - main
 
 jobs:
   build:
@@ -29,7 +29,7 @@ jobs:
           sudo apt-get install -y autoconf cmake gcc g++ libtool gfortran llvm-${{ matrix.llvm }}-dev libomp-${{ matrix.llvm }}-dev clang-${{ matrix.llvm }} libeigen3-dev libboost-dev
           sudo pip install lit
           sudo touch /usr/lib/llvm-${{ matrix.llvm }}/bin/yaml-bench
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v1
       with:
           fetch-depth: 1
     - name: mkdir

.github/workflows/enzyme-linux.yml

@@ -33,7 +33,7 @@ jobs:
           fi
           sudo pip install lit
           sudo touch /usr/lib/llvm-${{ matrix.llvm }}/bin/yaml-bench
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v1
       with:
           fetch-depth: 1
     - name: mkdir

.github/workflows/format.yml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-20.04
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v1
       with:
           fetch-depth: 1
     - uses: DoozyX/clang-format-lint-action@v0.11

enzyme/CMakeLists.txt

@@ -98,4 +98,9 @@ include_directories("${CMAKE_CURRENT_BINARY_DIR}/include")
 
 add_subdirectory(Enzyme)
 add_subdirectory(test)
-add_subdirectory(benchmarks)
+
+# The benchmarks data are not in git-exported source archives to minimize size.
+# Only add the benchmarks if the directory exists.
+if (EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/benchmarks")
+    add_subdirectory(benchmarks)
+endif()