Source coverage (#48)

* Support stable rust

Updated dependencies such that Rust stable 1.53 is now supported.
The optimised avx_2 option will NOT rust on stable because there's
still an unstable feature on subtle-ng. BUT this feature is actually
for doc generation and has been removed from Rust. As soon as subtle-ng
merges dalek-cryptography/subtle#85, avx2 will
probably be supported on stable as well.

The rand dep update breaks the benchmarks, but these will be fixed in
the next commit.

* Update benchmarks and fmt

* Update benchmark code to use new dependency APIs
* Run rust-fmt

* Use source coverage in tests

Replace the grcov action with the more accurate source coverage approach
as detailed in
https://doc.rust-lang.org/nightly/unstable-book/compiler-flags/instrument-coverage.html

This PR also provides the `test_coverage.sh` script that generates a
test coverage report lcoally (see the comments for setting up
pre-requisites)

* Exclude std lib from coverage

Author: CjS77

.github/actions-rs/grcov.yml

@@ -0,0 +1,32 @@
+name: Source Coverage
+  push:
+    branches:
+      - main
+jobs:
+  coverage:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v1
+      - name: Install dependencies
+        run: |
+          sudo apt update
+          sudo apt install -y jq lcov
+      - name: Download Rust
+        uses: actions-rs/toolchain@v1
+      - name: Install llvm-tools
+        run: |
+          rustup component add llvm-tools-preview
+          cargo install cargo-binutils
+          cargo install rustfilt
+      - name: Run test coverage
+        id: coverage
+        env:
+          SKIP_HTML: '1'
+        run: |
+          /bin/bash -c ./test_coverage.sh
+      - name: Coveralls upload
+        uses: coverallsapp/github-action@master
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          path-to-lcov: ./cov_raw/tari_crypto.lcov

.github/workflows/grcov.yml

@@ -21,7 +21,8 @@ tags
 .clippy.toml
 
 # Ignore Code Coverage Report files
-report
+cov_raw/
+coverage_report/
 
 Cargo.lock
 *.log
@@ -30,4 +31,4 @@ Cargo.lock
 /libtari/tari_crypto.h
 
 # C-demo output
-bin/
+bin/

.github/workflows/source-cov.yml

@@ -0,0 +1,50 @@
+#!/bin/bash
+# Prerequisites
+# 1. You need LLVM-COV tools:
+# $ rustup component add llvm-tools-preview
+# 2. and Rust wrappers for llvm-cov:
+# $ cargo install cargo-binutils
+# 3. The rust name demangler
+# $ cargo install rustfilt
+# 4. jq
+# 5. genhtml
+# $ sudo apt install lcov
+
+RUSTFLAGS="-Z instrument-coverage"
+LLVM_PROFILE_FILE="./cov_raw/tari_crypto-%m.profraw"
+
+get_binaries() {
+  files=$( RUSTFLAGS=$RUSTFLAGS cargo test --tests --no-run --message-format=json \
+              | jq -r "select(.profile.test == true) | .filenames[]" \
+              | grep -v dSYM - \
+        );
+  files=("${files[@]/#/-object }")
+}
+
+get_binaries
+echo $files
+
+RUSTFLAGS=$RUSTFLAGS LLVM_PROFILE_FILE=$LLVM_PROFILE_FILE cargo test --tests
+
+cargo profdata -- \
+  merge -sparse ./cov_raw/tari_crypto-*.profraw -o ./cov_raw/tari_crypto.profdata
+
+cargo cov -- \
+  export \
+    --Xdemangler=rustfilt \
+    --format=lcov \
+    --show-branch-summary \
+    --show-instantiation-summary \
+    --show-region-summary \
+    --ignore-filename-regex='/.cargo/registry' \
+    --ignore-filename-regex="^/rustc" \
+    --instr-profile=cov_raw/tari_crypto.profdata \
+    $files \
+    > cov_raw/tari_crypto.lcov
+
+if [ -z ${SKIP_HTML+x} ]; then
+  genhtml -o coverage_report cov_raw/tari_crypto.lcov
+else
+  echo "Skipping html generation"
+fi
+# open coverage_report/src/index.html