Upload code coverage

Author: D4nte

.github/workflows/build.yml

@@ -22,6 +22,7 @@ jobs:
             build-net-tokio-tokio: true
           - toolchain: 1.39.0
             build-net-tokio: true
+            coverage: true
     runs-on: ubuntu-latest
     steps:
       - name: Checkout source code
@@ -44,6 +45,24 @@ jobs:
       - name: Test on Rust ${{ matrix.toolchain }}
         if: ${{ matrix.build-net-tokio }} != true
         run: RUSTFLAGS="-C link-dead-code" cargo test --verbose -p lightning
+      - name: Install kcov
+        if: ${{ matrix.coverage }}
+        run: |
+          wget https://github.com/SimonKagstrom/kcov/archive/master.tar.gz
+          tar xzf master.tar.gz
+          cd kcov-master &&mkdir build && cd build
+          cmake .. && make
+          make install DESTDIR=../../kcov-build
+          cd ../.. && rm -rf kcov-master
+      - name: Upload coverage
+        if: ${{ matrix.coverage }}
+        run: |
+          for file in target/debug/lightning-*; do
+            [ -x "${file}" ] || continue;
+            mkdir -p "target/cov/$(basename $file)";
+            ./kcov-build/usr/local/bin/kcov --exclude-pattern=/.cargo,/usr/lib --verify "target/cov/$(basename $file)" "$file";
+          done
+          bash <(curl -s https://codecov.io/bash)
 
   fuzz:
     runs-on: ubuntu-latest