diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index df8cadb26..91129d22f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -42,7 +42,6 @@ jobs:
     - name: Test
       run: cargo xtask test --build-type ${{env.BUILD_TYPE}}
 
-
   build_with_hash:
     runs-on: ubuntu-latest
 
@@ -55,4 +54,43 @@ jobs:
       run: cargo xtask build --build-type ${{env.BUILD_TYPE}} --with-rust false --with-hash true --verbose true
 
     - name: Test
-      run: cargo xtask test --build-type ${{env.BUILD_TYPE}} --with-rust false
+      run: cargo xtask test --build-type ${{env.BUILD_TYPE}}
+
+  coverage:
+    strategy:
+      matrix:
+        with_rust: ['true', 'false']
+    runs-on: ubuntu-latest
+    name: with_rust=${{ matrix.with_rust }}
+
+    steps:
+    - uses: actions/checkout@v3
+      with:
+        submodules: 'true'
+
+    - name: Setup rustup
+      run: |
+        rustup default stable
+        rustup update
+        rustup component add llvm-tools
+
+    - name: Setup grcov
+      run: |
+        curl -LO https://github.com/mozilla/grcov/releases/download/v0.8.19/grcov-x86_64-unknown-linux-gnu.tar.bz2
+        echo 098be4d60b8016913542d58456fea6e771890096d1bf86e7f83dac650ba4b58a grcov-x86_64-unknown-linux-gnu.tar.bz2 | sha256sum -c -
+        tar xf grcov-x86_64-unknown-linux-gnu.tar.bz2
+
+    - name: Build
+      env:
+        CC: clang
+      run: cargo xtask build --build-type Debug --with-rust ${{matrix.with_rust}} --with-coverage true --verbose true
+
+    - name: Test
+      run: |
+        cargo xtask test --build-type Debug
+        ./grcov . -s . -b . --keep-only 'src/*' --llvm  -t lcov -o coverage.lcov
+
+    - name: Upload coverage reports to Codecov
+      uses: codecov/codecov-action@v3
+      env:
+        CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 05fb63613..6b2ea79dc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -23,7 +23,11 @@ if(${CMAKE_C_COMPILER_ID} STREQUAL "GNU" OR
     add_compile_definitions(_GNU_SOURCE)
     option(ENABLE_GCOV "Coverage support" false)
     if(ENABLE_GCOV)
-        set(CMAKE_C_FLAGS "-coverage ${CMAKE_C_FLAGS}")
+        if (WITH_RUST AND ${CMAKE_C_COMPILER_ID} STREQUAL "Clang")
+            set(CMAKE_C_FLAGS "-fprofile-instr-generate -fcoverage-mapping ${CMAKE_C_FLAGS}")
+        else()
+            set(CMAKE_C_FLAGS "--coverage ${CMAKE_C_FLAGS}")
+        endif()
     endif()
 
     # Use NO_UNDEFINED=no when running with address sanitizer
@@ -55,6 +59,7 @@ elseif(MSVC)
     set(BUILD_DLL false)
 endif()
 
+
 check_c_compiler_flag(-fvisibility=hidden FVISIBILITY_HIDDEN)
 if(${FVISIBILITY_HIDDEN})
     set(CMAKE_C_FLAGS "-fvisibility=hidden ${CMAKE_C_FLAGS}")
@@ -80,13 +85,18 @@ option(USE_VALGRIND "Use valgrind when testing" true)
 option(WITH_RUST "Use rust implemented internals (experimental)" false)
 if (WITH_RUST)
     add_subdirectory(cmake/corrosion)
-    if (${CMAKE_BUILD_TYPE} STREQUAL "Debug")
+    if (CMAKE_BUILD_TYPE MATCHES DEBUG)
         corrosion_import_crate(MANIFEST_PATH Cargo.toml CRATES chewing FEATURES capi test-tracing)
     else()
         corrosion_import_crate(MANIFEST_PATH Cargo.toml CRATES chewing FEATURES capi)
     endif()
     corrosion_import_crate(MANIFEST_PATH Cargo.toml CRATES chewing-tools)
     add_compile_definitions(WITH_RUST)
+    corrosion_set_env_vars(chewing CMAKE_BINARY_DIR=${CMAKE_BINARY_DIR})
+    if(ENABLE_GCOV)
+        corrosion_set_env_vars(chewing CARGO_INCREMENTAL=0)
+        corrosion_add_target_local_rustflags(chewing -Cinstrument-coverage -Ccodegen-units=1 -Cinline-threshold=0 -Clink-dead-code -Coverflow-checks=off -Cpanic=abort)
+    endif()
 endif()
 
 # Feature probe
@@ -287,8 +297,8 @@ if (BUILD_DLL OR NOT MSVC)
         $<TARGET_OBJECTS:common>
     )
     if (WITH_RUST)
-        corrosion_set_env_vars(chewing CMAKE_BINARY_DIR=${CMAKE_BINARY_DIR})
-        if (${CMAKE_C_COMPILER_ID} STREQUAL "GNU")
+        if (${CMAKE_C_COMPILER_ID} STREQUAL "GNU" OR
+            ${CMAKE_C_COMPILER_ID} STREQUAL "Clang")
             target_link_options(chewing_shared PRIVATE "-Wl,-version-script,${CMAKE_BINARY_DIR}/symbols.map")
             target_link_options(chewing_shared PRIVATE "-Wl,--gc-sections")
         elseif (${CMAKE_C_COMPILER_ID} STREQUAL "AppleClang")
diff --git a/xtask/src/cli.rs b/xtask/src/cli.rs
index 0a964d6dd..57837765c 100644
--- a/xtask/src/cli.rs
+++ b/xtask/src/cli.rs
@@ -26,6 +26,10 @@ pub struct CmdBuild {
     #[argh(option, default = "false")]
     pub with_hash: bool,
 
+    /// instrument binary to generate coverage infomation
+    #[argh(option, default = "false")]
+    pub with_coverage: bool,
+
     /// show more information during build
     #[argh(option, default = "false")]
     pub verbose: bool,
diff --git a/xtask/src/main.rs b/xtask/src/main.rs
index 982bd602c..8c4e9f8f9 100644
--- a/xtask/src/main.rs
+++ b/xtask/src/main.rs
@@ -12,6 +12,7 @@ use cli::{Cli, Cmds};
 struct BuildOpts {
     with_rust: bool,
     with_hash: bool,
+    with_coverage: bool,
     verbose: bool,
     build_type: String,
 }
@@ -28,10 +29,11 @@ impl BuildOpts {
         // Configure CMake
         let with_rust: String = format!("-DWITH_RUST={}", self.with_rust);
         let with_sqlite3: String = format!("-DWITH_SQLITE3={}", !self.with_hash);
+        let with_coverage: String = format!("-DENABLE_GCOV={}", self.with_coverage);
         let build_type: String = format!("-DCMAKE_BUILD_TYPE={}", self.build_type);
         cmd!(
             sh,
-            "cmake -B ./build {with_rust} {build_type} {with_sqlite3}"
+            "cmake -B ./build {with_rust} {build_type} {with_sqlite3} {with_coverage}"
         )
         .run()
         .with_context(|| "cannot configure cmake")?;
@@ -70,6 +72,7 @@ fn main() -> Result<()> {
             BuildOpts {
                 with_rust: cmd.with_rust,
                 with_hash: cmd.with_hash,
+                with_coverage: cmd.with_coverage,
                 verbose: cmd.verbose,
                 build_type: cmd.build_type.clone(),
             }