Add coverage support (minimal)

Author: ramsafin

CMakeLists.txt

@@ -21,19 +21,29 @@ if(CMAKE_CONFIGURATION_TYPES)
   set(CMAKE_CONFIGURATION_TYPES "${CMAKE_CONFIGURATION_TYPES}" CACHE STRING "" FORCE)
 endif()
 
+# Add custom "Coverage" build type
+if(CMAKE_CONFIGURATION_TYPES)
+  list(APPEND CMAKE_CONFIGURATION_TYPES Coverage)
+  list(REMOVE_DUPLICATES CMAKE_CONFIGURATION_TYPES)
+  set(CMAKE_CONFIGURATION_TYPES "${CMAKE_CONFIGURATION_TYPES}" CACHE STRING "" FORCE)
+endif()
+
 # Load cmake modules
 list(APPEND CMAKE_MODULE_PATH "${CMAKE_SOURCE_DIR}/cmake")
 
-# Warnings, sanitizers, Link Time Optimization (LTO)
+# Warnings, Sanitizers, Link Time Optimization (LTO)
 include(options/LTO)
 include(options/Warnings)
 include(options/Sanitizers)
 
+# Coverage
+include(tools/Coverage)
+
 # === Libraries ===
 add_subdirectory(src) # modern_cpp_project::math
 
 # === Application ===
-if(BUILD_APP)
+if(BUILD_APP AND NOT CMAKE_BUILD_TYPE STREQUAL "Coverage")
   add_subdirectory(app) # modern_cpp_project_app
 endif()
 
@@ -43,8 +53,10 @@ if(ENABLE_TESTING)
   add_subdirectory(tests)
 endif()
 
-if(ENABLE_BENCHMARKS AND NOT CMAKE_BUILD_TYPE STREQUAL "Sanitize")
-  add_subdirectory(benchmarks)
+if(ENABLE_BENCHMARKS)
+  if (NOT CMAKE_BUILD_TYPE STREQUAL "Coverage" AND NOT CMAKE_BUILD_TYPE STREQUAL "Sanitize")
+    add_subdirectory(benchmarks)
+  endif()
 endif()
 
 # === Docs ===

CMakePresets.json

@@ -43,10 +43,22 @@
       "name": "gcc-RelWithDebInfo-lto",
       "inherits": "gcc-RelWithDebInfo",
       "cacheVariables": {
+        "CMAKE_C_COMPILER": "gcc",
+        "CMAKE_CXX_COMPILER": "g++",
         "CMAKE_INTERPROCEDURAL_OPTIMIZATION": "TRUE"
       },
       "description": "GCC RelWithDebInfo build with Link Time Optimization (LTO)"
     },
+    {
+      "name": "gcc-Coverage",
+      "inherits": "base",
+      "cacheVariables": {
+        "CMAKE_C_COMPILER": "gcc",
+        "CMAKE_CXX_COMPILER": "g++",
+        "CMAKE_BUILD_TYPE": "Coverage"
+      },
+      "description": "GCC build with coverage"
+    },
     {
       "name": "clang-RelWithDebInfo",
       "inherits": "base",
@@ -71,9 +83,21 @@
       "name": "clang-RelWithDebInfo-lto",
       "inherits": "clang-RelWithDebInfo",
       "cacheVariables": {
+        "CMAKE_C_COMPILER": "clang",
+        "CMAKE_CXX_COMPILER": "clang++",
         "CMAKE_INTERPROCEDURAL_OPTIMIZATION": "TRUE"
       },
       "description": "Clang RelWithDebInfo build with Link Time Optimization (LTO)"
+    },
+    {
+      "name": "clang-Coverage",
+      "inherits": "base",
+      "cacheVariables": {
+        "CMAKE_C_COMPILER": "clang",
+        "CMAKE_CXX_COMPILER": "clang++",
+        "CMAKE_BUILD_TYPE": "Coverage"
+      },
+      "description": "Clang build with coverage"
     }
   ],
   "buildPresets": [
@@ -103,6 +127,12 @@
       "configurePreset": "gcc-RelWithDebInfo-lto",
       "description": "Build using GCC + LTO (RelWithDebInfo)"
     },
+    {
+      "name": "gcc-Coverage",
+      "inherits": "build-base",
+      "configurePreset": "gcc-Coverage",
+      "description": "Build using GCC + Coverage"
+    },
     {
       "name": "clang-RelWithDebInfo",
       "inherits": "build-base",
@@ -120,6 +150,12 @@
       "inherits": "build-base",
       "configurePreset": "clang-RelWithDebInfo-lto",
       "description": "Build using Clang + LTO (RelWithDebInfo)"
+    },
+    {
+      "name": "clang-Coverage",
+      "inherits": "build-base",
+      "configurePreset": "clang-Coverage",
+      "description": "Build using Clang + Coverage"
     }
   ],
   "testPresets": [
@@ -153,6 +189,12 @@
       "configurePreset": "gcc-RelWithDebInfo-lto",
       "description": "Test using GCC + LTO (RelWithDebInfo)"
     },
+    {
+      "name": "gcc-Coverage",
+      "inherits": "test-base",
+      "configurePreset": "gcc-Coverage",
+      "description": "Test using GCC + Coverage"
+    },
     {
       "name": "clang-RelWithDebInfo",
       "inherits": "test-base",
@@ -170,6 +212,12 @@
       "inherits": "test-base",
       "configurePreset": "clang-RelWithDebInfo-lto",
       "description": "Test using Clang + LTO (RelWithDebInfo)"
+    },
+    {
+      "name": "clang-Coverage",
+      "inherits": "test-base",
+      "configurePreset": "clang-Coverage",
+      "description": "Test using Clang + Coverage"
     }
   ]
-}
+}

cmake/tools/Coverage.cmake

@@ -0,0 +1,43 @@
+function(enable_coverage target)
+  if(CMAKE_BUILD_TYPE STREQUAL "Coverage")
+    target_compile_options(${target} PRIVATE --coverage -O0 -g)
+    target_link_options(${target} PRIVATE --coverage)
+    message(STATUS "Coverage enabled for target ${target}")
+  endif()
+endfunction()
+
+find_program(LCOV_EXECUTABLE lcov)
+find_program(GENHTML_EXECUTABLE genhtml)
+
+if(LCOV_EXECUTABLE)
+  set(COVERAGE_INFO "${CMAKE_BINARY_DIR}/coverage.info")
+  set(COVERAGE_CLEANED "${CMAKE_BINARY_DIR}/coverage.info.cleaned")
+  set(COVERAGE_REPORT_DIR "${CMAKE_BINARY_DIR}/coverage-report")
+
+  add_custom_target(coverage
+    COMMAND ${LCOV_EXECUTABLE} --directory . --capture --output-file ${COVERAGE_INFO} --ignore-errors mismatch
+    COMMAND ${LCOV_EXECUTABLE} --remove ${COVERAGE_INFO}
+            /usr/* ${CMAKE_BINARY_DIR}/*
+            --output-file ${COVERAGE_CLEANED}
+    COMMAND ${GENHTML_EXECUTABLE} ${COVERAGE_CLEANED}
+            --output-directory ${COVERAGE_REPORT_DIR}
+    WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
+    COMMENT "Generating code coverage report with lcov + genhtml"
+    VERBATIM
+  )
+
+  message(STATUS "Coverage support enabled (run: cmake --build --target coverage)")
+endif()
+
+if(GENHTML_EXECUTABLE)
+  add_custom_target(genhtml
+    COMMAND ${GENHTML_EXECUTABLE}
+      ${CMAKE_BINARY_DIR}/coverage.info.cleaned
+      --output-directory ${CMAKE_BINARY_DIR}/coverage-report
+    WORKING_DIRECTORY ${CMAKE_BINARY_DIR}
+    COMMENT "Generating HTML coverage report with genhtml"
+    VERBATIM
+  )
+else()
+  message(STATUS "genhtml not found — 'genhtml' target will not be available.")
+endif()

include/math/arithmetic.hpp

@@ -27,6 +27,15 @@ int add(int left, int right);
  */
 int subtract(int left, int right);
 
+/**
+ * @brief Multiplies two integers.
+ *
+ * @param left First integer.
+ * @param right Second integer.
+ * @return Multiplication of left and right.
+ */
+int multiply(int left, int right);
+
 }  // namespace math
 
 #endif

src/CMakeLists.txt

@@ -10,6 +10,8 @@ target_include_directories(math
     $<INSTALL_INTERFACE:include>
 )
 
+enable_coverage(math)
+
 enable_lto(math)
 enable_sanitizers(math)
 enable_strict_warnings(math)

src/arithmetic.cpp

@@ -13,4 +13,9 @@ int subtract(int left, int right)
   return left - right;
 }
 
+int multiply(int left, int right)
+{
+  return left * right;
+}
+
 }  // namespace math

tests/CMakeLists.txt

@@ -25,6 +25,7 @@ target_link_libraries(unit_tests
 )
 
 enable_warnings(unit_tests)
+enable_coverage(unit_tests)
 enable_sanitizers(unit_tests)
 
 # Automatically discover and register all test cases