fail builds in CI on compiler warnings

.github/workflows/CI-unixish.yml

@@ -31,6 +31,12 @@ jobs:
         sudo apt-get update
         sudo apt-get install libc++-18-dev
 
+      # coreutils contains "nproc"
+    - name: Install missing software on macos
+      if: contains(matrix.os, 'macos')
+      run: |
+        brew install coreutils
+
     - name: Install missing software on macos
       if: contains(matrix.os, 'macos')
       run: |
@@ -41,9 +47,11 @@ jobs:
         python3 -m pip config set global.break-system-packages true
         python3 -m pip install pytest
 
+    # TODO: bail out on warnings
     - name: make simplecpp
       run: make -j$(nproc)
 
+    # TODO: bail out on warnings
     - name: make test
       run: make -j$(nproc) test
 
@@ -57,7 +65,7 @@ jobs:
 
     - name: Run CMake
       run: |
-        cmake -S . -B cmake.output
+        cmake -S . -B cmake.output -DCMAKE_COMPILE_WARNING_AS_ERROR=On
 
     - name: CMake simplecpp
       run: |
@@ -80,27 +88,27 @@ jobs:
       if: matrix.os == 'ubuntu-24.04' && matrix.compiler == 'g++'
       run: |
         make clean
-        make -j$(nproc) test selfcheck CXXFLAGS="-g3 -D_GLIBCXX_DEBUG"
+        make -j$(nproc) test selfcheck CXXFLAGS="-Werror -Wno-multichar -g3 -D_GLIBCXX_DEBUG"
 
     - name: Run with libc++ hardening mode
       if: matrix.os == 'ubuntu-24.04' && matrix.compiler == 'clang++'
       run: |
         make clean
-        make -j$(nproc) test selfcheck CXXFLAGS="-stdlib=libc++ -g3 -D_LIBCPP_HARDENING_MODE=_LIBCPP_HARDENING_MODE_DEBUG" LDFLAGS="-lc++"
+        make -j$(nproc) test selfcheck CXXFLAGS="-Werror -Wno-multichar -stdlib=libc++ -g3 -D_LIBCPP_HARDENING_MODE=_LIBCPP_HARDENING_MODE_DEBUG" LDFLAGS="-lc++"
 
     - name: Run AddressSanitizer
       if: matrix.os == 'ubuntu-24.04'
       run: |
         make clean
-        make -j$(nproc) test selfcheck CXXFLAGS="-O2 -g3 -fsanitize=address" LDFLAGS="-fsanitize=address"
+        make -j$(nproc) test selfcheck CXXFLAGS="-Werror -Wno-multichar -O2 -g3 -fsanitize=address" LDFLAGS="-fsanitize=address"
       env:
         ASAN_OPTIONS: detect_stack_use_after_return=1
 
     - name: Run UndefinedBehaviorSanitizer
       if: matrix.os == 'ubuntu-24.04'
       run: |
         make clean
-        make -j$(nproc) test selfcheck CXXFLAGS="-O2 -g3 -fsanitize=undefined -fno-sanitize=signed-integer-overflow" LDFLAGS="-fsanitize=undefined -fno-sanitize=signed-integer-overflow"
+        make -j$(nproc) test selfcheck CXXFLAGS="-Werror -Wno-multichar -O2 -g3 -fsanitize=undefined -fno-sanitize=signed-integer-overflow" LDFLAGS="-fsanitize=undefined -fno-sanitize=signed-integer-overflow"
       env:
         UBSAN_OPTIONS: print_stacktrace=1:halt_on_error=1:report_error_type=1
 
@@ -109,4 +117,4 @@ jobs:
       if: false && matrix.os == 'ubuntu-24.04' && matrix.compiler == 'clang++'
       run: |
         make clean
-        make -j$(nproc) test selfcheck CXXFLAGS="-O2 -g3 -stdlib=libc++ -fsanitize=memory" LDFLAGS="-lc++ -fsanitize=memory"
+        make -j$(nproc) test selfcheck CXXFLAGS="-Werror -Wno-multichar -O2 -g3 -stdlib=libc++ -fsanitize=memory" LDFLAGS="-lc++ -fsanitize=memory"

.github/workflows/CI-windows.yml

@@ -40,12 +40,14 @@ jobs:
 
       - name: Run CMake
         run: |
-          cmake -G "Visual Studio 17 2022" -A x64 . || exit /b !errorlevel!
+          cmake -G "Visual Studio 17 2022" -A x64 -DCMAKE_COMPILE_WARNING_AS_ERROR=On . || exit /b !errorlevel!
 
       - name: Build
         run: |
            msbuild -m simplecpp.sln /p:Configuration=${{ matrix.config }} /p:Platform=x64 || exit /b !errorlevel!
-
+        env:
+          _CL_: /WX
+
       - name: Test
         run: |
           .\${{ matrix.config }}\testrunner.exe || exit /b !errorlevel!

.github/workflows/clang-tidy.yml

@@ -30,7 +30,7 @@ jobs:
 
       - name: Prepare CMake
         run: |
-          cmake -S . -B cmake.output -G "Unix Makefiles" -DCMAKE_EXPORT_COMPILE_COMMANDS=ON
+          cmake -S . -B cmake.output -G "Unix Makefiles" -DCMAKE_COMPILE_WARNING_AS_ERROR=On -DCMAKE_EXPORT_COMPILE_COMMANDS=ON
         env:
           CXX: clang-20
 

CMakeLists.txt

@@ -38,6 +38,8 @@ if (CMAKE_CXX_COMPILER_ID MATCHES "GNU")
 
     add_compile_options(-Wsuggest-attribute=noreturn)
     add_compile_options_safe(-Wuseless-cast)
+
+    add_compile_options(-Wno-shadow) # TODO: fix these
 elseif (CMAKE_CXX_COMPILER_ID MATCHES "MSVC")
     add_compile_definitions(_CRT_SECURE_NO_WARNINGS)
 elseif (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
@@ -56,6 +58,10 @@ elseif (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
     # TODO: fix these?
     add_compile_options(-Wno-padded -Wno-sign-conversion -Wno-implicit-int-conversion -Wno-shorten-64-to-32 -Wno-shadow-field-in-constructor)
 
+    if (CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang")
+        add_compile_options(-Wno-c++11-long-long)
+    endif()
+
     if (CMAKE_CXX_COMPILER_VERSION VERSION_EQUAL 14 OR CMAKE_CXX_COMPILER_VERSION VERSION_GREATER 14)
         # TODO: verify this regression still exists in clang-15
         if (CMAKE_BUILD_TYPE STREQUAL "Release" OR CMAKE_BUILD_TYPE STREQUAL "RelWithDebInfo")

simplecpp.cpp

@@ -745,7 +745,7 @@ void simplecpp::TokenList::readfile(Stream &stream, const std::string &filename,
 
         // number or name
         if (isNameChar(ch)) {
-            const bool num = std::isdigit(ch);
+            const bool num = !!std::isdigit(ch);
             while (stream.good() && isNameChar(ch)) {
                 currentToken += ch;
                 ch = stream.readChar();
@@ -886,7 +886,7 @@ void simplecpp::TokenList::readfile(Stream &stream, const std::string &filename,
             }
 
             if (prefix.empty())
-                push_back(new Token(s, location, std::isspace(stream.peekChar()))); // push string without newlines
+                push_back(new Token(s, location, !!std::isspace(stream.peekChar()))); // push string without newlines
             else
                 back()->setstr(prefix + s);
 
@@ -916,7 +916,7 @@ void simplecpp::TokenList::readfile(Stream &stream, const std::string &filename,
             }
         }
 
-        push_back(new Token(currentToken, location, std::isspace(stream.peekChar())));
+        push_back(new Token(currentToken, location, !!std::isspace(stream.peekChar())));
 
         if (multiline)
             location.col += currentToken.size();