Add compile-check target and adjust Clang warning flags

Introduce a compile-check target to ensure the umbrella header compiles successfully in isolation. Remove the `-Wno-character-conversion` flag in Clang MaxWarn configuration and update the MaxSan preset to include relevant profiles.

Author: MarkusB

CMakePresets.json

@@ -76,9 +76,9 @@
     {
       "name": "MaxWarnClang",
       "hidden": true,
-      "description": "Duplicates mb_ul_set_target_warnings Clang compile options via global CMAKE_CXX_FLAGS so they apply project-wide; this can break builds that pull in third-party sources (e.g. FetchContent) that do not compile cleanly under -Werror and the rest. Does not pass -D_FORTIFY_SOURCE=3 here (glibc requires -O; Debug would fail with -Werror); mb_ul_set_target_warnings still sets it for Release-family configs. Adds -Wno-unused-command-line-argument so globally ignored -f flags on some platforms do not fail the build. Adds -Wno-poison-system-directories so -Werror does not fail when Clang rejects host include paths (e.g. /usr/local/include) during cross-compilation. Adds -Wno-character-conversion so -Wconversion does not fail third-party code (e.g. GoogleTest gtest-printers); devenv/cmake/detail/warnings.cmake strips this flag for Apple Clang, which does not support it.",
+      "description": "Duplicates mb_ul_set_target_warnings Clang compile options via global CMAKE_CXX_FLAGS so they apply project-wide; this can break builds that pull in third-party sources (e.g. FetchContent) that do not compile cleanly under -Werror and the rest. Does not pass -D_FORTIFY_SOURCE=3 here (glibc requires -O; Debug would fail with -Werror); mb_ul_set_target_warnings still sets it for Release-family configs. Adds -Wno-unused-command-line-argument so globally ignored -f flags on some platforms do not fail the build. Adds -Wno-poison-system-directories so -Werror does not fail when Clang rejects host include paths (e.g. /usr/local/include) during cross-compilation",
       "cacheVariables": {
-        "CMAKE_CXX_FLAGS": "-D_GLIBCXX_ASSERTIONS -fexceptions -fno-builtin -fstack-clash-protection -fstack-protector-strong -U_FORTIFY_SOURCE -fno-delete-null-pointer-checks -fno-strict-overflow -fno-strict-aliasing -fno-limit-debug-info -fstrict-flex-arrays=3 -Wall -Wconversion -Werror -Wextra -Wformat -Wformat=2 -Wimplicit-fallthrough -Wno-deprecated-declarations -Wpedantic -Wsign-conversion -Wdocumentation -Wmissing-prototypes -Wno-c++11-narrowing -Wno-c++20-compat -Wno-switch-default -Wno-unused-command-line-argument -Wno-poison-system-directories -Wno-character-conversion",
+        "CMAKE_CXX_FLAGS": "-D_GLIBCXX_ASSERTIONS -fexceptions -fno-builtin -fstack-clash-protection -fstack-protector-strong -U_FORTIFY_SOURCE -fno-delete-null-pointer-checks -fno-strict-overflow -fno-strict-aliasing -fno-limit-debug-info -fstrict-flex-arrays=3 -Wall -Wconversion -Werror -Wextra -Wformat -Wformat=2 -Wimplicit-fallthrough -Wno-deprecated-declarations -Wpedantic -Wsign-conversion -Wdocumentation -Wmissing-prototypes -Wno-c++11-narrowing -Wno-c++20-compat -Wno-switch-default -Wno-unused-command-line-argument -Wno-poison-system-directories",
         "MB_DEVENV_ALL_WARNINGS": "ON"
       }
     },
@@ -178,6 +178,7 @@
         "appleclang",
         "debug",
         "MaxWarnClang",
+        "MaxSan",
         "base"
       ]
     },

devenv

@@ -4,6 +4,14 @@ if(NOT MB_CPP_LIB_TEMPLATE_HEADER_ONLY)
     target_sources(mb.cpp-lib-template PRIVATE ${sources})
 endif()
 
+add_executable(mb.cpp-lib-template.compile-check)
+target_sources(mb.cpp-lib-template.compile-check PRIVATE compile-check.cpp)
+target_link_libraries(
+    mb.cpp-lib-template.compile-check
+    PRIVATE mb::cpp-lib-template
+)
+mb_devenv_set_target_defaults(mb.cpp-lib-template.compile-check)
+
 if(NOT MB_CPP_LIB_TEMPLATE_BUILD_TESTS)
     return()
 endif()

src/CMakeLists.txt

@@ -0,0 +1,7 @@
+// TUs that include the umbrella header force a full compile of the header-only surface.
+#include "mb/cpp-lib-template/cpp-lib-template.hpp"
+#include <cstdint>
+
+int32_t main() {
+    return 0;
+}