# Our principle is to enable as many warnings as possible and always do it with "warnings as errors" flag. # # But it comes with some cost: # - we have to disable some warnings in 3rd party libraries (they are located in "contrib" directory) # - we have to include headers of these libraries as -isystem to avoid warnings from headers # (this is the same behaviour as if these libraries were located in /usr/include) # - sometimes warnings from 3rd party libraries may come from macro substitutions in our code # and we have to wrap them with #pragma GCC/clang diagnostic ignored set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wextra") # Add some warnings that are not available even with -Wall -Wextra -Wpedantic. # Intended for exploration of new compiler warnings that may be found useful. # Applies to clang only option (WEVERYTHING "Enable -Weverything option with some exceptions." ON) # Control maximum size of stack frames. It can be important if the code is run in fibers with small stack size. # Only in release build because debug has too large stack frames. if ((NOT CMAKE_BUILD_TYPE_UC STREQUAL "DEBUG") AND (NOT SANITIZE) AND (NOT CMAKE_CXX_COMPILER_ID MATCHES "AppleClang")) add_warning(frame-larger-than=65536) endif () if (COMPILER_CLANG) add_warning(pedantic) no_warning(vla-extension) no_warning(zero-length-array) no_warning(c11-extensions) if (WEVERYTHING) add_warning(everything) no_warning(c++98-compat-pedantic) no_warning(c++98-compat) no_warning(c99-extensions) no_warning(conversion) no_warning(ctad-maybe-unsupported) # clang 9+, linux-only no_warning(deprecated-dynamic-exception-spec) no_warning(disabled-macro-expansion) no_warning(documentation-unknown-command) no_warning(double-promotion) no_warning(exit-time-destructors) no_warning(float-equal) no_warning(global-constructors) no_warning(missing-prototypes) no_warning(missing-variable-declarations) no_warning(nested-anon-types) no_warning(packed) no_warning(padded) no_warning(return-std-move-in-c++11) # clang 7+ no_warning(shift-sign-overflow) no_warning(sign-conversion) no_warning(switch-enum) no_warning(undefined-func-template) no_warning(unused-template) no_warning(vla) no_warning(weak-template-vtables) no_warning(weak-vtables) # TODO Enable conversion, sign-conversion, double-promotion warnings. else () add_warning(comma) add_warning(conditional-uninitialized) add_warning(covered-switch-default) add_warning(deprecated) add_warning(embedded-directive) add_warning(empty-init-stmt) # linux-only add_warning(extra-semi-stmt) # linux-only add_warning(extra-semi) add_warning(gnu-case-range) add_warning(inconsistent-missing-destructor-override) add_warning(newline-eof) add_warning(old-style-cast) add_warning(range-loop-analysis) add_warning(redundant-parens) add_warning(reserved-id-macro) add_warning(shadow-field) add_warning(shadow-uncaptured-local) add_warning(shadow) add_warning(string-plus-int) add_warning(undef) add_warning(unreachable-code-return) add_warning(unreachable-code) add_warning(unused-exception-parameter) add_warning(unused-macros) add_warning(unused-member-function) add_warning(unneeded-internal-declaration) add_warning(implicit-int-float-conversion) add_warning(no-delete-null-pointer-checks) add_warning(anon-enum-enum-conversion) add_warning(assign-enum) add_warning(bitwise-op-parentheses) add_warning(int-in-bool-context) add_warning(sometimes-uninitialized) add_warning(tautological-bitwise-compare) # XXX: libstdc++ has some of these for 3way compare add_warning(zero-as-null-pointer-constant) endif () elseif (COMPILER_GCC) # Add compiler options only to c++ compiler function(add_cxx_compile_options option) add_compile_options("$<$,CXX>:${option}>") endfunction() # Warn about boolean expression compared with an integer value different from true/false add_cxx_compile_options(-Wbool-compare) # Warn whenever a pointer is cast such that the required alignment of the target is increased. add_cxx_compile_options(-Wcast-align) # Warn whenever a pointer is cast so as to remove a type qualifier from the target type. add_cxx_compile_options(-Wcast-qual) # Warn when deleting a pointer to incomplete type, which may cause undefined behavior at runtime add_cxx_compile_options(-Wdelete-incomplete) # Warn if a requested optimization pass is disabled. Code is too big or too complex add_cxx_compile_options(-Wdisabled-optimization) # Warn about duplicated conditions in an if-else-if chain add_cxx_compile_options(-Wduplicated-cond) # Warn about a comparison between values of different enumerated types add_cxx_compile_options(-Wenum-compare) # Warn about uninitialized variables that are initialized with themselves add_cxx_compile_options(-Winit-self) # Warn about logical not used on the left hand side operand of a comparison add_cxx_compile_options(-Wlogical-not-parentheses) # Warn about suspicious uses of logical operators in expressions add_cxx_compile_options(-Wlogical-op) # Warn if there exists a path from the function entry to a use of the variable that is uninitialized. add_cxx_compile_options(-Wmaybe-uninitialized) # Warn when the indentation of the code does not reflect the block structure add_cxx_compile_options(-Wmisleading-indentation) # Warn if a global function is defined without a previous declaration - disabled because of build times # add_cxx_compile_options(-Wmissing-declarations) # Warn if a user-supplied include directory does not exist add_cxx_compile_options(-Wmissing-include-dirs) # Obvious add_cxx_compile_options(-Wnon-virtual-dtor) # Obvious add_cxx_compile_options(-Wno-return-local-addr) # This warning is disabled due to false positives if compiled with libc++: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90037 #add_cxx_compile_options(-Wnull-dereference) # Obvious add_cxx_compile_options(-Wodr) # Obvious add_cxx_compile_options(-Wold-style-cast) # Warn when a function declaration hides virtual functions from a base class # add_cxx_compile_options(-Woverloaded-virtual) # Warn about placement new expressions with undefined behavior add_cxx_compile_options(-Wplacement-new=2) # Warn about anything that depends on the “size of” a function type or of void add_cxx_compile_options(-Wpointer-arith) # Warn if anything is declared more than once in the same scope add_cxx_compile_options(-Wredundant-decls) # Member initialization reordering add_cxx_compile_options(-Wreorder) # Obvious add_cxx_compile_options(-Wshadow) # Warn if left shifting a negative value add_cxx_compile_options(-Wshift-negative-value) # Warn about a definition of an unsized deallocation function add_cxx_compile_options(-Wsized-deallocation) # Warn when the sizeof operator is applied to a parameter that is declared as an array in a function definition add_cxx_compile_options(-Wsizeof-array-argument) # Warn for suspicious length parameters to certain string and memory built-in functions if the argument uses sizeof add_cxx_compile_options(-Wsizeof-pointer-memaccess) # Warn about overriding virtual functions that are not marked with the override keyword add_cxx_compile_options(-Wsuggest-override) # Warn whenever a switch statement has an index of boolean type and the case values are outside the range of a boolean type add_cxx_compile_options(-Wswitch-bool) # Warn if a self-comparison always evaluates to true or false add_cxx_compile_options(-Wtautological-compare) # Warn about trampolines generated for pointers to nested functions add_cxx_compile_options(-Wtrampolines) # Obvious add_cxx_compile_options(-Wunused) add_cxx_compile_options(-Wundef) # Warn if vector operation is not implemented via SIMD capabilities of the architecture add_cxx_compile_options(-Wvector-operation-performance) # Warn when a literal 0 is used as null pointer constant. add_cxx_compile_options(-Wzero-as-null-pointer-constant) # The following warnings are generally useful but had to be disabled because of compiler bugs with older GCCs. # XXX: We should try again on more recent GCCs (--> see CMake variable GCC_MINIMUM_VERSION). # gcc10 stuck with this option while compiling GatherUtils code, anyway there are builds with clang that will warn add_cxx_compile_options(-Wno-sequence-point) # gcc10 false positive with this warning in MergeTreePartition.cpp # inlined from 'void writeHexByteLowercase(UInt8, void*)' at ../src/Common/hex.h:39:11, # inlined from 'DB::String DB::MergeTreePartition::getID(const DB::Block&) const' at ../src/Storages/MergeTree/MergeTreePartition.cpp:85:30: # ../contrib/libc-headers/x86_64-linux-gnu/bits/string_fortified.h:34:33: error: writing 2 bytes into a region of size 0 [-Werror=stringop-overflow=] # 34 | return __builtin___memcpy_chk (__dest, __src, __len, __bos0 (__dest)); # For some reason (bug in gcc?) macro 'GCC diagnostic ignored "-Wstringop-overflow"' doesn't help. add_cxx_compile_options(-Wno-stringop-overflow) # reinterpretAs.cpp:182:31: error: ‘void* memcpy(void*, const void*, size_t)’ copying an object of non-trivial type # ‘using ToFieldType = using FieldType = using UUID = struct StrongTypedef, DB::UUIDTag>’ # {aka ‘struct StrongTypedef, DB::UUIDTag>’} from an array of ‘const char8_t’ add_cxx_compile_options(-Wno-error=class-memaccess) # Maybe false positive... # In file included from /home/jakalletti/ClickHouse/ClickHouse/contrib/libcxx/include/memory:673, # In function ‘void std::__1::__libcpp_operator_delete(_Args ...) [with _Args = {void*, long unsigned int}]’, # inlined from ‘void std::__1::__do_deallocate_handle_size(void*, size_t, _Args ...) [with _Args = {}]’ at /home/jakalletti/ClickHouse/ClickHouse/contrib/libcxx/include/new:271:34, # inlined from ‘void std::__1::__libcpp_deallocate(void*, size_t, size_t)’ at /home/jakalletti/ClickHouse/ClickHouse/contrib/libcxx/include/new:285:41, # inlined from ‘constexpr void std::__1::allocator<_Tp>::deallocate(_Tp*, size_t) [with _Tp = char]’ at /home/jakalletti/ClickHouse/ClickHouse/contrib/libcxx/include/memory:849:39, # inlined from ‘static constexpr void std::__1::allocator_traits<_Alloc>::deallocate(std::__1::allocator_traits<_Alloc>::allocator_type&, std::__1::allocator_traits<_Alloc>::pointer, std::__1::allocator_traits<_Alloc>::size_type) [with _Alloc = std::__1::allocator]’ at /home/jakalletti/ClickHouse/ClickHouse/contrib/libcxx/include/__memory/allocator_traits.h:476:24, # inlined from ‘std::__1::basic_string<_CharT, _Traits, _Allocator>::~basic_string() [with _CharT = char; _Traits = std::__1::char_traits; _Allocator = std::__1::allocator]’ at /home/jakalletti/ClickHouse/ClickHouse/contrib/libcxx/include/string:2219:35, # inlined from ‘std::__1::basic_string<_CharT, _Traits, _Allocator>::~basic_string() [with _CharT = char; _Traits = std::__1::char_traits; _Allocator = std::__1::allocator]’ at /home/jakalletti/ClickHouse/ClickHouse/contrib/libcxx/include/string:2213:1, # inlined from ‘DB::JSONBuilder::JSONMap::Pair::~Pair()’ at /home/jakalletti/ClickHouse/ClickHouse/src/Common/JSONBuilder.h:90:12, # inlined from ‘void DB::JSONBuilder::JSONMap::add(std::__1::string, DB::JSONBuilder::ItemPtr)’ at /home/jakalletti/ClickHouse/ClickHouse/src/Common/JSONBuilder.h:97:68, # inlined from ‘virtual void DB::ExpressionStep::describeActions(DB::JSONBuilder::JSONMap&) const’ at /home/jakalletti/ClickHouse/ClickHouse/src/Processors/QueryPlan/ExpressionStep.cpp:102:12: # /home/jakalletti/ClickHouse/ClickHouse/contrib/libcxx/include/new:247:20: error: ‘void operator delete(void*, size_t)’ called on a pointer to an unallocated object ‘7598543875853023301’ [-Werror=free-nonheap-object] add_cxx_compile_options(-Wno-error=free-nonheap-object) # AggregateFunctionAvg.h:203:100: error: ‘this’ pointer is null [-Werror=nonnull] add_cxx_compile_options(-Wno-error=nonnull) endif ()