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Enable -Wswitch-enum GCC and Clang flag #2087

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Enable -Wswitch-enum GCC and Clang flag #2087

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d7291b3
C flags: enable -Wswitch-enum on both GCC and Clang
bettio Feb 5, 2026
112c2ff
term.c: fix enumeration value not handled in switch warning
bettio Feb 5, 2026
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4 changes: 2 additions & 2 deletions src/libAtomVM/CMakeLists.txt
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Expand Up @@ -132,9 +132,9 @@ add_library(libAtomVM ${SOURCE_FILES} ${HEADER_FILES})
target_include_directories(libAtomVM PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
target_compile_features(libAtomVM PUBLIC c_std_11)
if (CMAKE_C_COMPILER_ID STREQUAL "GNU")
target_compile_options(libAtomVM PUBLIC -Wall ${MAYBE_PEDANTIC_FLAG} ${MAYBE_WERROR_FLAG} -Wextra -ggdb -Werror=incompatible-pointer-types)
target_compile_options(libAtomVM PUBLIC -Wall ${MAYBE_PEDANTIC_FLAG} ${MAYBE_WERROR_FLAG} -Wextra -ggdb -Werror=incompatible-pointer-types -Wswitch-enum)
elseif (CMAKE_C_COMPILER_ID MATCHES "Clang")
target_compile_options(libAtomVM PUBLIC -Wall ${MAYBE_PEDANTIC_FLAG} -Wno-gnu-zero-variadic-macro-arguments --extra-warnings -Werror=incompatible-pointer-types ${MAYBE_WERROR_FLAG} -g)
target_compile_options(libAtomVM PUBLIC -Wall ${MAYBE_PEDANTIC_FLAG} -Wno-gnu-zero-variadic-macro-arguments --extra-warnings -Werror=incompatible-pointer-types -Wswitch-enum ${MAYBE_WERROR_FLAG} -g)
endif()

if (ENABLE_REALLOC_GC)
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5 changes: 5 additions & 0 deletions src/libAtomVM/term.c
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Expand Up @@ -1024,6 +1024,11 @@ TermCompareResult term_compare(term t, term other, TermCompareOpts opts, GlobalC
break;
}
}
case TERM_TYPE_INDEX_NIL:
// This cannot happen, since this branch is executed only when
// `type_t == type_other`,
// but we do `t == other` as the first thing, making this case unreachable.
case TERM_TYPE_INDEX_INVALID:
default:
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@mat-hek mat-hek Feb 6, 2026

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Suggested change
default:

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@bettio bettio Feb 6, 2026

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default: UNREACHABLE(); tells the compiler that any other value is undefined behavior, so it can perform additional optimizations. Otherwise it stills emit code for handling values outside the cases we defined.
Variables having an enum type are glorified integers, so the compiler by default doesn't infer that only allowed values are the enum values.

UNREACHABLE();
}
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