Enable -Werror=switch-enum

switch statements must now match all enum values or disable the
warning.

Explicit is good. This has helped us find two bugs, after solving
another one by debugging.

From now on, adding to an enum will raise errors where they are
not explicitly handled, which is good for productivity, and helps
us decide the correct behavior in all usages.

Notably still excluded from this though are the cases where the
warning is disabled by local pragmas.

fromTOML.cc did not build despite a top-level pragma, so I've had
to resort to a makefile solution for that.
This commit is contained in:
Robert Hensing 2023-04-03 18:11:42 +02:00
parent 9470ee877d
commit fba7be80eb
4 changed files with 8 additions and 4 deletions

View file

@ -1,6 +1,8 @@
clean-files += Makefile.config
GLOBAL_CXXFLAGS += -Wno-deprecated-declarations
GLOBAL_CXXFLAGS += -Wno-deprecated-declarations -Werror=switch
# Allow switch-enum to be overridden for files that do not support it, usually because of dependency headers.
ERROR_SWITCH_ENUM = -Werror=switch-enum
$(foreach i, config.h $(wildcard src/lib*/*.hh), \
$(eval $(call install-file-in, $(i), $(includedir)/nix, 0644)))

View file

@ -1,10 +1,10 @@
$(buildprefix)%.o: %.cc
@mkdir -p "$(dir $@)"
$(trace-cxx) $(CXX) -o $@ -c $< $(CPPFLAGS) $(GLOBAL_CXXFLAGS_PCH) $(GLOBAL_CXXFLAGS) $(CXXFLAGS) $($@_CXXFLAGS) -MMD -MF $(call filename-to-dep, $@) -MP
$(trace-cxx) $(CXX) -o $@ -c $< $(CPPFLAGS) $(GLOBAL_CXXFLAGS_PCH) $(GLOBAL_CXXFLAGS) $(CXXFLAGS) $($@_CXXFLAGS) $(ERROR_SWITCH_ENUM) -MMD -MF $(call filename-to-dep, $@) -MP
$(buildprefix)%.o: %.cpp
@mkdir -p "$(dir $@)"
$(trace-cxx) $(CXX) -o $@ -c $< $(CPPFLAGS) $(GLOBAL_CXXFLAGS_PCH) $(GLOBAL_CXXFLAGS) $(CXXFLAGS) $($@_CXXFLAGS) -MMD -MF $(call filename-to-dep, $@) -MP
$(trace-cxx) $(CXX) -o $@ -c $< $(CPPFLAGS) $(GLOBAL_CXXFLAGS_PCH) $(GLOBAL_CXXFLAGS) $(CXXFLAGS) $($@_CXXFLAGS) $(ERROR_SWITCH_ENUM) -MMD -MF $(call filename-to-dep, $@) -MP
$(buildprefix)%.o: %.c
@mkdir -p "$(dir $@)"

View file

@ -46,3 +46,5 @@ $(foreach i, $(wildcard src/libexpr/flake/*.hh), \
$(d)/primops.cc: $(d)/imported-drv-to-derivation.nix.gen.hh $(d)/primops/derivation.nix.gen.hh $(d)/fetchurl.nix.gen.hh
$(d)/flake/flake.cc: $(d)/flake/call-flake.nix.gen.hh
src/libexpr/primops/fromTOML.o: ERROR_SWITCH_ENUM =

View file

@ -68,7 +68,7 @@ public:
case lvlNotice: case lvlInfo: c = '5'; break;
case lvlTalkative: case lvlChatty: c = '6'; break;
case lvlDebug: case lvlVomit: c = '7';
default: c = '7'; break;
default: c = '7'; break; // should not happen, and missing enum case is reported by -Werror=switch-enum
}
prefix = std::string("<") + c + ">";
}