Note, not trying to address every last error, just some obvious/easy ones.
```
/usr/local/google/home/jperkins/dev/carbon-lang/common/string_helpers.cpp:200:13: warning: prefer transparent functors 'less_equal<>' [modernize-use-transparent-functors]
auto le = std::less_equal<const char*>();
^
/usr/local/google/home/jperkins/dev/carbon-lang/toolchain/semantics/nodes/function.h:22:45: warning: pass by value and use std::move [modernize-pass-by-value]
Function(ParseTree::Node node, NodeId id, llvm::SmallVector<NodeRef> body)
^
/usr/local/google/home/jperkins/dev/carbon-lang/explorer/ast/declaration.cpp:230:14: warning: static member accessed through instance [readability-static-accessed-through-instance]
return cast<SelfDeclaration>(declaration).name();
^
/usr/local/google/home/jperkins/dev/carbon-lang/explorer/interpreter/type_checker.cpp:1104:33: warning: std::move of the variable 'impl' of the trivially-copyable type 'ConstraintType::ImplConstraint' has no effect [performance-move-const-arg]
impl_constraints_.push_back(std::move(impl));
^
/usr/local/google/home/jperkins/dev/carbon-lang/explorer/interpreter/type_checker.cpp:1145:36: warning: std::move of the variable 'rewrite' of the trivially-copyable type 'ConstraintType::RewriteConstraint' has no effect [performance-move-const-arg]
rewrite_constraints_.push_back(std::move(rewrite));
^
/usr/local/google/home/jperkins/dev/carbon-lang/explorer/interpreter/type_checker.cpp:1156:32: warning: std::move of the variable 'context' of the trivially-copyable type 'ConstraintType::LookupContext' has no effect [performance-move-const-arg]
lookup_contexts_.push_back(std::move(context));
^
/usr/local/google/home/jperkins/dev/carbon-lang/explorer/fuzzing/fuzzverter.cpp:74:42: warning: argument name 'trace' in comment does not match parameter name 'parser_debug' [bugprone-argument-comment]
/*trace=*/false);
^
./explorer/syntax/parse.h:19:17: note: 'parser_debug' declared here
bool parser_debug) -> ErrorOr<Carbon::AST>;
^
/usr/local/google/home/jperkins/dev/carbon-lang/explorer/fuzzing/proto_to_carbon_test.cpp:34:55: warning: argument name 'trace' in comment does not match parameter name 'parser_debug' [bugprone-argument-comment]
const ErrorOr<AST> ast = Carbon::Parse(&arena, f, /*trace=*/false);
^
./explorer/syntax/parse.h:19:17: note: 'parser_debug' declared here
bool parser_debug) -> ErrorOr<Carbon::AST>;
^
/usr/local/google/home/jperkins/dev/carbon-lang/explorer/fuzzing/proto_to_carbon_test.cpp:42:41: warning: argument name 'trace' in comment does not match parameter name 'parser_debug' [bugprone-argument-comment]
&arena, f, source_from_proto, /*trace=*/false);
^
./explorer/syntax/parse.h:25:59: note: 'parser_debug' declared here
std::string_view file_contents, bool parser_debug)
^
/usr/local/google/home/jperkins/dev/carbon-lang/explorer/syntax/parse_test.cpp:27:60: warning: argument name 'trace' in comment does not match parameter name 'parser_debug' [bugprone-argument-comment]
ParseFromString(&arena, "file.carbon", FileContents, /*trace=*/false);
^
./explorer/syntax/parse.h:25:59: note: 'parser_debug' declared here
std::string_view file_contents, bool parser_debug)
^
/usr/local/google/home/jperkins/dev/carbon-lang/migrate_cpp/cpp_refactoring/var_decl.cpp:57:58: warning: string concatenation results in allocation of unnecessary temporary strings; consider using 'operator+=' or 'string::append()' instead [performance-inefficient-string-concatenation]
segments.push_back({type_loc_class, qual_str + " " + range_str});
^
/usr/local/google/home/jperkins/dev/carbon-lang/explorer/fuzzing/ast_to_proto_test.cpp:105:55: warning: argument name 'trace' in comment does not match parameter name 'parser_debug' [bugprone-argument-comment]
const ErrorOr<AST> ast = Carbon::Parse(&arena, f, /*trace=*/false);
^
./explorer/syntax/parse.h:19:17: note: 'parser_debug' declared here
bool parser_debug) -> ErrorOr<Carbon::AST>;
^
```
This is to help with frequent build breakages cased by proto changes.
Fuzzer corpus can be periodically auto-regenerated.
Crashing samples from the fuzzer are better 'preserved' in the form of fail_xx.carbon tests.
I'm doing this to avoid macro name conflicts, following https://google.github.io/styleguide/cppguide.html#Preprocessor_Macros: "If you do export a macro from a header, it must have a globally unique name. To achieve this, it must be named with a prefix consisting of your project's namespace name (but upper case)."
Commands run:
```
sed -i 's/\(DCHECK\|CHECK\|FATAL\|MAKE_UNIQUE_NAME\|MAKE_UNIQUE_NAME_IMPL\|RAW_EXITING_STREAM\|RETURN_IF_ERROR\|RETURN_IF_ERROR_IMPL\|ASSIGN_OR_RETURN\|ASSIGN_OR_RETURN_IMPL\|DIAGNOSTIC_KIND\|RETURN_IF_STACK_LIMITED\)(/CARBON_\1(/g' $(git ls-files *.cpp *.h *.lpp *.ypp *.def ':!third_party')
sed -i 's/#undef DIAGNOSTIC_KIND/#undef CARBON_DIAGNOSTIC_KIND/' toolchain/diagnostics/diagnostic_registry.def
```
Note this isn't *quite* everything, but it's intended to be a large pass at everything:
```
╚╡git grep '#define ' *.cpp *.h *.lpp *.ypp *.def ':!third_party' | grep -v '#define CARBON' | grep -v _H_
explorer/syntax/lexer.lpp: #define YY_USER_ACTION \
explorer/syntax/lexer.lpp: #define SIMPLE_TOKEN(name) \
explorer/syntax/lexer.lpp: #define ARG_TOKEN(name, arg) \
explorer/syntax/parse_and_lex_context.h:#define YY_DECL \
migrate_cpp/cpp_refactoring/var_decl.cpp:#define ABSTRACT_TYPE(Class, Base)
migrate_cpp/cpp_refactoring/var_decl.cpp:#define TYPE(Class, Base) \
```
We may in particular want to do a pass to clean up #ifdef guards and make them be CARBON_ rooted.