http://llvm.org/bugs/show_bug.cgi?id=19596
Bug ID: 19596
Summary: -Wunused-const-variable is too aggressive, shouldn't
be part of "-Wall" anyway
Product: clang
Version: 3.4
Hardware: All
OS: All
Status: NEW
Severity: normal
Priority: P
Component: Static Analyzer
Assignee: [email protected]
Reporter: [email protected]
CC: [email protected]
Classification: Unclassified
cat >type_safe_enum.h <<EOF
#pragma once
#define ENUM_CONST(a) a,
#define ENUM_COUNT(a) +1
#define ENUM_NAME(a) #a,
#define TYPE_SAFE_ENUM(NAME, TYPE, VALUES) \
enum class NAME : TYPE { VALUES(ENUM_CONST) }; \
static const TYPE EnumSize_##NAME = 0 VALUES(ENUM_COUNT); \
inline const char* EnumName(NAME a) { const char* names[] = {
VALUES(ENUM_NAME) }; return names[static_cast<TYPE>(a)]; }
EOF
cat >test.cc <<EOF
#include <string>
#include "type_safe_enum.h"
#define TABLE_ROLE_VALUES(F) \
F(Slave) \
F(Master)
TYPE_SAFE_ENUM(TableRole, int, TABLE_ROLE_VALUES);
TableRole g_foo = TableRole::Slave;
TableRole GetFoo() { return g_foo; }
std::string GetFooName() { return EnumName(g_foo); }
EOF
clang++ -std=c++11 -c test.cc -Wall
The above test case gives a spurious warning about the "unused const variable"
EnumSize_TableRole, even though there's nothing the programmer can do about
that.
I would like to see this warning either
(1) moved out of -Wall to preserve GCC-compatibility (I think the appropriate
place for it is -Weverything), and/or
(2) toned down so that it doesn't warn about variables generated by macro
expansions.
$ clang++ -std=c++11 -c test.cc -Wall
test.cc:7:1: warning: unused variable 'EnumSize_TableRole'
[-Wunused-const-variable]
TYPE_SAFE_ENUM(TableRole, int, TABLE_ROLE_VALUES);
^
./type_safe_enum.h:7:117: note: expanded from macro 'TYPE_SAFE_ENUM'
#define TYPE_SAFE_ENUM(NAME, TYPE, VALUES) enum class NAME : TYPE {
VALUES(ENUM_CONST) }; static const TYPE EnumSize_##NAME = 0 VALUES...
^
<scratch space>:159:1: note: expanded from here
EnumSize_TableRole
^
1 warning generated.
$ clang++ --version
Apple LLVM version 5.1 (clang-503.0.38) (based on LLVM 3.4svn)
Target: x86_64-apple-darwin12.5.0
Thread model: posix
--
You are receiving this mail because:
You are on the CC list for the bug.
_______________________________________________
LLVMbugs mailing list
[email protected]
http://lists.cs.uiuc.edu/mailman/listinfo/llvmbugs
