gcc编译警告

1. gcc 6新增编译警告

1.1 literal-suffix——宏和字符串中间要加空格

unlink(FILE_DIR "/"TRIGSCENE_FILE);

警告内容：

invalid suffix on literal; C++11 requires a space between literal and string macro [-Wliteral-suffix]

修复方法：

unlink(FILE_DIR "/" TRIGSCENE_FILE);

说明：实际上只要

unlink(FILE_DIR"/" TRIGSCENE_FILE);

即宏后面允许为字符串，而宏前面有字符串常量必须空一格。

1.2 misleading-indentation——缩进问题

if (m_nEvgeObject == 0)
return -1;

m_bShow = false;

警告内容：

if (m_nEvgeObject == 0)
^~
note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'if'

感觉这问题经常在tab和空格混用时出现。

修复方法：

if (m_nEvgeObject == 0)
return -1;

m_bShow = false;

1.3 模板展开时机修改

#define malloc   my_malloc
#define free     my_free

警告内容：

In file included from malloc_allocator.h:39:0,
dlmalloc.h:11:18: error: 'std::my_free' has not been declared
#define free     my_free
^
dlmalloc.h:10:18: error: 'std::my_malloc' has not been declared
#define malloc   my_malloc
^

修复方法：

#define malloc(x)   my_malloc(x)
#define free(x)     my_free(x)

2. gcc 5（x86）新增警告

2.1 unused-variable——静态变量未使用

static CXmlInstance& myInstance = CXmlInstance::GetInstance();

警告：

error: ‘myInstance’ defined but not used [-Werror=unused-variable]
static CXmlInstance& myInstance = CXmlInstance::GetInstance();
^

修复方法：

static CXmlInstance& myInstance __attribute__((unused)) = CXmlInstance::GetInstance();

注意：好像只在x86上Release编译默认开启，好奇怪。