如何获取错误的字符串格式警告（C ++） [英] How to get warnings of incorrect string formatting (C++)

问题描述

当我使用gdb编译C ++应用程序并使用printf（）时，请提前道歉。

例如，这段代码：

  printf（％s％s， foo）; 
  

导致编译器警告格式的参数太少，这很有用。
还将给出有关格式字符串类型与参数类型的警告。
它必须检查格式字符串并将其与提供的参数类型进行比较。
-这种编译时自省的东西可以添加到普通的源代码中吗，还是需要将其编译为gcc本身？

在os x上这在gcc 4.2.1下。

解决方案

您可以为自己的printf-like做类似的事情函数（以及用于scanf / strftime / strfmon之类的函数）：

  #define PRINTF_FORMAT_CHECK（format_index，args_index）__attribute__（ （__format __（printf，format_index，args_index）））
 
 void my_printf（const char * fmt，...）PRINTF_FORMAT_CHECK（1、2）; 
  

请参见 gcc手册以获取更多详细信息。

apologies in advance if i use poor terminology.

when i compile a C++ app under gdb and use printf() it gives me awesome warnings relating to the consistency of the format string and the arguments passed in.

eg, this code:

printf("%s %s", "foo");

results in a compiler warning "too few arguments for format", which is super-useful. it will also give warnings about format string type vs. argument type. it must have inspected the format string and compared that against the supplied argument types. - is this sort of compile-time introspection something which can be added to ordinary source code, or is it something which needs to be compiled into gcc itself ?

fwiw this is under gcc 4.2.1 on os x.

解决方案

You can do stuff like this for your own printf-like functions (as well as for scanf/strftime/strfmon-like functions):

#define PRINTF_FORMAT_CHECK(format_index, args_index) __attribute__ ((__format__(printf, format_index, args_index)))

void my_printf(const char *fmt, ...) PRINTF_FORMAT_CHECK(1, 2);

See the gcc manual for further details.

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