GCC -Wall-优快云博客

本文详细介绍了 GCC 4.7.2 编译器中 -Wall 选项所包含的各种警告标志，这些标志帮助开发者识别并避免潜在的问题代码。文章覆盖了 C/C++/Objective-C 的特定警告，例如未初始化变量、不安全的类型转换等。

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官网：http://gcc.gnu.org/onlinedocs/gcc-4.7.2/gcc/Warning-Options.html#Warning-Options
3.8 Options to Request or Suppress Warnings
.....
-Wall
This enables all the warnings about constructions that some users consider questionable, and that are easy to avoid (or modify to prevent the warning), even in conjunction with macros. This also enables some language-specific warnings described in C++ Dialect Options and Objective-C and Objective-C++ Dialect Options.
-Wall turns on the following warning flags:

          -Waddress
          -Warray-bounds (only with -O2)
          -Wc++11-compat
          -Wchar-subscripts
          -Wenum-compare (in C/Objc; this is on by default in C++)
          -Wimplicit-int (C and Objective-C only)
          -Wimplicit-function-declaration (C and Objective-C only)
          -Wcomment
          -Wformat
          -Wmain (only for C/ObjC and unless -ffreestanding)
          -Wmaybe-uninitialized
          -Wmissing-braces
          -Wnonnull
          -Wparentheses
          -Wpointer-sign
          -Wreorder
          -Wreturn-type
          -Wsequence-point
          -Wsign-compare (only in C++)
          -Wstrict-aliasing
          -Wstrict-overflow=1
          -Wswitch
          -Wtrigraphs
          -Wuninitialized
          -Wunknown-pragmas
          -Wunused-function
          -Wunused-label
          -Wunused-value
          -Wunused-variable
          -Wvolatile-register-var