| Index: gcc/doc/invoke.texi |
| diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi |
| index cffc70d..fa247b6 100644 |
| --- a/gcc/doc/invoke.texi |
| +++ b/gcc/doc/invoke.texi |
| @@ -259,6 +259,7 @@ Objective-C and Objective-C++ Dialects}. |
| -Wpointer-arith -Wno-pointer-to-int-cast @gol |
| -Wredundant-decls -Wreturn-type -Wripa-opt-mismatch @gol |
| -Wself-assign -Wself-assign-non-pod -Wsequence-point -Wshadow @gol |
| +-Wshadow-compatible-local -Wshadow-local @gol |
| -Wsign-compare -Wsign-conversion -Wstack-protector @gol |
| -Wstrict-aliasing -Wstrict-aliasing=n @gol |
| -Wstrict-overflow -Wstrict-overflow=@var{n} @gol |
| @@ -4052,6 +4053,43 @@ parameter, type, or class member (in C++), or whenever a built-in function |
| is shadowed. Note that in C++, the compiler will not warn if a local variable |
| shadows a struct/class/enum, but will warn if it shadows an explicit typedef. |
| +@item -Wshadow-local |
| +@opindex Wshadow-local |
| +@opindex Wno-shadow-local |
| +Warn when a local variable shadows another local variable or parameter. |
| + |
| +@item -Wshadow-compatible-local |
| +@opindex Wshadow-compatible-local |
| +@opindex Wno-shadow-compatible-local |
| +Warn when a local variable shadows another local variable or parameter |
| +whose type is compatible with that of the shadowing variable. In C++, |
| +type compatibility here means the type of the shadowing variable can be |
| +converted to that of the shadowed variable. The creation of this flag |
| +(in addition to @option{-Wshadow-local}) is based on the idea that when |
| +a local variable shadows another one of incompatible type, it is most |
| +likely intentional, not a bug or typo, as shown in the following example: |
| + |
| +@smallexample |
| +@group |
| +for (SomeIterator i = SomeObj.begin(); i != SomeObj.end(); ++i) |
| +@{ |
| + for (int i = 0; i < N; ++i) |
| + @{ |
| + ... |
| + @} |
| + ... |
| +@} |
| +@end group |
| +@end smallexample |
| + |
| +Since the two variable @code{i} in the example above have incompatible types, |
| +enabling only @option{-Wshadow-compatible-local} will not emit a warning. |
| +Because their types are incompatible, if a programmer accidentally uses one |
| +in place of the other, type checking will catch that and emit an error or |
| +warning. So not warning (about shadowing) in this case will not lead to |
| +undetected bugs. Use of this flag instead of @option{-Wshadow-local} can |
| +possibly reduce the number of warnings triggered by intentional shadowing. |
| + |
| @item -Wlarger-than=@var{len} |
| @opindex Wlarger-than=@var{len} |
| @opindex Wlarger-than-@var{len} |
