2012-06-01 Manuel López-Ibáñez <m...@gcc.gnu.org>
Jonathan Wakely <jwakely....@gmail.com>
PR c++/50134
* doc/invoke.texi (Warning Options): Explain purpose and differences
between -Wmissing-prototypes and -Wmissing-declarations.
This patch tries to improve the docs to clarify the intent of these options.
The new wording isn't strictly accurate when it says that in C++ "all
function declarations provide prototypes" because C++ doesn't use the
term "prototype" at all, but I think it's clear what it means.
OK for trunk?
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 3ad07f3..eb582b3 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -4416,8 +4416,12 @@ This warning is also enabled by @option{-Wextra}.
@opindex Wno-missing-prototypes
Warn if a global function is defined without a previous prototype
declaration. This warning is issued even if the definition itself
-provides a prototype. The aim is to detect global functions that
-are not declared in header files.
+provides a prototype. Use this option to detect global functions
+that do not have a matching prototype declaration in a header file.
+This option is not valid for C++ because all function declarations
+provide prototypes and a non-matching declaration will declare an
+overload rather than conflict with an earlier declaration.
+Use @option{-Wmissing-declarations} to detect missing declarations in C++.
@item -Wmissing-declarations
@opindex Wmissing-declarations
@@ -4425,7 +4429,9 @@ are not declared in header files.
Warn if a global function is defined without a previous declaration.
Do so even if the definition itself provides a prototype.
Use this option to detect global functions that are not declared in
-header files. In C++, no warnings are issued for function templates,
+header files. In C, no warnings are issued for functions with previous
+non-prototype declarations; use @option{-Wmissing-prototype} to detect
+missing prototypes. In C++, no warnings are issued for function templates,
or for inline functions, or for functions in anonymous namespaces.
@item -Wmissing-field-initializers
