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Diffstat (limited to 'gcc/doc/invoke.texi')
| -rw-r--r-- | gcc/doc/invoke.texi | 30 |
1 files changed, 28 insertions, 2 deletions
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index 56a0bdadc55..40c3df16594 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -15207,8 +15207,34 @@ a single-threaded environment since stack overflow is automatically detected on nearly all systems if there is only one stack. Note that this switch does not actually cause checking to be done; the -operating system must do that. The switch causes generation of code -to ensure that the operating system sees the stack being extended. +operating system or the language runtime must do that. The switch causes +generation of code to ensure that they see the stack being extended. + +You can additionally specify a string parameter: @code{no} means no +checking, @code{generic} means force the use of old-style checking, +@code{specific} means use the best checking method and is equivalent +to bare @option{-fstack-check}. + +Old-style checking is a generic mechanism that requires no specific +target support in the compiler but comes with the following drawbacks: + +@enumerate +@item +Modified allocation strategy for large objects: they will always be +allocated dynamically if their size exceeds a fixed threshold. + +@item +Fixed limit on the size of the static frame of functions: when it is +topped by a particular function, stack checking is not reliable and +a warning is issued by the compiler. + +@item +Inefficiency: because of both the modified allocation strategy and the +generic implementation, the performances of the code are hampered. +@end enumerate + +Note that old-style stack checking is also the fallback method for +@code{specific} if no target support has been added in the compiler. @item -fstack-limit-register=@var{reg} @itemx -fstack-limit-symbol=@var{sym} |