diff options
Diffstat (limited to 'contrib/gcc/doc/invoke.texi')
| -rw-r--r-- | contrib/gcc/doc/invoke.texi | 161 |
1 files changed, 154 insertions, 7 deletions
diff --git a/contrib/gcc/doc/invoke.texi b/contrib/gcc/doc/invoke.texi index c980bba..51ac30f 100644 --- a/contrib/gcc/doc/invoke.texi +++ b/contrib/gcc/doc/invoke.texi @@ -214,7 +214,8 @@ in the following sections. -Wimport -Wno-import -Winit-self -Winline @gol -Wno-int-to-pointer-cast @gol -Wno-invalid-offsetof -Winvalid-pch @gol --Wlarger-than-@var{len} -Wunsafe-loop-optimizations -Wlong-long @gol +-Wlarger-than-@var{len} -Wframe-larger-than-@var{len} @gol +-Wunsafe-loop-optimizations -Wlong-long @gol -Wmain -Wmissing-braces -Wmissing-field-initializers @gol -Wmissing-format-attribute -Wmissing-include-dirs @gol -Wmissing-noreturn @gol @@ -230,7 +231,8 @@ in the following sections. -Wsystem-headers -Wtrigraphs -Wundef -Wuninitialized @gol -Wunknown-pragmas -Wno-pragmas -Wunreachable-code @gol -Wunused -Wunused-function -Wunused-label -Wunused-parameter @gol --Wunused-value -Wunused-variable -Wvariadic-macros @gol +-Wunused-value -Wunused-variable @gol +-Wvariadic-macros -Wvla @gol -Wvolatile-register-var -Wwrite-strings} @item C-only Warning Options @@ -274,6 +276,8 @@ in the following sections. -ftest-coverage -ftime-report -fvar-tracking @gol -g -g@var{level} -gcoff -gdwarf-2 @gol -ggdb -gstabs -gstabs+ -gvms -gxcoff -gxcoff+ @gol +-femit-struct-debug-baseonly -femit-struct-debug-reduced @gol +-femit-struct-debug-detailed@r{[}=@var{spec-list}@r{]} @gol -p -pg -print-file-name=@var{library} -print-libgcc-file-name @gol -print-multi-directory -print-multi-lib @gol -print-prog-name=@var{program} -print-search-dirs -Q @gol @@ -755,6 +759,8 @@ See S/390 and zSeries Options. -fnon-call-exceptions -funwind-tables @gol -fasynchronous-unwind-tables @gol -finhibit-size-directive -finstrument-functions @gol +-finstrument-functions-exclude-function-list=@var{sym},@var{sym},@dots{} @gol +-finstrument-functions-exclude-file-list=@var{file},@var{file},@dots{} @gol -fno-common -fno-ident @gol -fpcc-struct-return -fpic -fPIC -fpie -fPIE @gol -fno-jump-tables @gol @@ -2502,14 +2508,40 @@ It warns about code which might break the strict aliasing rules that the compiler is using for optimization. The warning does not catch all cases, but does attempt to catch the more common pitfalls. It is included in @option{-Wall}. +It is equivalent to -Wstrict-aliasing=3 -@item -Wstrict-aliasing=2 -@opindex Wstrict-aliasing=2 +@item -Wstrict-aliasing=n +@opindex Wstrict-aliasing=n This option is only active when @option{-fstrict-aliasing} is active. It warns about code which might break the strict aliasing rules that the -compiler is using for optimization. This warning catches more cases than -@option{-Wstrict-aliasing}, but it will also give a warning for some ambiguous -cases that are safe. +compiler is using for optimization. +Higher levels correspond to higher accuracy (fewer false positives). +Higher levels also correspond to more effort, similar to the way -O works. +@option{-Wstrict-aliasing} is equivalent to @option{-Wstrict-aliasing=n}, +with n=3. + +Level 1: Most aggressive, quick, least accurate. +Possibly useful when higher levels +do not warn but -fstrict-aliasing still breaks the code, as it has very few +false negatives. However, it has many false positives. +Warns for all pointer conversions between possibly incompatible types, +even if never dereferenced. Runs in the frontend only. + +Level 2: Aggressive, quick, not too precise. +May still have many false positives (not as many as level 1 though), +and few false negatives (but possibly more than level 1). +Unlike level 1, it only warns when an address is taken. Warns about +incomplete types. Runs in the frontend only. + +Level 3 (default for @option{-Wstrict-aliasing}): +Should have very few false positives and few false +negatives. Slightly slower than levels 1 or 2 when optimization is enabled. +Takes care of the common punn+dereference pattern in the frontend: +@code{*(int*)&some_float}. +If optimization is enabled, it also runs in the backend, where it deals +with multiple statement cases using flow-sensitive points-to information. +Only warns when the converted pointer is dereferenced. +Does not warn about incomplete types. @item -Wstrict-overflow @item -Wstrict-overflow=@var{n} @@ -2825,6 +2857,10 @@ global variable or whenever a built-in function is shadowed. @opindex Wlarger-than Warn whenever an object of larger than @var{len} bytes is defined. +@item -Wframe-larger-than-@var{len} +@opindex Wframe-larger-than +Warn whenever the frame size of a function is larger than @var{len} bytes. + @item -Wunsafe-loop-optimizations @opindex Wunsafe-loop-optimizations Warn if the loop cannot be optimized because the compiler could not @@ -3201,6 +3237,13 @@ Warn if variadic macros are used in pedantic ISO C90 mode, or the GNU alternate syntax when in pedantic ISO C99 mode. This is default. To inhibit the warning messages, use @option{-Wno-variadic-macros}. +@item -Wvla +@opindex Wvla +@opindex Wno-vla +Warn if variable length array is used in the code. +@option{-Wno-vla} will prevent the @option{-pedantic} warning of +the variable length array. + @item -Wvolatile-register-var @opindex Wvolatile-register-var @opindex Wno-volatile-register-var @@ -3403,6 +3446,78 @@ Compress DWARF2 debugging information by eliminating duplicated information about each symbol. This option only makes sense when generating DWARF2 debugging information with @option{-gdwarf-2}. +@item -femit-struct-debug-baseonly +Emit debug information for struct-like types +only when the base name of the compilation source file +matches the base name of file in which the struct was defined. + +This option substantially reduces the size of debugging information, +but at significant potential loss in type information to the debugger. +See @option{-femit-struct-debug-reduced} for a less aggressive option. +See @option{-femit-struct-debug-detailed} for more detailed control. + +This option works only with DWARF 2. + +@item -femit-struct-debug-reduced +Emit debug information for struct-like types +only when the base name of the compilation source file +matches the base name of file in which the type was defined, +unless the struct is a template or defined in a system header. + +This option significantly reduces the size of debugging information, +with some potential loss in type information to the debugger. +See @option{-femit-struct-debug-baseonly} for a more aggressive option. +See @option{-femit-struct-debug-detailed} for more detailed control. + +This option works only with DWARF 2. + +@item -femit-struct-debug-detailed@r{[}=@var{spec-list}@r{]} +Specify the struct-like types +for which the compiler will generate debug information. +The intent is to reduce duplicate struct debug information +between different object files within the same program. + +This option is a detailed version of +@option{-femit-struct-debug-reduced} and @option{-femit-struct-debug-baseonly}, +which will serve for most needs. + +A specification has the syntax +[@samp{dir:}|@samp{ind:}][@samp{ord:}|@samp{gen:}](@samp{any}|@samp{sys}|@samp{base}|@samp{none}) + +The optional first word limits the specification to +structs that are used directly (@samp{dir:}) or used indirectly (@samp{ind:}). +A struct type is used directly when it is the type of a variable, member. +Indirect uses arise through pointers to structs. +That is, when use of an incomplete struct would be legal, the use is indirect. +An example is +@samp{struct one direct; struct two * indirect;}. + +The optional second word limits the specification to +ordinary structs (@samp{ord:}) or generic structs (@samp{gen:}). +Generic structs are a bit complicated to explain. +For C++, these are non-explicit specializations of template classes, +or non-template classes within the above. +Other programming languages have generics, +but @samp{-femit-struct-debug-detailed} does not yet implement them. + +The third word specifies the source files for those +structs for which the compiler will emit debug information. +The values @samp{none} and @samp{any} have the normal meaning. +The value @samp{base} means that +the base of name of the file in which the type declaration appears +must match the base of the name of the main compilation file. +In practice, this means that +types declared in @file{foo.c} and @file{foo.h} will have debug information, +but types declared in other header will not. +The value @samp{sys} means those types satisfying @samp{base} +or declared in system or compiler headers. + +You may need to experiment to determine the best settings for your application. + +The default is @samp{-femit-struct-debug-detailed=all}. + +This option works only with DWARF 2. + @cindex @command{prof} @item -p @opindex p @@ -13273,6 +13388,37 @@ interrupt routines, and any functions from which the profiling functions cannot safely be called (perhaps signal handlers, if the profiling routines generate output or allocate memory). +@item -finstrument-functions-exclude-file-list=@var{file},@var{file},@dots{} +@opindex finstrument-functions-exclude-file-list + +Set the list of functions that are excluded from instrumentation (see +the description of @code{-finstrument-functions}). If the file that +contains a function definition matches with one of @var{file}, then +that function is not instrumented. The match is done on substrings: +if the @var{file} parameter is a substring of the file name, it is +considered to be a match. + +For example, +@code{-finstrument-functions-exclude-file-list=/bits/stl,include/sys} +will exclude any inline function defined in files whose pathnames +contain @code{/bits/stl} or @code{include/sys}. + +If, for some reason, you want to include letter @code{','} in one of +@var{sym}, write @code{'\,'}. For example, +@code{-finstrument-functions-exclude-file-list='\,\,tmp'} +(note the single quote surrounding the option). + +@item -finstrument-functions-exclude-function-list=@var{sym},@var{sym},@dots{} +@opindex finstrument-functions-exclude-function-list + +This is similar to @code{-finstrument-functions-exclude-file-list}, +but this option sets the list of function names to be excluded from +instrumentation. The function name to be matched is its user-visible +name, such as @code{vector<int> blah(const vector<int> &)}, not the +internal mangled name (e.g., @code{_Z4blahRSt6vectorIiSaIiEE}). The +match is done on substrings: if the @var{sym} parameter is a substring +of the function name, it is considered to be a match. + @item -fstack-check @opindex fstack-check Generate code to verify that you do not go beyond the boundary of the @@ -13850,3 +13996,4 @@ exist, because otherwise they won't get converted. @xref{Protoize Caveats}, for more information on how to use @code{protoize} successfully. + |
