diff options
Diffstat (limited to 'gcc/doc/invoke.texi')
| -rw-r--r-- | gcc/doc/invoke.texi | 101 |
1 files changed, 60 insertions, 41 deletions
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index 4757f22dcd7..b14238d4168 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -259,8 +259,8 @@ Objective-C and Objective-C++ Dialects}. -Wswitch -Wswitch-default -Wswitch-enum -Wsync-nand @gol -Wsystem-headers -Wtrigraphs -Wtype-limits -Wundef -Wuninitialized @gol -Wunknown-pragmas -Wno-pragmas -Wunreachable-code @gol --Wunused -Wunused-function -Wunused-label -Wunused-parameter @gol --Wunused-value -Wunused-variable @gol +-Wunsuffixed-float-constants -Wunused -Wunused-function @gol +-Wunused-label -Wunused-parameter -Wunused-value -Wunused-variable @gol -Wvariadic-macros -Wvla @gol -Wvolatile-register-var -Wwrite-strings} @@ -3152,7 +3152,7 @@ Warn whenever a function is defined with a return-type that defaults to @code{int}. Also warn about any @code{return} statement with no return-value in a function whose return-type is not @code{void} (falling off the end of the function body is considered returning -without a value), and about a @code{return} statement with a +without a value), and about a @code{return} statement with an expression in a function whose return-type is @code{void}. For C++, a function without return type always produces a diagnostic @@ -4218,6 +4218,15 @@ minimum maximum, so we do not diagnose overlength strings in C++@. This option is implied by @option{-pedantic}, and can be disabled with @option{-Wno-overlength-strings}. + +@item -Wunsuffixed-float-constants +@opindex Wunsuffixed-float-constants + +GCC will issue a warning for any floating constant that does not have +a suffix. When used together with @option{-Wsystem-headers} it will +warn about such constants in system header files. This can be useful +when preparing code to use with the @code{FLOAT_CONST_DECIMAL64} pragma +from the decimal floating-point extension to C99. @end table @node Debugging Options @@ -4593,13 +4602,14 @@ and dbg_cnt(tail_call) will return false always. @itemx -fdump-rtl-@var{pass} @opindex d Says to make debugging dumps during compilation at times specified by -@var{letters}. This is used for debugging the RTL-based passes of the -compiler. The file names for most of the dumps are made by appending a -pass number and a word to the @var{dumpname}. @var{dumpname} is generated -from the name of the output file, if explicitly specified and it is not -an executable, otherwise it is the basename of the source file. These -switches may have different effects when @option{-E} is used for -preprocessing. +@var{letters}. This is used for debugging the RTL-based passes of the +compiler. The file names for most of the dumps are made by appending +a pass number and a word to the @var{dumpname}, and the files are +created in the directory of the output file. @var{dumpname} is +generated from the name of the output file, if explicitly specified +and it is not an executable, otherwise it is the basename of the +source file. These switches may have different effects when +@option{-E} is used for preprocessing. Debug dumps can be enabled with a @option{-fdump-rtl} switch or some @option{-d} option @var{letters}. Here are the possible @@ -4927,7 +4937,8 @@ invocations with different options, in particular with and without @opindex fdump-translation-unit Dump a representation of the tree structure for the entire translation unit to a file. The file name is made by appending @file{.tu} to the -source file name. If the @samp{-@var{options}} form is used, @var{options} +source file name, and the file is created in the same directory as the +output file. If the @samp{-@var{options}} form is used, @var{options} controls the details of the dump as described for the @option{-fdump-tree} options. @@ -4935,16 +4946,19 @@ controls the details of the dump as described for the @itemx -fdump-class-hierarchy-@var{options} @r{(C++ only)} @opindex fdump-class-hierarchy Dump a representation of each class's hierarchy and virtual function -table layout to a file. The file name is made by appending @file{.class} -to the source file name. If the @samp{-@var{options}} form is used, -@var{options} controls the details of the dump as described for the -@option{-fdump-tree} options. +table layout to a file. The file name is made by appending +@file{.class} to the source file name, and the file is created in the +same directory as the output file. If the @samp{-@var{options}} form +is used, @var{options} controls the details of the dump as described +for the @option{-fdump-tree} options. @item -fdump-ipa-@var{switch} @opindex fdump-ipa Control the dumping at various stages of inter-procedural analysis -language tree to a file. The file name is generated by appending a switch -specific suffix to the source file name. The following dumps are possible: +language tree to a file. The file name is generated by appending a +switch specific suffix to the source file name, and the file is created +in the same directory as the output file. The following dumps are +possible: @table @samp @item all @@ -4962,22 +4976,25 @@ Dump after function inlining. @item -fdump-statistics-@var{option} @opindex -fdump-statistics Enable and control dumping of pass statistics in a separate file. The -file name is generated by appending a suffix ending in @samp{.statistics} -to the source file name. If the @samp{-@var{option}} form is used, -@samp{-stats} will cause counters to be summed over the whole compilation unit -while @samp{-details} will dump every event as the passes generate them. -The default with no option is to sum counters for each function compiled. +file name is generated by appending a suffix ending in +@samp{.statistics} to the source file name, and the file is created in +the same directory as the output file. If the @samp{-@var{option}} +form is used, @samp{-stats} will cause counters to be summed over the +whole compilation unit while @samp{-details} will dump every event as +the passes generate them. The default with no option is to sum +counters for each function compiled. @item -fdump-tree-@var{switch} @itemx -fdump-tree-@var{switch}-@var{options} @opindex fdump-tree Control the dumping at various stages of processing the intermediate -language tree to a file. The file name is generated by appending a switch -specific suffix to the source file name. If the @samp{-@var{options}} -form is used, @var{options} is a list of @samp{-} separated options that -control the details of the dump. Not all options are applicable to all -dumps, those which are not meaningful will be ignored. The following -options are available +language tree to a file. The file name is generated by appending a +switch specific suffix to the source file name, and the file is +created in the same directory as the output file. If the +@samp{-@var{options}} form is used, @var{options} is a list of +@samp{-} separated options that control the details of the dump. Not +all options are applicable to all dumps, those which are not +meaningful will be ignored. The following options are available @table @samp @item address @@ -5545,8 +5562,8 @@ instructions and checks if the result can be simplified. If loop unrolling is active, two passes are performed and the second is scheduled after loop unrolling. -This option is enabled by default at optimization levels @option{-O2}, -@option{-O3}, @option{-Os}. +This option is enabled by default at optimization levels @option{-O}, +@option{-O2}, @option{-O3}, @option{-Os}. @item -fomit-frame-pointer @opindex fomit-frame-pointer @@ -6219,8 +6236,8 @@ This flag is enabled by default at @option{-O3}. @item -fipa-matrix-reorg @opindex fipa-matrix-reorg Perform matrix flattening and transposing. -Matrix flattening tries to replace a m-dimensional matrix -with its equivalent n-dimensional matrix, where n < m. +Matrix flattening tries to replace an @math{m}-dimensional matrix +with its equivalent @math{n}-dimensional matrix, where @math{n < m}. This reduces the level of indirection needed for accessing the elements of the matrix. The second optimization is matrix transposing that attempts to change the order of the matrix's dimensions in order to @@ -6784,13 +6801,13 @@ Enabled by default with @option{-funroll-loops}. @item -fwhole-program @opindex fwhole-program -Assume that the current compilation unit represents whole program being +Assume that the current compilation unit represents the whole program being compiled. All public functions and variables with the exception of @code{main} and those merged by attribute @code{externally_visible} become static functions -and in a affect gets more aggressively optimized by interprocedural optimizers. -While this option is equivalent to proper use of @code{static} keyword for -programs consisting of single file, in combination with option -@option{--combine} this flag can be used to compile most of smaller scale C +and in effect are optimized more aggressively by interprocedural optimizers. +While this option is equivalent to proper use of the @code{static} keyword for +programs consisting of a single file, in combination with option +@option{--combine} this flag can be used to compile many smaller scale C programs since the functions and variables become local for the whole combined compilation unit, not for the single source file itself. @@ -9131,7 +9148,7 @@ assembly code. Permissible names are: @samp{arm2}, @samp{arm250}, @samp{arm10tdmi}, @samp{arm1020t}, @samp{arm1026ej-s}, @samp{arm10e}, @samp{arm1020e}, @samp{arm1022e}, @samp{arm1136j-s}, @samp{arm1136jf-s}, @samp{mpcore}, @samp{mpcorenovfp}, -@samp{arm1156t2-s}, @samp{arm1176jz-s}, @samp{arm1176jzf-s}, +@samp{arm1156t2-s}, @samp{arm1156t2f-s}, @samp{arm1176jz-s}, @samp{arm1176jzf-s}, @samp{cortex-a8}, @samp{cortex-a9}, @samp{cortex-r4}, @samp{cortex-r4f}, @samp{cortex-m3}, @samp{cortex-m1}, @@ -9383,7 +9400,7 @@ Change only the low 8 bits of the stack pointer. @item -mint8 @opindex mint8 Assume int to be 8 bit integer. This affects the sizes of all types: A -char will be 1 byte, an int will be 1 byte, an long will be 2 bytes +char will be 1 byte, an int will be 1 byte, a long will be 2 bytes and long long will be 4 bytes. Please note that this option does not comply to the C standards, but it will provide you with smaller code size. @@ -9754,7 +9771,7 @@ that GCC is targetting, like @option{-mcpu} or @option{-march}. The The Darwin tools vary in their behavior when presented with an ISA mismatch. The assembler, @file{as}, will only permit instructions to be used that are valid for the subtype of the file it is generating, -so you cannot put 64-bit instructions in an @samp{ppc750} object file. +so you cannot put 64-bit instructions in a @samp{ppc750} object file. The linker for shared libraries, @file{/usr/bin/libtool}, will fail and print an error if asked to create a shared library with a less restrictive subtype than its input files (for instance, trying to put @@ -16141,7 +16158,9 @@ 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. +of the function name, it is considered to be a match. For C99 and C++ +extended identifiers, the function name must be given in UTF-8, not +using universal character names. @item -fstack-check @opindex fstack-check |