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Diffstat (limited to 'gcc/doc/invoke.texi')
| -rw-r--r-- | gcc/doc/invoke.texi | 209 |
1 files changed, 161 insertions, 48 deletions
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index 0980230..c0b7aab 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -268,7 +268,7 @@ in the following sections. -Wrange-loop-construct -Wredundant-move -Wredundant-tags -Wreorder -Wregister -Wno-sfinae-incomplete -Wstrict-null-sentinel -Wno-subobject-linkage -Wtemplates --Wno-non-template-friend -Wold-style-cast +-Wno-non-c-typedef-for-linkage -Wno-non-template-friend -Wold-style-cast -Woverloaded-virtual -Wno-pmf-conversions -Wself-move -Wsign-promo -Wsized-deallocation -Wsuggest-final-methods -Wsuggest-final-types -Wsuggest-override -Wno-template-body @@ -322,6 +322,9 @@ Objective-C and Objective-C++ Dialects}. -fno-diagnostics-show-cwe -fno-diagnostics-show-rules -fno-diagnostics-show-highlight-colors +-fno-diagnostics-show-nesting +-fno-diagnostics-show-nesting-locations +-fdiagnostics-show-nesting-levels -fdiagnostics-minimum-margin-width=@var{width} -fdiagnostics-parseable-fixits -fdiagnostics-generate-patch -fdiagnostics-show-template-tree -fno-elide-type @@ -331,7 +334,8 @@ Objective-C and Objective-C++ Dialects}. -fdiagnostics-column-unit=@r{[}display@r{|}byte@r{]} -fdiagnostics-column-origin=@var{origin} -fdiagnostics-escape-format=@r{[}unicode@r{|}bytes@r{]} --fdiagnostics-text-art-charset=@r{[}none@r{|}ascii@r{|}unicode@r{|}emoji@r{]}} +-fdiagnostics-text-art-charset=@r{[}none@r{|}ascii@r{|}unicode@r{|}emoji@r{]} +-fdiagnostics-show-context@r{[}=@var{depth}@r{]}} @item Warning Options @xref{Warning Options,,Options to Request or Suppress Warnings}. @@ -388,6 +392,7 @@ Objective-C and Objective-C++ Dialects}. -Winit-self -Winline -Wno-int-conversion -Wint-in-bool-context -Wno-int-to-pointer-cast -Wno-invalid-memory-model -Winvalid-pch -Winvalid-utf8 -Wno-unicode -Wjump-misses-init +-Wkeyword-macro -Wlarger-than=@var{byte-size} -Wleading-whitespace=@var{kind} -Wlogical-not-parentheses -Wlogical-op -Wlong-long -Wno-lto-type-mismatch -Wmain -Wmaybe-uninitialized @@ -915,7 +920,7 @@ Objective-C and Objective-C++ Dialects}. @emph{AVR Options} (@ref{AVR Options}) @gccoptlist{-mmcu=@var{mcu} -mabsdata -maccumulate-args -mcvt -mbranch-cost=@var{cost} -mfuse-add=@var{level} -mfuse-move=@var{level} --mcall-prologues -mgas-isr-prologues -mint8 -mflmap +-mfuse-move2 -mcall-prologues -mgas-isr-prologues -mint8 -mflmap -mdouble=@var{bits} -mlong-double=@var{bits} -mno-call-main -mn_flash=@var{size} -mfract-convert-truncate -mno-interrupts -mmain-is-OS_task -mrelax -mrmw -mstrict-X -mtiny-stack @@ -1098,7 +1103,8 @@ Objective-C and Objective-C++ Dialects}. -mcmodel=@var{code-model} -mrelax -mpass-mrelax-to-as -mrecip -mrecip=@var{opt} -mfrecipe -mno-frecipe -mdiv32 -mno-div32 -mlam-bh -mno-lam-bh -mlamcas -mno-lamcas -mld-seq-sa -mno-ld-seq-sa --mtls-dialect=@var{opt} -mannotate-tablejump -mno-annotate-tablejump} +-mscq -mno-scq -mtls-dialect=@var{opt} +-mannotate-tablejump -mno-annotate-tablejump} @emph{M32C Options} (@ref{M32C Options}) @gccoptlist{-mcpu=@var{cpu} -msim -memregs=@var{number}} @@ -1259,7 +1265,7 @@ See RS/6000 and PowerPC Options. @emph{PRU Options} (@ref{PRU Options}) @gccoptlist{-mmcu=@var{mcu} -minrt -mno-relax -mloop --mabi=@var{variant}} +-mmul -mfillzero -mabi=@var{variant}} @emph{RISC-V Options} (@ref{RISC-V Options}) @gccoptlist{-mbranch-cost=@var{N-instruction} @@ -3016,8 +3022,9 @@ Version 20, which first appeared in G++ 15, fixes manglings of lambdas in static data member initializers. Version 21, which first appeared in G++ 16, fixes unnecessary captures -in noexcept lambdas (c++/119764) and layout of a base class -with all explicitly defaulted constructors (c++/120012). +in noexcept lambdas (c++/119764), layout of a base class with all explicitly +defaulted constructors (c++/120012), and mangling of class and array +objects with implicitly zero-initialized non-trailing subobjects (c++/121231). See also @option{-Wabi}. @@ -4489,6 +4496,28 @@ to @code{__null}. Although it is a null pointer constant rather than a null pointer, it is guaranteed to be of the same size as a pointer. But this use is not portable across different compilers. +@opindex Wno-non-c-typedef-for-linkage +@opindex Wnon-c-typedef-for-linkage +@item -Wno-non-c-typedef-for-linkage @r{(C++ and Objective-C++ only)} +Disable pedwarn for unnamed classes with a typedef name for linkage purposes +containing C++ specific members, base classes, default member initializers +or lambda expressions, including those on nested member classes. + +@smallexample +typedef struct @{ + int a; // non-static data members are ok + struct T @{ int b; @}; // member classes too + enum E @{ E1, E2, E3 @}; // member enumerations as well + int c = 42; // default member initializers are not ok + struct U : A @{ int c; @}; // classes with base classes are not ok + typedef int V; // typedef is not ok + using W = int; // using declaration is not ok + decltype([]()@{@}) x; // lambda expressions not ok +@} S; +@end smallexample + +In all these cases, the tag name S should be added after the struct keyword. + @opindex Wno-non-template-friend @opindex Wnon-template-friend @item -Wno-non-template-friend @r{(C++ and Objective-C++ only)} @@ -5427,7 +5456,8 @@ options: -fdiagnostics-urls=never -fdiagnostics-path-format=separate-events -fdiagnostics-text-art-charset=none --fno-diagnostics-show-event-links} +-fno-diagnostics-show-event-links +-fno-diagnostics-show-nesting} In the future, if GCC changes the default appearance of its diagnostics, the corresponding option to disable the new behavior will be added to this list. @@ -5764,6 +5794,22 @@ left margin. This option controls the minimum width of the left margin printed by @option{-fdiagnostics-show-line-numbers}. It defaults to 6. +@opindex fdiagnostics-show-context +@item -fdiagnostics-show-context[=@var{depth}] +@itemx -fno-diagnostics-show-context +With this option, the compiler might print the interesting control flow +chain that guards the basic block of the statement which has the warning. +@var{depth} is the maximum depth of the control flow chain. +Currently, The list of the impacted warning options includes: +@option{-Warray-bounds}, @option{-Wstringop-overflow}, +@option{-Wstringop-overread}, @option{-Wstringop-truncation}. +and @option{-Wrestrict}. +More warning options might be added to this list in future releases. +The forms @option{-fdiagnostics-show-context} and +@option{-fno-diagnostics-show-context} are aliases for +@option{-fdiagnostics-show-context=1} and +@option{-fdiagnostics-show-context=0}, respectively. + @opindex fdiagnostics-parseable-fixits @item -fdiagnostics-parseable-fixits Emit fix-it hints in a machine-parseable format, suitable for consumption @@ -6049,6 +6095,40 @@ emoji variant of the character). The default is @samp{emoji}, except when the environment variable @env{LANG} is set to @samp{C}, in which case the default is @samp{ascii}. +@opindex fno-diagnostics-show-nesting +@opindex fdiagnostics-show-nesting +@item -fno-diagnostics-show-nesting +Some GCC diagnostics have an internal tree-like structure of nested +sub-diagnostics, such as for problems when instantiating C++ templates. + +By default GCC uses indentation and bullet points in its text output to +show the nesting structure of these diagnostics, moves location +information to separate lines to make the structure clearer, and +eliminates redundant repeated information. + +Selecting @option{-fno-diagnostics-show-nesting} suppresses this +indentation, reformatting, and elision, restoring an older `look'' for the +diagnostics. + +@opindex fno-diagnostics-show-nesting-locations +@opindex fdiagnostics-show-nesting-locations +@item -fno-diagnostics-show-nesting-locations + +When @option{fdiagnostics-show-nesting} is enabled, file names and +line- and column- numbers are displayed on separate lines from the +messages. This location information can be disabled altogether with +@option{-fno-diagnostics-show-nesting-locations}. +This option exists for use by GCC developers, for writing DejaGnu test cases. + +@opindex fdiagnostics-show-nesting-levels +@opindex fno-diagnostics-show-nesting-levels +@item -fdiagnostics-show-nesting-levels +When @option{fdiagnostics-show-nesting} is enabled, use +@option{fdiagnostics-show-nesting-levels} to also display numbers +showing the depth of the nesting. +This option exists for use by GCC developers for debugging nested +diagnostics, but may be of use to plugin authors. + @opindex fdiagnostics-format @item -fdiagnostics-format=@var{FORMAT} Select a different format for printing diagnostics. @@ -6097,18 +6177,18 @@ Supported keys are: Override colorization settings from @option{-fdiagnostics-color} for this text output. -@item experimental-nesting=@r{[}yes@r{|}no@r{]} -Enable an experimental mode that emphasizes hierarchical relationships -within diagnostics messages, displaying location information on separate -lines. +@item show-nesting=@r{[}yes@r{|}no@r{]} +Enable a mode that emphasizes hierarchical relationships +within diagnostics messages, as per @option{-fdiagnostics-show-nesting}. +Defaults to @code{yes}. -@item experimental-nesting-show-locations=@r{[}yes@r{|}no@r{]} -If @code{experimental-nesting=yes}, then by default locations are +@item show-nesting-locations=@r{[}yes@r{|}no@r{]} +If @code{show-nesting=yes}, then by default locations are shown; set this key to @code{no} to disable printing such locations. This exists for use by GCC developers, for writing DejaGnu test cases. -@item experimental-nesting-show-levels=@r{[}yes@r{|}no@r{]} -This is a debugging option for use with @code{experimental-nesting=yes}. +@item show-nesting-levels=@r{[}yes@r{|}no@r{]} +This is a debugging option for use with @code{show-nesting=yes}. Set this key to @code{yes} to print explicit nesting levels in the output. This exists for use by GCC developers. @@ -10398,6 +10478,14 @@ Do not warn if certain built-in macros are redefined. This suppresses warnings for redefinition of @code{__TIMESTAMP__}, @code{__TIME__}, @code{__DATE__}, @code{__FILE__}, and @code{__BASE_FILE__}. +@opindex Wkeyword-macro +@opindex Wno-keyword-macro +@item -Wkeyword-macro +Warn if a keyword is defined as a macro or undefined. +For C++ identifiers with special meaning or standard attribute identifiers +are diagnosed as well. This warning is enabled by default for C++26 +if @code{-Wpedantic} and emits a pedwarn in that case. + @opindex Wfree-labels @opindex Wno-free-labels @item -Wfree-labels @r{(C and Objective-C only)} @@ -15563,7 +15651,7 @@ If omitted, it defaults to @file{fbdata.afdo} in the current directory. Producing an AutoFDO profile data file requires running your program with the @command{perf} utility on a supported GNU/Linux target system. -For more information, see @uref{https://perf.wiki.kernel.org/}. +For more information, see @uref{https://perfwiki.github.io/main/}. E.g. @smallexample @@ -17784,6 +17872,9 @@ Instructions number above which STFL stall penalty can be compensated. The maximum number of use and def visits when discovering a STV chain before the discovery is aborted. +@item ix86-vect-unroll-limit +Limit how much the autovectorizer may unroll a loop. + @end table @end table @@ -20612,18 +20703,22 @@ LTO output files. @opindex fdump-rtl-@var{pass} @item -d@var{letters} @itemx -fdump-rtl-@var{pass} -@itemx -fdump-rtl-@var{pass}=@var{filename} +@itemx -fdump-rtl-@var{pass}-@var{options} +@itemx -fdump-rtl-@var{pass}-@var{options}=@var{filename} Says to make debugging dumps during compilation at times specified by -@var{letters}. This is used for debugging the RTL-based passes of the +@var{letters} when using @option{-d} or by @var{pass} when using +@option{-fdump-rtl}. This is used for debugging the RTL-based passes of the compiler. Some @option{-d@var{letters}} switches have different meaning when @option{-E} is used for preprocessing. @xref{Preprocessor Options}, for information about preprocessor-specific dump options. -Debug dumps can be enabled with a @option{-fdump-rtl} switch or some -@option{-d} option @var{letters}. Here are the possible -letters for use in @var{pass} and @var{letters}, and their meanings: +The @samp{-@var{options}} form allows greater control over the details of the +dump. See @option{-fdump-tree}. + +Here are actual instances of command-line options following these patterns and +their meanings: @table @gcctabopt @@ -21150,8 +21245,7 @@ GraphViz to @file{@var{file}.@var{passid}.@var{pass}.dot}. Each function in the file is pretty-printed as a subgraph, so that GraphViz can render them all in a single plot. -This option currently only works for RTL dumps, and the RTL is always -dumped in slim form. +RTL is always dumped in slim form. @item vops Enable showing virtual operands for every statement. @item lineno @@ -22846,7 +22940,7 @@ Compile for the CDNA3 gfx950 devices. (Experimental) @item gfx9-generic Compile generic code for Vega devices, executable on the following subset of -GFX9 devices: gfx900, gfx902, gfx904, gfx906, gfx909 and gfx90c. (Experimental) +GFX9 devices: gfx900, gfx902, gfx904, gfx906, gfx909 and gfx90c. @item gfx9-4-generic Compile generic code for CDNA3 devices, executable on the following subset of @@ -22875,7 +22969,7 @@ Compile for RDNA2 gfx1036 devices (GFX10 series). @item gfx10-3-generic Compile generic code for GFX10-3 devices, executable on gfx1030, -gfx1031, gfx1032, gfx1033, gfx1034, gfx1035, and gfx1036. (Experimental) +gfx1031, gfx1032, gfx1033, gfx1034, gfx1035, and gfx1036. @item gfx1100 Compile for RDNA3 gfx1100 devices (GFX11 series). @@ -22903,7 +22997,7 @@ Compile for RDNA3 gfx1153 devices (GFX11 series). (Experimental) @item gfx11-generic Compile generic code for GFX11 devices, executable on gfx1100, gfx1101, -gfx1102, gfx1103, gfx1150, gfx1151, gfx1152, and gfx1153. (Experimental) +gfx1102, gfx1103, gfx1150, gfx1151, gfx1152, and gfx1153. @end table @opindex msram-ecc @@ -25110,6 +25204,10 @@ Valid values for @var{level} are in the range @code{0} @dots{} @code{23} which is a 3:2:2:2 mixed radix value. Each digit controls some aspect of the optimization. +@opindex mfuse-move2 +@item -mfuse-move2 +Run a post combine optimization pass that tries to fuse move instructions. + @opindex mstrict-X @item -mstrict-X Use address register @code{X} in a way proposed by the hardware. This means @@ -28496,6 +28594,14 @@ Whether a same-address load-load barrier (@code{dbar 0x700}) is needed. When build with @option{-march=la664}, it is enabled by default. The default is @option{-mno-ld-seq-sa}, the load-load barrier is needed. +@opindex mscq +@opindex mno-scq +@item -mscq +@item -mno-scq +Use (do not use) the 16-byte conditional store instruction @code{sc.q}. +The default is @option{-mscq} if the machine type specified with +@option{-march=} supports this instruction, @option{-mno-scq} otherwise. + @opindex mtls-dialect @item -mtls-dialect=@var{opt} This option controls which tls dialect may be used for general dynamic and @@ -31219,6 +31325,14 @@ instead of the @option{--relax} option. @item -mloop Allow (or do not allow) GCC to use the LOOP instruction. +@opindex mmul +@item -mmul +Allow (or do not allow) GCC to use the PRU multiplier unit. + +@opindex mfillzero +@item -mfillzero +Allow (or do not allow) GCC to use the FILL and ZERO instructions. + @opindex mabi @item -mabi=@var{variant} Specify the ABI variant to output code for. @option{-mabi=ti} selects the @@ -31329,7 +31443,7 @@ The default is @option{-misa-spec=20191213} unless GCC has been configured with @option{--with-isa-spec=} specifying a different default version. @opindex march -@item -march=@var{ISA-string|Profiles|Profile_ISA-string} +@item -march=@var{ISA-string|Profiles|Profile_ISA-string|help|unset} Generate code for given RISC-V ISA or Profiles or a combination of them (e.g.@: @samp{rv64im} @samp{rvi20u64} @samp{rvi20u64_zbb}). ISA strings and Profiles must be lower-case. Examples include @samp{rv64i}, @samp{rv32g}, @@ -31340,6 +31454,12 @@ at the beginning of the option, then use underline connect ISA-string (e.g.@: @option{help} (@option{-march=help}) is accepted to list all supported extensions. +@samp{-march=unset} causes the compiler to ignore any @samp{-march=@dots{}} options +that appear earlier on the command line, behaving as if the option was never +passed. This is useful for ensuring that the architecture is taken from the +@samp{-mcpu} option, and it will result in an error if no @samp{-mcpu} option +is given when @samp{-march=unset} is used. + The syntax of the ISA string is defined as follows: @table @code @@ -31370,31 +31490,14 @@ When the RISC-V specifications define an extension as depending on other extensions, GCC will implicitly add the dependent extensions to the enabled extension set if they weren't added explicitly. -@opindex mcpu -@item -mcpu=@var{processor-string} -Use architecture of and optimize the output for the given processor, specified -by particular CPU name. -Permissible values for this option are: @samp{mips-p8700}, @samp{sifive-e20}, -@samp{sifive-e21}, @samp{sifive-e24}, @samp{sifive-e31}, @samp{sifive-e34}, -@samp{sifive-e76}, @samp{sifive-s21}, @samp{sifive-s51}, @samp{sifive-s54}, -@samp{sifive-s76}, @samp{sifive-u54}, @samp{sifive-u74}, @samp{sifive-x280}, -@samp{sifive-xp450}, @samp{sifive-x670}, @samp{thead-c906}, @samp{tt-ascalon-d8}, -@samp{xiangshan-nanhu}, @samp{xiangshan-kunminghu}, @samp{xt-c908}, @samp{xt-c908v}, -@samp{xt-c910}, @samp{xt-c910v2}, @samp{xt-c920}, @samp{xt-c920v2}. +@include riscv-mcpu.texi Note that @option{-mcpu} does not override @option{-march} or @option{-mtune}. -@opindex mtune -@item -mtune=@var{processor-string} -Optimize the output for the given processor, specified by microarchitecture or -particular CPU name. Permissible values for this option are: -@samp{generic-ooo}, @samp{mips-p8700}, @samp{rocket}, @samp{sifive-3-series}, -@samp{sifive-5-series}, @samp{sifive-7-series}, @samp{size}, -@samp{sifive-p400-series}, @samp{sifive-p600-series}, and all valid options for -@option{-mcpu=}. +@include riscv-mtune.texi When @option{-mtune=} is not specified, use the setting from @option{-mcpu}, -the default is @samp{rocket} if both are not specified. +the default is @samp{generic} if both are not specified. The @samp{size} choice is not intended for use by end-users. This is used when @option{-Os} is specified. It overrides the instruction cost info @@ -37804,6 +37907,16 @@ compilation which is to be used as input to the next stage: for example, the output of the preprocessor, which is the input to the compiler proper. +@vindex GCC_DIAGNOSTICS_LOG +@item GCC_DIAGNOSTICS_LOG +If @env{GCC_DIAGNOSTICS_LOG} is set, then additional information +about the diagnostics subsystem will be emitted. If it is set to an empty +value, then the information will be written to stderr; otherwise, GCC will +attempt to open that file and write the information there. + +The precise content and format of the information is subject to change; +it is intended for use by GCC developers, rather than end-users. + @vindex GCC_COMPARE_DEBUG @item GCC_COMPARE_DEBUG Setting @env{GCC_COMPARE_DEBUG} is nearly equivalent to passing |