-@c Copyright (C) 1988-2019 Free Software Foundation, Inc.
+@c Copyright (C) 1988-2020 Free Software Foundation, Inc.
@c This is part of the GCC manual.
@c For copying conditions, see the file gcc.texi.
@c man end
@c man begin COPYRIGHT
-Copyright @copyright{} 1988-2019 Free Software Foundation, Inc.
+Copyright @copyright{} 1988-2020 Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3 or
* Diagnostic Message Formatting Options:: Controlling how diagnostics should
be formatted.
* Warning Options:: How picky should the compiler be?
+* Static Analyzer Options:: More expensive warnings.
* Debugging Options:: Producing debuggable code.
* Optimize Options:: How much optimization?
* Instrumentation Options:: Enabling profiling and extra run-time error checking.
-Wabi=@var{n} -Wabi-tag -Wcomma-subscript -Wconversion-null @gol
-Wctor-dtor-privacy @gol
-Wdelete-non-virtual-dtor -Wdeprecated-copy -Wdeprecated-copy-dtor @gol
--Wliteral-suffix @gol
+-Wliteral-suffix -Wmismatched-tags @gol
-Wmultiple-inheritance -Wno-init-list-lifetime @gol
-Wnamespaces -Wnarrowing @gol
--Wpessimizing-move -Wredundant-move @gol
+-Wpessimizing-move -Wredundant-move -Wredundant-tags @gol
-Wnoexcept -Wnoexcept-type -Wclass-memaccess @gol
-Wnon-virtual-dtor -Wreorder -Wregister @gol
-Weffc++ -Wstrict-null-sentinel -Wtemplates @gol
-fdiagnostics-format=@r{[}text@r{|}json@r{]} @gol
-fno-diagnostics-show-option -fno-diagnostics-show-caret @gol
-fno-diagnostics-show-labels -fno-diagnostics-show-line-numbers @gol
+-fno-diagnostics-show-cwe @gol
-fdiagnostics-minimum-margin-width=@var{width} @gol
-fdiagnostics-parseable-fixits -fdiagnostics-generate-patch @gol
-fdiagnostics-show-template-tree -fno-elide-type @gol
+-fdiagnostics-path-format=@r{[}none@r{|}separate-events@r{|}inline-events@r{]} @gol
+-fdiagnostics-show-path-depths @gol
-fno-show-column}
@item Warning Options
@xref{Warning Options,,Options to Request or Suppress Warnings}.
-@gccoptlist{-fsyntax-only -fmax-errors=@var{n} -Wpedantic @gol
+@gccoptlist{-fanalyzer -fsyntax-only -fmax-errors=@var{n} -Wpedantic @gol
-pedantic-errors @gol
-w -Wextra -Wall -Waddress -Waddress-of-packed-member @gol
-Waggregate-return -Waligned-new @gol
-Walloc-zero -Walloc-size-larger-than=@var{byte-size} @gol
-Walloca -Walloca-larger-than=@var{byte-size} @gol
--Wno-aggressive-loop-optimizations -Warray-bounds -Warray-bounds=@var{n} @gol
+-Wno-aggressive-loop-optimizations @gol
+-Wno-analyzer-double-fclose @gol
+-Wno-analyzer-double-free @gol
+-Wno-analyzer-exposure-through-output-file @gol
+-Wno-analyzer-file-leak @gol
+-Wno-analyzer-free-of-non-heap @gol
+-Wno-analyzer-malloc-leak @gol
+-Wno-analyzer-possible-null-argument @gol
+-Wno-analyzer-possible-null-dereference @gol
+-Wno-analyzer-null-argument @gol
+-Wno-analyzer-null-dereference @gol
+-Wno-analyzer-stale-setjmp-buffer @gol
+-Wno-analyzer-tainted-array-index @gol
+-Wno-analyzer-unsafe-call-within-signal-handler @gol
+-Wno-analyzer-use-after-free @gol
+-Wno-analyzer-use-of-pointer-in-stale-stack-frame @gol
+-Wno-analyzer-use-of-uninitialized-value @gol
+-Wanalyzer-too-complex @gol
+-Warith-conversion @gol
+-Warray-bounds -Warray-bounds=@var{n} @gol
-Wno-attributes -Wattribute-alias=@var{n} @gol
-Wbool-compare -Wbool-operation @gol
-Wno-builtin-declaration-mismatch @gol
-Wwrite-strings @gol
-Wzero-as-null-pointer-constant}
+@item Static Analyzer Options
+@gccoptlist{-Wanalyzer-double-fclose @gol
+-Wanalyzer-double-free @gol
+-Wanalyzer-exposure-through-output-file @gol
+-Wanalyzer-file-leak @gol
+-Wanalyzer-free-of-non-heap @gol
+-Wanalyzer-malloc-leak @gol
+-Wanalyzer-null-argument @gol
+-Wanalyzer-null-dereference @gol
+-Wanalyzer-possible-null-argument @gol
+-Wanalyzer-possible-null-dereference @gol
+-Wanalyzer-stale-setjmp-buffer @gol
+-Wanalyzer-tainted-array-index @gol
+-Wanalyzer-unsafe-call-within-signal-handler @gol
+-Wanalyzer-use-after-free @gol
+-Wanalyzer-use-of-pointer-in-stale-stack-frame @gol
+-Wanalyzer-use-of-uninitialized-value @gol
+-Wanalyzer-too-complex @gol
+-fanalyzer-call-summaries @gol
+-fanalyzer-checker=@var{name} @gol
+-fanalyzer-fine-grained @gol
+-fanalyzer-state-merge @gol
+-fanalyzer-state-purge @gol
+-fanalyzer-transitivity @gol
+-fanalyzer-verbose-edges @gol
+-fanalyzer-verbose-state-changes @gol
+-fanalyzer-verbosity=@var{level} @gol
+-fdump-analyzer @gol
+-fdump-analyzer-stderr @gol
+-fdump-analyzer-callgraph @gol
+-fdump-analyzer-exploded-graph @gol
+-fdump-analyzer-exploded-nodes @gol
+-fdump-analyzer-exploded-nodes-2 @gol
+-fdump-analyzer-exploded-nodes-3 @gol
+-fdump-analyzer-state-purge @gol
+-fdump-analyzer-supergraph @gol
+}
+
@item C and Objective-C-only Warning Options
@gccoptlist{-Wbad-function-cast -Wmissing-declarations @gol
-Wmissing-parameter-type -Wmissing-prototypes -Wnested-externs @gol
-mn_flash=@var{size} -mno-interrupts @gol
-mmain-is-OS_task -mrelax -mrmw -mstrict-X -mtiny-stack @gol
-mfract-convert-truncate @gol
--mshort-calls -nodevicelib @gol
+-mshort-calls -nodevicelib -nodevicespecs @gol
-Waddr-space-convert -Wmisspelled-isr}
@emph{Blackfin Options}
Enable handling of OpenACC directives @code{#pragma acc} in C/C++ and
@code{!$acc} in Fortran. When @option{-fopenacc} is specified, the
compiler generates accelerated code according to the OpenACC Application
-Programming Interface v2.0 @w{@uref{https://www.openacc.org}}. This option
+Programming Interface v2.6 @w{@uref{https://www.openacc.org}}. This option
implies @option{-pthread}, and thus is only supported on targets that
have support for @option{-pthread}.
evaluation might take too long.
The default is 33554432 (1<<25).
+@item -fcoroutines
+@opindex fcoroutines
+Enable support for the C++ coroutines extension (experimental).
+
@item -fno-elide-constructors
@opindex fno-elide-constructors
@opindex felide-constructors
This warning is enabled by @option{-Wextra}.
+@item -Wredundant-tags @r{(C++ and Objective-C++ only)}
+@opindex Wredundant-tags
+@opindex Wno-redundant-tags
+Warn about redundant class-key and enum-key in references to class types
+and enumerated types in contexts where the key can be eliminated without
+causing an ambiguity. For example
+
+@smallexample
+struct foo;
+struct foo *p; // -Wredundant-tags, keyword struct can be eliminated
+
+void foo (); // "hides" struct foo
+void bar (struct foo&); // no warning, keyword struct cannot be eliminated
+@end smallexample
+
@item -fext-numeric-literals @r{(C++ and Objective-C++ only)}
@opindex fext-numeric-literals
@opindex fno-ext-numeric-literals
one can still use the STL. One may also instantiate or specialize
templates.
+@item -Wmismatched-tags @r{(C++ and Objective-C++ only)}
+@opindex Wmismatched-tags
+@opindex Wno-mismatched-tags
+Warn for declarations of structs, classes, and class templates and their
+specializations with a class-key that does not match either the definition
+or the first declaration if no definition is provided.
+
+For example, the declaration of @code{struct Object} in the argument list
+of @code{draw} triggers the warning. To avoid it, either remove the redundant
+class-key @code{struct} or replace it with @code{class} to match its definition.
+@smallexample
+class Object @{
+public:
+ virtual ~Object () = 0;
+@};
+void draw (struct Object*);
+@end smallexample
+
+It is not wrong to declare a class with the class-key @code{struct} as
+the example above shows. The @option{-Wmismatched-tags} option is intended
+to help achieve a consistent style of class declarations. In code that is
+intended to be portable to Windows-based compilers the warning helps prevent
+unresolved references due to the difference in the mangling of symbols
+declared with different class-keys. The option can be used either on its
+own or in conjunction with @option{-Wredundant-tags}.
+
@item -Wmultiple-inheritance @r{(C++ and Objective-C++ only)}
@opindex Wmultiple-inheritance
@opindex Wno-multiple-inheritance
The default @env{GCC_COLORS} is
@smallexample
error=01;31:warning=01;35:note=01;36:range1=32:range2=34:locus=01:\
-quote=01:fixit-insert=32:fixit-delete=31:\
+quote=01:path=01;36:fixit-insert=32:fixit-delete=31:\
diff-filename=01:diff-hunk=32:diff-delete=31:diff-insert=32:\
type-diff=01;32
@end smallexample
@vindex note GCC_COLORS @r{capability}
SGR substring for note: markers.
+@item path=
+@vindex path GCC_COLORS @r{capability}
+SGR substring for colorizing paths of control-flow events as printed
+via @option{-fdiagnostics-path-format=}, such as the identifiers of
+individual events and lines indicating interprocedural calls and returns.
+
@item range1=
@vindex range1 GCC_COLORS @r{capability}
SGR substring for first additional range.
This option suppresses the printing of these labels (in the example above,
the vertical bars and the ``char *'' and ``long int'' text).
+@item -fno-diagnostics-show-cwe
+@opindex fno-diagnostics-show-cwe
+@opindex fdiagnostics-show-cwe
+Diagnostic messages can optionally have an associated
+@url{https://cwe.mitre.org/index.html, CWE} identifier.
+GCC itself only provides such metadata for some of the @option{-fanalyzer}
+diagnostics. GCC plugins may also provide diagnostics with such metadata.
+By default, if this information is present, it will be printed with
+the diagnostic. This option suppresses the printing of this metadata.
+
@item -fno-diagnostics-show-line-numbers
@opindex fno-diagnostics-show-line-numbers
@opindex fdiagnostics-show-line-numbers
This flag also affects the output of the
@option{-fdiagnostics-show-template-tree} flag.
+@item -fdiagnostics-path-format=@var{KIND}
+@opindex fdiagnostics-path-format
+Specify how to print paths of control-flow events for diagnostics that
+have such a path associated with them.
+
+@var{KIND} is @samp{none}, @samp{separate-events}, or @samp{inline-events},
+the default.
+
+@samp{none} means to not print diagnostic paths.
+
+@samp{separate-events} means to print a separate ``note'' diagnostic for
+each event within the diagnostic. For example:
+
+@smallexample
+test.c:29:5: error: passing NULL as argument 1 to 'PyList_Append' which requires a non-NULL parameter
+test.c:25:10: note: (1) when 'PyList_New' fails, returning NULL
+test.c:27:3: note: (2) when 'i < count'
+test.c:29:5: note: (3) when calling 'PyList_Append', passing NULL from (1) as argument 1
+@end smallexample
+
+@samp{inline-events} means to print the events ``inline'' within the source
+code. This view attempts to consolidate the events into runs of
+sufficiently-close events, printing them as labelled ranges within the source.
+
+For example, the same events as above might be printed as:
+
+@smallexample
+ 'test': events 1-3
+ |
+ | 25 | list = PyList_New(0);
+ | | ^~~~~~~~~~~~~
+ | | |
+ | | (1) when 'PyList_New' fails, returning NULL
+ | 26 |
+ | 27 | for (i = 0; i < count; i++) @{
+ | | ~~~
+ | | |
+ | | (2) when 'i < count'
+ | 28 | item = PyLong_FromLong(random());
+ | 29 | PyList_Append(list, item);
+ | | ~~~~~~~~~~~~~~~~~~~~~~~~~
+ | | |
+ | | (3) when calling 'PyList_Append', passing NULL from (1) as argument 1
+ |
+@end smallexample
+
+Interprocedural control flow is shown by grouping the events by stack frame,
+and using indentation to show how stack frames are nested, pushed, and popped.
+
+For example:
+
+@smallexample
+ 'test': events 1-2
+ |
+ | 133 | @{
+ | | ^
+ | | |
+ | | (1) entering 'test'
+ | 134 | boxed_int *obj = make_boxed_int (i);
+ | | ~~~~~~~~~~~~~~~~~~
+ | | |
+ | | (2) calling 'make_boxed_int'
+ |
+ +--> 'make_boxed_int': events 3-4
+ |
+ | 120 | @{
+ | | ^
+ | | |
+ | | (3) entering 'make_boxed_int'
+ | 121 | boxed_int *result = (boxed_int *)wrapped_malloc (sizeof (boxed_int));
+ | | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ | | |
+ | | (4) calling 'wrapped_malloc'
+ |
+ +--> 'wrapped_malloc': events 5-6
+ |
+ | 7 | @{
+ | | ^
+ | | |
+ | | (5) entering 'wrapped_malloc'
+ | 8 | return malloc (size);
+ | | ~~~~~~~~~~~~~
+ | | |
+ | | (6) calling 'malloc'
+ |
+ <-------------+
+ |
+ 'test': event 7
+ |
+ | 138 | free_boxed_int (obj);
+ | | ^~~~~~~~~~~~~~~~~~~~
+ | | |
+ | | (7) calling 'free_boxed_int'
+ |
+(etc)
+@end smallexample
+
+@item -fdiagnostics-show-path-depths
+@opindex fdiagnostics-show-path-depths
+This option provides additional information when printing control-flow paths
+associated with a diagnostic.
+
+If this is option is provided then the stack depth will be printed for
+each run of events within @option{-fdiagnostics-path-format=separate-events}.
+
+This is intended for use by GCC developers and plugin developers when
+debugging diagnostics that report interprocedural control flow.
+
@item -fno-show-column
@opindex fno-show-column
@opindex fshow-column
are expressed via an empty value for @code{string}, insertions by
having @code{start} equal @code{next}.
+If the diagnostic has a path of control-flow events associated with it,
+it has a @code{path} array of objects representing the events. Each
+event object has a @code{description} string, a @code{location} object,
+along with a @code{function} string and a @code{depth} number for
+representing interprocedural paths. The @code{function} represents the
+current function at that event, and the @code{depth} represents the
+stack depth relative to some baseline: the higher, the more frames are
+within the stack.
+
+For example, the intraprocedural example shown for
+@option{-fdiagnostics-path-format=} might have this JSON for its path:
+
+@smallexample
+ "path": [
+ @{
+ "depth": 0,
+ "description": "when 'PyList_New' fails, returning NULL",
+ "function": "test",
+ "location": @{
+ "column": 10,
+ "file": "test.c",
+ "line": 25
+ @}
+ @},
+ @{
+ "depth": 0,
+ "description": "when 'i < count'",
+ "function": "test",
+ "location": @{
+ "column": 3,
+ "file": "test.c",
+ "line": 27
+ @}
+ @},
+ @{
+ "depth": 0,
+ "description": "when calling 'PyList_Append', passing NULL from (1) as argument 1",
+ "function": "test",
+ "location": @{
+ "column": 5,
+ "file": "test.c",
+ "line": 29
+ @}
+ @}
+ ]
+@end smallexample
+
@end table
@node Warning Options
with old compilers, but if something goes wrong, the compiler
warns that an unrecognized option is present.
+The effectiveness of some warnings depends on optimizations also being
+enabled. For example @option{-Wsuggest-final-types} is more effective
+with link-time optimization and @option{-Wmaybe-uninitialized} will not
+warn at all unless optimization is enabled.
+
@table @gcctabopt
@item -Wpedantic
@itemx -pedantic
Disable @option{-Walloca-larger-than=} warnings. The option is
equivalent to @option{-Walloca-larger-than=}@samp{SIZE_MAX} or larger.
+@item -Wno-analyzer-double-fclose
+@opindex Wanalyzer-double-fclose
+@opindex Wno-analyzer-double-fclose
+This warning requires @option{-fanalyzer}, which enables it; use
+@option{-Wno-analyzer-double-fclose} to disable it.
+
+This diagnostic warns for paths through the code in which a @code{FILE *}
+can have @code{fclose} called on it more than once.
+
+@item -Wno-analyzer-double-free
+@opindex Wanalyzer-double-free
+@opindex Wno-analyzer-double-free
+This warning requires @option{-fanalyzer}, which enables it; use
+@option{-Wno-analyzer-double-free} to disable it.
+
+This diagnostic warns for paths through the code in which a pointer
+can have @code{free} called on it more than once.
+
+@item -Wno-analyzer-exposure-through-output-file
+@opindex Wanalyzer-exposure-through-output-file
+@opindex Wno-analyzer-exposure-through-output-file
+This warning requires @option{-fanalyzer}, which enables it; use
+@option{-Wno-analyzer-exposure-through-output-file}
+to disable it.
+
+This diagnostic warns for paths through the code in which a
+security-sensitive value is written to an output file
+(such as writing a password to a log file).
+
+@item -Wno-analyzer-file-leak
+@opindex Wanalyzer-file-leak
+@opindex Wno-analyzer-file-leak
+This warning requires @option{-fanalyzer}, which enables it; use
+@option{-Wno-analyzer-file-leak}
+to disable it.
+
+This diagnostic warns for paths through the code in which a
+@code{<stdio.h>} @code{FILE *} stream object is leaked.
+
+@item -Wno-analyzer-free-of-non-heap
+@opindex Wanalyzer-free-of-non-heap
+@opindex Wno-analyzer-free-of-non-heap
+This warning requires @option{-fanalyzer}, which enables it; use
+@option{-Wno-analyzer-free-of-non-heap}
+to disable it.
+
+This diagnostic warns for paths through the code in which @code{free}
+is called on a non-heap pointer (e.g. an on-stack buffer, or a global).
+
+@item -Wno-analyzer-malloc-leak
+@opindex Wanalyzer-malloc-leak
+@opindex Wno-analyzer-malloc-leak
+This warning requires @option{-fanalyzer}, which enables it; use
+@option{-Wno-analyzer-malloc-leak}
+to disable it.
+
+This diagnostic warns for paths through the code in which a
+pointer allocated via @code{malloc} is leaked.
+
+@item -Wno-analyzer-possible-null-argument
+@opindex Wanalyzer-possible-null-argument
+@opindex Wno-analyzer-possible-null-argument
+This warning requires @option{-fanalyzer}, which enables it; use
+@option{-Wno-analyzer-possible-null-argument} to disable it.
+
+This diagnostic warns for paths through the code in which a
+possibly-NULL value is passed to a function argument marked
+with @code{__attribute__((nonnull))} as requiring a non-NULL
+value.
+
+@item -Wno-analyzer-possible-null-dereference
+@opindex Wanalyzer-possible-null-dereference
+@opindex Wno-analyzer-possible-null-dereference
+This warning requires @option{-fanalyzer}, which enables it; use
+@option{-Wno-analyzer-possible-null-dereference} to disable it.
+
+This diagnostic warns for paths through the code in which a
+possibly-NULL value is dereferenced.
+
+@item -Wno-analyzer-null-argument
+@opindex Wanalyzer-null-argument
+@opindex Wno-analyzer-null-argument
+This warning requires @option{-fanalyzer}, which enables it; use
+@option{-Wno-analyzer-null-argument} to disable it.
+
+This diagnostic warns for paths through the code in which a
+value known to be NULL is passed to a function argument marked
+with @code{__attribute__((nonnull))} as requiring a non-NULL
+value.
+
+@item -Wno-analyzer-null-dereference
+@opindex Wanalyzer-null-dereference
+@opindex Wno-analyzer-null-dereference
+This warning requires @option{-fanalyzer}, which enables it; use
+@option{-Wno-analyzer-null-dereference} to disable it.
+
+This diagnostic warns for paths through the code in which a
+value known to be NULL is dereferenced.
+
+@item -Wno-analyzer-stale-setjmp-buffer
+@opindex Wanalyzer-stale-setjmp-buffer
+@opindex Wno-analyzer-stale-setjmp-buffer
+This warning requires @option{-fanalyzer}, which enables it; use
+@option{-Wno-analyzer-stale-setjmp-buffer} to disable it.
+
+This diagnostic warns for paths through the code in which
+@code{longjmp} is called to rewind to a @code{jmp_buf} relating
+to a @code{setjmp} call in a function that has returned.
+
+When @code{setjmp} is called on a @code{jmp_buf} to record a rewind
+location, it records the stack frame. The stack frame becomes invalid
+when the function containing the @code{setjmp} call returns. Attempting
+to rewind to it via @code{longjmp} would reference a stack frame that
+no longer exists, and likely lead to a crash (or worse).
+
+@item -Wno-analyzer-tainted-array-index
+@opindex Wanalyzer-tainted-array-index
+@opindex Wno-analyzer-tainted-array-index
+This warning requires @option{-fanalyzer}, which enables it; use
+@option{-Wno-analyzer-tainted-array-index} to disable it.
+
+This diagnostic warns for paths through the code in which a value
+that could be under an attacker's control is used as the index
+of an array access without being sanitized.
+
+@item -Wno-analyzer-unsafe-call-within-signal-handler
+@opindex Wanalyzer-unsafe-call-within-signal-handler
+@opindex Wno-analyzer-unsafe-call-within-signal-handler
+This warning requires @option{-fanalyzer}, which enables it; use
+@option{-Wno-analyzer-unsafe-call-within-signal-handler} to disable it.
+
+This diagnostic warns for paths through the code in which a
+function known to be async-signal-unsafe (such as @code{fprintf}) is
+called from a signal handler.
+
+@item -Wno-analyzer-use-after-free
+@opindex Wanalyzer-use-after-free
+@opindex Wno-analyzer-use-after-free
+This warning requires @option{-fanalyzer}, which enables it; use
+@option{-Wno-analyzer-use-after-free} to disable it.
+
+This diagnostic warns for paths through the code in which a
+pointer is used after @code{free} is called on it.
+
+@item -Wno-analyzer-use-of-pointer-in-stale-stack-frame
+@opindex Wanalyzer-use-of-pointer-in-stale-stack-frame
+@opindex Wno-analyzer-use-of-pointer-in-stale-stack-frame
+This warning requires @option{-fanalyzer}, which enables it; use
+@option{-Wno-analyzer-use-of-pointer-in-stale-stack-frame}
+to disable it.
+
+This diagnostic warns for paths through the code in which a pointer
+is dereferenced that points to a variable in a stale stack frame.
+
+@item -Wno-analyzer-use-of-uninitialized-value
+@opindex Wanalyzer-use-of-uninitialized-value
+@opindex Wno-analyzer-use-of-uninitialized-value
+This warning requires @option{-fanalyzer}, which enables it; use
+@option{-Wno-analyzer-use-of-uninitialized-value} to disable it.
+
+This diagnostic warns for paths through the code in which an uninitialized
+value is used.
+
+@item -Warith-conversion
+@opindex Warith-conversion
+@opindex Wno-arith-conversion
+Do warn about implicit conversions from arithmetic operations even
+when conversion of the operands to the same type cannot change their
+values. This affects warnings from @option{-Wconversion},
+@option{-Wfloat-conversion}, and @option{-Wsign-conversion}.
+
+@smallexample
+@group
+void f (char c, int i)
+@{
+ c = c + i; // warns with @option{-Wconversion}
+ c = c + 1; // only warns with @option{-Warith-conversion}
+@}
+@end group
+@end smallexample
+
@item -Warray-bounds
@itemx -Warray-bounds=@var{n}
@opindex Wno-array-bounds
unsigned integers are disabled by default in C++ unless
@option{-Wsign-conversion} is explicitly enabled.
+Warnings about conversion from arithmetic on a small type back to that
+type are only given with @option{-Warith-conversion}.
+
@item -Wno-conversion-null @r{(C++ and Objective-C++ only)}
@opindex Wconversion-null
@opindex Wno-conversion-null
@end table
+@node Static Analyzer Options
+@section Options That Control Static Analysis
+
+@table @gcctabopt
+@item -fanalyzer
+@opindex analyzer
+@opindex fanalyzer
+@opindex fno-analyzer
+This option enables an static analysis of program flow which looks
+for ``interesting'' interprocedural paths through the
+code, and issues warnings for problems found on them.
+
+This analysis is much more expensive than other GCC warnings.
+
+Enabling this option effectively enables the following warnings:
+
+@gccoptlist{ @gol
+-Wanalyzer-double-fclose @gol
+-Wanalyzer-double-free @gol
+-Wanalyzer-exposure-through-output-file @gol
+-Wanalyzer-file-leak @gol
+-Wanalyzer-free-of-non-heap @gol
+-Wanalyzer-malloc-leak @gol
+-Wanalyzer-possible-null-argument @gol
+-Wanalyzer-possible-null-dereference @gol
+-Wanalyzer-null-argument @gol
+-Wanalyzer-null-dereference @gol
+-Wanalyzer-tainted-array-index @gol
+-Wanalyzer-unsafe-call-within-signal-handler @gol
+-Wanalyzer-use-after-free @gol
+-Wanalyzer-use-of-uninitialized-value @gol
+-Wanalyzer-use-of-pointer-in-stale-stack-frame @gol
+}
+
+This option is only available if GCC was configured with analyzer
+support enabled.
+
+@item -Wanalyzer-too-complex
+@opindex Wanalyzer-too-complex
+@opindex Wno-analyzer-too-complex
+If @option{-fanalyzer} is enabled, the analyzer uses various heuristics
+to attempt to explore the control flow and data flow in the program,
+but these can be defeated by sufficiently complicated code.
+
+By default, the analysis will silently stop if the code is too
+complicated for the analyzer to fully explore and it reaches an internal
+limit.
+
+The @option{-Wanalyzer-too-complex} option will warn if this occurs.
+
+@end table
+
+Pertinent parameters for controlling the exploration are:
+@option{--param analyzer-bb-explosion-factor=@var{value}},
+@option{--param analyzer-max-enodes-per-program-point=@var{value}},
+@option{--param analyzer-max-recursion-depth=@var{value}}, and
+@option{--param analyzer-min-snodes-for-call-summary=@var{value}}.
+
+The following options control the analyzer.
+
+@table @gcctabopt
+
+@item -fanalyzer-call-summaries
+@opindex fanalyzer-call-summaries
+@opindex fno-analyzer-call-summaries
+Simplify interprocedural analysis by computing the effect of certain calls,
+rather than exploring all paths through the function from callsite to each
+possible return.
+
+If enabled, call summaries are only used for functions with more than one
+call site, and that are sufficiently complicated (as per
+@option{--param analyzer-min-snodes-for-call-summary=@var{value}}).
+
+@item -fanalyzer-checker=@var{name}
+@opindex fanalyzer-checker
+Restrict the analyzer to run just the named checker.
+
+@item -fanalyzer-fine-grained
+@opindex fanalyzer-fine-grained
+@opindex fno-analyzer-fine-grained
+This option is intended for analyzer developers.
+
+Internally the analyzer builds an ``exploded graph'' that combines
+control flow graphs with data flow information.
+
+By default, an edge in this graph can contain the effects of a run
+of multiple statements within a basic block. With
+@option{-fanalyzer-fine-grained}, each statement gets its own edge.
+
+@item -fno-analyzer-state-merge
+@opindex fanalyzer-state-merge
+@opindex fno-analyzer-state-merge
+This option is intended for analyzer developers.
+
+By default the analyzer will attempt to simplify analysis by merging
+sufficiently similar states at each program point as it builds its
+``exploded graph''. With @option{-fno-analyzer-state-merge} this
+merging can be suppressed, for debugging state-handling issues.
+
+@item -fno-analyzer-state-purge
+@opindex fanalyzer-state-purge
+@opindex fno-analyzer-state-purge
+This option is intended for analyzer developers.
+
+By default the analyzer will attempt to simplify analysis by purging
+aspects of state at a program point that appear to no longer be relevant
+e.g. the values of locals that aren't accessed later in the function
+and which aren't relevant to leak analysis.
+
+With @option{-fno-analyzer-state-purge} this purging of state can
+be suppressed, for debugging state-handling issues.
+
+@item -fanalyzer-transitivity
+@opindex fanalyzer-transitivity
+@opindex fno-analyzer-transitivity
+This option enables transitivity of constraints within the analyzer.
+
+@item -fanalyzer-verbose-edges
+This option is intended for analyzer developers. It enables more
+verbose, lower-level detail in the descriptions of control flow
+within diagnostic paths.
+
+@item -fanalyzer-verbose-state-changes
+This option is intended for analyzer developers. It enables more
+verbose, lower-level detail in the descriptions of events relating
+to state machines within diagnostic paths.
+
+@item -fanalyzer-verbosity=@var{level}
+This option controls the complexity of the control flow paths that are
+emitted for analyzer diagnostics.
+
+The @var{level} can be one of:
+
+@table @samp
+@item 0
+At this level, interprocedural call and return events are displayed,
+along with the most pertinent state-change events relating to
+a diagnostic. For example, for a double-@code{free} diagnostic,
+both calls to @code{free} will be shown.
+
+@item 1
+As per the previous level, but also show events for the entry
+to each function.
+
+@item 2
+As per the previous level, but also show events relating to
+control flow (e.g. ``true path taken'' at a conditional).
+
+This level is the default.
+
+@item 3
+This level is intended for analyzer developers; it adds various
+other events intended for debugging the analyzer.
+
+@end table
+
+@item -fdump-analyzer
+@opindex fdump-analyzer
+Dump internal details about what the analyzer is doing to
+@file{@var{file}.analyzer.txt}.
+This option is overridden by @option{-fdump-analyzer-stderr}.
+
+@item -fdump-analyzer-stderr
+@opindex fdump-analyzer-stderr
+Dump internal details about what the analyzer is doing to stderr.
+This option overrides @option{-fdump-analyzer}.
+
+@item -fdump-analyzer-callgraph
+@opindex fdump-analyzer-callgraph
+Dump a representation of the call graph suitable for viewing with
+GraphViz to @file{@var{file}.callgraph.dot}.
+
+@item -fdump-analyzer-exploded-graph
+@opindex fdump-analyzer-exploded-graph
+Dump a representation of the ``exploded graph'' suitable for viewing with
+GraphViz to @file{@var{file}.eg.dot}.
+Nodes are color-coded based on state-machine states to emphasize
+state changes.
+
+@item -fdump-analyzer-exploded-nodes
+@opindex dump-analyzer-exploded-nodes
+Emit diagnostics showing where nodes in the ``exploded graph'' are
+in relation to the program source.
+
+@item -fdump-analyzer-exploded-nodes-2
+@opindex dump-analyzer-exploded-nodes-2
+Dump a textual representation of the ``exploded graph'' to
+@file{@var{file}.eg.txt}.
+
+@item -fdump-analyzer-exploded-nodes-3
+@opindex dump-analyzer-exploded-nodes-3
+Dump a textual representation of the ``exploded graph'' to
+one dump file per node, to @file{@var{file}.eg-@var{id}.txt}.
+This is typically a large number of dump files.
+
+@item -fdump-analyzer-state-purge
+@opindex fdump-analyzer-state-purge
+As per @option{-fdump-analyzer-supergraph}, dump a representation of the
+``supergraph'' suitable for viewing with GraphViz, but annotate the
+graph with information on what state will be purged at each node.
+The graph is written to @file{@var{file}.state-purge.dot}.
+
+@item -fdump-analyzer-supergraph
+@opindex fdump-analyzer-supergraph
+Dump a representation of the ``supergraph'' suitable for viewing with
+GraphViz to @file{@var{file}.supergraph.dot}. This shows all of the
+control flow graphs in the program, with interprocedural edges for
+calls and returns.
+
+@end table
+
@node Debugging Options
@section Options for Debugging Your Program
@cindex options, debugging
storage persisting beyond the lifetime of the object, you can use this
flag to disable this optimization. To preserve stores before the
constructor starts (e.g.@: because your operator new clears the object
-storage) but still treat the object as dead after the destructor you,
+storage) but still treat the object as dead after the destructor, you
can use @option{-flifetime-dse=1}. The default behavior can be
explicitly selected with @option{-flifetime-dse=2}.
@option{-flifetime-dse=0} is equivalent to @option{-fno-lifetime-dse}.
over @option{-ffp-contract=fast}. You can override them at link time.
To enable debug info generation you need to supply @option{-g} at
-compile-time. If any of the input files at link time were built
+compile time. If any of the input files at link time were built
with debug info generation enabled the link will enable debug info
generation as well. Any elaborate debug info settings
like the dwarf level @option{-gdwarf-5} need to be explicitly repeated
@samp{ares}, @samp{exynos-m1}, @samp{emag}, @samp{falkor},
@samp{neoverse-e1},@samp{neoverse-n1},@samp{qdf24xx}, @samp{saphira},
@samp{phecda}, @samp{xgene1}, @samp{vulcan}, @samp{octeontx},
-@samp{octeontx81}, @samp{octeontx83}, @samp{thunderx}, @samp{thunderxt88},
+@samp{octeontx81}, @samp{octeontx83},
+@samp{octeontx2}, @samp{octeontx2t98}, @samp{octeontx2t96}
+@samp{octeontx2t93}, @samp{octeontx2f95}, @samp{octeontx2f95n},
+@samp{octeontx2f95mm}
+@samp{thunderx}, @samp{thunderxt88},
@samp{thunderxt88p1}, @samp{thunderxt81}, @samp{tsv110},
@samp{thunderxt83}, @samp{thunderx2t99},
@samp{cortex-a57.cortex-a53}, @samp{cortex-a72.cortex-a53},
@samp{256}, @samp{512}, @samp{1024} and @samp{2048}.
Specifying @samp{scalable} selects vector-length agnostic
output. At present @samp{-msve-vector-bits=128} also generates vector-length
-agnostic output. All other values generate vector-length specific code.
-The behavior of these values may change in future releases and no value except
-@samp{scalable} should be relied on for producing code that is portable across
-different hardware SVE vector lengths.
+agnostic output for big-endian targets. All other values generate
+vector-length specific code. The behavior of these values may change
+in future releases and no value except @samp{scalable} should be
+relied on for producing code that is portable across different
+hardware SVE vector lengths.
The default is @samp{-msve-vector-bits=scalable}, which produces
vector-length agnostic code.
Advanced SIMD and floating-point instructions. This option is enabled by
default for @option{-march=armv8.6-a}. Use of this option with architectures
prior to Armv8.2-A is not supported.
+@item f32mm
+Enable 32-bit Floating point Matrix Multiply instructions. This also enables
+SVE instructions. Use of this option with architectures prior to Armv8.2-A is
+not supported.
+@item f64mm
+Enable 64-bit Floating point Matrix Multiply instructions. This also enables
+SVE instructions. Use of this option with architectures prior to Armv8.2-A is
+not supported.
@item bf16
Enable brain half-precision floating-point instructions. This also enables
Advanced SIMD and floating-point instructions. This option is enabled by
@samp{armv8-a}, @samp{armv8.1-a}, @samp{armv8.2-a}, @samp{armv8.3-a},
@samp{armv8.4-a},
@samp{armv8.5-a},
+@samp{armv8.6-a},
@samp{armv7-r},
@samp{armv8-r},
@samp{armv6-m}, @samp{armv6s-m},
@samp{armv7-m}, @samp{armv7e-m},
@samp{armv8-m.base}, @samp{armv8-m.main},
+@samp{armv8.1-m.main},
@samp{iwmmxt} and @samp{iwmmxt2}.
Additionally, the following architectures, which lack support for the
@item +predres
Execution and Data Prediction Restriction Instructions.
+
+@item +i8mm
+8-bit Integer Matrix Multiply instructions.
+This also enables Advanced SIMD and floating-point instructions.
+
+@item +bf16
+Brain half-precision floating-point instructions.
+This also enables Advanced SIMD and floating-point instructions.
@end table
@item armv8.4-a
@item +predres
Execution and Data Prediction Restriction Instructions.
+
+@item +i8mm
+8-bit Integer Matrix Multiply instructions.
+This also enables Advanced SIMD and floating-point instructions.
+
+@item +bf16
+Brain half-precision floating-point instructions.
+This also enables Advanced SIMD and floating-point instructions.
@end table
@item armv8.5-a
@item +nofp
Disable the floating-point, Advanced SIMD and cryptographic instructions.
+
+@item +i8mm
+8-bit Integer Matrix Multiply instructions.
+This also enables Advanced SIMD and floating-point instructions.
+
+@item +bf16
+Brain half-precision floating-point instructions.
+This also enables Advanced SIMD and floating-point instructions.
+@end table
+
+@item armv8.6-a
+@table @samp
+@item +fp16
+The half-precision floating-point data processing instructions.
+This also enables the Advanced SIMD and floating-point instructions as well
+as the Dot Product extension and the half-precision floating-point fmla
+extension.
+
+@item +simd
+The ARMv8.3-A Advanced SIMD and floating-point instructions as well as the
+Dot Product extension.
+
+@item +crypto
+The cryptographic instructions. This also enables the Advanced SIMD and
+floating-point instructions as well as the Dot Product extension.
+
+@item +nocrypto
+Disable the cryptographic extension.
+
+@item +nofp
+Disable the floating-point, Advanced SIMD and cryptographic instructions.
+
+@item +i8mm
+8-bit Integer Matrix Multiply instructions.
+This also enables Advanced SIMD and floating-point instructions.
+
+@item +bf16
+Brain half-precision floating-point instructions.
+This also enables Advanced SIMD and floating-point instructions.
@end table
@item armv7-r
Disable the floating-point extensions.
@end table
+@item armv8.1-m.main
+@table @samp
+
+@item +dsp
+The DSP instructions.
+
+@item +mve
+The M-Profile Vector Extension (MVE) integer instructions.
+
+@item +mve.fp
+The M-Profile Vector Extension (MVE) integer and single precision
+floating-point instructions.
+
+@item +fp
+The single-precision floating-point instructions.
+
+@item +fp.dp
+The single- and double-precision floating-point instructions.
+
+@item +nofp
+Disable the floating-point extension.
+@end table
+
@item armv8-m.main
@table @samp
@item +dsp
Do not allow constant data to be placed in code sections.
Additionally, when compiling for ELF object format give all text sections the
ELF processor-specific section attribute @code{SHF_ARM_PURECODE}. This option
-is only available when generating non-pic code for M-profile targets with the
-MOVT instruction.
+is only available when generating non-pic code for M-profile targets.
@item -mcmse
@opindex mcmse
@opindex mdouble
@opindex mlong-double
Set the size (in bits) of the @code{double} or @code{long double} type,
-respectively. Possible values for @var{bits} are 32 an 64.
+respectively. Possible values for @var{bits} are 32 and 64.
Whether or not a specific value for @var{bits} is allowed depends on
-the @code{--with--double=} and @code{--with-long-double=}
+the @code{--with-double=} and @code{--with-long-double=}
@w{@uref{https://gcc.gnu.org/install/configure.html#avr,configure options}},
and the same applies for the default values of the options.
@opindex nodevicelib
Don't link against AVR-LibC's device specific library @code{lib<mcu>.a}.
+@item -nodevicespecs
+@opindex nodevicespecs
+Don't add @option{-specs=device-specs/specs-@var{mcu}} to the compiler driver's
+command line. The user takes responsibility for supplying the sub-processes
+like compiler proper, assembler and linker with appropriate command line
+options. This means that the user has to supply her private device specs
+file by means of @option{-specs=@var{path-to-specs-file}}. There is no
+more need for option @option{-mmcu=@var{mcu}}.
+
+This option can also serve as a replacement for the older way of
+specifying custom device-specs files that needed @option{-B @var{some-path}} to point to a directory
+which contains a folder named @code{device-specs} which contains a specs file named
+@code{specs-@var{mcu}}, where @var{mcu} was specified by @option{-mmcu=@var{mcu}}.
+
@item -Waddr-space-convert
@opindex Waddr-space-convert
@opindex Wno-addr-space-convert
The compiler is configured to be used together with AVR-Libc.
See the @option{--with-avrlibc} configure option.
+@item __HAVE_DOUBLE_MULTILIB__
+Defined if @option{-mdouble=} acts as a multilib option.
+
+@item __HAVE_DOUBLE32__
+@itemx __HAVE_DOUBLE64__
+Defined if the compiler supports 32-bit double resp. 64-bit double.
+The actual layout is specified by option @option{-mdouble=}.
+
+@item __DEFAULT_DOUBLE__
+The size in bits of @code{double} if @option{-mdouble=} is not set.
+To test the layout of @code{double} in a program, use the built-in
+macro @code{__SIZEOF_DOUBLE__}.
+
+@item __HAVE_LONG_DOUBLE32__
+@itemx __HAVE_LONG_DOUBLE64__
+@itemx __HAVE_LONG_DOUBLE_MULTILIB__
+@itemx __DEFAULT_LONG_DOUBLE__
+Same as above, but for @code{long double} instead of @code{double}.
+
+@item __WITH_DOUBLE_COMPARISON__
+Reflects the @code{--with-double-comparison=@{tristate|bool|libf7@}}
+@w{@uref{https://gcc.gnu.org/install/configure.html#avr,configure option}}
+and is defined to @code{2} or @code{3}.
+
+@item __WITH_LIBF7_LIBGCC__
+@itemx __WITH_LIBF7_MATH__
+@itemx __WITH_LIBF7_MATH_SYMBOLS__
+Reflects the @code{--with-libf7=@{libgcc|math|math-symbols@}}
+@w{@uref{https://gcc.gnu.org/install/configure.html#avr,configure option}}.
+
@end table
@node Blackfin Options
also be registered as an include path, and linker library path. Header files
and linker scripts in this directory can therefore be used without manually
specifying @code{-I} and @code{-L} on the command line.
-@item The @samp{msp430-elf/include/devices} directory
-Finally, GCC will examine @samp{msp430-elf/include/devices} from the
+@item The @samp{msp430-elf@{,bare@}/include/devices} directory
+Finally, GCC will examine @samp{msp430-elf@{,bare@}/include/devices} from the
toolchain root directory. This directory does not exist in a default
installation, but if the user has created it and copied @samp{devices.csv}
there, then the MCU data will be read. As above, this directory will
CPUs based on AMD Family 15h cores with x86-64 instruction set support. (This
supersets FMA4, AVX, XOP, LWP, AES, PCLMUL, CX16, MMX, SSE, SSE2, SSE3, SSE4A,
SSSE3, SSE4.1, SSE4.2, ABM and 64-bit instruction set extensions.)
+
@item bdver2
AMD Family 15h core based CPUs with x86-64 instruction set support. (This
supersets BMI, TBM, F16C, FMA, FMA4, AVX, XOP, LWP, AES, PCLMUL, CX16, MMX,
SSE, SSE2, SSE3, SSE4A, SSSE3, SSE4.1, SSE4.2, ABM and 64-bit instruction set
extensions.)
+
@item bdver3
AMD Family 15h core based CPUs with x86-64 instruction set support. (This
supersets BMI, TBM, F16C, FMA, FMA4, FSGSBASE, AVX, XOP, LWP, AES,
PCLMUL, CX16, MMX, SSE, SSE2, SSE3, SSE4A, SSSE3, SSE4.1, SSE4.2, ABM and
-64-bit instruction set extensions.
+64-bit instruction set extensions.)
+
@item bdver4
AMD Family 15h core based CPUs with x86-64 instruction set support. (This
supersets BMI, BMI2, TBM, F16C, FMA, FMA4, FSGSBASE, AVX, AVX2, XOP, LWP,
AES, PCLMUL, CX16, MOVBE, MMX, SSE, SSE2, SSE3, SSE4A, SSSE3, SSE4.1,
-SSE4.2, ABM and 64-bit instruction set extensions.
+SSE4.2, ABM and 64-bit instruction set extensions.)
@item znver1
AMD Family 17h core based CPUs with x86-64 instruction set support. (This
supersets BMI, BMI2, F16C, FMA, FSGSBASE, AVX, AVX2, ADCX, RDSEED, MWAITX,
SHA, CLZERO, AES, PCLMUL, CX16, MOVBE, MMX, SSE, SSE2, SSE3, SSE4A, SSSE3,
SSE4.1, SSE4.2, ABM, XSAVEC, XSAVES, CLFLUSHOPT, POPCNT, and 64-bit
-instruction set extensions.
+instruction set extensions.)
+
@item znver2
AMD Family 17h core based CPUs with x86-64 instruction set support. (This
-supersets BMI, BMI2, ,CLWB, F16C, FMA, FSGSBASE, AVX, AVX2, ADCX, RDSEED,
+supersets BMI, BMI2, CLWB, F16C, FMA, FSGSBASE, AVX, AVX2, ADCX, RDSEED,
MWAITX, SHA, CLZERO, AES, PCLMUL, CX16, MOVBE, MMX, SSE, SSE2, SSE3, SSE4A,
-SSSE3, SSE4.1, SSE4.2, ABM, XSAVEC, XSAVES, CLFLUSHOPT, POPCNT, and 64-bit
-instruction set extensions.)
-
+SSSE3, SSE4.1, SSE4.2, ABM, XSAVEC, XSAVES, CLFLUSHOPT, POPCNT, RDPID,
+WBNOINVD, and 64-bit instruction set extensions.)
@item btver1
CPUs based on AMD Family 14h cores with x86-64 instruction set support. (This
projects / gcc.git / blobdiff