Merge branch 'master' into devel/sphinx

6 files changed, 117 insertions, 22 deletions

diff --git a/gcc/doc/analyzer.texi b/gcc/doc/analyzer.texi
index 06eb98f..ec49f95 100644
--- a/gcc/doc/analyzer.texi
+++ b/gcc/doc/analyzer.texi
@@ -544,6 +544,10 @@ __analyzer_eval (expr);
 will emit a warning with text "TRUE", FALSE" or "UNKNOWN" based on the
 truthfulness of the argument.  This is useful for writing DejaGnu tests.
 
+@smallexample
+__analyzer_get_unknown_ptr ();
+@end smallexample
+will obtain an unknown @code{void *}.
 
 @subsection Other Debugging Techniques
 
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 46eeb98..71a4c1b 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -7454,6 +7454,32 @@ This warning can be disabled by @option{-Wno-if-not-aligned}.
 The @code{warn_if_not_aligned} attribute can also be used for types
 (@pxref{Common Type Attributes}.)
 
+@cindex @code{strict_flex_array} variable attribute
+@item strict_flex_array (@var{level})
+The @code{strict_flex_array} attribute should be attached to the trailing
+array field of a structure.  It controls when to treat the trailing array
+field of a structure as a flexible array member for the purposes of accessing
+the elements of such an array.
+@var{level} must be an integer betwen 0 to 3.
+
+@var{level}=0 is the least strict level, all trailing arrays of structures
+are treated as flexible array members. @var{level}=3 is the strictest level,
+only when the trailing array is declared as a flexible array member per C99
+standard onwards (@samp{[]}), it is treated as a flexible array member.
+
+There are two more levels in between 0 and 3, which are provided to support
+older codes that use GCC zero-length array extension (@samp{[0]}) or one-element
+array as flexible array members (@samp{[1]}):
+When @var{level} is 1, the trailing array is treated as a flexible array member
+when it is declared as either @samp{[]}, @samp{[0]}, or @samp{[1]};
+When @var{level} is 2, the trailing array is treated as a flexible array member
+when it is declared as either @samp{[]}, or @samp{[0]}.
+
+This attribute can be used with or without the @option{-fstrict-flex-arrays}.
+When both the attribute and the option present at the same time, the level of
+the strictness for the specific trailing array field is determined by the
+attribute.
+
 @item alloc_size (@var{position})
 @itemx alloc_size (@var{position-1}, @var{position-2})
 @cindex @code{alloc_size} variable attribute
@@ -9182,6 +9208,20 @@ available for functions (@pxref{Function Attributes}), variables
 (@pxref{Variable Attributes}), labels (@pxref{Label Attributes}), enumerators
 (@pxref{Enumerator Attributes}), and for types (@pxref{Type Attributes}).
 
+@table @code
+@item fallthrough
+@cindex @code{fallthrough} statement attribute
+The @code{fallthrough} attribute with a null statement serves as a
+fallthrough statement.  It hints to the compiler that a statement
+that falls through to another case label, or user-defined label
+in a switch statement is intentional and thus the
+@option{-Wimplicit-fallthrough} warning must not trigger.  The
+fallthrough attribute may appear at most once in each attribute
+list, and may not be mixed with other attributes.  It can only
+be used in a switch statement (the compiler will issue an error
+otherwise), after a preceding statement and before a logically
+succeeding case label, or user-defined label.
+
 This example uses the @code{fallthrough} statement attribute to indicate that
 the @option{-Wimplicit-fallthrough} warning should not be emitted:
 
@@ -9196,19 +9236,28 @@ switch (cond)
   @}
 @end smallexample
 
-@table @code
-@item fallthrough
-@cindex @code{fallthrough} statement attribute
-The @code{fallthrough} attribute with a null statement serves as a
-fallthrough statement.  It hints to the compiler that a statement
-that falls through to another case label, or user-defined label
-in a switch statement is intentional and thus the
-@option{-Wimplicit-fallthrough} warning must not trigger.  The
-fallthrough attribute may appear at most once in each attribute
-list, and may not be mixed with other attributes.  It can only
-be used in a switch statement (the compiler will issue an error
-otherwise), after a preceding statement and before a logically
-succeeding case label, or user-defined label.
+@item assume
+@cindex @code{assume} statement attribute
+The @code{assume} attribute with a null statement serves as portable
+assumption.  It should have a single argument, a conditional expression,
+which is not evaluated.  If the argument would evaluate to true
+at the point where it appears, it has no effect, otherwise there
+is undefined behavior.  This is a GNU variant of the ISO C++23
+standard @code{assume} attribute, but it can be used in any version of
+both C and C++.
+
+@smallexample
+int
+foo (int x, int y)
+@{
+  __attribute__((assume(x == 42)));
+  __attribute__((assume(++y == 43)));
+  return x + y;
+@}
+@end smallexample
+
+@code{y} is not actually incremented and the compiler can but does not
+have to optimize it to just @code{return 42 + 42;}.
 
 @end table
 
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index cc9754b..3101021 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -169,7 +169,8 @@ in the following sections.
 -fopenmp  -fopenmp-simd @gol
 -fpermitted-flt-eval-methods=@var{standard} @gol
 -fplan9-extensions  -fsigned-bitfields  -funsigned-bitfields @gol
--fsigned-char  -funsigned-char  -fsso-struct=@var{endianness}}
+-fsigned-char  -funsigned-char -fstrict-flex-arrays[=@var{n}] @gol
+-fsso-struct=@var{endianness}}
 
 @item C++ Language Options
 @xref{C++ Dialect Options,,Options Controlling C++ Dialect}.
@@ -2496,7 +2497,10 @@ this switch.  You may want to use the @option{-fno-gnu-keywords} flag
 instead, which disables @code{typeof} but not @code{asm} and
 @code{inline}.  In C99 mode (@option{-std=c99} or @option{-std=gnu99}),
 this switch only affects the @code{asm} and @code{typeof} keywords,
-since @code{inline} is a standard keyword in ISO C99.
+since @code{inline} is a standard keyword in ISO C99.  In C2X mode
+(@option{-std=c2x} or @option{-std=gnu2x}), this switch only affects
+the @code{asm} keyword, since @code{typeof} is a standard keyword in
+ISO C2X.
 
 @item -fno-builtin
 @itemx -fno-builtin-@var{function}
@@ -2699,7 +2703,8 @@ can be omitted, to use a target-specific default value.
 @item -fopenmp
 @opindex fopenmp
 @cindex OpenMP parallel
-Enable handling of OpenMP directives @code{#pragma omp} in C/C++ and
+Enable handling of OpenMP directives @code{#pragma omp} in C/C++,
+@code{[[omp::directive(...)]]} and @code{[[omp::sequence(...)]]} in C++ and
 @code{!$omp} in Fortran.  When @option{-fopenmp} is specified, the
 compiler generates parallel code according to the OpenMP Application
 Program Interface v4.5 @w{@uref{https://www.openmp.org}}.  This option
@@ -2711,9 +2716,12 @@ have support for @option{-pthread}. @option{-fopenmp} implies
 @opindex fopenmp-simd
 @cindex OpenMP SIMD
 @cindex SIMD
-Enable handling of OpenMP's SIMD directives with @code{#pragma omp}
-in C/C++ and @code{!$omp} in Fortran. Other OpenMP directives
-are ignored.
+Enable handling of OpenMP's @code{simd}, @code{declare simd},
+@code{declare reduction}, @code{assume}, @code{ordered}, @code{scan},
+@code{loop} directives and combined or composite directives with
+@code{simd} as constituent with @code{#pragma omp} in C/C++,
+@code{[[omp::directive(...)]]} and @code{[[omp::sequence(...)]]} in C++
+and @code{!$omp} in Fortran.  Other OpenMP directives are ignored.
 
 @item -fpermitted-flt-eval-methods=@var{style}
 @opindex fpermitted-flt-eval-methods
@@ -2790,6 +2798,31 @@ The type @code{char} is always a distinct type from each of
 @code{signed char} or @code{unsigned char}, even though its behavior
 is always just like one of those two.
 
+@item -fstrict-flex-arrays
+@opindex fstrict-flex-arrays
+@opindex fno-strict-flex-arrays
+Control when to treat the trailing array of a structure as a flexible array
+member for the purpose of accessing the elements of such an array.
+The positive form is equivalent to @option{-fstrict-flex-arrays=3}, which is the
+strictest.  A trailing array is treated as a flexible array member only when it
+is declared as a flexible array member per C99 standard onwards.
+The negative form is equivalent to @option{-fstrict-flex-arrays=0}, which is the
+least strict.  All trailing arrays of structures are treated as flexible array
+members.
+
+@item -fstrict-flex-arrays=@var{level}
+@opindex fstrict-flex-arrays=@var{level}
+Control when to treat the trailing array of a structure as a flexible array
+member for the purpose of accessing the elements of such an array.  The value
+of @var{level} controls the level of strictness.
+
+The possible values of @var{level} are the same as for the
+@code{strict_flex_array} attribute (@pxref{Variable Attributes}).
+
+You can control this behavior for a specific trailing array field of a
+structure by using the variable attribute @code{strict_flex_array} attribute
+(@pxref{Variable Attributes}).
+
 @item -fsso-struct=@var{endianness}
 @opindex fsso-struct
 Set the default scalar storage order of structures and unions to the
diff --git a/gcc/doc/md.texi b/gcc/doc/md.texi
index bb42ee1..d0a71ecb 100644
--- a/gcc/doc/md.texi
+++ b/gcc/doc/md.texi
@@ -3267,9 +3267,6 @@ Like @code{b}, if @option{-mpowerpc64} is used; otherwise, @code{NO_REGS}.
 @item wB
 Signed 5-bit constant integer that can be loaded into an Altivec register.
 
-@item wD
-Int constant that is the element number of the 64-bit scalar in a vector.
-
 @item wE
 Vector constant that can be loaded with the XXSPLTIB instruction.
 
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index 4f4f090..4ce7574 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -3423,6 +3423,12 @@ someone decided it was a good idea to use that register number to
 terminate the stack backtrace.  New ports should avoid this.
 @end defmac
 
+@defmac DWARF_VERSION_DEFAULT
+A C expression whose value is the default dwarf standard version we'll honor
+and advertise when generating dwarf debug information, in absence of
+an explicit @option{-gdwarf-@var{version}} option on the command line.
+@end defmac
+
 @deftypefn {Target Hook} void TARGET_DWARF_HANDLE_FRAME_UNSPEC (const char *@var{label}, rtx @var{pattern}, int @var{index})
 @c hook-start:TARGET_DWARF_HANDLE_FRAME_UNSPEC
 This target hook allows the backend to emit frame-related insns that
diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in
index 21b849e..501ddf1 100644
--- a/gcc/doc/tm.texi.in
+++ b/gcc/doc/tm.texi.in
@@ -2575,6 +2575,12 @@ someone decided it was a good idea to use that register number to
 terminate the stack backtrace.  New ports should avoid this.
 @end defmac
 
+@defmac DWARF_VERSION_DEFAULT
+A C expression whose value is the default dwarf standard version we'll honor
+and advertise when generating dwarf debug information, in absence of
+an explicit @option{-gdwarf-@var{version}} option on the command line.
+@end defmac
+
 @hook TARGET_DWARF_HANDLE_FRAME_UNSPEC
 
 @hook TARGET_DWARF_POLY_INDETERMINATE_VALUE