@c This file is part of the GDB manual.
@c
-@c Copyright (C) 2003, 2004, 2005, 2006, 2009, 2010, 2011
-@c Free Software Foundation, Inc.
+@c Copyright (C) 2003-2019 Free Software Foundation, Inc.
@c
@c See the file gdb.texinfo for copying conditions.
@item @code{zero_ext} (0x2a) @var{n}: @var{a} @result{} @var{a}, zero-extended from @var{n} bits
Pop an unsigned value from the stack; zero all but the bottom @var{n}
-bits. This means that all bits to the left of bit @var{n-1} (where the
-least significant bit is bit 0) are set to the value of bit @var{n-1}.
+bits.
The number of source bits to preserve, @var{n}, is encoded as a single
byte unsigned integer following the @code{zero_ext} bytecode.
the item under the top item, etc. If @var{n} exceeds the number of
items on the stack, terminate with an error.
-@item @code{rot} (0x33): @var{a} @var{b} @var{c} => @var{c} @var{b} @var{a}
-Rotate the top three items on the stack.
+@item @code{rot} (0x33): @var{a} @var{b} @var{c} => @var{c} @var{a} @var{b}
+Rotate the top three items on the stack. The top item (c) becomes the third
+item, the next-to-top item (b) becomes the top item and the third item (a) from
+the top becomes the next-to-top item.
@item @code{if_goto} (0x20) @var{offset}: @var{a} @result{}
Pop an integer off the stack; if it is non-zero, branch to the given
16-bit on an unaligned address raises an exception, you should fetch the
register number one byte at a time.
-@item @code{setv} (0x2d) @var{n}: @result{} @var{v}
+@item @code{setv} (0x2d) @var{n}: @var{v} @result{} @var{v}
Set trace state variable number @var{n} to the value found on the top
of the stack. The stack is unchanged, so that the value is readily
available if the assignment is part of a larger expression. The
Record the value of trace state variable number @var{n} in the trace
buffer. The handling of @var{n} is as described for @code{getv}.
-@item @code{printf} (0x31) @var{n} @var{template}: @result{}
-Print the values in the stack under the control of the string template.
-The end of @var{template} is 0x00.
-If @var{n} is 0, just output the string template.
-If @var{n} is 1, pop a value from the stack and print it under the control
-of the string template.
+@item @code{tracenz} (0x2f) @var{addr} @var{size} @result{}
+Record the bytes at @var{addr} in a trace buffer, for later retrieval
+by GDB. Stop at either the first zero byte, or when @var{size} bytes
+have been recorded, whichever occurs first.
+
+@item @code{printf} (0x34) @var{numargs} @var{string} @result{}
+Do a formatted print, in the style of the C function @code{printf}).
+The value of @var{numargs} is the number of arguments to expect on the
+stack, while @var{string} is the format string, prefixed with a
+two-byte length. The last byte of the string must be zero, and is
+included in the length. The format string includes escaped sequences
+just as it appears in C source, so for instance the format string
+@code{"\t%d\n"} is six characters long, and the output will consist of
+a tab character, a decimal number, and a newline. At the top of the
+stack, above the values to be printed, this bytecode will pop a
+``function'' and ``channel''. If the function is nonzero, then the
+target may treat it as a function and call it, passing the channel as
+a first argument, as with the C function @code{fprintf}. If the
+function is zero, then the target may simply call a standard formatted
+print function of its choice. In all, this bytecode pops 2 +
+@var{numargs} stack elements, and pushes nothing.
@item @code{end} (0x27): @result{}
Stop executing bytecode; the result should be the top element of the
projects / deliverable / binutils-gdb.git / blobdiff