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diff --git a/share/doc/gdb/Omissions-from-Ada.html b/share/doc/gdb/Omissions-from-Ada.html new file mode 100644 index 0000000..d8d80a3 --- /dev/null +++ b/share/doc/gdb/Omissions-from-Ada.html @@ -0,0 +1,197 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> +<html> +<!-- Copyright (C) 1988-2023 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 +any later version published by the Free Software Foundation; with the +Invariant Sections being "Free Software" and "Free Software Needs +Free Documentation", with the Front-Cover Texts being "A GNU Manual," +and with the Back-Cover Texts as in (a) below. + +(a) The FSF's Back-Cover Text is: "You are free to copy and modify +this GNU Manual. Buying copies from GNU Press supports the FSF in +developing GNU and promoting software freedom." --> +<!-- Created by GNU Texinfo 5.1, http://www.gnu.org/software/texinfo/ --> +<head> +<title>Debugging with GDB: Omissions from Ada</title> + +<meta name="description" content="Debugging with GDB: Omissions from Ada"> +<meta name="keywords" content="Debugging with GDB: Omissions from Ada"> +<meta name="resource-type" content="document"> +<meta name="distribution" content="global"> +<meta name="Generator" content="makeinfo"> +<meta http-equiv="Content-Type" content="text/html; charset=utf-8"> +<link href="index.html#Top" rel="start" title="Top"> +<link href="Concept-Index.html#Concept-Index" rel="index" title="Concept Index"> +<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> +<link href="Ada.html#Ada" rel="up" title="Ada"> +<link href="Additions-to-Ada.html#Additions-to-Ada" rel="next" title="Additions to Ada"> +<link href="Ada-Mode-Intro.html#Ada-Mode-Intro" rel="previous" title="Ada Mode Intro"> +<style type="text/css"> +<!-- +a.summary-letter {text-decoration: none} +blockquote.smallquotation {font-size: smaller} +div.display {margin-left: 3.2em} +div.example {margin-left: 3.2em} +div.indentedblock {margin-left: 3.2em} +div.lisp {margin-left: 3.2em} +div.smalldisplay {margin-left: 3.2em} +div.smallexample {margin-left: 3.2em} +div.smallindentedblock {margin-left: 3.2em; font-size: smaller} +div.smalllisp {margin-left: 3.2em} +kbd {font-style:oblique} +pre.display {font-family: inherit} +pre.format {font-family: inherit} +pre.menu-comment {font-family: serif} +pre.menu-preformatted {font-family: serif} +pre.smalldisplay {font-family: inherit; font-size: smaller} +pre.smallexample {font-size: smaller} +pre.smallformat {font-family: inherit; font-size: smaller} +pre.smalllisp {font-size: smaller} +span.nocodebreak {white-space:nowrap} +span.nolinebreak {white-space:nowrap} +span.roman {font-family:serif; font-weight:normal} +span.sansserif {font-family:sans-serif; font-weight:normal} +ul.no-bullet {list-style: none} +--> +</style> + + +</head> + +<body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000"> +<a name="Omissions-from-Ada"></a> +<div class="header"> +<p> +Next: <a href="Additions-to-Ada.html#Additions-to-Ada" accesskey="n" rel="next">Additions to Ada</a>, Previous: <a href="Ada-Mode-Intro.html#Ada-Mode-Intro" accesskey="p" rel="previous">Ada Mode Intro</a>, Up: <a href="Ada.html#Ada" accesskey="u" rel="up">Ada</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p> +</div> +<hr> +<a name="Omissions-from-Ada-1"></a> +<h4 class="subsubsection">15.4.10.2 Omissions from Ada</h4> +<a name="index-Ada_002c-omissions-from"></a> + +<p>Here are the notable omissions from the subset: +</p> +<ul> +<li> Only a subset of the attributes are supported: + +<ul class="no-bullet"> +<li>- <tt>'First</tt>, <tt>'Last</tt>, and <tt>'Length</tt> + on array objects (not on types and subtypes). + +</li><li>- <tt>'Min</tt> and <tt>'Max</tt>. + +</li><li>- <tt>'Pos</tt> and <tt>'Val</tt>. + +</li><li>- <tt>'Tag</tt>. + +</li><li>- <tt>'Range</tt> on array objects (not subtypes), but only as the right +operand of the membership (<code>in</code>) operator. + +</li><li>- <tt>'Access</tt>, <tt>'Unchecked_Access</tt>, and +<tt>'Unrestricted_Access</tt> (a GNAT extension). + +</li><li>- <tt>'Address</tt>. +</li></ul> + +</li><li> The names in <code>Characters.Latin_1</code> are not available. + +</li><li> Equality tests (‘<samp>=</samp>’ and ‘<samp>/=</samp>’) on arrays test for bitwise +equality of representations. They will generally work correctly +for strings and arrays whose elements have integer or enumeration types. +They may not work correctly for arrays whose element +types have user-defined equality, for arrays of real values +(in particular, IEEE-conformant floating point, because of negative +zeroes and NaNs), and for arrays whose elements contain unused bits with +indeterminate values. + +</li><li> The other component-by-component array operations (<code>and</code>, <code>or</code>, +<code>xor</code>, <code>not</code>, and relational tests other than equality) +are not implemented. + +</li><li> <a name="index-array-aggregates-_0028Ada_0029"></a> +<a name="index-record-aggregates-_0028Ada_0029"></a> +<a name="index-aggregates-_0028Ada_0029"></a> +There is limited support for array and record aggregates. They are +permitted only on the right sides of assignments, as in these examples: + +<div class="smallexample"> +<pre class="smallexample">(gdb) set An_Array := (1, 2, 3, 4, 5, 6) +(gdb) set An_Array := (1, others => 0) +(gdb) set An_Array := (0|4 => 1, 1..3 => 2, 5 => 6) +(gdb) set A_2D_Array := ((1, 2, 3), (4, 5, 6), (7, 8, 9)) +(gdb) set A_Record := (1, "Peter", True); +(gdb) set A_Record := (Name => "Peter", Id => 1, Alive => True) +</pre></div> + +<p>Changing a +discriminant’s value by assigning an aggregate has an +undefined effect if that discriminant is used within the record. +However, you can first modify discriminants by directly assigning to +them (which normally would not be allowed in Ada), and then performing an +aggregate assignment. For example, given a variable <code>A_Rec</code> +declared to have a type such as: +</p> +<div class="smallexample"> +<pre class="smallexample">type Rec (Len : Small_Integer := 0) is record + Id : Integer; + Vals : IntArray (1 .. Len); +end record; +</pre></div> + +<p>you can assign a value with a different size of <code>Vals</code> with two +assignments: +</p> +<div class="smallexample"> +<pre class="smallexample">(gdb) set A_Rec.Len := 4 +(gdb) set A_Rec := (Id => 42, Vals => (1, 2, 3, 4)) +</pre></div> + +<p>As this example also illustrates, <small>GDB</small> is very loose about the usual +rules concerning aggregates. You may leave out some of the +components of an array or record aggregate (such as the <code>Len</code> +component in the assignment to <code>A_Rec</code> above); they will retain their +original values upon assignment. You may freely use dynamic values as +indices in component associations. You may even use overlapping or +redundant component associations, although which component values are +assigned in such cases is not defined. +</p> +</li><li> Calls to dispatching subprograms are not implemented. + +</li><li> The overloading algorithm is much more limited (i.e., less selective) +than that of real Ada. It makes only limited use of the context in +which a subexpression appears to resolve its meaning, and it is much +looser in its rules for allowing type matches. As a result, some +function calls will be ambiguous, and the user will be asked to choose +the proper resolution. + +</li><li> The <code>new</code> operator is not implemented. + +</li><li> Entry calls are not implemented. + +</li><li> Aside from printing, arithmetic operations on the native VAX floating-point +formats are not supported. + +</li><li> It is not possible to slice a packed array. + +</li><li> The names <code>True</code> and <code>False</code>, when not part of a qualified name, +are interpreted as if implicitly prefixed by <code>Standard</code>, regardless of +context. +Should your program +redefine these names in a package or procedure (at best a dubious practice), +you will have to use fully qualified names to access their new definitions. + +</li><li> Based real literals are not implemented. +</li></ul> + +<hr> +<div class="header"> +<p> +Next: <a href="Additions-to-Ada.html#Additions-to-Ada" accesskey="n" rel="next">Additions to Ada</a>, Previous: <a href="Ada-Mode-Intro.html#Ada-Mode-Intro" accesskey="p" rel="previous">Ada Mode Intro</a>, Up: <a href="Ada.html#Ada" accesskey="u" rel="up">Ada</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p> +</div> + + + +</body> +</html> |