Вы не можете выбрать более 25 тем Темы должны начинаться с буквы или цифры, могут содержать дефисы(-) и должны содержать не более 35 символов.

94 lines
3.9KB

  1. <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
  2. <html>
  3. <!-- Copyright (C) 1988-2020 Free Software Foundation, Inc.
  4. Permission is granted to copy, distribute and/or modify this document
  5. under the terms of the GNU Free Documentation License, Version 1.3 or
  6. any later version published by the Free Software Foundation; with the
  7. Invariant Sections being "Funding Free Software", the Front-Cover
  8. Texts being (a) (see below), and with the Back-Cover Texts being (b)
  9. (see below). A copy of the license is included in the section entitled
  10. "GNU Free Documentation License".
  11. (a) The FSF's Front-Cover Text is:
  12. A GNU Manual
  13. (b) The FSF's Back-Cover Text is:
  14. You have freedom to copy and modify this GNU Manual, like GNU
  15. software. Copies published by the Free Software Foundation raise
  16. funds for GNU development. -->
  17. <!-- Created by GNU Texinfo 6.5, http://www.gnu.org/software/texinfo/ -->
  18. <head>
  19. <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
  20. <title>Empty Statements (GNU Compiler Collection (GCC) Internals)</title>
  21. <meta name="description" content="Empty Statements (GNU Compiler Collection (GCC) Internals)">
  22. <meta name="keywords" content="Empty Statements (GNU Compiler Collection (GCC) Internals)">
  23. <meta name="resource-type" content="document">
  24. <meta name="distribution" content="global">
  25. <meta name="Generator" content="makeinfo">
  26. <link href="index.html#Top" rel="start" title="Top">
  27. <link href="Option-Index.html#Option-Index" rel="index" title="Option Index">
  28. <link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
  29. <link href="Statements.html#Statements" rel="up" title="Statements">
  30. <link href="Jumps.html#Jumps" rel="next" title="Jumps">
  31. <link href="Statement-Sequences.html#Statement-Sequences" rel="prev" title="Statement Sequences">
  32. <style type="text/css">
  33. <!--
  34. a.summary-letter {text-decoration: none}
  35. blockquote.indentedblock {margin-right: 0em}
  36. blockquote.smallindentedblock {margin-right: 0em; font-size: smaller}
  37. blockquote.smallquotation {font-size: smaller}
  38. div.display {margin-left: 3.2em}
  39. div.example {margin-left: 3.2em}
  40. div.lisp {margin-left: 3.2em}
  41. div.smalldisplay {margin-left: 3.2em}
  42. div.smallexample {margin-left: 3.2em}
  43. div.smalllisp {margin-left: 3.2em}
  44. kbd {font-style: oblique}
  45. pre.display {font-family: inherit}
  46. pre.format {font-family: inherit}
  47. pre.menu-comment {font-family: serif}
  48. pre.menu-preformatted {font-family: serif}
  49. pre.smalldisplay {font-family: inherit; font-size: smaller}
  50. pre.smallexample {font-size: smaller}
  51. pre.smallformat {font-family: inherit; font-size: smaller}
  52. pre.smalllisp {font-size: smaller}
  53. span.nolinebreak {white-space: nowrap}
  54. span.roman {font-family: initial; font-weight: normal}
  55. span.sansserif {font-family: sans-serif; font-weight: normal}
  56. ul.no-bullet {list-style: none}
  57. -->
  58. </style>
  59. </head>
  60. <body lang="en">
  61. <a name="Empty-Statements"></a>
  62. <div class="header">
  63. <p>
  64. Next: <a href="Jumps.html#Jumps" accesskey="n" rel="next">Jumps</a>, Previous: <a href="Statement-Sequences.html#Statement-Sequences" accesskey="p" rel="prev">Statement Sequences</a>, Up: <a href="Statements.html#Statements" accesskey="u" rel="up">Statements</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Option-Index.html#Option-Index" title="Index" rel="index">Index</a>]</p>
  65. </div>
  66. <hr>
  67. <a name="Empty-Statements-1"></a>
  68. <h4 class="subsection">11.7.4 Empty Statements</h4>
  69. <a name="index-Empty-Statements"></a>
  70. <p>Whenever possible, statements with no effect are discarded. But
  71. if they are nested within another construct which cannot be
  72. discarded for some reason, they are instead replaced with an
  73. empty statement, generated by <code>build_empty_stmt</code>.
  74. Initially, all empty statements were shared, after the pattern of
  75. the Java front end, but this caused a lot of trouble in practice.
  76. </p>
  77. <p>An empty statement is represented as <code>(void)0</code>.
  78. </p>
  79. </body>
  80. </html>