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| author | alk3pInjection <webmaster@raspii.tech> | 2024-02-04 16:16:35 +0800 |
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| committer | alk3pInjection <webmaster@raspii.tech> | 2024-02-04 16:16:35 +0800 |
| commit | abdaadbcae30fe0c9a66c7516798279fdfd97750 (patch) | |
| tree | 00a54a6e25601e43876d03c1a4a12a749d4a914c /share/doc/gccint/Macros-for-Initialization.html | |
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diff --git a/share/doc/gccint/Macros-for-Initialization.html b/share/doc/gccint/Macros-for-Initialization.html new file mode 100644 index 0000000..cc2dc50 --- /dev/null +++ b/share/doc/gccint/Macros-for-Initialization.html @@ -0,0 +1,264 @@ +<!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 "Funding Free Software", the Front-Cover +Texts being (a) (see below), and with the Back-Cover Texts being (b) +(see below). A copy of the license is included in the section entitled +"GNU Free Documentation License". + +(a) The FSF's Front-Cover Text is: + +A GNU Manual + +(b) The FSF's Back-Cover Text is: + +You have freedom to copy and modify this GNU Manual, like GNU + software. Copies published by the Free Software Foundation raise + funds for GNU development. --> +<!-- Created by GNU Texinfo 5.1, http://www.gnu.org/software/texinfo/ --> +<head> +<title>GNU Compiler Collection (GCC) Internals: Macros for Initialization</title> + +<meta name="description" content="GNU Compiler Collection (GCC) Internals: Macros for Initialization"> +<meta name="keywords" content="GNU Compiler Collection (GCC) Internals: Macros for Initialization"> +<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="Option-Index.html#Option-Index" rel="index" title="Option Index"> +<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> +<link href="Assembler-Format.html#Assembler-Format" rel="up" title="Assembler Format"> +<link href="Instruction-Output.html#Instruction-Output" rel="next" title="Instruction Output"> +<link href="Initialization.html#Initialization" rel="previous" title="Initialization"> +<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="Macros-for-Initialization"></a> +<div class="header"> +<p> +Next: <a href="Instruction-Output.html#Instruction-Output" accesskey="n" rel="next">Instruction Output</a>, Previous: <a href="Initialization.html#Initialization" accesskey="p" rel="previous">Initialization</a>, Up: <a href="Assembler-Format.html#Assembler-Format" accesskey="u" rel="up">Assembler Format</a> [<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> +</div> +<hr> +<a name="Macros-Controlling-Initialization-Routines"></a> +<h4 class="subsection">18.20.6 Macros Controlling Initialization Routines</h4> + +<p>Here are the macros that control how the compiler handles initialization +and termination functions: +</p> +<dl> +<dt><a name="index-INIT_005fSECTION_005fASM_005fOP-1"></a>Macro: <strong>INIT_SECTION_ASM_OP</strong></dt> +<dd><p>If defined, a C string constant, including spacing, for the assembler +operation to identify the following data as initialization code. If not +defined, GCC will assume such a section does not exist. When you are +using special sections for initialization and termination functions, this +macro also controls how <samp>crtstuff.c</samp> and <samp>libgcc2.c</samp> arrange to +run the initialization functions. +</p></dd></dl> + +<dl> +<dt><a name="index-HAS_005fINIT_005fSECTION"></a>Macro: <strong>HAS_INIT_SECTION</strong></dt> +<dd><p>If defined, <code>main</code> will not call <code>__main</code> as described above. +This macro should be defined for systems that control start-up code +on a symbol-by-symbol basis, such as OSF/1, and should not +be defined explicitly for systems that support <code>INIT_SECTION_ASM_OP</code>. +</p></dd></dl> + +<dl> +<dt><a name="index-LD_005fINIT_005fSWITCH"></a>Macro: <strong>LD_INIT_SWITCH</strong></dt> +<dd><p>If defined, a C string constant for a switch that tells the linker that +the following symbol is an initialization routine. +</p></dd></dl> + +<dl> +<dt><a name="index-LD_005fFINI_005fSWITCH"></a>Macro: <strong>LD_FINI_SWITCH</strong></dt> +<dd><p>If defined, a C string constant for a switch that tells the linker that +the following symbol is a finalization routine. +</p></dd></dl> + +<dl> +<dt><a name="index-COLLECT_005fSHARED_005fINIT_005fFUNC"></a>Macro: <strong>COLLECT_SHARED_INIT_FUNC</strong> <em>(<var>stream</var>, <var>func</var>)</em></dt> +<dd><p>If defined, a C statement that will write a function that can be +automatically called when a shared library is loaded. The function +should call <var>func</var>, which takes no arguments. If not defined, and +the object format requires an explicit initialization function, then a +function called <code>_GLOBAL__DI</code> will be generated. +</p> +<p>This function and the following one are used by collect2 when linking a +shared library that needs constructors or destructors, or has DWARF2 +exception tables embedded in the code. +</p></dd></dl> + +<dl> +<dt><a name="index-COLLECT_005fSHARED_005fFINI_005fFUNC"></a>Macro: <strong>COLLECT_SHARED_FINI_FUNC</strong> <em>(<var>stream</var>, <var>func</var>)</em></dt> +<dd><p>If defined, a C statement that will write a function that can be +automatically called when a shared library is unloaded. The function +should call <var>func</var>, which takes no arguments. If not defined, and +the object format requires an explicit finalization function, then a +function called <code>_GLOBAL__DD</code> will be generated. +</p></dd></dl> + +<dl> +<dt><a name="index-INVOKE_005f_005fmain"></a>Macro: <strong>INVOKE__main</strong></dt> +<dd><p>If defined, <code>main</code> will call <code>__main</code> despite the presence of +<code>INIT_SECTION_ASM_OP</code>. This macro should be defined for systems +where the init section is not actually run automatically, but is still +useful for collecting the lists of constructors and destructors. +</p></dd></dl> + +<dl> +<dt><a name="index-SUPPORTS_005fINIT_005fPRIORITY"></a>Macro: <strong>SUPPORTS_INIT_PRIORITY</strong></dt> +<dd><p>If nonzero, the C++ <code>init_priority</code> attribute is supported and the +compiler should emit instructions to control the order of initialization +of objects. If zero, the compiler will issue an error message upon +encountering an <code>init_priority</code> attribute. +</p></dd></dl> + +<dl> +<dt><a name="index-TARGET_005fHAVE_005fCTORS_005fDTORS"></a>Target Hook: <em>bool</em> <strong>TARGET_HAVE_CTORS_DTORS</strong></dt> +<dd><p>This value is true if the target supports some “native” method of +collecting constructors and destructors to be run at startup and exit. +It is false if we must use <code>collect2</code>. +</p></dd></dl> + +<dl> +<dt><a name="index-TARGET_005fDTORS_005fFROM_005fCXA_005fATEXIT"></a>Target Hook: <em>bool</em> <strong>TARGET_DTORS_FROM_CXA_ATEXIT</strong></dt> +<dd><p>This value is true if the target wants destructors to be queued to be +run from __cxa_atexit. If this is the case then, for each priority level, +a new constructor will be entered that registers the destructors for that +level with __cxa_atexit (and there will be no destructors emitted). +It is false the method implied by <code>have_ctors_dtors</code> is used. +</p></dd></dl> + +<dl> +<dt><a name="index-TARGET_005fASM_005fCONSTRUCTOR"></a>Target Hook: <em>void</em> <strong>TARGET_ASM_CONSTRUCTOR</strong> <em>(rtx <var>symbol</var>, int <var>priority</var>)</em></dt> +<dd><p>If defined, a function that outputs assembler code to arrange to call +the function referenced by <var>symbol</var> at initialization time. +</p> +<p>Assume that <var>symbol</var> is a <code>SYMBOL_REF</code> for a function taking +no arguments and with no return value. If the target supports initialization +priorities, <var>priority</var> is a value between 0 and <code>MAX_INIT_PRIORITY</code>; +otherwise it must be <code>DEFAULT_INIT_PRIORITY</code>. +</p> +<p>If this macro is not defined by the target, a suitable default will +be chosen if (1) the target supports arbitrary section names, (2) the +target defines <code>CTORS_SECTION_ASM_OP</code>, or (3) <code>USE_COLLECT2</code> +is not defined. +</p></dd></dl> + +<dl> +<dt><a name="index-TARGET_005fASM_005fDESTRUCTOR"></a>Target Hook: <em>void</em> <strong>TARGET_ASM_DESTRUCTOR</strong> <em>(rtx <var>symbol</var>, int <var>priority</var>)</em></dt> +<dd><p>This is like <code>TARGET_ASM_CONSTRUCTOR</code> but used for termination +functions rather than initialization functions. +</p></dd></dl> + +<p>If <code>TARGET_HAVE_CTORS_DTORS</code> is true, the initialization routine +generated for the generated object file will have static linkage. +</p> +<p>If your system uses <code>collect2</code> as the means of processing +constructors, then that program normally uses <code>nm</code> to scan +an object file for constructor functions to be called. +</p> +<p>On certain kinds of systems, you can define this macro to make +<code>collect2</code> work faster (and, in some cases, make it work at all): +</p> +<dl> +<dt><a name="index-OBJECT_005fFORMAT_005fCOFF"></a>Macro: <strong>OBJECT_FORMAT_COFF</strong></dt> +<dd><p>Define this macro if the system uses COFF (Common Object File Format) +object files, so that <code>collect2</code> can assume this format and scan +object files directly for dynamic constructor/destructor functions. +</p> +<p>This macro is effective only in a native compiler; <code>collect2</code> as +part of a cross compiler always uses <code>nm</code> for the target machine. +</p></dd></dl> + +<dl> +<dt><a name="index-REAL_005fNM_005fFILE_005fNAME"></a>Macro: <strong>REAL_NM_FILE_NAME</strong></dt> +<dd><p>Define this macro as a C string constant containing the file name to use +to execute <code>nm</code>. The default is to search the path normally for +<code>nm</code>. +</p></dd></dl> + +<dl> +<dt><a name="index-NM_005fFLAGS"></a>Macro: <strong>NM_FLAGS</strong></dt> +<dd><p><code>collect2</code> calls <code>nm</code> to scan object files for static +constructors and destructors and LTO info. By default, <samp>-n</samp> is +passed. Define <code>NM_FLAGS</code> to a C string constant if other options +are needed to get the same output format as GNU <code>nm -n</code> +produces. +</p></dd></dl> + +<p>If your system supports shared libraries and has a program to list the +dynamic dependencies of a given library or executable, you can define +these macros to enable support for running initialization and +termination functions in shared libraries: +</p> +<dl> +<dt><a name="index-LDD_005fSUFFIX"></a>Macro: <strong>LDD_SUFFIX</strong></dt> +<dd><p>Define this macro to a C string constant containing the name of the program +which lists dynamic dependencies, like <code>ldd</code> under SunOS 4. +</p></dd></dl> + +<dl> +<dt><a name="index-PARSE_005fLDD_005fOUTPUT"></a>Macro: <strong>PARSE_LDD_OUTPUT</strong> <em>(<var>ptr</var>)</em></dt> +<dd><p>Define this macro to be C code that extracts filenames from the output +of the program denoted by <code>LDD_SUFFIX</code>. <var>ptr</var> is a variable +of type <code>char *</code> that points to the beginning of a line of output +from <code>LDD_SUFFIX</code>. If the line lists a dynamic dependency, the +code must advance <var>ptr</var> to the beginning of the filename on that +line. Otherwise, it must set <var>ptr</var> to <code>NULL</code>. +</p></dd></dl> + +<dl> +<dt><a name="index-SHLIB_005fSUFFIX"></a>Macro: <strong>SHLIB_SUFFIX</strong></dt> +<dd><p>Define this macro to a C string constant containing the default shared +library extension of the target (e.g., ‘<samp>".so"</samp>’). <code>collect2</code> +strips version information after this suffix when generating global +constructor and destructor names. This define is only needed on targets +that use <code>collect2</code> to process constructors and destructors. +</p></dd></dl> + +<hr> +<div class="header"> +<p> +Next: <a href="Instruction-Output.html#Instruction-Output" accesskey="n" rel="next">Instruction Output</a>, Previous: <a href="Initialization.html#Initialization" accesskey="p" rel="previous">Initialization</a>, Up: <a href="Assembler-Format.html#Assembler-Format" accesskey="u" rel="up">Assembler Format</a> [<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> +</div> + + + +</body> +</html> |