aarch64-linux-gnu-4.9/share/doc/gccint/Macros-for-Initialization.html - toolchains/linux-x86/gcc - Git at Google

 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
 <html>
 <!-- Copyright (C) 1988-2015 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 5.2, 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="prev" 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="prev">Initialization</a>, Up: <a href="Assembler-Format.html#Assembler-Format" accesskey="u" rel="up">Assembler Format</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>
 </div>
 <hr>
 <a name="Macros-Controlling-Initialization-Routines"></a>
 <h4 class="subsection">17.21.6 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 &ldquo;native&rdquo; 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_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., &lsquo;<samp>&quot;.so&quot;</samp>&rsquo;).  <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="prev">Initialization</a>, Up: <a href="Assembler-Format.html#Assembler-Format" accesskey="u" rel="up">Assembler Format</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>
 </div>


 </body>
 </html>
	<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
	<html>
	<!-- Copyright (C) 1988-2015 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 5.2, 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="prev" 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="prev">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">17.21.6 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_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="prev">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>