diff options
Diffstat (limited to 'ld/ld.texinfo')
| -rw-r--r-- | ld/ld.texinfo | 66 |
1 files changed, 54 insertions, 12 deletions
diff --git a/ld/ld.texinfo b/ld/ld.texinfo index b6ff46b..bdb7644 100644 --- a/ld/ld.texinfo +++ b/ld/ld.texinfo @@ -340,6 +340,17 @@ the @code{GNUTARGET} environment variable) are more flexible, but written to call the old linker. @end ifclear +@kindex --force-exe-suffix +@item --force-exe-suffix +Make sure that an output file has a .exe suffix. + +If a successfully built fully linked output file does not have a +@code{.exe} or @code{.dll} suffix, this option forces the linker to copy +the output file to one of the same name with a @code{.exe} suffix. This +option is useful when using unmodified Unix makefiles on a Microsoft +Windows host, since some versions of Windows won't run an image unless +it ends in a @code{.exe} suffix. + @kindex -g @item -g Ignored. Provided for compatibility with other tools. @@ -2481,18 +2492,49 @@ command-line options. @cindex C++ constructors, arranging in link @cindex constructors, arranging in link @item CONSTRUCTORS -This command ties up C++ style constructor and destructor records. The -details of the constructor representation vary from one object format to -another, but usually lists of constructors and destructors appear as -special sections. The @code{CONSTRUCTORS} command specifies where the -linker is to place the data from these sections, relative to the rest of -the linked output. Constructor data is marked by the symbol -@w{@code{__CTOR_LIST__}} at the start, and @w{@code{__CTOR_LIST_END}} at -the end; destructor data is bracketed similarly, between -@w{@code{__DTOR_LIST__}} and @w{@code{__DTOR_LIST_END}}. (The compiler -must arrange to actually run this code; @sc{gnu} C++ calls constructors from -a subroutine @code{__main}, which it inserts automatically into the -startup code for @code{main}, and destructors from @code{_exit}.) +When linking using the @code{a.out} object file format, the linker uses +an unusual set construct to support C++ global constructors and +destructors. When linking object file formats which do not support +arbitrary sections, such as @code{ECOFF} and @code{XCOFF}, the linker +will automatically recognize C++ global constructors and destructors by +name. For these object file formats, the @code{CONSTRUCTORS} command +tells the linker where this information should be placed. The +@code{CONSTRUCTORS} command is ignored for other object file formats. + +The symbol @w{@code{__CTOR_LIST__}} marks the start of the global +constructors, and the symbol @w{@code{__DTOR_LIST}} marks the end. The +first word in the list is the number of entries, followed by the address +of each constructor or destructor, followed by a zero word. The +compiler must arrange to actually run the code. For these object file +formats @sc{gnu} C++ calls constructors from a subroutine @code{__main}; +a call to @code{__main} is automatically inserted into the startup code +for @code{main}. @sc{gnu} C++ runs destructors either by using +@code{atexit}, or directly from the function @code{exit}. + +For object file formats such as @code{COFF} or @code{ELF} which support +multiple sections, @sc{gnu} C++ will normally arrange to put the +addresses of global constructors and destructors into the @code{.ctors} +and @code{.dtors} sections. Placing the following sequence into your +linker script will build the sort of table which the @sc{gnu} C++ +runtime code expects to see. + +@smallexample + __CTOR_LIST__ = .; + LONG((__CTOR_END__ - __CTOR_LIST__) / 4 - 2) + *(.ctors) + LONG(0) + __CTOR_END__ = .; + __DTOR_LIST__ = .; + LONG((__DTOR_END__ - __DTOR_LIST__) / 4 - 2) + *(.dtors) + LONG(0) + __DTOR_END__ = .; +@end smallexample + +Normally the compiler and linker will handle these issues automatically, +and you will not need to concern yourself with them. However, you may +need to consider this if you are using C++ and writing your own linker +scripts. @need 1000 @kindex FLOAT |