Mercurial > hg > CbC > CbC_gcc
annotate gcc/doc/collect2.texi @ 55:77e2b8dfacca gcc-4.4.5
update it from 4.4.3 to 4.5.0
| author | ryoma <e075725@ie.u-ryukyu.ac.jp> |
|---|---|
| date | Fri, 12 Feb 2010 23:39:51 +0900 |
| parents | a06113de4d67 |
| children | 04ced10e8804 |
| rev | line source |
|---|---|
| 0 | 1 @c Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc. |
| 2 @c This is part of the GCC manual. | |
| 3 @c For copying conditions, see the file gcc.texi. | |
| 4 | |
| 5 @node Collect2 | |
| 6 @chapter @code{collect2} | |
| 7 | |
| 8 GCC uses a utility called @code{collect2} on nearly all systems to arrange | |
| 9 to call various initialization functions at start time. | |
| 10 | |
| 11 The program @code{collect2} works by linking the program once and | |
| 12 looking through the linker output file for symbols with particular names | |
| 13 indicating they are constructor functions. If it finds any, it | |
| 14 creates a new temporary @samp{.c} file containing a table of them, | |
| 15 compiles it, and links the program a second time including that file. | |
| 16 | |
| 17 @findex __main | |
| 18 @cindex constructors, automatic calls | |
| 19 The actual calls to the constructors are carried out by a subroutine | |
| 20 called @code{__main}, which is called (automatically) at the beginning | |
| 21 of the body of @code{main} (provided @code{main} was compiled with GNU | |
| 22 CC)@. Calling @code{__main} is necessary, even when compiling C code, to | |
| 23 allow linking C and C++ object code together. (If you use | |
| 24 @option{-nostdlib}, you get an unresolved reference to @code{__main}, | |
| 25 since it's defined in the standard GCC library. Include @option{-lgcc} at | |
| 26 the end of your compiler command line to resolve this reference.) | |
| 27 | |
| 28 The program @code{collect2} is installed as @code{ld} in the directory | |
| 29 where the passes of the compiler are installed. When @code{collect2} | |
| 30 needs to find the @emph{real} @code{ld}, it tries the following file | |
| 31 names: | |
| 32 | |
| 33 @itemize @bullet | |
| 34 @item | |
|
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
35 a hard coded linker file name, if GCC was configured with the |
|
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
36 @option{--with-ld} option. |
|
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
37 |
|
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
38 @item |
| 0 | 39 @file{real-ld} in the directories listed in the compiler's search |
| 40 directories. | |
| 41 | |
| 42 @item | |
| 43 @file{real-ld} in the directories listed in the environment variable | |
| 44 @code{PATH}. | |
| 45 | |
| 46 @item | |
| 47 The file specified in the @code{REAL_LD_FILE_NAME} configuration macro, | |
| 48 if specified. | |
| 49 | |
| 50 @item | |
| 51 @file{ld} in the compiler's search directories, except that | |
| 52 @code{collect2} will not execute itself recursively. | |
| 53 | |
| 54 @item | |
| 55 @file{ld} in @code{PATH}. | |
| 56 @end itemize | |
| 57 | |
| 58 ``The compiler's search directories'' means all the directories where | |
| 59 @command{gcc} searches for passes of the compiler. This includes | |
| 60 directories that you specify with @option{-B}. | |
| 61 | |
| 62 Cross-compilers search a little differently: | |
| 63 | |
| 64 @itemize @bullet | |
| 65 @item | |
| 66 @file{real-ld} in the compiler's search directories. | |
| 67 | |
| 68 @item | |
| 69 @file{@var{target}-real-ld} in @code{PATH}. | |
| 70 | |
| 71 @item | |
| 72 The file specified in the @code{REAL_LD_FILE_NAME} configuration macro, | |
| 73 if specified. | |
| 74 | |
| 75 @item | |
| 76 @file{ld} in the compiler's search directories. | |
| 77 | |
| 78 @item | |
| 79 @file{@var{target}-ld} in @code{PATH}. | |
| 80 @end itemize | |
| 81 | |
| 82 @code{collect2} explicitly avoids running @code{ld} using the file name | |
| 83 under which @code{collect2} itself was invoked. In fact, it remembers | |
| 84 up a list of such names---in case one copy of @code{collect2} finds | |
| 85 another copy (or version) of @code{collect2} installed as @code{ld} in a | |
| 86 second place in the search path. | |
| 87 | |
| 88 @code{collect2} searches for the utilities @code{nm} and @code{strip} | |
| 89 using the same algorithm as above for @code{ld}. |