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Diffstat (limited to 'FAQ')
| -rw-r--r-- | FAQ | 68 |
1 files changed, 33 insertions, 35 deletions
@@ -1,8 +1,8 @@ Frequently Asked Question on GNU C Library -As every FAQ this one also tries to answer the questions the user -might when using the pacakge. Please make sure you read this before -sending questions/bug reports to the maintainers. +As every FAQ this one also tries to answer questions the user might have +when using the pacakge. Please make sure you read this before sending +questions or bug reports to the maintainers. The GNU C Library is very complex. The building process exploits the features available in tools generally available. But many things can @@ -11,17 +11,17 @@ understand because it has to be portable but on the other hand must be fast. But you need not understand the details to use GNU C Library. This will only be necessary if you intend to contribute or change it. -If you have any question which you think might be worth answered in -this document let me know. +If you have any questions you think should be answered in this document, +please let me know. --drepper@cygnus.com ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ -[Q1] ``What systems the GNU C Library runs on?'' +[Q1] ``What systems does the GNU C Library run on?'' -[Q2] ``What compiler do I need to translate GNU libc?'' +[Q2] ``What compiler do I need to build GNU libc?'' -[Q3] ``When starting make I get only errors messages. +[Q3] ``When starting make I get only error messages. What's wrong?'' [Q4] ``After I changed configure.in I get `Autoconf version X.Y. @@ -39,7 +39,7 @@ this document let me know. ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ -[Q1] ``What systems the GNU C Library runs on?'' +[Q1] ``What systems does the GNU C Library run on?'' [A1] {UD} This is difficult to answer. The file `README' lists the architectures GNU libc is known to run *at some time*. This does not @@ -57,12 +57,11 @@ some success reports first. If you have a system not listed above (or in the `README' file) and you are really interested in porting it, contact - Roland McGrath <roland@gnu.ai.mit.edu> -or Ulrich Drepper <drepper@cygnus.com> + <bug-glibc@prep.ai.mit.edu> ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ -[Q2] ``What compiler do I need to translate GNU libc?'' +[Q2] ``What compiler do I need to build GNU libc?'' [A2] {UD} It is (almost) impossible to compile GNU C Library using a different compiler than GNU CC. A lot of extensions of GNU CC are @@ -111,6 +110,9 @@ will not get a really ISO C compliant C library. Generally speaking you should use the GNU binutils if they provide at least the same functionality as your system's tools. +Always get the newest release of GNU binutils available. +Older releases are known to have bugs that affect building the GNU C library. + ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ [Q6] ``Do I need some more things to compile GNU C Library?'' @@ -125,7 +127,7 @@ functionality as your system's tools. * plenty of time (approx 1h for i386-linux on i586@133 or 2.5h or i486@66). - If you have some more interested measurements let me know. + If you are interested in some more measurements let me know. ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ @@ -146,7 +148,7 @@ symbols: is linked against libm, too.) Generally, you should make sure you find a real program which produces -errors while linking. +errors while linking before deciding there is a problem. ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ @@ -154,21 +156,19 @@ errors while linking. the old Linux based GNU libc. Why isn't it like this?'' [A8] {DMT} Not every extension in Linux libc's history was well -thought. In fact it had a lot of problems with standard compliance -and cleanliness. With the introduction of a new version number these -errors now can be corrected. The following list shows a list of the -know source code incompatibilities. - -* _GNU_SOURCE: glibc does not automatically define _GNU_SOURCE. Thus, - if a program depends on GNU extensions, it is necessary - to compile it with C compiler option -D_GNU_SOURCE. This difference - normally mainfests itself in the form of missing prototypes and/or - data type definitions. Thus, if you get such errors, the first thing you - should do is grep the header files in /usr/include and /usr/include/sys - to check whether the functions are really missing or whether it is - just necessary to add a define of _GNU_SOURCE. Similar comments apply - to _BSD_SOURCE, _POSIX_SOURCE, _SVID_SOURCE etc (see - /usr/include/features.h). +thought-out. In fact it had a lot of problems with standards compliance +and with cleanliness. With the introduction of a new version number these +errors now can be corrected. Here is a list of the known source code +incompatibilities: + +* _GNU_SOURCE: glibc does not automatically define _GNU_SOURCE. Thus, if a + program depends on GNU extensions, it is necessary to compile it with C + compiler option -D_GNU_SOURCE, or better, to put `#define _GNU_SOURCE' at + the beginning of your source files, before any C library header files are + included. This difference normally mainfests itself in the form of + missing prototypes and/or data type definitions. Thus, if you get such + errors, the first thing you should do is try defining _GNU_SOURCE and see + if that makes the problem go away. * reboot(): GNU libc sanitizes the interface of reboot() to be more compatible with the interface used on other OSes. In particular, @@ -194,16 +194,12 @@ know source code incompatibilities. syscall name: wrapper name: declaring header file: ------------- ------------- ---------------------- - bdflush bdflush <unistd.h> + bdflush bdflush ??? create_module create_module <sys/module.h> delete_module delete_module <sys/module.h> get_kernel_syms get_kernel_syms <sys/module.h> init_module init_module <sys/module.h> - syslog ksyslog_ctl <unistd.h> - - To get the Linux-specific declarations in <unistd.h>, you'll need - to define C pre-processor macro _LINUX_SOURCE during compilation. - + syslog ksyslog_ctl ??? ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ @@ -212,6 +208,8 @@ Answers were given by: {UD} Ulrich Drepper, <drepper@cygnus.com> {DMT} David Mosberger-Tang, <davidm@AZStarNet.com> +Amended by: +{RM} Roland McGrath <roland@gnu.ai.mit.edu> Local Variables: mode:text |