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Diffstat (limited to 'FAQ')
| -rw-r--r-- | FAQ | 42 |
1 files changed, 36 insertions, 6 deletions
@@ -50,6 +50,9 @@ please let me know. 1.21. Which compiler should I use for powerpc64? 1.22. `make' fails when running rpcgen the first time, what is going on? How do I fix this? +1.23. Why do I get: + `#error "glibc cannot be compiled without optimization"', + when trying to compile GNU libc with GNU CC? 2. Installation and configuration issues @@ -484,12 +487,12 @@ down the build process and need more disk space. failure should be looked into. Depending on the failures, you probably should not install the library at all. -You should consider using the `glibcbug' script to report the failure, -providing as much detail as possible. If you run a test directly, please -remember to set up the environment correctly. You want to test the compiled -library - and not your installed one. The best way is to copy the exact -command line which failed and run the test from the subdirectory for this -test in the sources. +You should consider reporting it in bugzilla +<http://sourceware.org/bugzilla/> providing as much detail as possible. +If you run a test directly, please remember to set up the environment +correctly. You want to test the compiled library - and not your installed +one. The best way is to copy the exact command line which failed and run +the test from the subdirectory for this test in the sources. There are some failures which are not directly related to the GNU libc: - Some compilers produce buggy code. No compiler gets single precision @@ -589,6 +592,32 @@ yourself. Please remember that for each architecture there may be various patches required to get glibc HEAD into a runnable state. The best course of action is to determine if you have all the required patches. + +1.23. Why do I get: + `#error "glibc cannot be compiled without optimization"', + when trying to compile GNU libc with GNU CC? + +{AJ,CO} There are a couple of reasons why the GNU C library will not work +correctly if it is not complied with optimzation. + +In the early startup of the dynamic loader (_dl_start), before +relocation of the PLT, you cannot make function calls. You must inline +the functions you will use during early startup, or call compiler +builtins (__builtin_*). + +Without optimizations enabled GNU CC will not inline functions. The +early startup of the dynamic loader will make function calls via an +unrelocated PLT and crash. + +Without auditing the dynamic linker code it would be difficult to remove +this requirement. + +Another reason is that nested functions must be inlined in many cases to +avoid executable stacks. + +In practice there is no reason to compile without optimizations, therefore +we require that GNU libc be compiled with optimizations enabled. + . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . @@ -1957,6 +1986,7 @@ Answers were given by: {AO} Alexandre Oliva, <aoliva@redhat.com> {BH} Bruno Haible, <haible@clisp.cons.org> {SM} Steven Munroe, <sjmunroe@us.ibm.com> +{CO} Carlos O'Donell, <carlos@systemhalted.org> Local Variables: mode:outline |