==========================
In this release, the GDB debugger sources, the generic GNU include
-files, the BFD ("binary file description") library, the readline library,
-and other libraries all have directories of their own underneath
-the gdb-4.9 directory. The idea is that a variety of GNU tools can
-share a common copy of these things. Configuration scripts and
-makefiles exist to cruise up and down this directory tree and
-automatically build all the pieces in the right order.
+files, the BFD ("binary file description") library, the readline
+library, and other libraries all have directories of their own
+underneath the gdb-4.9 directory. The idea is that a variety of GNU
+tools can share a common copy of these things. Be aware of variation
+over time--for example don't try to build gdb with a copy of bfd from
+a release other than the gdb release (such as a binutils or gas
+release), especially if the releases are more than a few weeks apart.
+Configuration scripts and makefiles exist to cruise up and down this
+directory tree and automatically build all the pieces in the right
+order.
When you unpack the gdb-4.9.tar.z or gdb-4.9.tar.Z file, you'll find
a directory called `gdb-4.9', which contains:
Languages other than C
=======================
-GDB provides some support for debugging C++ progams. Partial Modula-2
-and Chill support is now in GDB. GDB should work with FORTRAN programs.
-(If you have problems, please send a bug report; you may have to refer to
-some FORTRAN variables with a trailing underscore). Pascal programs which
-use sets, subranges, file variables, or nested functions will not
-currently work.
+GDB provides some support for debugging C++ programs, however that support
+only works well with GNU C++, and even then only on systems that use stabs
+debugging format. In particular, cfront based compilers such as Sun's C++
+are not fully supported.
+
+GDB should work with FORTRAN programs. If you have problems, please send a
+bug report; you may have to refer to some FORTRAN variables with a trailing
+underscore.
+
+Pascal programs which use sets, subranges, file variables, or nested functions
+will not currently work.
+
+Partial Modula-2 and Chill support is now in GDB.
Kernel debugging
Known bugs:
- * Under Ultrix 4.2 (DECstation-3100), we have seen problems with backtraces
- after interrupting the inferior out of a read(). The problem is caused by
- ptrace() returning an incorrect value for register 30. As far as we can
- tell, this is a kernel problem. Any help with this would be greatly
- appreciated.
+ * Under Ultrix 4.2 (DECstation-3100) or Alphas under OSF/1, we have
+ seen problems with backtraces after interrupting the inferior out
+ of a read(). The problem is caused by ptrace() returning an
+ incorrect value for the frame pointer register (register 15 or
+ 30). As far as we can tell, this is a kernel problem. Any help
+ with this would be greatly appreciated.
* On the SPARC GDB reports incorrect values of struct arguments to
functions, for the seventh and subsequent arguments. We have been looking
various BFD modules. None of them is a cause for alarm, they are actually
a result of bugs in the DECstation compiler.
- * On Solaris using the "run" command when the program is already running
- restarts the program, but may leave a core dump from the previous
- execution in the current directory. Other SVR4 based systems don't seem
- to have this problem, using the same gdb source code.
+ * On Solaris (2.1, at least) using the "run" command when the program
+ is already running restarts the program, but may leave a core dump
+ from the previous execution in the current directory. Other SVR4
+ based systems don't seem to have this problem, using the same gdb
+ source code.
+
+ * Notes for the DEC Alpha using OSF/1:
+ The debugging output of native cc has two known problems; we view these
+ as compiler bugs.
+ The linker miscompacts symbol tables, which causes gdb to confuse the
+ type of variables or results in `struct <illegal>' type outputs.
+ dbx has the same problems with those executables. A workaround is to
+ specify -Wl,-b when linking, but that will increase the executable size
+ considerably.
+ If a structure has incomplete type in one file (e.g. "struct foo *"
+ without a definition for "struct foo"), gdb will be unable to find the
+ structure definition from another file.
+ It has been reported that the Ultrix 4.3A compiler on decstations has the
+ same problems.
+
+ If you intend to compile gdb with gcc-2.4.5, be warned that the file
+ bfd/libbfd.c will be miscompiled due to a bug in gcc, you have
+ to compile this file with native cc. You will get many warnings from
+ gcc while compiling gdb, but these can be ignored for now. Again, these
+ problems are Alpha-specific.
GDB can produce warnings about symbols that it does not understand. By
default, these warnings are disabled. You can enable them by executing