106 lines
3.8 KiB
Plaintext
106 lines
3.8 KiB
Plaintext
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Known problems in GDB 6.1
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See also: http://www.gnu.org/software/gdb/bugs/
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*** Misc
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gdb/1560: Control-C does not always interrupt GDB.
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When GDB is busy processing a command which takes a long time to
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complete, hitting Control-C does not have the expected effect.
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The command execution is not aborted, and the "QUIT" message confirming
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the abortion is displayed only after the command has been completed.
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*** C++ support
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gdb/931: GDB could be more generous when reading types C++ templates on input
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When the user types a template, GDB frequently requires the type to be
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typed in a certain way (e.g. "const char*" as opposed to "const char *"
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or "char const *" or "char const*").
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gdb/1512: no canonical way to output names of C++ types
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We currently don't have any canonical way to output names of C++ types.
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E.g. "const char *" versus "char const *"; more subtleties arise when
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dealing with templates.
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gdb/1516: [regression] local classes, gcc 2.95.3, dwarf-2
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With gcc 2.95.3 and the dwarf-2 debugging format, classes which are
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defined locally to a function include the demangled name of the function
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as part of their name. For example, if a function "foobar" contains a
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local class definition "Local", gdb will say that the name of the class
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type is "foobar__Fi.0:Local".
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This applies only to classes where the class type is defined inside a
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function, not to variables defined with types that are defined somewhere
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outside any function (which most types are).
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gdb/1588: names of c++ nested types in casts must be enclosed in quotes
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You must type
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(gdb) print ('Foo::Bar') x
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or
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(gdb) print ('Foo::Bar' *) y
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instead of
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(gdb) print (Foo::Bar) x
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or
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(gdb) print (Foo::Bar *) y
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respectively.
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gdb/1091: Constructor breakpoints ignored
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gdb/1193: g++ 3.3 creates multiple constructors: gdb 5.3 can't set breakpoints
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When gcc 3.x compiles a C++ constructor or C++ destructor, it generates
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2 or 3 different versions of the object code. These versions have
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unique mangled names (they have to, in order for linking to work), but
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they have identical source code names, which leads to a great deal of
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confusion. Specifically, if you set a breakpoint in a constructor or a
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destructor, gdb will put a breakpoint in one of the versions, but your
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program may execute the other version. This makes it impossible to set
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breakpoints reliably in constructors or destructors.
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gcc 3.x generates these multiple object code functions in order to
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implement virtual base classes. gcc 2.x generated just one object code
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function with a hidden parameter, but gcc 3.x conforms to a multi-vendor
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ABI for C++ which requires multiple object code functions.
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*** Stack backtraces
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GDB's core code base has been updated to use a new backtrace
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mechanism. This mechanism makes it possible to support new features
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such DWARF 2 Call Frame Information (which in turn makes possible
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backtraces through optimized code).
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Since this code is new, it is known to still have a few problems:
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gdb/1505: [regression] gdb prints a bad backtrace for a thread
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When backtracing a thread, gdb does not stop when it reaches the
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outermost frame, instead continuing until it hits garbage. This is
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sensitive to the operating system and thread library.
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hppa*-*-*
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mips*-*-*
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The MIPS and HPPA backtrace code has only very recently been updated
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to use GDB's new frame mechanism. At present there are still a few
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problems, in particular backtraces through signal handlers do not
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work.
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People encountering problems with these architectures should consult
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GDB's web pages and mailing lists (http://www.gnu.org/software/gdb/)
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to see if there are updates.
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powerpc*-*-*
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PowerPC architecture support, in 6.1, does not use the new frame code.
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Fortunately, PowerPC architecture support, in GDB's mainline sources,
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have been updated. People encountering problems should consider
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downloading a more current snapshot of GDB
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(http://www.gnu.org/software/gdb/current/).
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