Info Catalog gdb: Numbers gdb: Controlling GDB gdb: Auto-loading

gdb: ABI

 
 22.7 Configuring the Current ABI
 ================================
 
 GDB can determine the "ABI" (Application Binary Interface) of your
 application automatically.  However, sometimes you need to override its
 conclusions.  Use these commands to manage GDB's view of the current
 ABI.
 
    One GDB configuration can debug binaries for multiple operating
 system targets, either via remote debugging or native emulation.  GDB
 will autodetect the "OS ABI" (Operating System ABI) in use, but you can
 override its conclusion using the 'set osabi' command.  One example
 where this is useful is in debugging of binaries which use an alternate
 C library (e.g. UCLIBC for GNU/Linux) which does not have the same
 identifying marks that the standard C library for your platform
 provides.
 
    When GDB is debugging the AArch64 architecture, it provides a
 "Newlib" OS ABI. This is useful for handling 'setjmp' and 'longjmp' when
 debugging binaries that use the NEWLIB C library.  The "Newlib" OS ABI
 can be selected by 'set osabi Newlib'.
 
 'show osabi'
      Show the OS ABI currently in use.
 
 'set osabi'
      With no argument, show the list of registered available OS ABI's.
 
 'set osabi ABI'
      Set the current OS ABI to ABI.
 
    Generally, the way that an argument of type 'float' is passed to a
 function depends on whether the function is prototyped.  For a
 prototyped (i.e. ANSI/ISO style) function, 'float' arguments are passed
 unchanged, according to the architecture's convention for 'float'.  For
 unprototyped (i.e. K&R style) functions, 'float' arguments are first
 promoted to type 'double' and then passed.
 
    Unfortunately, some forms of debug information do not reliably
 indicate whether a function is prototyped.  If GDB calls a function that
 is not marked as prototyped, it consults 'set coerce-float-to-double'.
 
 'set coerce-float-to-double'
 'set coerce-float-to-double on'
      Arguments of type 'float' will be promoted to 'double' when passed
      to an unprototyped function.  This is the default setting.
 
 'set coerce-float-to-double off'
      Arguments of type 'float' will be passed directly to unprototyped
      functions.
 
 'show coerce-float-to-double'
      Show the current setting of promoting 'float' to 'double'.
 
    GDB needs to know the ABI used for your program's C++ objects.  The
 correct C++ ABI depends on which C++ compiler was used to build your
 application.  GDB only fully supports programs with a single C++ ABI; if
 your program contains code using multiple C++ ABI's or if GDB can not
 identify your program's ABI correctly, you can tell GDB which ABI to
 use.  Currently supported ABI's include "gnu-v2", for 'g++' versions
 before 3.0, "gnu-v3", for 'g++' versions 3.0 and later, and "hpaCC" for
 the HP ANSI C++ compiler.  Other C++ compilers may use the "gnu-v2" or
 "gnu-v3" ABI's as well.  The default setting is "auto".
 
 'show cp-abi'
      Show the C++ ABI currently in use.
 
 'set cp-abi'
      With no argument, show the list of supported C++ ABI's.
 
 'set cp-abi ABI'
 'set cp-abi auto'
      Set the current C++ ABI to ABI, or return to automatic detection.
 

Info Catalog gdb: Numbers gdb: Controlling GDB gdb: Auto-loading