From mboxrd@z Thu Jan 1 00:00:00 1970 From: Elena Zannoni To: David Edelsohn Cc: Elena Zannoni , Kevin Buettner , "Zack Weinberg" , Matthew Conway , Mark Mitchell , gcc-patches@gcc.gnu.org, gdb@sources.redhat.com Subject: Re: Limited success with 3.0 branch on AIX Date: Wed, 16 May 2001 21:29:00 -0000 Message-id: <15107.21410.608878.788866@kwikemart.cygnus.com> References: <15106.54023.177141.275660@kwikemart.cygnus.com> <200105162006.QAA25648@makai.watson.ibm.com> X-SW-Source: 2001-05/msg00286.html David Edelsohn writes: > First, I agree that the XFT_CV field of the File Auxilliary Entry > for C_FILE Symbols is the optimal location for this type of GCC DBX > Marker. We just do not have a way of accessing that field with the > current tools. > > What exactly is the "gcc2_compiled." symbol used to enable in GDB? > How much will it hurt if GDB debugs a GCC-compiled application and does > not know it was compiled with GCC? It is looked for in dbxread.c and os9kread.c only. It is used to set the processing_gcc_compilation variable (which in other platforms is set using different debug information). Such variable is then used in VARIABLES_INSIDE_BLOCK (which I didn't notice before) defined for sparc and arm, and for USE_STRUCT_CONVENTION (only the generic version of the macro). With regard to the first macro, I don't know if something running on arm can have xcoff debug info, if not then, not being able to distinguish between gcc 2 vs. older versions vs. native compilers wouldn't be a problem. About the the second macro, if the AIX targets don't use the generic version of use_struct_convention, then it is already a non-problem. > > We seem to have the following options: > > 1) Do not include "gcc2_compiled." symbol in AIX XCOFF files until > assembler provides feature to access XFT_CV field. > 2) Always use compatible assembler feature available now, e.g. C_GSYM. > 3) Use XFT_CV field if assembler supports the feature, otherwise fallback > to C_GSYM. Have GDB look in both locations, in addition to historical > "gcc2_compiled." label. > I would prefer to do option 3, so that it would work no matter what. But if we all agree that we can take the risk of not having gcc2_compiled defined at all, then we are off the hook. Elena > David >