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Before we can make full use of the debugger, we must recompile hello.adb using the compiler's debug option. This option tells the compiler to include information about the source code, and the mapping of source code to generated code. Then the debugger can operate at source code level rather than at machine code level.
The debug information does not alter the generated code in any way but it does make object code files much bigger. Normally this is not a problem, but if you wish to remove the debug information from a file, then use the object code utility leon-coff-strip.
This is how we recompile hello.adb with the
-g option. There are other debug options too. See the
LEON Ada User's Guide for more information on debug
options.
Example 2-13. Recompiling with the Debug Option
$ leon-coff-gnatmake -f -g hello leon-coff-gcc -c -g hello.adb leon-coff-gnatbind -x hello.ali leon-coff-gnatlink -g hello.ali
The debugger is leon-coff-gdb. By default the debugger will run a LEON program on the LEON simulator. If you prefer to run and debug on a real LEON then you must arrange for your target to communicate with the host using the debugger's remote debug protocol. This is described in Section 2.8.
Example 2-14. Running under the Debugger
$ leon-coff-gdb hello XGC leon-ada Version 1.8 (debugger) Copyright (c) 1996, 2002, XGC Software. Based on gdb version 5.1.1 Copyright (c) 1998 Free Software Foundation. (gdb) br main Breakpoint 1 at 0x20010b4: file b_hello.adb, line 17. (gdb)run Starting program: .../examples/hello Connected to the simulator. Breakpoint 1, main () at b~hello.adb:34 34 adainit; (gdb)c Continuing. Hello world Program exited normally. (gdb)quit
You can view the debug information using the object dump utility, as follows:
Example 2-15. Dump of Debug Information
bash$ leon-coff-objdump -G hello hello: file format coff-erc Contents of .stab section: Symnum n_type n_othr n_desc n_value n_strx String -1 HdrSym 0 256 00000c46 1 0 SO 0 0 02001318 14 .../rts/ 1 SO 0 0 02001318 61 x-textio.adb 2 LSYM 0 0 00000000 74 long int:t1=r1;-21.8483648;21.8483647; 3 LSYM 0 0 00000000 113 unsigned char:t2=r2;0;255; 4 LSYM 0 36 00000000 140 natural___XDLU_0__21.8483647:t3=r1;0;21.8483647; 5 LSYM 0 36 00000000 189 character:t4=r4;0;255; 6 LSYM 0 36 00000000 212 access_character:t5=*4 ...