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|Oracle Solaris Studio 12.3: Debugging a Program With dbx Oracle Solaris Studio 12.3 Information Library|
Machine-instruction level commands behave the same as their source level counterparts except that they operate at the level of single instructions instead of source lines.
The nexti command and the stepi command behave the same as their source-code level counterparts: the nexti command steps over functions, the stepi command steps into a function called by the next instruction (stopping at the first instruction in the called function). The command forms are also the same. See next Command and step Command for a description.
The output from the nexti command and the stepi command differ from the corresponding source level commands in two ways:
The output includes the address of the instruction at which the program is stopped (instead of the source code line number).
The default output contains the disassembled instruction instead of the source code line.
(dbx) func hand::ungrasp (dbx) nexti ungrasp +0x18: call support (dbx)
Tracing techniques at the machine-instruction level work the same as at the source code level, except you use the tracei command. For the tracei command, dbx executes a single instruction only after each check of the address being executed or the value of the variable being traced. The tracei command produces automatic stepi-like behavior: the program advances one instruction at a time, stepping into function calls.
When you use the tracei command, it causes the program to stop for a moment after each instruction while dbx checks for the address execution or the value of the variable or expression being traced. Using the tracei command can slow execution considerably.
Here is the general syntax for the tracei command:
tracei event-specification [modifier]
Commonly used forms of the tracei command are:
For more information, see tracei Command.
(dbx) tracei next -in main (dbx) cont 0x00010814: main+0x0004: clr %l0 0x00010818: main+0x0008: st %l0, [%fp - 0x8] 0x0001081c: main+0x000c: call foo 0x00010820: main+0x0010: nop 0x00010824: main+0x0014: clr %l0 .... .... (dbx) (dbx) tracei step -in foo -if glob == 0 (dbx) cont 0x000107dc: foo+0x0004: mov 0x2, %l1 0x000107e0: foo+0x0008: sethi %hi(0x20800), %l0 0x000107e4: foo+0x000c: or %l0, 0x1f4, %l0 ! glob 0x000107e8: foo+0x0010: st %l1, [%l0] 0x000107ec: foo+0x0014: ba foo+0x1c .... ....