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Diffstat (limited to 'doc/mdk_mixvm.texi')
| -rw-r--r-- | doc/mdk_mixvm.texi | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/doc/mdk_mixvm.texi b/doc/mdk_mixvm.texi index f5538cd..480abbc 100644 --- a/doc/mdk_mixvm.texi +++ b/doc/mdk_mixvm.texi @@ -373,6 +373,53 @@ actual MIXAL code that was compiled into the executed instruction. The tracing behaviour is stored as a configuration parameter in @file{~/.mdk}. @end deffn +@deffn {debug command} pbt [INS_NUMBER] +This command prints a backtrace of executed instructions. Its optional +argument @var{ins_number} is the number of instructions to print. If it +is omitted or equals zero, all executed instructions are printed. For +instance, if you compile and load the following program (@file{bt.mixal}): + +@example + ORIG 0 +BEG JMP *+1 + JMP *+1 +FOO JMP BAR +BAR HLT + END BEG +@end example + +@noindent +you could get the following traces: + +@example +MIX > load bt +Program loaded. Start address: 0 +MIX > next +MIX > pbt +#0 BEG in bt.mixal:2 +MIX > next +MIX > pbt +#0 1 in bt.mixal:3 +#1 BEG in bt.mixal:2 +MIX > run +Running ... +... done +MIX > pbt 3 +#0 BAR in bt.mixal:5 +#1 FOO in bt.mixal:4 +#2 1 in bt.mixal:3 +MIX > pbt +#0 BAR in bt.mixal:5 +#1 FOO in bt.mixal:4 +#2 1 in bt.mixal:3 +#3 BEG in bt.mixal:2 +MIX > +@end example + +Note that the executed instruction trace gives you the label of the +executed line or, if it has no label, the its address. +@end deffn + As you have probably observed, @code{mixvm} prints timing statistics when running programs. This behaviour can be controlled using the @code{timing} command (@pxref{Configuration commands}). |