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Source Location Availability

debug optimization quality Source location information is only available when the debug optimization quality is at least 2. If source location information is unavailable, the source commands will give an error message.

If source location information is available, but the source location is unknown because of an interrupt or unexpected hardware error ( see section unknown-locations), then the command will print:

Unknown location: using block start.
and then proceed to print the source location for the start of the basic block enclosing the code location. basic start location It's a bit complicated to explain exactly what a basic block is, but here are some properties of the block start location:

In other words, the true location lies between the printed location and the next conditional (but watch out because the compiler may have changed the program on you.)


next up previous contents index
Next: Compiler Policy Control Up: Source Location Printing Previous: How the Source is   Contents   Index
Peter Van Eynde 2001-03-08