Category: Programming

The Go language is generally safe, in that errors in your program do not lead to unpredictable crashes (unless you use the facilities in the unsafe package). There is one classic cause of problems, however, which Go does not protect you from: race conditions. A race condition occurs when one goroutine modifies a variable and…

When I started using networked computers, I had two inboxes: e-mail and Usenet. I read every e-mail message I received. I read most Usenet postings in the groups I followed, but it was no big deal if I missed some. Those are the two main types of inboxes: the ones where you pay attention to…

Throwing an exception in C++ requires more than unwinding the stack. As the program unwinds, local variable destructors must be executed. Catch clauses must be examined to see if they should catch the exception. Exception specifications must be checked to see if the exception should be redirected to the unexpected handler. Similar issues arise in…

If you followed my last post, you will see that in order to unwind the stack you have to find the FDE associated with a given program counter value. There are two steps to this problem. The first one is finding the CIEs and FDEs at all. The second one is, given the set of…

When gcc generates code that handles exceptions, it produces tables that describe how to unwind the stack. These tables are found in the .eh_frame section. The format of the .eh_frame section is very similar to the format of a DWARF .debug_frame section. Unfortunately, it is not precisely identical. I don’t know of any documentation which…