commit da1aebcaa3343a252aab929a2cf8060486271244
author jcd <jcd@golang.org> Tue Mar 08 14:39:35 2016 +1100
committer jcd . <jcd@golang.org> Thu Mar 17 00:54:50 2016 +0000
tree a9ab863d8a917d62f7f369ec3c93ed636f0c0b90
parent 0a1bed407317d827eb12812a6e289e822ca16524

x/debug: speed up various DWARF information queries.

Builds auxiliary tables from the DWARF data to speed up requests for:
- Entries with a given name or matching a regexp (using a map from
  symbol name to a linked list of *Entry)
- Mapping a PC to a function (using a slice of function bounds, sorted
  by PC).
- Mapping a PC to a source line (using a slice of structs containing
  (PC, file, line), sorted by PC).
- Mapping a source line to breakpoint addresses (using a slice
  containing, for each file, a slice of (line, PC) pairs sorted by line.)

Renames some functions to better reflect their return values
(lookupFunction->functionStartAddress, lookupRE->LookupMatchingSymbols,
lookupPC/entryForPC->PCToFunction, LineToPCs->LineToBreakpointPCs).

Uses more specific lookups for entries that must be variables
(LookupEntry->LookupVariable).

Change-Id: Ia57514887495a7cfca242fa4af5517acf5eecf45
Reviewed-on: https://go-review.googlesource.com/20314
Reviewed-by: Dave Day <djd@golang.org>