1 2On 4 Apr 06, the debuginfo reader (m_debuginfo) was majorly cleaned up 3and restructured. It has been a bit of a tangle for a while. The new 4structure looks like this: 5 6 debuginfo.c 7 8 readelf.c 9 10 readdwarf.c readstabs.c 11 12 storage.c 13 14Each .c can only call those below it on the page. 15 16storage.c contains the SegInfo structure and stuff for 17maintaining/searching arrays of symbols, line-numbers, and Dwarf CF 18info records. 19 20readdwarf.c and readstabs.c parse the relevant kind of info and 21call storage.c to store the results. 22 23readelf.c reads ELF format, hands syms directly to storage.c, 24then delegates to readdwarf.c/readstabs.c for debug info. All 25straightforward. 26 27debuginfo.c is the top-level file, and is quite small. 28 29There are 3 goals to this: 30 31(1) Generally tidy up something which needs tidying up 32 33(2) Introduce more modularity, so as to make it easier to add 34 readers for other formats, if needed 35 36(3) Simplify the stabs reader. 37 38Rationale for (1) and (2) are obvious. 39 40Re (3), the stabs reader has for a good year contained a sophisticated 41and impressive parser for stabs strings, with the aim of recording in 42detail the types of variables (I think) (Jeremy's work). Unfortunately 43that has caused various segfaults reading stabs info in the past few months 44(#77869, #117936, #119914, #120345 and another to do with deeply nested 45template types). 46 47The worst thing is that it is the stabs type reader that is crashing, 48not the stabs line-number reader, but the type info is only used by 49Helgrind, which is looking pretty dead at the moment. So I have lifed 50out the type-reader code and put it in UNUSED_STABS.txt for safe 51storage, just leaving the line-number reader in place. 52 53If Helgrind ever does come back to life we will need to reinstate the 54type storage/reader stuff but with DWARF as its primary target. 55Placing the existing stabs type-reader in hibernation improves 56stability whilst retaining the development effort/expertise that went 57into it for possible future reinstatement. 58