Incorrect Compiler Identification

[forrestsmithfb]

symbolResolverCreate has some logic to determine what type of compiler/toolchain was used. The function hasRichheader is used to determine whether MSVC or GCC was used on Windows.

The function hasRichHeader is pure magic with no documentation. Unfortunately it appears to be an incomplete function. For my exe that function is returning false and the GCC toolchain is selected. This results in no symbols being loaded for my binary.

However my binary was built by MSVC. And if I modify source to force the toolchain to MSVC the symbols are correctly loaded. I'm not sure what hasRichHeader is doing wrong.

Unfortunately I can not share my exe as it's is proprietary and internal. :(

[milostosic]

Thanks for reporting this, it may explain some strange reports from before!

hasRichHeader checks, as the name implies, for presence of rich header which MTuner assumes was generated by MSVC. This is not 100% reliable as it is possible to remove rich header from PE, more info here: https://bytepointer.com/articles/the_microsoft_rich_header.htm

So even without seeing your exe, I guess some part of your build process removes rich header from it. I'd be happy to replace this with something more reliable - suggestions welcome! :)

[milostosic]

Would be curious to know what return statement in hasRichheader is triggered with your exe.

[forrestsmithfb]

It goes through the whole loop to determine roffset, doesn't find the magic value 0x68636952, and returns 0. https://github.com/milostosic/rdebug/blob/master/src/symbols.cpp#L84

Here's the values it did read:

0x0eba1f0e
0xcd09b400
0x4c01b821
0x685421cd
0x70207369
0x72676f72
0x63206d61
0x6f6e6e61
0x65622074
0x6e757220
0x206e6920
0x20534f44
0x65646f6d
0x0000242e

suggestions welcome! :)

Unfortunately I do not. I've never delved into the internals of the PE file format before. :( But here's what ChatGPT suggested? :) https://chat.openai.com/share/1a419c22-24e9-4312-8ed0-c1e3f92f103d

[akrieger]

The 'rich header' appears to be an artifact of link.exe. Binaries linked with lld-link.exe (despite objects being compiled with msvc) do not seem to possess it.