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digitalmars.D.learn - What kind of mangling has the LDC2 -X JsonFile "deco" field?

reply realhet <real_het hotmail.com> writes:
Hello,

I'm trying to get information from the JsonFile produced by LDC2, 
but having no clue how to decode this:

For example:
header: KeywordCat kwCatOf(int k)
   "deco" : "FAyaZE3het8keywords10KeywordCat",

The "deco" field contains the full name of the return type 
het.keywords.KeywordCat, but in front of that I don't know how to 
decode that "FAyaZE".

Also this is how a string return type is encoded: "FiZAya"

I tried std.demangle and and online GCC demangler, but no luck.

Anyone can help me telling how to decode these please?

Thank you in advance!
Sep 16 2020
next sibling parent Adam D. Ruppe <destructionator gmail.com> writes:
On Thursday, 17 September 2020 at 03:06:45 UTC, realhet wrote:

 I'm trying to get information from the JsonFile produced by 
 LDC2, but having no clue how to decode this:

 For example:
 header: KeywordCat kwCatOf(int k)
   "deco" : "FAyaZE3het8keywords10KeywordCat",


That's a D mangle but just of one individual variable, without an 
attached name. std.demangle looks for the _D prefix and the name 
so it prolly can't read it.

https://dlang.org/spec/abi.html#name_mangling

But from eyeball it is a extern(D) function taking a string 
argument and returning a KeywordCat enum..

The "F" means extern(D). After this are the argument list. "Aya" 
you'll get to recognize as "string", but formally it means "Array 
(A) of immutable (y) chars (a)". Then "Z" means non-variadic 
function and this ends the argument list, so the next thing is 
the return type. "E" means enum, then the name comes with a count 
of chars in this name piece, then the chars.
Sep 16 2020
prev sibling parent reply Adam D. Ruppe <destructionator gmail.com> writes:
On Thursday, 17 September 2020 at 03:06:45 UTC, realhet wrote:

 Anyone can help me telling how to decode these please?


so here's a cool trick to get hte other demanglers to help.

Just prepend

_D4name

to the string. so like:


$ ./ddemangle
_D4nameFAyaZE3het8keywords10KeywordCat
het.keywords.KeywordCat name(immutable(char)[])


so then the demangler will recognize it and use your placeholder 
name while spitting out the rest.

of course you can change that 4name to whatever you want.
Sep 16 2020
parent realhet <real_het hotmail.com> writes:
On Thursday, 17 September 2020 at 04:01:11 UTC, Adam D. Ruppe 
wrote:

 On Thursday, 17 September 2020 at 03:06:45 UTC, realhet wrote:

 Anyone can help me telling how to decode these please?


 Just prepend

 _D4name


Thank you very much!
Sep 17 2020