[LLVMdev] code-generating constant strings
Alexander Popolitov
popolit at gmail.com
Mon Dec 2 16:56:11 PST 2013
Hi, everyone!
I have maybe very naive question, but nontheless.
I'm experimenting with Kaleidoscope tutorial and I want to morph it into
something similar to McCarthy's initial Lisp.
For that, I need to implement symbols, which I thought I should
implement as pointers to structures, and those
structures would contain at least one field, which would be symbol's name.
So, here's a question: how do I generate a code, that represents a
literal string on LLVM side using LLVM's C++ API
I'm asking, because to simply generate constant floating-point value C++
API uses
an incantation 'ConstantFP::get(getGlobalContext(), APFloat(Val));' so I
guess string generation is also not obvious.
In the textual LLVM, what I want to generate is something like
'@.foo_sym = private unnamed_addr constant {[13 x i8] c"hello world\0A\00"}'
I just modified the example of a constant string from LLVM reference
manual, adding curly braces.
So, what I really want is for any newly encountered symbol to generate
code, that declares variable, which is structure, which contains
that symbol name, and a way to access the address of that structure,
substituting all occurencies of that symbol in a code I'm generating
by the pointer to that structure.
So, how would I (using C++ API):
1. generate code that defines constant string
2. generate code, that defines structure, that contains a string
3. when generating further code, be able to insert a pointer to this
structure?
Yours sincerely,
Alex
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