I hope this is the correct forum in which to ask this question.
Currently I am writing code meant to compile with LLVM 3.0. I am trying
to figure out, using the C++ API, how to create a constant static
struct, or the equivalent. Since I am copying data from existing C
structs, I am currently I am using a ConstantArray global variable, and
then pointer casting it to the appropriate type when I use it, but this
seems overly clunky.
Constant *cip = ConstantArray::get(
ctx(), StringRef((char *)&addr_, sizeof(addr_)), false);
return new GlobalVariable(
*mod(), cip->getType(), true,
GlobalVariable::PrivateLinkage, cip);
In a previous version of my code, I replaced cip->getType() with the
llvm equivalent of the type of addr_. This worked until I tried with a
build of llvm that had assertions turned on. Even without that, I am
hoping there is a better way to do this that I have managed to overlook.
--
Michael Welsh Duggan
(md5i at md5i.com)
Hi Michael,> I hope this is the correct forum in which to ask this question. > > Currently I am writing code meant to compile with LLVM 3.0. I am trying > to figure out, using the C++ API, how to create a constant static > struct, or the equivalent. Since I am copying data from existing C > structs, I am currently I am using a ConstantArray global variable, and > then pointer casting it to the appropriate type when I use it, but this > seems overly clunky. > > Constant *cip = ConstantArray::get( > ctx(), StringRef((char *)&addr_, sizeof(addr_)), false); > return new GlobalVariable( > *mod(), cip->getType(), true, > GlobalVariable::PrivateLinkage, cip); > > In a previous version of my code, I replaced cip->getType() with the > llvm equivalent of the type of addr_. This worked until I tried with a > build of llvm that had assertions turned on. Even without that, I am > hoping there is a better way to do this that I have managed to overlook. >I'm not sure I understood your question, but it sounds like you may want to call this ConstantArray method (with AddNull = false). /// This method constructs a ConstantArray and initializes it with a text /// string. The default behavior (AddNull==true) causes a null terminator to /// be placed at the end of the array. This effectively increases the length /// of the array by one (you've been warned). However, in some situations /// this is not desired so if AddNull==false then the string is copied without /// null termination. static Constant *get(LLVMContext &Context, StringRef Initializer, bool AddNull = true); Ciao, Duncan.
Duncan Sands <baldrick at free.fr> writes:>> I hope this is the correct forum in which to ask this question. >> >> Currently I am writing code meant to compile with LLVM 3.0. I am trying >> to figure out, using the C++ API, how to create a constant static >> struct, or the equivalent. Since I am copying data from existing C >> structs, I am currently I am using a ConstantArray global variable, and >> then pointer casting it to the appropriate type when I use it, but this >> seems overly clunky. >> >> Constant *cip = ConstantArray::get( >> ctx(), StringRef((char *)&addr_, sizeof(addr_)), false); >> return new GlobalVariable( >> *mod(), cip->getType(), true, >> GlobalVariable::PrivateLinkage, cip); >> >> In a previous version of my code, I replaced cip->getType() with the >> llvm equivalent of the type of addr_. This worked until I tried with a >> build of llvm that had assertions turned on. Even without that, I am >> hoping there is a better way to do this that I have managed to overlook. >> > > I'm not sure I understood your question, but it sounds like you may > want to call this ConstantArray method (with AddNull = false).Um... That's exactly what the example above demonstrates. But maybe I did not explain my problem well enough. If I have a type like, for example: { i32, [ 4 x i8 ] } How can I create a constant of this type like this: { i32 0x1ffff, [ i8 0, i8 4, i8 10, i8 8 ] } from the C++ API without going through nasty pointer cast tricks? -- Michael Welsh Duggan (md5i at md5i.com)