[LLVMdev] Some additions to the C bindings

[Erick Tryzelaar]

On Tue, Oct 6, 2009 at 5:47 PM, Kenneth Uildriks <kennethuil at gmail.com> wrote:
> On Tue, Oct 6, 2009 at 2:13 PM, Kenneth Uildriks <kennethuil at gmail.com> wrote:
>
> LLVMGetAttribute had a bug in it.  Here's the revised version of the patch

Hi Kenneth!

I wouldn't say that I'm the best reviewer, but I've been doing some
work with the c bindings recently so hopefully I have some idea of
what I'm talking about :) Comments are inlined:


+/** See the llvm::Use class. */
+typedef struct LLVMOpaqueUse *LLVMUseRef;
+
...
+void LLVMReplaceAllUsesWith(LLVMValueRef OldVal, LLVMValueRef NewVal);
...
+/* Operations on Uses */
+LLVMUseRef LLVMGetFirstUse(LLVMValueRef Val);
+LLVMUseRef LLVMGetNextUse(LLVMUseRef U);
+LLVMValueRef LLVMGetUser(LLVMUseRef U);
+LLVMValueRef LLVMGetUsedValue(LLVMUseRef U);


These seem okay to me, but I don't have too much experience with using
the Use classes. The impression I've gotten from the other developers
is that the C bindings is really designed to just get data into llvm,
and any complex manipulations should really be done in C++ passes.
What's your use case for exposing these more complex manipulations?


+/* Operations on Users */
+LLVMValueRef LLVMGetOperand(LLVMValueRef Val, unsigned Index);


So how are you using this, since you aren't exposing any of the other
operand functionality?


+unsigned long long LLVMConstIntGetZExtValue(LLVMValueRef ConstantVal);
+long long LLVMConstIntGetSExtValue(LLVMValueRef ConstantVal);


I'm not sure about these functions. There really isn't any other way
to get to the value of any other constant, so why do you need this?


 /* Operations on composite constants */
@@ -464,6 +479,7 @@
 LLVMValueRef LLVMConstVector(LLVMValueRef *ScalarConstantVals, unsigned Size);

 /* Constant expressions */
+unsigned LLVMGetConstOpcode(LLVMValueRef ConstantVal);


This seems okay with me, but there really should be an LLVMInstruction
enum defined instead of a raw unsigned value. Could you also add a
LLVMConstExpr that wraps ConstantExpr::get?


+int LLVMHasInitializer(LLVMValueRef GlobalVar);


Seems fine to me. I can commit this now.


+LLVMAttribute LLVMGetFunctionAttr(LLVMValueRef Fn);
+LLVMAttribute LLVMGetAttribute(LLVMValueRef Arg);


I've never really done much with attributes. What are you using this for?