Linker errors on MacOSX this morning?

Subprojects LLDB
1

I just updated all my repos and I’m seeing this when I build lldb-tool using the Xcode solution:

Undefined symbols for architecture x86_64:

“llvm::ConstantExpr::getGetElementPtr(llvm::Constant*, llvm::ArrayRefllvm::Value*, bool)”, referenced from:

llvm::ConstantExpr::getGetElementPtr(llvm::Constant*, llvm::ArrayRefllvm::Constant*, bool) in liblldb-core.a(IRForTarget.o)

(maybe you meant: __ZN4llvm12ConstantExpr16getGetElementPtrEPNS_8ConstantENS_8ArrayRefIPNS_5ValueEEEbPNS_4TypeE)

“llvm::ConstantExpr::getBitCast(llvm::Constant*, llvm::Type*)”, referenced from:

IRForTarget::RewriteObjCConstString(llvm::GlobalVariable*, llvm::GlobalVariable*) in liblldb-core.a(IRForTarget.o)

IRForTarget::RewriteObjCSelector(llvm::Instruction*) in liblldb-core.a(IRForTarget.o)

IRForTarget::BuildRelocation(llvm::Type*, unsigned long long) in liblldb-core.a(IRForTarget.o)

IRForTarget::ReplaceStrings() in liblldb-core.a(IRForTarget.o)

(maybe you meant: __ZN4llvm12ConstantExpr10getBitCastEPNS_8ConstantEPNS_4TypeEb)

“llvm::ConstantExpr::getIntToPtr(llvm::Constant*, llvm::Type*)”, referenced from:

IRForTarget::BuildFunctionPointer(llvm::Type*, unsigned long long) in liblldb-core.a(IRForTarget.o)

IRForTarget::RewriteObjCConstString(llvm::GlobalVariable*, llvm::GlobalVariable*) in liblldb-core.a(IRForTarget.o)

IRForTarget::RewriteObjCSelector(llvm::Instruction*) in liblldb-core.a(IRForTarget.o)

IRForTarget::HandleSymbol(llvm::Value*) in liblldb-core.a(IRForTarget.o)

IRForTarget::HandleObjCClass(llvm::Value*) in liblldb-core.a(IRForTarget.o)

IRForTarget::CompleteDataAllocation() in liblldb-core.a(IRForTarget.o)

(maybe you meant: __ZN4llvm12ConstantExpr11getIntToPtrEPNS_8ConstantEPNS_4TypeEb)

ld: symbol(s) not found for architecture x86_64

clang: error: linker command failed with exit code 1 (use -v to see invocation)

Is anyone else seeing this?

2

You might want to nuke your lldb/llvm-build folder and try again. Sometimes when updating the dependencies aren't tracked 100% and can result in bad .a files from the llvm build.

3

I think Jason also mentioned in another thread that this was necessary and don’t waste time tracking it down.

4

Didn’t seem to fix it. Still getting the same errors.

5

Did you also do a Build|Clean?

So full steps:
(command line)
cd lldb
rm -rf llvm-build

(back in Xcode)
Product>Clean
Cmd-B

?

6

I will try that. One thing I did yesterday was try to make a change to llvm. To do this I went into my lldb/llvm directory, created a build directory, and from inside there generated an Xcode project for just the llvm / clang stuff, and built llvm using this. Is it possible that it installed itself somewhere in a way that conflicts what what I’m trying to do using the LLDB xcode build?

7

(above my pay grade… I defer…)

8

The Xcode project will check out the sources for you into:

lldb/llvm

If they aren't already there. Then it will create lldb/lldb-build and configure/build into that directory in a way that works for multiple architectures.

So making a build folder inside llvm might work for you, but it won't be used by Xcode. If you want to do manual builds you can cd into:

lldb/llvm-build/Release+Asserts/x86_64

Then run make from there.

9

It works now, after Todd’s suggestion. rm -rf llvm-build wasn’t sufficient, I also had to clean the Xcode project. Thanks!

10

Glad you’re up and running!

Jason actually saved me here. I would have otherwise investigated for the loss.

11

If header files change, Xcode has some dependency tracking issues that are being tracked by a bug report I filed and was able to help the Xcode team diagnose. So doing a Clean when you run into link errors is always a good idea.