problem building ponyc if an older version of ponyc is installed

[aturley]

System Information

• Mac OS X 10.11.6
• LLVM 3.9

Description

If you have an older version of ponyc installed it can cause problems building a new version. In my case I was getting errors like this:

Linking ponyc
undef: __ZN4llvm19SmallPtrSetImplBaseD2Ev
undef: __ZN4llvm18PassManagerBuilder12addExtensionENS0_16ExtensionPointTyEPFvRKS0_RNS_6legacy15PassManagerBaseEE
undef: __ZN4llvm9DIBuilder20createSubroutineTypeENS_14DITypeRefArrayEj
undef: __ZN4llvm9DIBuilder12createMethodEPNS_7DIScopeENS_9StringRefES3_PNS_6DIFileEjPNS_16DISubroutineTypeEbbjjPNS_6DITypeEjbNS_24MDTupleTypedArrayWrapperINS_19DITemplateParameterEEE
undef: _LLVMGetTargetMachineData
undef: __ZN4llvm9DIBuilder17createCompileUnitEjNS_9StringRefES1_S1_bS1_jS1_NS0_17DebugEmissionKindEyb
Undefined symbols for architecture x86_64:
  "llvm::SmallPtrSetImplBase::~SmallPtrSetImplBase()", referenced from:
      HeapToStack::canStackAlloc(llvm::Instruction*, llvm::DominatorTree&, llvm::SmallVector<llvm::CallInst*, 4u>&, llvm::SmallVector<llvm::Instruction*, 4u>&) in libponyc.a(genopt.o)
      HeapToStack::canBeReused(llvm::Instruction*, llvm::Instruction*, llvm::DominatorTree&) in libponyc.a(genopt.o)
  "llvm::PassManagerBuilder::addExtension(llvm::PassManagerBuilder::ExtensionPointTy, void (*)(llvm::PassManagerBuilder const&, llvm::legacy::PassManagerBase&))", referenced from:
      _genopt in libponyc.a(genopt.o)
  "llvm::DIBuilder::createSubroutineType(llvm::DITypeRefArray, unsigned int)", referenced from:
      _LLVMDIBuilderCreateSubroutineType in libponyc.a(gendebug.o)
      _make_function_debug in libponyc.a(genfun.o)
     (maybe you meant: __ZN4llvm9DIBuilder20createSubroutineTypeENS_14DITypeRefArrayEjj)
  "llvm::DIBuilder::createMethod(llvm::DIScope*, llvm::StringRef, llvm::StringRef, llvm::DIFile*, unsigned int, llvm::DISubroutineType*, bool, bool, unsigned int, unsigned int, llvm::DIType*, unsigned int, bool, llvm::MDTupleTypedArrayWrapper<llvm::DITemplateParameter>)", referenced from:
      _LLVMDIBuilderCreateMethod in libponyc.a(gendebug.o)
      _make_function_debug in libponyc.a(genfun.o)
  "_LLVMGetTargetMachineData", referenced from:
      _codegen in libponyc.a(codegen.o)
  "llvm::DIBuilder::createCompileUnit(unsigned int, llvm::StringRef, llvm::StringRef, llvm::StringRef, bool, llvm::StringRef, unsigned int, llvm::StringRef, llvm::DIBuilder::DebugEmissionKind, unsigned long long, bool)", referenced from:
      _codegen in libponyc.a(codegen.o)
      _LLVMDIBuilderCreateCompileUnit in libponyc.a(gendebug.o)
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [build/release/ponyc] Error 1

This seems to happen because -L /usr/local/lib (added in d59c185) comes before the local build directory, so the installed versions of libponyc.a and libponyrt.a are used rather than the ones that are created as part of the current build.

Steps To Reproduce

1. Checkout and install an older version of ponyc using sudo make install.
2. Checkout the latest version of ponyc and build it using make

Expected Result

You will get a build of ponyc.

Actual Result

You get errors.

Notes

@SeanTAllen believes he has a fix for this that involves moving the -L /usr/local/lib argument to a position after the local build directory in the arguments that are passed to the compiler.