broken source upgrade 9.3-STABLE to 10.3-STABLE

[Eugene Grosbein]

CC'ing Dimitry Andric <dim at freebsd.org>

On 14.12.2016 14:27, Eugene Grosbein wrote:

> I've got legacy FreeBSD server running 8.4-STABLE and I'm trying to upgrade it.
> Source upgrade for 8.4 to 9.3-STABLE r310015 went flawlessly.
> After reboot, I checked out stable/10 r310043 sources and ran buildworld again.
> It fails:
> 
> ===> lib/clang/libllvmanalysis (all)
> c++  -O2 -pipe -I/usr/src/lib/clang/libllvmanalysis/../../../contrib/llvm/include -I/usr/src/lib/clang/libllvmanalysis/../../../contrib/llvm/tools/clang/include -I/usr/src/lib/clang/libllvmanalysis/../../../contrib/llvm/lib/Analysis -I. -I/usr/src/lib/clang/libllvmanalysis/../../../contrib/llvm/../../lib/clang/include -DLLVM_ON_UNIX -DLLVM_ON_FREEBSD -D__STDC_LIMIT_MACROS -D__STDC_CONSTANT_MACROS -DNDEBUG -fno-strict-aliasing -DLLVM_DEFAULT_TARGET_TRIPLE=\"x86_64-unknown-freebsd10.3\" -DLLVM_HOST_TRIPLE=\"x86_64-unknown-freebsd10.3\" -DDEFAULT_SYSROOT=\"/usr/obj/usr/src/tmp\" -I/usr/obj/usr/src/tmp/legacy/usr/include  -fno-exceptions -fno-rtti -c /usr/src/lib/clang/libllvmanalysis/../../../contrib/llvm/lib/Analysis/LazyValueInfo.cpp -o LazyValueInfo.o
> /usr/src/lib/clang/libllvmanalysis/../../../contrib/llvm/lib/Analysis/LazyValueInfo.cpp: In member function 'llvm::Constant* llvm::LazyValueInfo::getConstant(llvm::Value*, llvm::BasicBlock*)':
> /usr/src/lib/clang/libllvmanalysis/../../../contrib/llvm/lib/Analysis/LazyValueInfo.cpp:1054: error: 'nullptr' was not declared in this scope
> *** Error code 1
> 
> Does it mean that FreeBSD clang version 3.4.1 (tags/RELEASE_34/dot1-final 208032) 20140512
> is unable to build more recent clang version?

There was r309722:

> Pull in r281586 from upstream llvm trunk (by Wei Mi):
> Add some shortcuts in LazyValueInfo to reduce compile time of Correlated Value Propagation.

And there was MFC for r309722 to stable/9,10,11 (r309857) that broke things.
And there was a fix r309860 committed to stable/9 but not to stable/10:

--- stable/9/contrib/llvm/lib/Analysis/LazyValueInfo.cpp	2016/12/11 23:36:11	309859
+++ stable/9/contrib/llvm/lib/Analysis/LazyValueInfo.cpp	2016/12/12 00:09:08	309860
@@ -1051,7 +1051,7 @@
 Constant *LazyValueInfo::getConstant(Value *V, BasicBlock *BB) {
   // Bail out early if V is known not to be a Constant.
   if (isKnownNonConstant(V))
-    return nullptr;
+    return 0;
 
   LVILatticeVal Result = getCache(PImpl).getValueInBlock(V, BB);
 

Please unbreak source upgrade from 9.3-STABLE to 10.3-STABLE.