MIR: Allow parsing of empty machine functions
If you run llc -stop-after=codegenprepare and feed the resulting MIR
to llc -start-after=codegenprepare, you'll have an empty machine
function since we haven't run any isel yet. Of course, this only works
if the MIRParser believes you that this is okay.
This is essentially a revert of r241862 with a fix for the problem it
was papering over.
llvm-svn: 299975
diff --git a/llvm/lib/CodeGen/MIRParser/MIRParser.cpp b/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
index d1f5ed4..a2773cc 100644
--- a/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
+++ b/llvm/lib/CodeGen/MIRParser/MIRParser.cpp
@@ -367,9 +367,6 @@
}
PFS.SM = &SM;
- if (MF.empty())
- return error(Twine("machine function '") + Twine(MF.getName()) +
- "' requires at least one machine basic block in its body");
// Initialize the frame information after creating all the MBBs so that the
// MBB references in the frame information can be resolved.
if (initializeFrameInfo(PFS, YamlMF))
diff --git a/llvm/lib/CodeGen/MachineVerifier.cpp b/llvm/lib/CodeGen/MachineVerifier.cpp
index fc40261..f49232b 100644
--- a/llvm/lib/CodeGen/MachineVerifier.cpp
+++ b/llvm/lib/CodeGen/MachineVerifier.cpp
@@ -528,7 +528,8 @@
lastIndex = SlotIndex();
regsReserved = MRI->getReservedRegs();
- markReachable(&MF->front());
+ if (!MF->empty())
+ markReachable(&MF->front());
// Build a set of the basic blocks in the function.
FunctionBlocks.clear();
@@ -548,7 +549,8 @@
// Check that the register use lists are sane.
MRI->verifyUseLists();
- verifyStackFrame();
+ if (!MF->empty())
+ verifyStackFrame();
}
// Does iterator point to a and b as the first two elements?