2 files changed, 57 insertions, 14 deletions

diff --git a/willow/lib/IR/Instruction.cpp b/willow/lib/IR/Instruction.cpp
index a61cd55..587736d 100644
--- a/willow/lib/IR/Instruction.cpp
+++ b/willow/lib/IR/Instruction.cpp
@@ -1,3 +1,38 @@
 #include <willow/IR/Instruction.h>
 
-namespace willow {};
+namespace willow {
+
+bool Instruction::isTerminatorOp(Opcode op) {
+  using enum Opcode;
+  switch (op) {
+  case Jmp:
+  case Br:
+  case Call:
+  case Ret:
+    return true;
+  case Add:
+  case Mul:
+  case Sub:
+  case Div:
+  case Mod:
+  case Shl:
+  case Shr:
+  case Ashl:
+  case Ashr:
+  case Eq:
+  case Lt:
+  case Gt:
+  case Le:
+  case Ge:
+  case And:
+  case Or:
+  case Not:
+  case Phi:
+  case Alloca:
+    return false;
+  }
+}
+
+Successors Instruction::succs();
+
+}; // namespace willow
diff --git a/willow/lib/IR/Verifier.cpp b/willow/lib/IR/Verifier.cpp
index 459989a..f016bbb 100644
--- a/willow/lib/IR/Verifier.cpp
+++ b/willow/lib/IR/Verifier.cpp
@@ -9,9 +9,12 @@ namespace willow {
 /// Verify that an instruction defines an SSA result
 LogicalResult verifyResult(const Instruction &inst, DiagnosticEngine &diags);
 
+/// Verify that an instruction has the expected number of operands
 LogicalResult verifyNumOperands(const Instruction &inst,
                                 DiagnosticEngine &diags, std::size_t expected);
 
+LogicalResult verifyBinaryInst(const Instruction &, DiagnosticEngine &);
+
 LogicalResult verifyModule(const Module &module, DiagnosticEngine &diags) {
   bool any_failure = false;
 
@@ -43,23 +46,24 @@ LogicalResult verifyModule(const Module &module, DiagnosticEngine &diags) {
 // }
 
 LogicalResult verifyBasicBlock(const BasicBlock &BB, DiagnosticEngine &diags) {
-  bool any_failure = false;
-
   if (BB.empty())
     return emit(diags, Severity::Error, BB.getLoc())
            << "Basic block '" << BB.getName() << "' has an empty body";
 
-  auto *trailer = BB.trailer();
-
-  if (!trailer->isTerminator()) {
-  }
-
   if (!BB.trailer()->isTerminator())
-    // TODO: terminator check
+    return emit(diags, Severity::Error, BB.getLoc())
+           << "Basic block '" << BB.getName()
+           << "' does not end with a terminator";
 
-    for (auto &inst : BB.getBody()) {
-      // verify inst
-    }
+  for (auto &inst : BB.getBody()) {
+    // verify inst
+    if (failed(verifyInst(inst, diags)))
+      return failure();
+
+    if (&inst != BB.trailer() && inst.isTerminator())
+      return emit(diags, Severity::Error, BB.getLoc())
+             << "Illegal terminator in the middle of a block";
+  }
 }
 
 // TODO: better instruction printing
@@ -149,6 +153,9 @@ LogicalResult verifyBinaryInst(const Instruction &inst,
            << "invalid instruction '" << inst << "': "
            << "expected an integral type, got '" << ty << "'";
 
+  if (failed(verifyNumOperands(inst, diags, 2)))
+    return failure();
+
   auto *lhs = inst.getOperand(0);
   auto *rhs = inst.getOperand(1);
 
@@ -177,8 +184,9 @@ LogicalResult verifyNumOperands(const Instruction &inst,
                                 DiagnosticEngine &diags, std::size_t expected) {
   std::size_t num_operands = inst.getNumOperands();
   if (num_operands != expected)
-    return emit(diags, Severity::Error, inst.getLoc()) << std::format(
-               "expected {} operands, but got {}", expected, num_operands);
+    return emit(diags, Severity::Error, inst.getLoc())
+           << std::format("'{}':, expected {} operands, got {}", inst.opcode(),
+                          expected, num_operands);
 
   return success();
 }