[LLVM-C] Use dyn_cast instead of unwrap in LLVMGetDebugLoc functions

[jberdine]

Summary

The unwrap<Type> calls can assert with:

Assertion failed: (isa<X>(Val) && "cast<Ty>() argument of incompatible type!"), function cast

so replace them with dyn_cast.

[whitequark]

So, these are going to be deprecated in D60484, but I see no harm in merging this patch, as it's a straightforward bugfix.

[jberdine]

AFAIU D60484 is about the accessors for the current debug location used by builders, while this diff's functions are about reading the debug info from existing IR values.

But given that these are redundant, as seen in D52239, shall we just remove them?

[jberdine]

@whitequark at least while D52239 and D60902 are up in the air, could I ask you to commit this fix for the existing functions?

[jberdine]

Thanks!

llvm/trunk/lib/IR/Core.cpp

void LLVMAddNamedMetadataOperand(LLVMModuleRef M, const char *Name,
   if (!Val)
     return;
   N->addOperand(extractMDNode(unwrap<MetadataAsValue>(Val)));
 }
 
 const char *LLVMGetDebugLocDirectory(LLVMValueRef Val, unsigned *Length) {
   if (!Length) return nullptr;
   StringRef S;
-  if (const auto *I = unwrap<Instruction>(Val)) {
-    S = I->getDebugLoc()->getDirectory();
-  } else if (const auto *GV = unwrap<GlobalVariable>(Val)) {
+  if (const auto *I = dyn_cast<Instruction>(unwrap(Val))) {
+    if (const auto &DL = I->getDebugLoc()) {
+      S = DL->getDirectory();
+    }
+  } else if (const auto *GV = dyn_cast<GlobalVariable>(unwrap(Val))) {
     SmallVector<DIGlobalVariableExpression *, 1> GVEs;
     GV->getDebugInfo(GVEs);
     if (GVEs.size())
       if (const DIGlobalVariable *DGV = GVEs[0]->getVariable())
         S = DGV->getDirectory();
-  } else if (const auto *F = unwrap<Function>(Val)) {
+  } else if (const auto *F = dyn_cast<Function>(unwrap(Val))) {
     if (const DISubprogram *DSP = F->getSubprogram())
       S = DSP->getDirectory();
   } else {
     assert(0 && "Expected Instruction, GlobalVariable or Function");
     return nullptr;
   }
   *Length = S.size();
   return S.data();
 }
 
 const char *LLVMGetDebugLocFilename(LLVMValueRef Val, unsigned *Length) {
   if (!Length) return nullptr;
   StringRef S;
-  if (const auto *I = unwrap<Instruction>(Val)) {
-    S = I->getDebugLoc()->getFilename();
-  } else if (const auto *GV = unwrap<GlobalVariable>(Val)) {
+  if (const auto *I = dyn_cast<Instruction>(unwrap(Val))) {
+    if (const auto &DL = I->getDebugLoc()) {
+      S = DL->getFilename();
+    }
+  } else if (const auto *GV = dyn_cast<GlobalVariable>(unwrap(Val))) {
     SmallVector<DIGlobalVariableExpression *, 1> GVEs;
     GV->getDebugInfo(GVEs);
     if (GVEs.size())
       if (const DIGlobalVariable *DGV = GVEs[0]->getVariable())
         S = DGV->getFilename();
-  } else if (const auto *F = unwrap<Function>(Val)) {
+  } else if (const auto *F = dyn_cast<Function>(unwrap(Val))) {
     if (const DISubprogram *DSP = F->getSubprogram())
       S = DSP->getFilename();
   } else {
     assert(0 && "Expected Instruction, GlobalVariable or Function");
     return nullptr;
   }
   *Length = S.size();
   return S.data();
 }
 
 unsigned LLVMGetDebugLocLine(LLVMValueRef Val) {
   unsigned L = 0;
-  if (const auto *I = unwrap<Instruction>(Val)) {
-    L = I->getDebugLoc()->getLine();
-  } else if (const auto *GV = unwrap<GlobalVariable>(Val)) {
+  if (const auto *I = dyn_cast<Instruction>(unwrap(Val))) {
+    if (const auto &DL = I->getDebugLoc()) {
+      L = DL->getLine();
+    }
+  } else if (const auto *GV = dyn_cast<GlobalVariable>(unwrap(Val))) {
     SmallVector<DIGlobalVariableExpression *, 1> GVEs;
     GV->getDebugInfo(GVEs);
     if (GVEs.size())
       if (const DIGlobalVariable *DGV = GVEs[0]->getVariable())
         L = DGV->getLine();
-  } else if (const auto *F = unwrap<Function>(Val)) {
+  } else if (const auto *F = dyn_cast<Function>(unwrap(Val))) {
     if (const DISubprogram *DSP = F->getSubprogram())
       L = DSP->getLine();
   } else {
     assert(0 && "Expected Instruction, GlobalVariable or Function");
     return -1;
   }
   return L;
 }
 
 unsigned LLVMGetDebugLocColumn(LLVMValueRef Val) {
   unsigned C = 0;
-  if (const auto *I = unwrap<Instruction>(Val))
-    if (const auto &L = I->getDebugLoc())
-      C = L->getColumn();
+  if (const auto *I = dyn_cast<Instruction>(unwrap(Val)))
+    if (const auto &DL = I->getDebugLoc())
+      C = DL->getColumn();
   return C;
 }
 
 /*--.. Operations on scalar constants ......................................--*/
 
 LLVMValueRef LLVMConstInt(LLVMTypeRef IntTy, unsigned long long N,
                           LLVMBool SignExtend) {
   return wrap(ConstantInt::get(unwrap<IntegerType>(IntTy), N, SignExtend != 0));