llvm-c: Add C APIs to access DebugLoc info

Add thin shims to C interface to provide access to DebugLoc info for
Instructions, GlobalVariables and Functions.  Patch by Josh Berdine!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@344202 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm-c/Core.h

@@ -929,6 +929,44 @@ void LLVMGetNamedMetadataOperands(LLVMModuleRef M, const char *Name,
 void LLVMAddNamedMetadataOperand(LLVMModuleRef M, const char *Name,
                                  LLVMValueRef Val);
 
+/**
+ * Return the directory of the debug location for this value, which must be
+ * an llvm::Instruction, llvm::GlobalVariable, or llvm::Function.
+ *
+ * @see llvm::Instruction::getDebugLoc()
+ * @see llvm::GlobalVariable::getDebugInfo()
+ * @see llvm::Function::getSubprogram()
+ */
+const char *LLVMGetDebugLocDirectory(LLVMValueRef Val, unsigned *Length);
+
+/**
+ * Return the filename of the debug location for this value, which must be
+ * an llvm::Instruction, llvm::GlobalVariable, or llvm::Function.
+ *
+ * @see llvm::Instruction::getDebugLoc()
+ * @see llvm::GlobalVariable::getDebugInfo()
+ * @see llvm::Function::getSubprogram()
+ */
+const char *LLVMGetDebugLocFilename(LLVMValueRef Val, unsigned *Length);
+
+/**
+ * Return the line number of the debug location for this value, which must be
+ * an llvm::Instruction, llvm::GlobalVariable, or llvm::Function.
+ *
+ * @see llvm::Instruction::getDebugLoc()
+ * @see llvm::GlobalVariable::getDebugInfo()
+ * @see llvm::Function::getSubprogram()
+ */
+unsigned LLVMGetDebugLocLine(LLVMValueRef Val);
+
+/**
+ * Return the column number of the debug location for this value, which must be
+ * an llvm::Instruction.
+ *
+ * @see llvm::Instruction::getDebugLoc()
+ */
+unsigned LLVMGetDebugLocColumn(LLVMValueRef Val);
+
 /**
  * Add a function to a module under a specified name.
  *

lib/IR/Core.cpp

@@ -17,6 +17,7 @@
 #include "llvm/IR/Attributes.h"
 #include "llvm/IR/CallSite.h"
 #include "llvm/IR/Constants.h"
+#include "llvm/IR/DebugInfoMetadata.h"
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/DiagnosticInfo.h"
 #include "llvm/IR/DiagnosticPrinter.h"
@@ -1189,6 +1190,78 @@ void LLVMAddNamedMetadataOperand(LLVMModuleRef M, const char *Name,
   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)) {
+    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)) {
+    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)) {
+    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)) {
+    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)) {
+    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)) {
+    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();
+  return C;
+}
+
 /*--.. Operations on scalar constants ......................................--*/
 
 LLVMValueRef LLVMConstInt(LLVMTypeRef IntTy, unsigned long long N,