[LLVM-C] Use Length-Providing Value Name Getters and Setters

Summary:
- Provide LLVMGetValueName2 and LLVMSetValueName2 that return and take the length of the provided C string respectively
- Deprecate LLVMGetValueName and LLVMSetValueName

Reviewers: whitequark, deadalnix

Reviewed By: whitequark

Subscribers: llvm-commits, harlanhaskins

Differential Revision: https://reviews.llvm.org/D46890

llvm-svn: 332810
diff --git a/llvm/include/llvm-c/Core.h b/llvm/include/llvm-c/Core.h
index a52f58e..6f1db31 100644
--- a/llvm/include/llvm-c/Core.h
+++ b/llvm/include/llvm-c/Core.h
@@ -1496,14 +1496,14 @@
  *
  * @see llvm::Value::getName()
  */
-const char *LLVMGetValueName(LLVMValueRef Val);
+const char *LLVMGetValueName2(LLVMValueRef Val, size_t *Length);
 
 /**
  * Set the string name of a value.
  *
  * @see llvm::Value::setName()
  */
-void LLVMSetValueName(LLVMValueRef Val, const char *Name);
+void LLVMSetValueName2(LLVMValueRef Val, const char *Name, size_t NameLen);
 
 /**
  * Dump a representation of a value to stderr.
@@ -1555,6 +1555,11 @@
 LLVMValueRef LLVMIsAMDNode(LLVMValueRef Val);
 LLVMValueRef LLVMIsAMDString(LLVMValueRef Val);
 
+/** Deprecated: Use LLVMGetValueName2 instead. */
+const char *LLVMGetValueName(LLVMValueRef Val);
+/** Deprecated: Use LLVMSetValueName2 instead. */
+void LLVMSetValueName(LLVMValueRef Val, const char *Name);
+
 /**
  * @}
  */
diff --git a/llvm/lib/IR/Core.cpp b/llvm/lib/IR/Core.cpp
index 5f13f23..33dbf4a 100644
--- a/llvm/lib/IR/Core.cpp
+++ b/llvm/lib/IR/Core.cpp
@@ -796,6 +796,16 @@
   }
 }
 
+const char *LLVMGetValueName2(LLVMValueRef Val, size_t *Length) {
+  auto *V = unwrap(Val);
+  *Length = V->getName().size();
+  return V->getName().data();
+}
+
+void LLVMSetValueName2(LLVMValueRef Val, const char *Name, size_t NameLen) {
+  unwrap(Val)->setName(StringRef(Name, NameLen));
+}
+
 const char *LLVMGetValueName(LLVMValueRef Val) {
   return unwrap(Val)->getName().data();
 }
diff --git a/llvm/tools/llvm-c-test/echo.cpp b/llvm/tools/llvm-c-test/echo.cpp
index fb7a4d7..ca3a1be 100644
--- a/llvm/tools/llvm-c-test/echo.cpp
+++ b/llvm/tools/llvm-c-test/echo.cpp
@@ -174,8 +174,9 @@
   LLVMValueRef SrcNext = nullptr;
   LLVMValueRef DstNext = nullptr;
   while (true) {
-    const char *Name = LLVMGetValueName(SrcCur);
-    LLVMSetValueName(DstCur, Name);
+    size_t NameLen;
+    const char *Name = LLVMGetValueName2(SrcCur, &NameLen);
+    LLVMSetValueName2(DstCur, Name, NameLen);
 
     VMap[SrcCur] = DstCur;
 
@@ -232,7 +233,8 @@
 
   // Maybe it is a symbol
   if (LLVMIsAGlobalValue(Cst)) {
-    const char *Name = LLVMGetValueName(Cst);
+    size_t NameLen;
+    const char *Name = LLVMGetValueName2(Cst, &NameLen);
 
     // Try function
     if (LLVMIsAFunction(Cst)) {
@@ -402,7 +404,8 @@
     if (!LLVMIsAInstruction(Src))
       report_fatal_error("Expected an instruction");
 
-    const char *Name = LLVMGetValueName(Src);
+    size_t NameLen;
+    const char *Name = LLVMGetValueName2(Src, &NameLen);
 
     // Check if this is something we already computed.
     {
@@ -734,7 +737,8 @@
       report_fatal_error("Basic block is not a basic block");
 
     const char *Name = LLVMGetBasicBlockName(Src);
-    const char *VName = LLVMGetValueName(V);
+    size_t NameLen;
+    const char *VName = LLVMGetValueName2(V, &NameLen);
     if (Name != VName)
       report_fatal_error("Basic block name mismatch");
 
@@ -830,7 +834,8 @@
   }
 
   while (true) {
-    const char *Name = LLVMGetValueName(Cur);
+    size_t NameLen;
+    const char *Name = LLVMGetValueName2(Cur, &NameLen);
     if (LLVMGetNamedGlobal(M, Name))
       report_fatal_error("GlobalVariable already cloned");
     LLVMAddGlobal(M, LLVMGetElementType(TypeCloner(M).Clone(Cur)), Name);
@@ -863,7 +868,8 @@
   Cur = Begin;
   Next = nullptr;
   while (true) {
-    const char *Name = LLVMGetValueName(Cur);
+    size_t NameLen;
+    const char *Name = LLVMGetValueName2(Cur, &NameLen);
     if (LLVMGetNamedFunction(M, Name))
       report_fatal_error("Function already cloned");
     auto Ty = LLVMGetElementType(TypeCloner(M).Clone(Cur));
@@ -909,7 +915,8 @@
   }
 
   while (true) {
-    const char *Name = LLVMGetValueName(Cur);
+    size_t NameLen;
+    const char *Name = LLVMGetValueName2(Cur, &NameLen);
     LLVMValueRef G = LLVMGetNamedGlobal(M, Name);
     if (!G)
       report_fatal_error("GlobalVariable must have been declared already");
@@ -952,13 +959,16 @@
   Cur = Begin;
   Next = nullptr;
   while (true) {
-    const char *Name = LLVMGetValueName(Cur);
+    size_t NameLen;
+    const char *Name = LLVMGetValueName2(Cur, &NameLen);
     LLVMValueRef Fun = LLVMGetNamedFunction(M, Name);
     if (!Fun)
       report_fatal_error("Function must have been declared already");
 
     if (LLVMHasPersonalityFn(Cur)) {
-      const char *FName = LLVMGetValueName(LLVMGetPersonalityFn(Cur));
+      size_t FNameLen;
+      const char *FName = LLVMGetValueName2(LLVMGetPersonalityFn(Cur),
+                                           &FNameLen);
       LLVMValueRef P = LLVMGetNamedFunction(M, FName);
       if (!P)
         report_fatal_error("Could not find personality function");