[LLVM] Add LLVMIntrinsicCopyName to LLVM C API

Also change `LLVMIntrinsicCopyOverloadedName` and
`LLVMIntrinsicCopyOverloadedName2` to return `char *` instead of
`const char*` since the returned memory is owned by the caller and
we expect that pointer to be passed to `free` to deallocate it.

Author: jurahul

llvm/docs/ReleaseNotes.md

@@ -258,6 +258,10 @@ Changes to the C API
 
 * Added `LLVMAtomicRMWBinOpUSubCond` and `LLVMAtomicRMWBinOpUSubSat` to `LLVMAtomicRMWBinOp` enum for AtomicRMW instructions.
 
+* Added `LLVMIntrinsicCopyName` and changed `LLVMIntrinsicCopyOverloadedName`
+  and `LLVMIntrinsicCopyOverloadedName2` to return `char *` instead of
+  `const char *`.
+
 Changes to the CodeGen infrastructure
 -------------------------------------
 

llvm/include/llvm-c/Core.h

@@ -2833,11 +2833,17 @@ LLVMTypeRef LLVMIntrinsicGetType(LLVMContextRef Ctx, unsigned ID,
  */
 const char *LLVMIntrinsicGetName(unsigned ID, size_t *NameLength);
 
+/**
+ * Copies the name of an intrinsic. The caller is responsible for freeing the
+ * returned string.
+ *
+ * @see llvm::Intrinsic::getName()
+ */
+char *LLVMIntrinsicCopyName(unsigned ID, size_t *NameLength);
+
 /** Deprecated: Use LLVMIntrinsicCopyOverloadedName2 instead. */
-const char *LLVMIntrinsicCopyOverloadedName(unsigned ID,
-                                            LLVMTypeRef *ParamTypes,
-                                            size_t ParamCount,
-                                            size_t *NameLength);
+char *LLVMIntrinsicCopyOverloadedName(unsigned ID, LLVMTypeRef *ParamTypes,
+                                      size_t ParamCount, size_t *NameLength);
 
 /**
  * Copies the name of an overloaded intrinsic identified by a given list of
@@ -2850,10 +2856,9 @@ const char *LLVMIntrinsicCopyOverloadedName(unsigned ID,
  *
  * @see llvm::Intrinsic::getName()
  */
-const char *LLVMIntrinsicCopyOverloadedName2(LLVMModuleRef Mod, unsigned ID,
-                                             LLVMTypeRef *ParamTypes,
-                                             size_t ParamCount,
-                                             size_t *NameLength);
+char *LLVMIntrinsicCopyOverloadedName2(LLVMModuleRef Mod, unsigned ID,
+                                       LLVMTypeRef *ParamTypes,
+                                       size_t ParamCount, size_t *NameLength);
 
 /**
  * Obtain if the intrinsic identified by the given ID is overloaded.

llvm/lib/IR/Core.cpp

@@ -2478,28 +2478,32 @@ const char *LLVMIntrinsicGetName(unsigned ID, size_t *NameLength) {
   return Str.data();
 }
 
+char *LLVMIntrinsicCopyName(unsigned ID, size_t *NameLength) {
+  auto IID = llvm_map_to_intrinsic_id(ID);
+  auto Str = llvm::Intrinsic::getName(IID);
+  *NameLength = Str.size();
+  return strdup(Str.data());
+}
+
 LLVMTypeRef LLVMIntrinsicGetType(LLVMContextRef Ctx, unsigned ID,
                                  LLVMTypeRef *ParamTypes, size_t ParamCount) {
   auto IID = llvm_map_to_intrinsic_id(ID);
   ArrayRef<Type*> Tys(unwrap(ParamTypes), ParamCount);
   return wrap(llvm::Intrinsic::getType(*unwrap(Ctx), IID, Tys));
 }
 
-const char *LLVMIntrinsicCopyOverloadedName(unsigned ID,
-                                            LLVMTypeRef *ParamTypes,
-                                            size_t ParamCount,
-                                            size_t *NameLength) {
+char *LLVMIntrinsicCopyOverloadedName(unsigned ID, LLVMTypeRef *ParamTypes,
+                                      size_t ParamCount, size_t *NameLength) {
   auto IID = llvm_map_to_intrinsic_id(ID);
   ArrayRef<Type*> Tys(unwrap(ParamTypes), ParamCount);
   auto Str = llvm::Intrinsic::getNameNoUnnamedTypes(IID, Tys);
   *NameLength = Str.length();
   return strdup(Str.c_str());
 }
 
-const char *LLVMIntrinsicCopyOverloadedName2(LLVMModuleRef Mod, unsigned ID,
-                                             LLVMTypeRef *ParamTypes,
-                                             size_t ParamCount,
-                                             size_t *NameLength) {
+char *LLVMIntrinsicCopyOverloadedName2(LLVMModuleRef Mod, unsigned ID,
+                                       LLVMTypeRef *ParamTypes,
+                                       size_t ParamCount, size_t *NameLength) {
   auto IID = llvm_map_to_intrinsic_id(ID);
   ArrayRef<Type *> Tys(unwrap(ParamTypes), ParamCount);
   auto Str = llvm::Intrinsic::getName(IID, Tys, unwrap(Mod));

llvm/unittests/IR/IntrinsicsTest.cpp

@@ -7,6 +7,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/IR/Intrinsics.h"
+#include "llvm-c/Core.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/IR/Constant.h"
 #include "llvm/IR/IRBuilder.h"
@@ -127,6 +128,50 @@ TEST(IntrinsicNameLookup, MSBuiltinLookup) {
     EXPECT_EQ(ID, getIntrinsicForMSBuiltin(Target, Builtin));
 }
 
+// Test C API to get/copy LLVM intrinsic name.
+TEST(IntrinsicNameLookup, LLVMIntrinsicGetCopyNameSimple) {
+  static constexpr struct {
+    Intrinsic::ID ID;
+    const char *Name;
+  } Tests[] = {{Intrinsic::not_intrinsic, "not_intrinsic"},
+               {Intrinsic::assume, "llvm.assume"},
+               {Intrinsic::coro_free, "llvm.coro.free"},
+               {Intrinsic::aarch64_break, "llvm.aarch64.break"},
+               {Intrinsic::x86_int, "llvm.x86.int"}};
+
+  for (auto [ID, ExpectedName] : Tests) {
+    size_t NameSize = 0;
+    const char *CName = LLVMIntrinsicGetName(ID, &NameSize);
+    StringRef Name(CName, NameSize);
+
+    // Verify we get correct name.
+    EXPECT_EQ(Name, ExpectedName);
+    const char *CName1 = LLVMIntrinsicGetName(ID, &NameSize);
+
+    // Verify we get the same pointer and length the second time.
+    EXPECT_EQ(CName, CName1);
+    EXPECT_EQ(NameSize, Name.size());
+  }
+
+  // Now test the copy API.
+  for (auto [ID, ExpectedName] : Tests) {
+    size_t NameSize = 0;
+    char *CName = LLVMIntrinsicCopyName(ID, &NameSize);
+    StringRef Name(CName, NameSize);
+
+    // Verify we get correct name.
+    EXPECT_EQ(Name, ExpectedName);
+
+    // Verify we get the different pointer and same length the second time.
+    char *CName1 = LLVMIntrinsicCopyName(ID, &NameSize);
+    EXPECT_NE(CName, CName1);
+    EXPECT_EQ(NameSize, Name.size());
+
+    free(CName);
+    free(CName1);
+  }
+}
+
 TEST_F(IntrinsicsTest, InstrProfInheritance) {
   auto isInstrProfInstBase = [](const Instruction &I) {
     return isa<InstrProfInstBase>(I);