[AMDGPU] HSAMD::fromString - replace std::string arg with StringRef. NFCI.

Removes an unnecessary chain of StringRef -> std::string -> StringRef conversions

Author: RKSimon

llvm/include/llvm/Support/AMDGPUMetadata.h

@@ -15,6 +15,7 @@
 #ifndef LLVM_SUPPORT_AMDGPUMETADATA_H
 #define LLVM_SUPPORT_AMDGPUMETADATA_H
 
+#include "llvm/ADT/StringRef.h"
 #include <cstdint>
 #include <string>
 #include <system_error>
@@ -430,7 +431,7 @@ struct Metadata final {
 };
 
 /// Converts \p String to \p HSAMetadata.
-std::error_code fromString(std::string String, Metadata &HSAMetadata);
+std::error_code fromString(StringRef String, Metadata &HSAMetadata);
 
 /// Converts \p HSAMetadata to \p String.
 std::error_code toString(Metadata HSAMetadata, std::string &String);

llvm/lib/Support/AMDGPUMetadata.cpp

@@ -210,7 +210,7 @@ struct MappingTraits<HSAMD::Metadata> {
 namespace AMDGPU {
 namespace HSAMD {
 
-std::error_code fromString(std::string String, Metadata &HSAMetadata) {
+std::error_code fromString(StringRef String, Metadata &HSAMetadata) {
   yaml::Input YamlInput(String);
   YamlInput >> HSAMetadata;
   return YamlInput.error();

llvm/lib/Target/AMDGPU/AMDGPUHSAMetadataStreamer.cpp

@@ -59,7 +59,7 @@ void MetadataStreamerV2::verify(StringRef HSAMetadataString) const {
   errs() << "AMDGPU HSA Metadata Parser Test: ";
 
   HSAMD::Metadata FromHSAMetadataString;
-  if (fromString(std::string(HSAMetadataString), FromHSAMetadataString)) {
+  if (fromString(HSAMetadataString, FromHSAMetadataString)) {
     errs() << "FAIL\n";
     return;
   }

llvm/lib/Target/AMDGPU/MCTargetDesc/AMDGPUTargetStreamer.cpp

@@ -33,9 +33,8 @@ using namespace llvm::AMDGPU;
 
 bool AMDGPUTargetStreamer::EmitHSAMetadataV2(StringRef HSAMetadataString) {
   HSAMD::Metadata HSAMetadata;
-  if (HSAMD::fromString(std::string(HSAMetadataString), HSAMetadata))
+  if (HSAMD::fromString(HSAMetadataString, HSAMetadata))
     return false;
-
   return EmitHSAMetadata(HSAMetadata);
 }