Explicitly assign constructed C++ classes

C++ style guides I am aware of recommend specifically preferring = syntax
for any classes with fairly obvious constructors[^0] that do not perform
any complicated logic in their constructor. I contend that all constructors
that the `rustc_llvm` code uses qualify. This has only become more common
since C++ 17 guaranteed many cases of copy initialization elision.

The other detail is that I tried to ask another contributor with
infinitely more C++ experience than me (i.e. any) what this constructor
syntax was, and they thought it was a macro. I know of no other language
that has adopted this same syntax. As the rustc codebase features many
contributors experienced in many other languages, using a less...
unique... style has many other benefits in making this code more
lucid and maintainable, which is something it direly needs.

[^0]: e.g. https://abseil.io/tips/88

1 files changed, 5 insertions, 4 deletions

diff --git a/compiler/rustc_llvm/llvm-wrapper/SymbolWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/SymbolWrapper.cpp
index 91f84692df8..ee8239ef8e7 100644
--- a/compiler/rustc_llvm/llvm-wrapper/SymbolWrapper.cpp
+++ b/compiler/rustc_llvm/llvm-wrapper/SymbolWrapper.cpp
@@ -11,6 +11,7 @@
 #include "llvm/ADT/SmallString.h"
 #include "llvm/IR/LLVMContext.h"
 #include "llvm/Object/ObjectFile.h"
+#include <llvm/Support/raw_ostream.h>
 
 using namespace llvm;
 using namespace llvm::sys;
@@ -42,7 +43,7 @@ extern "C" void *LLVMRustGetSymbols(
     MemoryBuffer::getMemBuffer(StringRef(BufPtr, BufLen), StringRef("LLVMRustGetSymbolsObject"),
                                false);
   SmallString<0> SymNameBuf;
-  raw_svector_ostream SymName(SymNameBuf);
+  auto SymName = raw_svector_ostream(SymNameBuf);
 
   // In the scenario when LLVMContext is populated SymbolicFile will contain a
   // reference to it, thus SymbolicFile should be destroyed first.
@@ -60,7 +61,7 @@ extern "C" void *LLVMRustGetSymbols(
     if (!ObjOrErr) {
       Error E = ObjOrErr.takeError();
       SmallString<0> ErrorBuf;
-      raw_svector_ostream Error(ErrorBuf);
+      auto Error = raw_svector_ostream(ErrorBuf);
       Error << E << '\0';
       return ErrorCallback(Error.str().data());
     }
@@ -70,7 +71,7 @@ extern "C" void *LLVMRustGetSymbols(
     if (!ObjOrErr) {
       Error E = ObjOrErr.takeError();
       SmallString<0> ErrorBuf;
-      raw_svector_ostream Error(ErrorBuf);
+      auto Error = raw_svector_ostream(ErrorBuf);
       Error << E << '\0';
       return ErrorCallback(Error.str().data());
     }
@@ -83,7 +84,7 @@ extern "C" void *LLVMRustGetSymbols(
       continue;
     if (Error E = S.printName(SymName)) {
       SmallString<0> ErrorBuf;
-      raw_svector_ostream Error(ErrorBuf);
+      auto Error = raw_svector_ostream(ErrorBuf);
       Error << E << '\0';
       return ErrorCallback(Error.str().data());
     }