Fix shadowed variable in gloo/gatherv.cc

Summary:
Our upcoming compiler upgrade will require us not to have shadowed variables. Such variables have a _high_ bug rate and reduce readability, so we would like to avoid them even if the compiler was not forcing us to do so.

This codemod attempts to fix an instance of a shadowed variable. Please review with care: if it's failed the result will be a silent bug.

**What's a shadowed variable?**

Shadowed variables are variables in an inner scope with the same name as another variable in an outer scope. Having the same name for both variables might be semantically correct, but it can make the code confusing to read! It can also hide subtle bugs.

This diff fixes such an issue by renaming the variable.

 - If you approve of this diff, please use the "Accept & Ship" button :-)

Reviewed By: dmm-fb

Differential Revision: D52959097

fbshipit-source-id: f9f99a8943e1d83e9ee18f17e6a6c0b752a15b24

Author: r-barnes

gloo/gatherv.cc

@@ -16,12 +16,12 @@
 
 namespace gloo {
 
-void GathervOptions::setElementSize(size_t elementSize) {
+void GathervOptions::setElementSize(size_t elementSize_2) {
   if (this->elementSize == 0) {
-    this->elementSize = elementSize;
+    this->elementSize = elementSize_2;
   } else {
     GLOO_ENFORCE_EQ(
-        elementSize,
+        elementSize_2,
         this->elementSize,
         "Element size does not match existing value. ",
         "Please double check that the input and output types match.");
@@ -30,30 +30,30 @@ void GathervOptions::setElementSize(size_t elementSize) {
 
 void GathervOptions::setInput(
     std::unique_ptr<transport::UnboundBuffer> buf,
-    size_t elementSize) {
-  this->setElementSize(elementSize);
+    size_t elementSize_2) {
+  this->setElementSize(elementSize_2);
   this->in = std::move(buf);
 }
 
 void GathervOptions::setInput(
     void* ptr,
     size_t elements,
-    size_t elementSize) {
-  this->setElementSize(elementSize);
-  this->in = context->createUnboundBuffer(ptr, elements * elementSize);
+    size_t elementSize_2) {
+  this->setElementSize(elementSize_2);
+  this->in = context->createUnboundBuffer(ptr, elements * elementSize_2);
 }
 
 void GathervOptions::setOutput(
     std::unique_ptr<transport::UnboundBuffer> buf,
-    std::vector<size_t> elementsPerRank,
-    size_t elementSize) {
+    std::vector<size_t> elementsPerRank_2,
+    size_t elementSize_2) {
   const auto totalElements =
       std::accumulate(
-          elementsPerRank.begin(), elementsPerRank.end(), size_t(0));
-  this->setElementSize(elementSize);
-  GLOO_ENFORCE_EQ(elementsPerRank.size(), context->size);
-  this->elementsPerRank = std::move(elementsPerRank);
-  GLOO_ENFORCE_EQ(totalElements * elementSize, buf->size);
+          elementsPerRank_2.begin(), elementsPerRank_2.end(), size_t(0));
+  this->setElementSize(elementSize_2);
+  GLOO_ENFORCE_EQ(elementsPerRank_2.size(), context->size);
+  this->elementsPerRank = std::move(elementsPerRank_2);
+  GLOO_ENFORCE_EQ(totalElements * elementSize_2, buf->size);
   this->out = std::move(buf);
 }