Fix shadowed variable in gloo/allgatherv.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: D52959187

fbshipit-source-id: 17c366f00985dd2523f0fd029c280e984d64cc6d

Author: r-barnes

gloo/allgatherv.cc

@@ -16,12 +16,12 @@
 
 namespace gloo {
 
-void AllgathervOptions::setElementSize(size_t elementSize) {
+void AllgathervOptions::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.");
@@ -30,29 +30,29 @@ void AllgathervOptions::setElementSize(size_t elementSize) {
 
 void AllgathervOptions::setInput(
     std::unique_ptr<transport::UnboundBuffer> buf,
-    size_t elementSize) {
-  setElementSize(elementSize);
+    size_t elementSize_2) {
+  setElementSize(elementSize_2);
   this->in = std::move(buf);
 }
 
 void AllgathervOptions::setInput(
     void* ptr,
-    size_t elements,
-    size_t elementSize) {
-  setElementSize(elementSize);
-  this->in = context->createUnboundBuffer(ptr, elements * elementSize);
+    size_t elements_2,
+    size_t elementSize_2) {
+  setElementSize(elementSize_2);
+  this->in = context->createUnboundBuffer(ptr, elements_2 * elementSize_2);
 }
 
 void AllgathervOptions::setOutput(
     std::unique_ptr<transport::UnboundBuffer> buf,
-    std::vector<size_t> elements,
-    size_t elementSize) {
+    std::vector<size_t> elements_2,
+    size_t elementSize_2) {
   const auto totalElements =
-      std::accumulate(elements.begin(), elements.end(), size_t(0));
-  setElementSize(elementSize);
-  GLOO_ENFORCE_EQ(elements.size(), context->size);
-  this->elements = std::move(elements);
-  GLOO_ENFORCE_EQ(totalElements * elementSize, buf->size);
+      std::accumulate(elements_2.begin(), elements_2.end(), size_t(0));
+  setElementSize(elementSize_2);
+  GLOO_ENFORCE_EQ(elements_2.size(), context->size);
+  this->elements = std::move(elements_2);
+  GLOO_ENFORCE_EQ(totalElements * elementSize_2, buf->size);
   this->out = std::move(buf);
 }