[flang-commits] [flang] [flang] Resolve "possible performance problem" issue spam (PR #79769)

[Peter Klausler via flang-commits]

https://github.com/klausler created https://github.com/llvm/llvm-project/pull/79769

Four "issues" on GitHub report possible performance problems, likely detected by static analysis.  None of them would ever make a measureable difference in compilation time, but I'm resolving them to clean up the open issues list.

Fixes https://github.com/llvm/llvm-project/issues/79703, .../79705, .../79706, & .../79707.

>From 25bb28983affb991150956a6d318bb011688e17c Mon Sep 17 00:00:00 2001
From: Peter Klausler <pklausler at nvidia.com>
Date: Sun, 28 Jan 2024 13:06:12 -0800
Subject: [PATCH] [flang] Resolve "possible performance problem" issue spam

Four "issues" on GitHub report possible performance problems,
likely detected by static analysis.  None of them would ever
make a measureable difference in compilation time, but I'm
resolving them to clean up the open issues list.

Fixes https://github.com/llvm/llvm-project/issues/79703, .../79705,
.../79706, & .../79707.
---
 flang/lib/Lower/OpenACC.cpp                     | 2 +-
 flang/lib/Optimizer/CodeGen/Target.cpp          | 2 +-
 flang/lib/Parser/preprocessor.cpp               | 2 +-
 flang/lib/Parser/preprocessor.h                 | 2 +-
 flang/lib/Semantics/check-directive-structure.h | 4 ++--
 5 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/flang/lib/Lower/OpenACC.cpp b/flang/lib/Lower/OpenACC.cpp
index ecfdaa5be99358..72a0c195d96bb1 100644
--- a/flang/lib/Lower/OpenACC.cpp
+++ b/flang/lib/Lower/OpenACC.cpp
@@ -3208,7 +3208,7 @@ static void createDeclareGlobalOp(mlir::OpBuilder &modBuilder,
                                   fir::FirOpBuilder &builder,
                                   mlir::Location loc, fir::GlobalOp globalOp,
                                   mlir::acc::DataClause clause,
-                                  const std::string declareGlobalName,
+                                  const std::string &declareGlobalName,
                                   bool implicit, std::stringstream &asFortran) {
   GlobalOp declareGlobalOp =
       modBuilder.create<GlobalOp>(loc, declareGlobalName);
diff --git a/flang/lib/Optimizer/CodeGen/Target.cpp b/flang/lib/Optimizer/CodeGen/Target.cpp
index a4df0b09177ab7..7d0c6d7e7906be 100644
--- a/flang/lib/Optimizer/CodeGen/Target.cpp
+++ b/flang/lib/Optimizer/CodeGen/Target.cpp
@@ -47,7 +47,7 @@ static const llvm::fltSemantics &floatToSemantics(const KindMapping &kindMap,
 }
 
 static void typeTodo(const llvm::fltSemantics *sem, mlir::Location loc,
-                     std::string context) {
+                     const std::string &context) {
   if (sem == &llvm::APFloat::IEEEhalf()) {
     TODO(loc, "COMPLEX(KIND=2): for " + context + " type");
   } else if (sem == &llvm::APFloat::BFloat()) {
diff --git a/flang/lib/Parser/preprocessor.cpp b/flang/lib/Parser/preprocessor.cpp
index 8c993e7ced0e8c..75e4c469774fe0 100644
--- a/flang/lib/Parser/preprocessor.cpp
+++ b/flang/lib/Parser/preprocessor.cpp
@@ -252,7 +252,7 @@ void Preprocessor::DefineStandardMacros() {
   Define("__LINE__"s, "__LINE__"s);
 }
 
-void Preprocessor::Define(std::string macro, std::string value) {
+void Preprocessor::Define(const std::string &macro, const std::string &value) {
   definitions_.emplace(SaveTokenAsName(macro), Definition{value, allSources_});
 }
 
diff --git a/flang/lib/Parser/preprocessor.h b/flang/lib/Parser/preprocessor.h
index 3b456364944c3d..b61f1577727beb 100644
--- a/flang/lib/Parser/preprocessor.h
+++ b/flang/lib/Parser/preprocessor.h
@@ -70,7 +70,7 @@ class Preprocessor {
   AllSources &allSources() { return allSources_; }
 
   void DefineStandardMacros();
-  void Define(std::string macro, std::string value);
+  void Define(const std::string &macro, const std::string &value);
   void Undefine(std::string macro);
   bool IsNameDefined(const CharBlock &);
   bool IsFunctionLikeDefinition(const CharBlock &);
diff --git a/flang/lib/Semantics/check-directive-structure.h b/flang/lib/Semantics/check-directive-structure.h
index 829405f99d64c0..97e13c59ac4167 100644
--- a/flang/lib/Semantics/check-directive-structure.h
+++ b/flang/lib/Semantics/check-directive-structure.h
@@ -176,8 +176,8 @@ template <typename D, typename C, typename PC, std::size_t ClauseEnumSize>
 class DirectiveStructureChecker : public virtual BaseChecker {
 protected:
   DirectiveStructureChecker(SemanticsContext &context,
-      std::unordered_map<D, DirectiveClauses<C, ClauseEnumSize>>
-          directiveClausesMap)
+      const std::unordered_map<D, DirectiveClauses<C, ClauseEnumSize>>
+          &directiveClausesMap)
       : context_{context}, directiveClausesMap_(directiveClausesMap) {}
   virtual ~DirectiveStructureChecker() {}