From d01998e8b9dc9bc4709e5dc6c621a24783fa535d Mon Sep 17 00:00:00 2001
From: Anton Korobeynikov <anton@korobeynikov.info>
Date: Mon, 9 Sep 2024 15:42:43 -0700
Subject: [PATCH] Improve const-correctness

Signed-off-by: Anton Korobeynikov <anton@korobeynikov.info>
---
 frontends/p4/def_use.cpp |  9 ++++-----
 frontends/p4/def_use.h   | 14 +++++++-------
 2 files changed, 11 insertions(+), 12 deletions(-)

diff --git a/frontends/p4/def_use.cpp b/frontends/p4/def_use.cpp
index f5bbdab6fe..0c15b27450 100644
--- a/frontends/p4/def_use.cpp
+++ b/frontends/p4/def_use.cpp
@@ -396,7 +396,7 @@ void ComputeWriteSet::enterScope(const IR::ParameterList *parameters,
 
     if (parameters != nullptr) {
         for (auto p : parameters->parameters) {
-            StorageLocation *loc = allDefinitions->getOrAddStorage(p);
+            const StorageLocation *loc = allDefinitions->getOrAddStorage(p);
             if (loc == nullptr) continue;
             if (p->direction == IR::Direction::In || p->direction == IR::Direction::InOut ||
                 p->direction == IR::Direction::None)
@@ -410,8 +410,7 @@ void ComputeWriteSet::enterScope(const IR::ParameterList *parameters,
     if (locals != nullptr) {
         for (auto d : *locals) {
             if (d->is<IR::Declaration_Variable>()) {
-                StorageLocation *loc = allDefinitions->getOrAddStorage(d);
-                if (loc != nullptr) {
+                if (const StorageLocation *loc = allDefinitions->getOrAddStorage(d)) {
                     defs->setDefinition(loc, uninit);
                     defs->setDefinition(loc->getValidBits(), startPoints);
                     defs->setDefinition(loc->getLastIndexField(), startPoints);
@@ -434,7 +433,7 @@ void ComputeWriteSet::exitScope(const IR::ParameterList *parameters,
     currentDefinitions = currentDefinitions->cloneDefinitions();
     if (parameters != nullptr) {
         for (auto p : parameters->parameters) {
-            StorageLocation *loc = allDefinitions->getStorage(p);
+            const StorageLocation *loc = allDefinitions->getStorage(p);
             if (loc != nullptr) {
                 LOG5("Removing location " << loc);
                 currentDefinitions->removeLocation(loc);
@@ -444,7 +443,7 @@ void ComputeWriteSet::exitScope(const IR::ParameterList *parameters,
     if (locals != nullptr) {
         for (auto d : *locals) {
             if (d->is<IR::Declaration_Variable>()) {
-                StorageLocation *loc = allDefinitions->getStorage(d);
+                const StorageLocation *loc = allDefinitions->getStorage(d);
                 if (loc != nullptr) {
                     LOG5("Removing location " << loc);
                     currentDefinitions->removeLocation(loc);
diff --git a/frontends/p4/def_use.h b/frontends/p4/def_use.h
index f6fdd80383..2a7f50eec8 100644
--- a/frontends/p4/def_use.h
+++ b/frontends/p4/def_use.h
@@ -355,7 +355,7 @@ class LocationSet : public IHasDbPrint {
 /// Maps a declaration to its associated storage.
 class StorageMap : public IHasDbPrint {
     /// Storage location for each declaration.
-    hvec_map<const IR::IDeclaration *, StorageLocation *> storage;
+    hvec_map<const IR::IDeclaration *, const StorageLocation *> storage;
     StorageFactory factory;
 
  public:
@@ -366,19 +366,19 @@ class StorageMap : public IHasDbPrint {
         CHECK_NULL(refMap);
         CHECK_NULL(typeMap);
     }
-    StorageLocation *add(const IR::IDeclaration *decl) {
+    const StorageLocation *add(const IR::IDeclaration *decl) {
         CHECK_NULL(decl);
         auto type = typeMap->getType(decl->getNode(), true);
         auto loc = factory.create(type, decl->getName() + "/" + decl->externalName());
         if (loc != nullptr) storage.emplace(decl, loc);
         return loc;
     }
-    StorageLocation *getOrAdd(const IR::IDeclaration *decl) {
-        auto s = getStorage(decl);
+    const StorageLocation *getOrAdd(const IR::IDeclaration *decl) {
+        const auto *s = getStorage(decl);
         if (s != nullptr) return s;
         return add(decl);
     }
-    StorageLocation *getStorage(const IR::IDeclaration *decl) const {
+    const StorageLocation *getStorage(const IR::IDeclaration *decl) const {
         CHECK_NULL(decl);
         auto result = ::P4::get(storage, decl);
         return result;
@@ -580,11 +580,11 @@ class AllDefinitions : public IHasDbPrint {
         atPoint[point] = defs;
     }
 
-    StorageLocation *getStorage(const IR::IDeclaration *decl) const {
+    const StorageLocation *getStorage(const IR::IDeclaration *decl) const {
         return storageMap.getStorage(decl);
     }
 
-    StorageLocation *getOrAddStorage(const IR::IDeclaration *decl) {
+    const StorageLocation *getOrAddStorage(const IR::IDeclaration *decl) {
         return storageMap.getOrAdd(decl);
     }