From 8f64141e7540aa32aff098e67348a302b38cea11 Mon Sep 17 00:00:00 2001
From: 0v0 <kduice@qq.com>
Date: Fri, 5 Jul 2024 04:56:43 +0800
Subject: [PATCH] simplify nested reference checking (#16656)

---
 compiler/src/dmd/canthrow.d   | 6 ++----
 compiler/src/dmd/cppmangle.d  | 3 +--
 compiler/src/dmd/delegatize.d | 9 +++------
 compiler/src/dmd/func.d       | 3 +--
 druntime/src/rt/config.d      | 3 +--
 druntime/src/rt/trace.d       | 3 +--
 6 files changed, 9 insertions(+), 18 deletions(-)

diff --git a/compiler/src/dmd/canthrow.d b/compiler/src/dmd/canthrow.d
index 31155f188dca..c96a65b8d40f 100644
--- a/compiler/src/dmd/canthrow.d
+++ b/compiler/src/dmd/canthrow.d
@@ -111,11 +111,9 @@ CT canThrow(Expression e, FuncDeclaration func, ErrorSink eSink)
             if (ce.f && ce.arguments.length > 0)
             {
                 Type tb = (*ce.arguments)[0].type.toBasetype();
-                auto tbNext = tb.nextOf();
-                if (tbNext)
+                if (auto tbNext = tb.nextOf())
                 {
-                    auto ts = tbNext.baseElemOf().isTypeStruct();
-                    if (ts)
+                    if (auto ts = tbNext.baseElemOf().isTypeStruct())
                     {
                         auto sd = ts.sym;
                         const id = ce.f.ident;
diff --git a/compiler/src/dmd/cppmangle.d b/compiler/src/dmd/cppmangle.d
index 0609778e4c77..79be1e5454cd 100644
--- a/compiler/src/dmd/cppmangle.d
+++ b/compiler/src/dmd/cppmangle.d
@@ -725,8 +725,7 @@ private final class CppMangleVisitor : Visitor
      */
     static Dsymbol getInstance(Dsymbol s)
     {
-        Dsymbol p = s.toParent();
-        if (p)
+        if (Dsymbol p = s.toParent())
         {
             if (TemplateInstance ti = p.isTemplateInstance())
                 return ti;
diff --git a/compiler/src/dmd/delegatize.d b/compiler/src/dmd/delegatize.d
index 62800d3fdb77..95064b0d16dc 100644
--- a/compiler/src/dmd/delegatize.d
+++ b/compiler/src/dmd/delegatize.d
@@ -215,15 +215,13 @@ bool lambdaCheckForNestedRef(Expression e, Scope* sc)
 
         override void visit(SymOffExp e)
         {
-            VarDeclaration v = e.var.isVarDeclaration();
-            if (v)
+            if (VarDeclaration v = e.var.isVarDeclaration())
                 result = v.checkNestedReference(sc, Loc.initial);
         }
 
         override void visit(VarExp e)
         {
-            VarDeclaration v = e.var.isVarDeclaration();
-            if (v)
+            if (VarDeclaration v = e.var.isVarDeclaration())
                 result = v.checkNestedReference(sc, Loc.initial);
         }
 
@@ -235,8 +233,7 @@ bool lambdaCheckForNestedRef(Expression e, Scope* sc)
 
         override void visit(DeclarationExp e)
         {
-            VarDeclaration v = e.declaration.isVarDeclaration();
-            if (v)
+            if (VarDeclaration v = e.declaration.isVarDeclaration())
             {
                 result = v.checkNestedReference(sc, Loc.initial);
                 if (result)
diff --git a/compiler/src/dmd/func.d b/compiler/src/dmd/func.d
index 54ff82670aeb..4f2b08cc8cb1 100644
--- a/compiler/src/dmd/func.d
+++ b/compiler/src/dmd/func.d
@@ -1262,8 +1262,7 @@ extern (C++) class FuncDeclaration : Declaration
     {
         if (type)
         {
-            TypeFunction fdtype = type.isTypeFunction();
-            if (fdtype) // Could also be TypeError
+            if (TypeFunction fdtype = type.isTypeFunction()) // Could also be TypeError
                 return fdtype.parameterList;
         }
 
diff --git a/druntime/src/rt/config.d b/druntime/src/rt/config.d
index a6605f4d6037..912b8fe36ad1 100644
--- a/druntime/src/rt/config.d
+++ b/druntime/src/rt/config.d
@@ -129,8 +129,7 @@ string rt_envvarsOption(string opt, scope rt_configCallBack dg) @nogc nothrow
             var[4 + i] = cast(char) toupper(c);
         var[4 + opt.length] = 0;
 
-        auto p = getenv(var.ptr);
-        if (p)
+        if (auto p = getenv(var.ptr))
         {
             string s = dg(cast(string) p[0 .. strlen(p)]);
             if (s != null)
diff --git a/druntime/src/rt/trace.d b/druntime/src/rt/trace.d
index 4cbf071f14e4..8afd7b899a6e 100644
--- a/druntime/src/rt/trace.d
+++ b/druntime/src/rt/trace.d
@@ -679,8 +679,7 @@ extern(C) void _c_trace_pro(size_t idlen, char* idptr)
 extern(C) void _c_trace_epi()
 {
     //printf("_c_trace_epi()\n");
-    auto tos = trace_tos;
-    if (tos)
+    if (auto tos = trace_tos)
     {
         timer_t endtime;
         QueryPerformanceCounter(&endtime);