Minor fixes to for-loop warning.

The warning for unchanged loop variables outputted a diagnostic that was
dependent on iteration order from a pointer set, which is not always
deterministic.  Switch to a set vector, which allows fast querying and
preserves ordering.

Also make other minor changes in this area.
Use more range-based for-loops.
Remove limitation on SourceRanges that no logner exists.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@304519 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 22 insertions, 29 deletions

diff --git a/lib/Sema/SemaStmt.cpp b/lib/Sema/SemaStmt.cpp
index 33a8f9c4af..dcb2c11c73 100644
--- a/lib/Sema/SemaStmt.cpp
+++ b/lib/Sema/SemaStmt.cpp
@@ -1288,17 +1288,22 @@ Sema::ActOnDoStmt(SourceLocation DoLoc, Stmt *Body,
 }
 
 namespace {
+  // Use SetVector since the diagnostic cares about the ordering of the Decl's.
+  using DeclSetVector =
+      llvm::SetVector<VarDecl *, llvm::SmallVector<VarDecl *, 8>,
+                      llvm::SmallPtrSet<VarDecl *, 8>>;
+
   // This visitor will traverse a conditional statement and store all
   // the evaluated decls into a vector.  Simple is set to true if none
   // of the excluded constructs are used.
   class DeclExtractor : public EvaluatedExprVisitor<DeclExtractor> {
-    llvm::SmallPtrSetImpl<VarDecl*> &Decls;
+    DeclSetVector &Decls;
     SmallVectorImpl<SourceRange> &Ranges;
     bool Simple;
   public:
     typedef EvaluatedExprVisitor<DeclExtractor> Inherited;
 
-    DeclExtractor(Sema &S, llvm::SmallPtrSetImpl<VarDecl*> &Decls,
+    DeclExtractor(Sema &S, DeclSetVector &Decls,
                   SmallVectorImpl<SourceRange> &Ranges) :
         Inherited(S.Context),
         Decls(Decls),
@@ -1370,14 +1375,13 @@ namespace {
   // DeclMatcher checks to see if the decls are used in a non-evaluated
   // context.
   class DeclMatcher : public EvaluatedExprVisitor<DeclMatcher> {
-    llvm::SmallPtrSetImpl<VarDecl*> &Decls;
+    DeclSetVector &Decls;
     bool FoundDecl;
 
   public:
     typedef EvaluatedExprVisitor<DeclMatcher> Inherited;
 
-    DeclMatcher(Sema &S, llvm::SmallPtrSetImpl<VarDecl*> &Decls,
-                Stmt *Statement) :
+    DeclMatcher(Sema &S, DeclSetVector &Decls, Stmt *Statement) :
         Inherited(S.Context), Decls(Decls), FoundDecl(false) {
       if (!Statement) return;
 
@@ -1459,7 +1463,7 @@ namespace {
       return;
 
     PartialDiagnostic PDiag = S.PDiag(diag::warn_variables_not_in_loop_body);
-    llvm::SmallPtrSet<VarDecl*, 8> Decls;
+    DeclSetVector Decls;
     SmallVector<SourceRange, 10> Ranges;
     DeclExtractor DE(S, Decls, Ranges);
     DE.Visit(Second);
@@ -1471,11 +1475,9 @@ namespace {
     if (Decls.size() == 0) return;
 
     // Don't warn on volatile, static, or global variables.
-    for (llvm::SmallPtrSetImpl<VarDecl*>::iterator I = Decls.begin(),
-                                                   E = Decls.end();
-         I != E; ++I)
-      if ((*I)->getType().isVolatileQualified() ||
-          (*I)->hasGlobalStorage()) return;
+    for (auto *VD : Decls)
+      if (VD->getType().isVolatileQualified() || VD->hasGlobalStorage())
+        return;
 
     if (DeclMatcher(S, Decls, Second).FoundDeclInUse() ||
         DeclMatcher(S, Decls, Third).FoundDeclInUse() ||
@@ -1483,25 +1485,16 @@ namespace {
       return;
 
     // Load decl names into diagnostic.
-    if (Decls.size() > 4)
+    if (Decls.size() > 4) {
       PDiag << 0;
-    else {
-      PDiag << Decls.size();
-      for (llvm::SmallPtrSetImpl<VarDecl*>::iterator I = Decls.begin(),
-                                                     E = Decls.end();
-           I != E; ++I)
-        PDiag << (*I)->getDeclName();
-    }
-
-    // Load SourceRanges into diagnostic if there is room.
-    // Otherwise, load the SourceRange of the conditional expression.
-    if (Ranges.size() <= PartialDiagnostic::MaxArguments)
-      for (SmallVectorImpl<SourceRange>::iterator I = Ranges.begin(),
-                                                  E = Ranges.end();
-           I != E; ++I)
-        PDiag << *I;
-    else
-      PDiag << Second->getSourceRange();
+    } else {
+      PDiag << (unsigned)Decls.size();
+      for (auto *VD : Decls)
+        PDiag << VD->getDeclName();
+    }
+
+    for (auto Range : Ranges)
+      PDiag << Range;
 
     S.Diag(Ranges.begin()->getBegin(), PDiag);
   }