[NFC] Extract method to SourceManager for traversing the macro "stack"

The code for going up the macro arg expansion is duplicated in many
places (and we need it for the analyzer as well, so I did not want to
duplicate it two more times).

This patch is an NFC, so the semantics should remain the same.

Differential Revision: https://reviews.llvm.org/D42458

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@324780 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 13 insertions, 9 deletions

diff --git a/include/clang/Basic/SourceManager.h b/include/clang/Basic/SourceManager.h
index fe5aedaf20..17601b8293 100644
--- a/include/clang/Basic/SourceManager.h
+++ b/include/clang/Basic/SourceManager.h
@@ -1646,6 +1646,9 @@ public:
     return getImmediateExpansionRange(Loc).first;
   }
 
+  /// \return Location of the top-level macro caller.
+  SourceLocation getTopMacroCallerLoc(SourceLocation Loc) const;
+
 private:
   friend class ASTReader;
   friend class ASTWriter;
diff --git a/lib/Basic/SourceManager.cpp b/lib/Basic/SourceManager.cpp
index 0a51985614..3bf70b6669 100644
--- a/lib/Basic/SourceManager.cpp
+++ b/lib/Basic/SourceManager.cpp
@@ -955,6 +955,12 @@ SourceManager::getImmediateExpansionRange(SourceLocation Loc) const {
   return Expansion.getExpansionLocRange();
 }
 
+SourceLocation SourceManager::getTopMacroCallerLoc(SourceLocation Loc) const {
+  while (isMacroArgExpansion(Loc))
+    Loc = getImmediateSpellingLoc(Loc);
+  return Loc;
+}
+
 /// getExpansionRange - Given a SourceLocation object, return the range of
 /// tokens covered by the expansion in the ultimate file.
 std::pair<SourceLocation,SourceLocation>
diff --git a/lib/Edit/Commit.cpp b/lib/Edit/Commit.cpp
index cb7a784a41..0cc152bf1e 100644
--- a/lib/Edit/Commit.cpp
+++ b/lib/Edit/Commit.cpp
@@ -225,8 +225,7 @@ bool Commit::canInsert(SourceLocation loc, FileOffset &offs) {
     isAtStartOfMacroExpansion(loc, &loc);
 
   const SourceManager &SM = SourceMgr;
-  while (SM.isMacroArgExpansion(loc))
-    loc = SM.getImmediateSpellingLoc(loc);
+  loc = SM.getTopMacroCallerLoc(loc);
 
   if (loc.isMacroID())
     if (!isAtStartOfMacroExpansion(loc, &loc))
@@ -256,8 +255,7 @@ bool Commit::canInsertAfterToken(SourceLocation loc, FileOffset &offs,
     isAtEndOfMacroExpansion(loc, &loc);
 
   const SourceManager &SM = SourceMgr;
-  while (SM.isMacroArgExpansion(loc))
-    loc = SM.getImmediateSpellingLoc(loc);
+  loc = SM.getTopMacroCallerLoc(loc);
 
   if (loc.isMacroID())
     if (!isAtEndOfMacroExpansion(loc, &loc))
diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index 8f6eef5984..8f6fa10dd8 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -9357,11 +9357,8 @@ static void DiagnoseNullConversion(Sema &S, Expr *E, QualType T,
   // Venture through the macro stacks to get to the source of macro arguments.
   // The new location is a better location than the complete location that was
   // passed in.
-  while (S.SourceMgr.isMacroArgExpansion(Loc))
-    Loc = S.SourceMgr.getImmediateMacroCallerLoc(Loc);
-
-  while (S.SourceMgr.isMacroArgExpansion(CC))
-    CC = S.SourceMgr.getImmediateMacroCallerLoc(CC);
+  Loc = S.SourceMgr.getTopMacroCallerLoc(Loc);
+  CC = S.SourceMgr.getTopMacroCallerLoc(CC);
 
   // __null is usually wrapped in a macro.  Go up a macro if that is the case.
   if (NullKind == Expr::NPCK_GNUNull && Loc.isMacroID()) {