[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

llvm-svn: 324780

3 files changed, 10 insertions, 9 deletions

diff --git a/clang/lib/Basic/SourceManager.cpp b/clang/lib/Basic/SourceManager.cpp
index 0a51985614c..3bf70b66693 100644
--- a/clang/lib/Basic/SourceManager.cpp
+++ b/clang/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/clang/lib/Edit/Commit.cpp b/clang/lib/Edit/Commit.cpp
index cb7a784a41a..0cc152bf1e7 100644
--- a/clang/lib/Edit/Commit.cpp
+++ b/clang/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/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index 8f6eef59843..8f6fa10dd8f 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/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()) {