From dea98de3fb4bea09b3ed3a68d90a03e21546b5b0 Mon Sep 17 00:00:00 2001
From: Eli Friedman <eli.friedman@gmail.com>
Date: Fri, 30 Nov 2012 06:19:40 +0000
Subject: [PATCH] Fix the computation of highlight ranges so we produce
 something sane when the beginning and end of the range are in different macro
 arguments. PR14399.

llvm-svn: 168984
---
 clang/lib/Frontend/DiagnosticRenderer.cpp | 40 +++++++++++++++++++++++--------
 clang/test/Misc/caret-diags-macros.c      | 14 +++++++++++
 2 files changed, 44 insertions(+), 10 deletions(-)

diff --git a/clang/lib/Frontend/DiagnosticRenderer.cpp b/clang/lib/Frontend/DiagnosticRenderer.cpp
index 2d156f7..3143cc7 100644
--- a/clang/lib/Frontend/DiagnosticRenderer.cpp
+++ b/clang/lib/Frontend/DiagnosticRenderer.cpp
@@ -242,20 +242,40 @@ static void mapDiagnosticRanges(
     SourceLocation Begin = I->getBegin(), End = I->getEnd();
     bool IsTokenRange = I->isTokenRange();
 
-    // Search the macro caller chain for the beginning of the range.
-    while (Begin.isMacroID() && SM->getFileID(Begin) != CaretLocFileID)
-      Begin = SM->getImmediateMacroCallerLoc(Begin);
-
-    // Search the macro caller chain for the beginning of the range.
-    while (End.isMacroID() && SM->getFileID(End) != CaretLocFileID) {
-      // The computation of the next End is an inlined version of
-      // getImmediateMacroCallerLoc, except it chooses the end of an
-      // expansion range.
-      if (SM->isMacroArgExpansion(End)) {
+    FileID BeginFileID = SM->getFileID(Begin);
+    FileID EndFileID = SM->getFileID(End);
+
+    // Find the common parent for the beginning and end of the range.
+
+    // First, crawl the expansion chain for the beginning of the range.
+    llvm::SmallDenseMap<FileID, SourceLocation> BeginLocsMap;
+    while (Begin.isMacroID() && BeginFileID != EndFileID) {
+      BeginLocsMap[BeginFileID] = Begin;
+      Begin = SM->getImmediateExpansionRange(Begin).first;
+      BeginFileID = SM->getFileID(Begin);
+    }
+
+    // Then, crawl the expansion chain for the end of the range.
+    if (BeginFileID != EndFileID) {
+      while (End.isMacroID() && !BeginLocsMap.count(EndFileID)) {
+        End = SM->getImmediateExpansionRange(End).second;
+        EndFileID = SM->getFileID(End);
+      }
+      if (End.isMacroID()) {
+        Begin = BeginLocsMap[EndFileID];
+        BeginFileID = EndFileID;
+      }
+    }
+
+    while (Begin.isMacroID() && BeginFileID != CaretLocFileID) {
+      if (SM->isMacroArgExpansion(Begin)) {
+        Begin = SM->getImmediateSpellingLoc(Begin);
         End = SM->getImmediateSpellingLoc(End);
       } else {
+        Begin = SM->getImmediateExpansionRange(Begin).first;
         End = SM->getImmediateExpansionRange(End).second;
       }
+      BeginFileID = SM->getFileID(Begin);
     }
 
     // Return the spelling location of the beginning and end of the range.
diff --git a/clang/test/Misc/caret-diags-macros.c b/clang/test/Misc/caret-diags-macros.c
index 5faddb6..a41816f 100644
--- a/clang/test/Misc/caret-diags-macros.c
+++ b/clang/test/Misc/caret-diags-macros.c
@@ -163,3 +163,17 @@ int y = Y;
 // CHECK-NEXT:    {{.*}}:134:15: note: expanded from macro 'QMARK'
 // CHECK-NEXT:    #define QMARK ?
 // CHECK-NEXT: {{^              \^}}
+
+// PR14399
+void iequals(int,int,int);
+void foo_aa()
+{
+#define /* */ BARC(c, /* */b, a, ...) (a+b+/* */c + __VA_ARGS__ +0)
+  iequals(__LINE__, BARC(4,3,2,6,8), 8);
+}
+// CHECK:         {{.*}}:172:21: warning: expression result unused
+// CHECK-NEXT:      iequals(__LINE__, BARC(4,3,2,6,8), 8);
+// CHECK-NEXT: {{^                    \^~~~~~~~~~~~~~~}}
+// CHECK-NEXT:    {{.*}}:171:51: note: expanded from macro 'BARC'
+// CHECK-NEXT:    #define /* */ BARC(c, /* */b, a, ...) (a+b+/* */c + __VA_ARGS__ +0)
+// CHECK-NEXT: {{^                                       ~~~~~~~~~~ \^}}
-- 
2.7.4