[modules] If a submodule has re-definitions of the same macro, only the last definiti...

Fixes rdar://13562262

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@178622 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Serialization/ASTWriter.cpp b/lib/Serialization/ASTWriter.cpp
index 033d48c1471b289723c0ad4ce7a47f5e79c2ee8b..6893b5003ffb24e0b425a81b233a6741abada4fa 100644 (file)
--- a/lib/Serialization/ASTWriter.cpp
+++ b/lib/Serialization/ASTWriter.cpp
@@ -2937,6 +2937,7 @@ class ASTIdentifierTableTrait {
     if (!MD)
       return 0;
 
+    SubmoduleID OrigModID = ModID;
     bool isUndefined = false;
     Optional<bool> isPublic;
     for (; MD; MD = MD->getPrevious()) {
@@ -2954,6 +2955,11 @@ class ASTIdentifierTableTrait {
         isUndefined = false;
         isPublic = Optional<bool>();
       }
+      // We are looking for a definition in a different submodule than the one
+      // that we started with. If a submodule has re-definitions of the same
+      // macro, only the last definition will be used as the "exported" one.
+      if (ModID == OrigModID)
+        continue;
 
       if (DefMacroDirective *DefMD = dyn_cast<DefMacroDirective>(MD)) {
         if (!isUndefined && (!isPublic.hasValue() || isPublic.getValue()))

diff --git a/test/Modules/Inputs/macros_top.h b/test/Modules/Inputs/macros_top.h
index 9c3f3c071fd0262364464f18f0e9e3771c3cfce5..dd303ffee4e1511fa914c98b73db57c54784205a 100644 (file)
--- a/test/Modules/Inputs/macros_top.h
+++ b/test/Modules/Inputs/macros_top.h
@@ -8,8 +8,8 @@
 
 
 
-
-
+#define TOP_RIGHT_REDEF float
+// The last definition will be exported from the sub-module.
 #define TOP_RIGHT_REDEF int
 
 #define TOP_RIGHT_UNDEF int