Replace custom alignment enforcement with LLVM_ALIGNAS.

This isn't perfect as it still assumes sizeof(void*) == alignof(void*),
but we can fix that when compiler support gets better.

Shrinks some Stmts that happen to inherit from Stmt and have a
SourceLocation as the first member (64 bit archs only).

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@233911 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 4 insertions, 18 deletions

diff --git a/include/clang/Basic/SourceManager.h b/include/clang/Basic/SourceManager.h
index 4fa95c59a1..3aea5ea982 100644
--- a/include/clang/Basic/SourceManager.h
+++ b/include/clang/Basic/SourceManager.h
@@ -82,7 +82,7 @@ namespace SrcMgr {
   /// \brief One instance of this struct is kept for every file loaded or used.
   ///
   /// This object owns the MemoryBuffer object.
-  class ContentCache {
+  class LLVM_ALIGNAS(8) ContentCache {
     enum CCFlags {
       /// \brief Whether the buffer is invalid.
       InvalidFlag = 0x01,
@@ -90,15 +90,6 @@ namespace SrcMgr {
       DoNotFreeFlag = 0x02
     };
 
-    // Note that the first member of this class is an aligned character buffer
-    // to ensure that this class has an alignment of 8 bytes. This wastes
-    // 8 bytes for every ContentCache object, but each of these corresponds to
-    // a file loaded into memory, so the 8 bytes doesn't seem terribly
-    // important. It is quite awkward to fit this aligner into any other part
-    // of the class due to the lack of portable ways to combine it with other
-    // members.
-    llvm::AlignedCharArray<8, 1> NonceAligner;
-
     /// \brief The actual buffer containing the characters from the input
     /// file.
     ///
@@ -142,14 +133,9 @@ namespace SrcMgr {
     /// \brief True if this content cache was initially created for a source
     /// file considered as a system one.
     unsigned IsSystemFile : 1;
-    
-    ContentCache(const FileEntry *Ent = nullptr)
-      : Buffer(nullptr, false), OrigEntry(Ent), ContentsEntry(Ent),
-        SourceLineCache(nullptr), NumLines(0), BufferOverridden(false),
-        IsSystemFile(false) {
-      (void)NonceAligner; // Silence warnings about unused member.
-    }
-    
+
+    ContentCache(const FileEntry *Ent = nullptr) : ContentCache(Ent, Ent) {}
+
     ContentCache(const FileEntry *Ent, const FileEntry *contentEnt)
       : Buffer(nullptr, false), OrigEntry(Ent), ContentsEntry(contentEnt),
         SourceLineCache(nullptr), NumLines(0), BufferOverridden(false),