Bitcode: add an auto-upgrade for LTO section name

The bitcode reader looks specifically for `__DATA, __objc_catlist` as a
section name.  However, SVN r304661 removed the spaces (the two names
are functionally equivalent but do not compare equally
lexicographically).  This causes compatibility issues.  Add an
auto-upgrade path for removing the spaces as well as use the new name in
the LTO plugin.

llvm-svn: 315086

1 files changed, 29 insertions, 0 deletions

diff --git a/llvm/lib/IR/AutoUpgrade.cpp b/llvm/lib/IR/AutoUpgrade.cpp
index e190b20..07d499b 100644
--- a/llvm/lib/IR/AutoUpgrade.cpp
+++ b/llvm/lib/IR/AutoUpgrade.cpp
@@ -2448,6 +2448,35 @@ bool llvm::UpgradeModuleFlags(Module &M) {
   return Changed;
 }
 
+void llvm::UpgradeSectionAttributes(Module &M) {
+  auto TrimSpaces = [](StringRef Section) -> std::string {
+    SmallVector<StringRef, 5> Components;
+    Section.split(Components, ',');
+
+    SmallString<32> Buffer;
+    raw_svector_ostream OS(Buffer);
+
+    for (auto Component : Components)
+      OS << ',' << Component.trim();
+
+    return OS.str().substr(1);
+  };
+
+  for (auto &GV : M.globals()) {
+    if (!GV.hasSection())
+      continue;
+
+    StringRef Section = GV.getSection();
+
+    if (!Section.startswith("__DATA, __objc_catlist"))
+      continue;
+
+    // __DATA, __objc_catlist, regular, no_dead_strip
+    // __DATA,__objc_catlist,regular,no_dead_strip
+    GV.setSection(TrimSpaces(Section));
+  }
+}
+
 static bool isOldLoopArgument(Metadata *MD) {
   auto *T = dyn_cast_or_null<MDTuple>(MD);
   if (!T)