Import LLVM 6.0.1 release including clang, lld and lldb.

"where is the kaboom?" deraadt@

1 files changed, 38 insertions, 2 deletions

diff --git a/gnu/llvm/lib/Target/Mips/MipsTargetObjectFile.cpp b/gnu/llvm/lib/Target/Mips/MipsTargetObjectFile.cpp
index 4d73c399103..f767c832198 100644
--- a/gnu/llvm/lib/Target/Mips/MipsTargetObjectFile.cpp
+++ b/gnu/llvm/lib/Target/Mips/MipsTargetObjectFile.cpp
@@ -36,6 +36,12 @@ ExternSData("mextern-sdata", cl::Hidden,
                      "current object."),
             cl::init(true));
 
+static cl::opt<bool>
+EmbeddedData("membedded-data", cl::Hidden,
+             cl::desc("MIPS: Try to allocate variables in the following"
+                      " sections if possible: .rodata, .sdata, .data ."),
+             cl::init(false));
+
 void MipsTargetObjectFile::Initialize(MCContext &Ctx, const TargetMachine &TM){
   TargetLoweringObjectFileELF::Initialize(Ctx, TM);
   InitializeELF(TM.Options.UseInitArray);
@@ -77,8 +83,9 @@ bool MipsTargetObjectFile::IsGlobalInSmallSection(
 bool MipsTargetObjectFile::
 IsGlobalInSmallSection(const GlobalObject *GO, const TargetMachine &TM,
                        SectionKind Kind) const {
-  return (IsGlobalInSmallSectionImpl(GO, TM) &&
-          (Kind.isData() || Kind.isBSS() || Kind.isCommon()));
+  return IsGlobalInSmallSectionImpl(GO, TM) &&
+         (Kind.isData() || Kind.isBSS() || Kind.isCommon() ||
+          Kind.isReadOnly());
 }
 
 /// Return true if this global address should be placed into small data/bss
@@ -99,6 +106,22 @@ IsGlobalInSmallSectionImpl(const GlobalObject *GO,
   if (!GVA)
     return false;
 
+  // If the variable has an explicit section, it is placed in that section but
+  // it's addressing mode may change.
+  if (GVA->hasSection()) {
+    StringRef Section = GVA->getSection();
+
+    // Explicitly placing any variable in the small data section overrides
+    // the global -G value.
+    if (Section == ".sdata" || Section == ".sbss")
+      return true;
+
+    // Otherwise reject accessing it through the gp pointer. There are some
+    // historic cases which GCC doesn't appear to respect any more. These
+    // are .lit4, .lit8 and .srdata. For the moment reject these as well.
+    return false;
+  }
+
   // Enforce -mlocal-sdata.
   if (!LocalSData && GVA->hasLocalLinkage())
     return false;
@@ -108,7 +131,18 @@ IsGlobalInSmallSectionImpl(const GlobalObject *GO,
                        GVA->hasCommonLinkage()))
     return false;
 
+  // Enforce -membedded-data.
+  if (EmbeddedData && GVA->isConstant())
+    return false;
+
   Type *Ty = GVA->getValueType();
+
+  // It is possible that the type of the global is unsized, i.e. a declaration
+  // of a extern struct. In this case don't presume it is in the small data
+  // section. This happens e.g. when building the FreeBSD kernel.
+  if (!Ty->isSized())
+    return false;
+
   return IsInSmallSection(
       GVA->getParent()->getDataLayout().getTypeAllocSize(Ty));
 }
@@ -123,6 +157,8 @@ MCSection *MipsTargetObjectFile::SelectSectionForGlobal(
     return SmallBSSSection;
   if (Kind.isData() && IsGlobalInSmallSection(GO, TM, Kind))
     return SmallDataSection;
+  if (Kind.isReadOnly() && IsGlobalInSmallSection(GO, TM, Kind))
+    return SmallDataSection;
 
   // Otherwise, we work the same as ELF.
   return TargetLoweringObjectFileELF::SelectSectionForGlobal(GO, Kind, TM);