4 files changed, 50 insertions, 5 deletions
diff --git a/clang/lib/Basic/TargetInfo.cpp b/clang/lib/Basic/TargetInfo.cpp
index 856ad50d378..dbd2f9ae995 100644
--- a/clang/lib/Basic/TargetInfo.cpp
+++ b/clang/lib/Basic/TargetInfo.cpp
@@ -50,6 +50,7 @@ TargetInfo::TargetInfo(const llvm::Triple &T) : TargetOpts(), Triple(T) {
   LargeArrayAlign = 0;
   MaxAtomicPromoteWidth = MaxAtomicInlineWidth = 0;
   MaxVectorAlign = 0;
+  MaxTLSAlign = 0;
   SimdDefaultAlign = 0;
   SizeType = UnsignedLong;
   PtrDiffType = SignedLong;
diff --git a/clang/lib/Basic/Targets.cpp b/clang/lib/Basic/Targets.cpp
index c5bf90fa784..3cf74bc8492 100644
--- a/clang/lib/Basic/Targets.cpp
+++ b/clang/lib/Basic/Targets.cpp
@@ -580,6 +580,8 @@ public:
   PS4OSTargetInfo(const llvm::Triple &Triple) : OSTargetInfo<Target>(Triple) {
     this->WCharType = this->UnsignedShort;
 
+    // On PS4, TLS variable cannot be aligned to more than 32 bytes (256 bits).
+    this->MaxTLSAlign = 256;
     this->UserLabelPrefix = "";
 
     switch (Triple.getArch()) {
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 5646099015b..99d4a79c466 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -9828,6 +9828,16 @@ void Sema::CheckCompleteVariableDeclaration(VarDecl *var) {
     FinalizeVarWithDestructor(var, recordType);
 }
 
+/// \brief Determines if a variable's alignment is dependent.
+static bool hasDependentAlignment(VarDecl *VD) {
+  if (VD->getType()->isDependentType())
+    return true;
+  for (auto *I : VD->specific_attrs<AlignedAttr>())
+    if (I->isAlignmentDependent())
+      return true;
+  return false;
+}
+
 /// FinalizeDeclaration - called by ParseDeclarationAfterDeclarator to perform
 /// any semantic actions necessary after any initializer has been attached.
 void
@@ -9841,6 +9851,22 @@ Sema::FinalizeDeclaration(Decl *ThisDecl) {
 
   checkAttributesAfterMerging(*this, *VD);
 
+  // Perform TLS alignment check here after attributes attached to the variable
+  // which may affect the alignment have been processed. Only perform the check
+  // if the target has a maximum TLS alignment (zero means no constraints).
+  if (unsigned MaxAlign = Context.getTargetInfo().getMaxTLSAlign()) {
+    // Protect the check so that it's not performed on dependent types and
+    // dependent alignments (we can't determine the alignment in that case).
+    if (VD->getTLSKind() && !hasDependentAlignment(VD)) {
+      CharUnits MaxAlignChars = Context.toCharUnitsFromBits(MaxAlign);
+      if (Context.getDeclAlign(VD) > MaxAlignChars) {
+        Diag(VD->getLocation(), diag::err_tls_var_aligned_over_maximum)
+          << (unsigned)Context.getDeclAlign(VD).getQuantity() << VD
+          << (unsigned)MaxAlignChars.getQuantity();
+      }
+    }
+  }
+
   // Static locals inherit dll attributes from their function.
   if (VD->isStaticLocal()) {
     if (FunctionDecl *FD =
diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index b8d08306859..191dbd05c9b 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -2985,11 +2985,27 @@ void Sema::AddAlignedAttr(SourceRange AttrRange, Decl *D, Expr *E,
   //      specifier shall have no effect
   // C11 6.7.5p6:
   //   An alignment specification of zero has no effect.
-  if (!(TmpAttr.isAlignas() && !Alignment) &&
-      !llvm::isPowerOf2_64(Alignment.getZExtValue())) {
-    Diag(AttrLoc, diag::err_alignment_not_power_of_two)
-      << E->getSourceRange();
-    return;
+  if (!(TmpAttr.isAlignas() && !Alignment)) {
+    if(!llvm::isPowerOf2_64(Alignment.getZExtValue())) {
+      Diag(AttrLoc, diag::err_alignment_not_power_of_two)
+        << E->getSourceRange();
+      return;
+    }
+    if (Context.getTargetInfo().isTLSSupported()) {
+      if (unsigned MaxAlign = Context.getTargetInfo().getMaxTLSAlign()) {
+        if (VarDecl *VD = dyn_cast<VarDecl>(D)) {
+          if (VD->getTLSKind()) {
+            CharUnits MaxAlignChars = Context.toCharUnitsFromBits(MaxAlign);
+            if (Alignment.getSExtValue() > MaxAlignChars.getQuantity()) {
+              Diag(VD->getLocation(), diag::err_tls_var_aligned_over_maximum)
+                << (unsigned)Alignment.getZExtValue() << VD
+                << (unsigned)MaxAlignChars.getQuantity();
+              return;
+            }
+          }
+        }
+      }
+    }
   }
 
   // Alignment calculations can wrap around if it's greater than 2**28.