[mips] Interrupt attribute support.

Summary: This patch adds support for the interrupt attribute for mips32r2+.

Patch by Simon Dardis.

Reviewers: dsanders, aaron.ballman

Subscribers: aaron.ballman, cfe-commits

Differential Revision: http://reviews.llvm.org/D10802

llvm-svn: 254205

1 files changed, 73 insertions, 1 deletions

diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index 13a11bcac9e..df1641af5f4 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -4450,14 +4450,86 @@ static void handleMSP430InterruptAttr(Sema &S, Decl *D,
   D->addAttr(UsedAttr::CreateImplicit(S.Context));
 }
 
+static void handleMipsInterruptAttr(Sema &S, Decl *D,
+                                    const AttributeList &Attr) {
+  // Only one optional argument permitted.
+  if (Attr.getNumArgs() > 1) {
+    S.Diag(Attr.getLoc(), diag::err_attribute_too_many_arguments)
+        << Attr.getName() << 1;
+    return;
+  }
+
+  StringRef Str;
+  SourceLocation ArgLoc;
+
+  if (Attr.getNumArgs() == 0)
+    Str = "";
+  else if (!S.checkStringLiteralArgumentAttr(Attr, 0, Str, &ArgLoc))
+    return;
+
+  // Semantic checks for a function with the 'interrupt' attribute for MIPS:
+  // a) Must be a function.
+  // b) Must have no parameters.
+  // c) Must have the 'void' return type.
+  // d) Cannot have the 'mips16' attribute, as that instruction set
+  //    lacks the 'eret' instruction.
+  // e) The attribute itself must either have no argument or one of the
+  //    valid interrupt types, see [MipsInterruptDocs].
+
+  if (!isFunctionOrMethod(D)) {
+    S.Diag(D->getLocation(), diag::warn_attribute_wrong_decl_type)
+        << "'interrupt'" << ExpectedFunctionOrMethod;
+    return;
+  }
+
+  if (hasFunctionProto(D) && getFunctionOrMethodNumParams(D) != 0) {
+    S.Diag(D->getLocation(), diag::warn_mips_interrupt_attribute)
+        << 0;
+    return;
+  }
+
+  if (!getFunctionOrMethodResultType(D)->isVoidType()) {
+    S.Diag(D->getLocation(), diag::warn_mips_interrupt_attribute)
+        << 1;
+    return;
+  }
+
+  if (checkAttrMutualExclusion<Mips16Attr>(S, D, Attr.getRange(),
+                                           Attr.getName()))
+    return;
+
+  MipsInterruptAttr::InterruptType Kind;
+  if (!MipsInterruptAttr::ConvertStrToInterruptType(Str, Kind)) {
+    S.Diag(Attr.getLoc(), diag::warn_attribute_type_not_supported)
+        << Attr.getName() << "'" + std::string(Str) + "'";
+    return;
+  }
+
+  D->addAttr(::new (S.Context) MipsInterruptAttr(
+      Attr.getLoc(), S.Context, Kind, Attr.getAttributeSpellingListIndex()));
+}
+
 static void handleInterruptAttr(Sema &S, Decl *D, const AttributeList &Attr) {
   // Dispatch the interrupt attribute based on the current target.
   if (S.Context.getTargetInfo().getTriple().getArch() == llvm::Triple::msp430)
     handleMSP430InterruptAttr(S, D, Attr);
+  else if (S.Context.getTargetInfo().getTriple().getArch() ==
+               llvm::Triple::mipsel ||
+           S.Context.getTargetInfo().getTriple().getArch() ==
+               llvm::Triple::mips)
+    handleMipsInterruptAttr(S, D, Attr);
   else
     handleARMInterruptAttr(S, D, Attr);
 }
 
+static void handleMips16Attribute(Sema &S, Decl *D, const AttributeList &Attr) {
+  if (checkAttrMutualExclusion<MipsInterruptAttr>(S, D, Attr.getRange(),
+                                                  Attr.getName()))
+    return;
+
+  handleSimpleAttribute<Mips16Attr>(S, D, Attr);
+}
+
 static void handleAMDGPUNumVGPRAttr(Sema &S, Decl *D,
                                     const AttributeList &Attr) {
   uint32_t NumRegs;
@@ -4847,7 +4919,7 @@ static void ProcessDeclAttribute(Sema &S, Scope *scope, Decl *D,
     handleDLLAttr(S, D, Attr);
     break;
   case AttributeList::AT_Mips16:
-    handleSimpleAttribute<Mips16Attr>(S, D, Attr);
+    handleMips16Attribute(S, D, Attr);
     break;
   case AttributeList::AT_NoMips16:
     handleSimpleAttribute<NoMips16Attr>(S, D, Attr);