[cfe-commits] mips16/nomips16 attr

reed kotler rkotler at mips.com
Mon Jan 14 19:20:13 PST 2013


I believe I have resolved all issues.

There is an open issue regarding the legality of the following:

void foo();
void __attribute__((nomips16) foo();

Gcc does not allow this but right now clang would.
I'm not convinced that we have to mimick this gcc behavior.
Currently I am discussing this internally at Mips and on the gcc 
developers list.

On 01/14/2013 02:31 PM, Dmitri Gribenko wrote:
> On Mon, Jan 14, 2013 at 8:42 AM, Reed Kotler <rkotler at mips.com> wrote:
>> Forget to say that I need to have this patch reviewd.
> +__attribute((nomips16)) int a; // expected-warning {{attribute only
> applies to functions}}
>
> I am concerned by the fact that this is just a warning -- I would
> suggest to make it an error.  This is a new attribute, so there's no
> code abusing this attribute (we don't need to be compatible with it).
>
> What does gcc do?
>
> +void __attribute__((nomips16)) foo32(); // expected-warning {{unknown
> attribute 'nomips16' ignored}}
>
> Same here.  What does gcc do in this case?  (I know that this behavior
> can not be changed without some refactoring.  But if GCC gives an
> error, we should, too.  So we would leave a comment in the test, or
> better -- do the required refactoring...)
>
> Dmitri
>

-------------- next part --------------
diff --git a/include/clang/Basic/Attr.td b/include/clang/Basic/Attr.td
index 858df3a..cee4ea8 100644
--- a/include/clang/Basic/Attr.td
+++ b/include/clang/Basic/Attr.td
@@ -403,6 +403,11 @@ def MBlazeSaveVolatiles : InheritableAttr {
   let SemaHandler = 0;
 }
 
+def Mips16 : InheritableAttr {
+  let Spellings = [GNU<"mips16">];
+  let Subjects = [Function];
+}
+
 def Mode : Attr {
   let Spellings = [GNU<"mode">];
   let Args = [IdentifierArgument<"Mode">];
@@ -441,6 +446,11 @@ def NoInline : InheritableAttr {
   let Spellings = [GNU<"noinline">];
 }
 
+def NoMips16 : InheritableAttr {
+  let Spellings = [GNU<"nomips16">];
+  let Subjects = [Function];
+}
+
 def NonNull : InheritableAttr {
   let Spellings = [GNU<"nonnull">];
   let Args = [VariadicUnsignedArgument<"Args">];
diff --git a/lib/CodeGen/TargetInfo.cpp b/lib/CodeGen/TargetInfo.cpp
index 5f2bd52..47005e7 100644
--- a/lib/CodeGen/TargetInfo.cpp
+++ b/lib/CodeGen/TargetInfo.cpp
@@ -3846,6 +3846,13 @@ public:
     return 29;
   }
 
+  void SetTargetAttributes(const Decl *D, llvm::GlobalValue *GV,
+                           CodeGen::CodeGenModule &CGM) const {
+    //
+    // can fill this in when new attribute work in llvm is done.
+    // attributes mips16 and nomips16 need to be handled here.
+    //
+  }
   bool initDwarfEHRegSizeTable(CodeGen::CodeGenFunction &CGF,
                                llvm::Value *Address) const;
 
diff --git a/lib/Sema/TargetAttributesSema.cpp b/lib/Sema/TargetAttributesSema.cpp
index 94f240c..1b8889d 100644
--- a/lib/Sema/TargetAttributesSema.cpp
+++ b/lib/Sema/TargetAttributesSema.cpp
@@ -262,6 +262,54 @@ namespace {
   };
 }
 
+static void HandleMips16Attr(Decl *D, const AttributeList &Attr, Sema &S) {
+  // check the attribute arguments.
+  if (Attr.hasParameterOrArguments()) {
+    S.Diag(Attr.getLoc(), diag::err_attribute_wrong_number_arguments) << 0;
+    return;
+  }
+  // Attribute can only be applied to function types.
+  if (!isa<FunctionDecl>(D)) {
+    S.Diag(Attr.getLoc(), diag::err_attribute_wrong_decl_type)
+      << Attr.getName() << /* function */0;
+    return;
+  }
+  D->addAttr(::new (S.Context) Mips16Attr(Attr.getRange(), S.Context));
+}
+
+static void HandleNoMips16Attr(Decl *D, const AttributeList &Attr, Sema &S) {
+  // check the attribute arguments.
+  if (Attr.hasParameterOrArguments()) {
+    S.Diag(Attr.getLoc(), diag::err_attribute_wrong_number_arguments) << 0;
+    return;
+  }
+  // Attribute can only be applied to function types.
+  if (!isa<FunctionDecl>(D)) {
+    S.Diag(Attr.getLoc(), diag::err_attribute_wrong_decl_type)
+      << Attr.getName() << /* function */0;
+    return;
+  }
+  D->addAttr(::new (S.Context) NoMips16Attr(Attr.getRange(), S.Context));
+}
+
+namespace {
+  class MipsAttributesSema : public TargetAttributesSema {
+  public:
+    MipsAttributesSema() { }
+    bool ProcessDeclAttribute(Scope *scope, Decl *D, const AttributeList &Attr,
+                              Sema &S) const {
+      if (Attr.getName()->getName() == "mips16") {
+        HandleMips16Attr(D, Attr, S);
+        return true;
+      } else if (Attr.getName()->getName() == "nomips16") {
+        HandleNoMips16Attr(D, Attr, S);
+        return true;
+      }
+      return false;
+    }
+  };
+}
+
 const TargetAttributesSema &Sema::getTargetAttributesSema() const {
   if (TheTargetAttributesSema)
     return *TheTargetAttributesSema;
@@ -275,6 +323,9 @@ const TargetAttributesSema &Sema::getTargetAttributesSema() const {
   case llvm::Triple::x86:
   case llvm::Triple::x86_64:
     return *(TheTargetAttributesSema = new X86AttributesSema);
+  case llvm::Triple::mips:
+  case llvm::Triple::mipsel:
+    return *(TheTargetAttributesSema = new MipsAttributesSema);
   default:
     return *(TheTargetAttributesSema = new TargetAttributesSema);
   }
diff --git a/test/Sema/mips16_attr_allowed.c b/test/Sema/mips16_attr_allowed.c
new file mode 100644
index 0000000..8ea7cc9
--- /dev/null
+++ b/test/Sema/mips16_attr_allowed.c
@@ -0,0 +1,27 @@
+// RUN: %clang_cc1 -triple mipsel-linux-gnu -fsyntax-only -verify %s
+
+void foo32();
+void foo16();
+void __attribute__((nomips16)) foo32(); 
+void __attribute__((mips16)) foo16(); 
+
+void __attribute__((nomips16)) foo32_(); 
+void __attribute__((mips16)) foo16_(); 
+void foo32_();
+void foo16_();
+
+void foo32__() __attribute__((nomips16)); 
+void foo32__() __attribute__((mips16)); 
+
+void foo32() __attribute__((nomips16(xyz))) ; // expected-error {{attribute takes no arguments}}
+void __attribute__((mips16(xyz))) foo16a(); // expected-error {{attribute takes no arguments}}
+
+void __attribute__((nomips16(1, 2))) foo32b(); // expected-error {{attribute takes no arguments}}
+void __attribute__((mips16(1, 2))) foo16c(); // expected-error {{attribute takes no arguments}}
+
+
+__attribute((nomips16)) int a; // expected-error {{attribute only applies to functions}}
+
+__attribute((mips16)) int b; // expected-error {{attribute only applies to functions}}
+
+
diff --git a/test/Sema/mips16_attr_not_allowed.c b/test/Sema/mips16_attr_not_allowed.c
new file mode 100644
index 0000000..54f27d6
--- /dev/null
+++ b/test/Sema/mips16_attr_not_allowed.c
@@ -0,0 +1,7 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fsyntax-only -verify %s
+
+void __attribute__((nomips16)) foo32(); // expected-warning {{unknown attribute 'nomips16' ignored}}
+void __attribute__((mips16)) foo16(); // expected-warning {{unknown attribute 'mips16' ignored}}
+
+
+


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