Move ABIInfo/ABIArgInfo classes into ABIInfo.h

llvm-svn: 63586

1 files changed, 116 insertions, 0 deletions

diff --git a/clang/lib/CodeGen/ABIInfo.h b/clang/lib/CodeGen/ABIInfo.h
new file mode 100644
index 00000000000..4b33c4e8065
--- /dev/null
+++ b/clang/lib/CodeGen/ABIInfo.h
@@ -0,0 +1,116 @@
+//===----- ABIInfo.h - ABI information access & encapsulation ---*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef CLANG_CODEGEN_ABIINFO_H
+#define CLANG_CODEGEN_ABIINFO_H
+
+namespace clang {
+  /* FIXME: All of this stuff should be part of the target interface
+     somehow. It is currently here because it is not clear how to factor
+     the targets to support this, since the Targets currently live in a
+     layer below types n'stuff.
+  */
+
+  /// ABIArgInfo - Helper class to encapsulate information about how a
+  /// specific C type should be passed to or returned from a function.
+  class ABIArgInfo {
+  public:
+    enum Kind {
+      Default,
+      StructRet, /// Only valid for return values. The return value
+                 /// should be passed through a pointer to a caller
+                 /// allocated location passed as an implicit first
+                 /// argument to the function.
+  
+      Ignore,    /// Ignore the argument (treat as void). Useful for
+                 /// void and empty structs.
+  
+      Coerce,    /// Only valid for aggregate return types, the argument
+                 /// should be accessed by coercion to a provided type.
+  
+      ByVal,     /// Only valid for aggregate argument types. The
+                 /// structure should be passed "byval" with the
+                 /// specified alignment (0 indicates default
+                 /// alignment).
+  
+      Expand,    /// Only valid for aggregate argument types. The
+                 /// structure should be expanded into consecutive
+                 /// arguments for its constituent fields. Currently
+                 /// expand is only allowed on structures whose fields
+                 /// are all scalar types or are themselves expandable
+                 /// types.
+  
+      KindFirst=Default, KindLast=Expand
+    };
+  
+  private:
+    Kind TheKind;
+    const llvm::Type *TypeData;
+    unsigned UIntData;
+  
+    ABIArgInfo(Kind K, const llvm::Type *TD=0,
+               unsigned UI=0) : TheKind(K),
+                                TypeData(TD),
+                                UIntData(0) {}
+  public:
+    static ABIArgInfo getDefault() { 
+      return ABIArgInfo(Default); 
+    }
+    static ABIArgInfo getStructRet() { 
+      return ABIArgInfo(StructRet); 
+    }
+    static ABIArgInfo getIgnore() {
+      return ABIArgInfo(Ignore);
+    }
+    static ABIArgInfo getCoerce(const llvm::Type *T) { 
+      return ABIArgInfo(Coerce, T);
+    }
+    static ABIArgInfo getByVal(unsigned Alignment) {
+      return ABIArgInfo(ByVal, 0, Alignment);
+    }
+    static ABIArgInfo getExpand() {
+      return ABIArgInfo(Expand);
+    }
+  
+    Kind getKind() const { return TheKind; }
+    bool isDefault() const { return TheKind == Default; }
+    bool isStructRet() const { return TheKind == StructRet; }
+    bool isIgnore() const { return TheKind == Ignore; }
+    bool isCoerce() const { return TheKind == Coerce; }
+    bool isByVal() const { return TheKind == ByVal; }
+    bool isExpand() const { return TheKind == Expand; }
+  
+    // Coerce accessors
+    const llvm::Type *getCoerceToType() const {
+      assert(TheKind == Coerce && "Invalid kind!");
+      return TypeData;
+    }
+  
+    // ByVal accessors
+    unsigned getByValAlignment() const {
+      assert(TheKind == ByVal && "Invalid kind!");
+      return UIntData;
+    }
+  };
+
+  /// ABIInfo - Target specific hooks for defining how a type should be
+  /// passed or returned from functions.
+  class ABIInfo {
+  public:
+    virtual ~ABIInfo();
+  
+    virtual ABIArgInfo classifyReturnType(QualType RetTy, 
+                                          ASTContext &Context) const = 0;
+  
+    virtual ABIArgInfo classifyArgumentType(QualType Ty,
+                                            ASTContext &Context) const = 0;
+  };
+}  // end namespace clang
+
+#endif