Add support for __declspec(code_seg("segname"))

This patch uses CodeSegAttr to represent __declspec(code_seg) rather than 
building on the existing support for #pragma code_seg.
The code_seg declspec is applied on functions and classes. This attribute 
enables the placement of code into separate named segments, including compiler-
generated codes and template instantiations.

For more information, please see the following:
https://msdn.microsoft.com/en-us/library/dn636922.aspx

This patch fixes the regression for the support for attribute ((section).
https://github.com/llvm-mirror/clang/commit/746b78de7812bc785fbb5207b788348040b23fa7

Patch by Soumi Manna (Manna)
Differential Revision: https://reviews.llvm.org/D48841

llvm-svn: 337420

1 files changed, 87 insertions, 0 deletions

diff --git a/clang/test/CodeGenCXX/code-seg1.cpp b/clang/test/CodeGenCXX/code-seg1.cpp
new file mode 100644
index 00000000000..93be3e520a5
--- /dev/null
+++ b/clang/test/CodeGenCXX/code-seg1.cpp
@@ -0,0 +1,87 @@
+// RUN: %clang_cc1 -emit-llvm -triple i686-pc-win32 -fms-extensions -verify -o - %s | FileCheck %s
+// expected-no-diagnostics
+// The Microsoft document says: "When this attribute is applied to a class,
+// all member functions of the class and nested classes - this includes
+// compiler-generated special member functions - are put in the specified segment."
+// But the MS compiler does not always follow that.  A bug has been reported:
+// see https://reviews.llvm.org/D22931, the Microsoft feedback page is no
+// longer available.
+// The MS compiler will apply a declspec from the parent class if there is no
+// #pragma code_seg active at the class definition.  If there is an active
+// code_seg that is used instead.
+
+// No active code_seg
+
+struct __declspec(code_seg("foo_outer")) Foo1 {
+  struct Inner {
+    void bar1();
+    static void bar2();
+  };
+};
+void Foo1::Inner::bar1() {}
+void Foo1::Inner::bar2() {}
+
+//CHECK: define {{.*}}bar1@Inner@Foo1{{.*}} section "foo_outer"
+//CHECK: define {{.*}}bar2@Inner@Foo1{{.*}} section "foo_outer"
+
+struct __declspec(code_seg("foo_outer")) Foo2 {
+  struct __declspec(code_seg("foo_inner")) Inner {
+    void bar1();
+    static void bar2();
+  };
+};
+void Foo2::Inner::bar1() {}
+void Foo2::Inner::bar2() {}
+
+//CHECK: define {{.*}}bar1@Inner@Foo2{{.*}} section "foo_inner"
+//CHECK: define {{.*}}bar2@Inner@Foo2{{.*}} section "foo_inner"
+
+#pragma code_seg(push, "otherseg")
+struct __declspec(code_seg("foo_outer")) Foo3 {
+  struct Inner {
+    void bar1();
+    static void bar2();
+  };
+};
+void Foo3::Inner::bar1() {}
+void Foo3::Inner::bar2() {}
+
+//CHECK: define {{.*}}bar1@Inner@Foo3{{.*}} section "otherseg"
+//CHECK: define {{.*}}bar2@Inner@Foo3{{.*}} section "otherseg"
+
+struct __declspec(code_seg("foo_outer")) Foo4 {
+  struct __declspec(code_seg("foo_inner")) Inner {
+    void bar1();
+    static void bar2();
+  };
+};
+void Foo4::Inner::bar1() {}
+void Foo4::Inner::bar2() {}
+
+//CHECK: define {{.*}}bar1@Inner@Foo4{{.*}} section "foo_inner"
+//CHECK: define {{.*}}bar2@Inner@Foo4{{.*}} section "foo_inner"
+
+#pragma code_seg(pop)
+// Back to no active pragma
+struct __declspec(code_seg("foo_outer")) Foo5 {
+  struct Inner {
+    void bar1();
+    static void bar2();
+    struct __declspec(code_seg("inner1_seg")) Inner1 {
+      struct Inner2 {
+        void bar1();
+        static void bar2();
+      };
+    };
+  };
+};
+void Foo5::Inner::bar1() {}
+void Foo5::Inner::bar2() {}
+void Foo5::Inner::Inner1::Inner2::bar1() {}
+void Foo5::Inner::Inner1::Inner2::bar2() {}
+
+//CHECK: define {{.*}}bar1@Inner@Foo5{{.*}} section "foo_outer"
+//CHECK: define {{.*}}bar2@Inner@Foo5{{.*}} section "foo_outer"
+//CHECK: define {{.*}}bar1@Inner2@Inner1@Inner@Foo5{{.*}} section "inner1_seg"
+//CHECK: define {{.*}}bar2@Inner2@Inner1@Inner@Foo5{{.*}} section "inner1_seg"
+