Add documentation for calling convention attributes

llvm-svn: 220415

2 files changed, 78 insertions, 6 deletions

diff --git a/clang/include/clang/Basic/Attr.td b/clang/include/clang/Basic/Attr.td
index 012988b9327..96699f058a8 100644
--- a/clang/include/clang/Basic/Attr.td
+++ b/clang/include/clang/Basic/Attr.td
@@ -680,7 +680,7 @@ def FastCall : InheritableAttr {
   let Spellings = [GCC<"fastcall">, Keyword<"__fastcall">,
                    Keyword<"_fastcall">];
 //  let Subjects = [Function, ObjCMethod];
-  let Documentation = [Undocumented];
+  let Documentation = [FastCallDocs];
 }
 
 def Final : InheritableAttr {
@@ -779,7 +779,7 @@ def MayAlias : InheritableAttr {
 def MSABI : InheritableAttr {
   let Spellings = [GCC<"ms_abi">];
 //  let Subjects = [Function, ObjCMethod];
-  let Documentation = [Undocumented];
+  let Documentation = [MSABIDocs];
 }
 
 def MSP430Interrupt : InheritableAttr, TargetSpecificAttr<TargetMSP430> {
@@ -1104,7 +1104,7 @@ def Pure : InheritableAttr {
 def Regparm : TypeAttr {
   let Spellings = [GCC<"regparm">];
   let Args = [UnsignedArgument<"NumParams">];
-  let Documentation = [Undocumented];
+  let Documentation = [RegparmDocs];
 }
 
 def ReqdWorkGroupSize : InheritableAttr {
@@ -1151,7 +1151,7 @@ def Sentinel : InheritableAttr {
 def StdCall : InheritableAttr {
   let Spellings = [GCC<"stdcall">, Keyword<"__stdcall">, Keyword<"_stdcall">];
 //  let Subjects = [Function, ObjCMethod];
-  let Documentation = [Undocumented];
+  let Documentation = [StdCallDocs];
 }
 
 def SysVABI : InheritableAttr {
@@ -1164,7 +1164,7 @@ def ThisCall : InheritableAttr {
   let Spellings = [GCC<"thiscall">, Keyword<"__thiscall">,
                    Keyword<"_thiscall">];
 //  let Subjects = [Function, ObjCMethod];
-  let Documentation = [Undocumented];
+  let Documentation = [ThisCallDocs];
 }
 
 def Pascal : InheritableAttr {
diff --git a/clang/include/clang/Basic/AttrDocs.td b/clang/include/clang/Basic/AttrDocs.td
index c72817f9dee..0207ebb084a 100644
--- a/clang/include/clang/Basic/AttrDocs.td
+++ b/clang/include/clang/Basic/AttrDocs.td
@@ -676,12 +676,84 @@ The semantics are as follows:
 def PcsDocs : Documentation {
   let Category = DocCatFunction;
   let Content = [{
-On ARM targets, this can attribute can be used to select calling conventions,
+On ARM targets, this attribute can be used to select calling conventions
 similar to ``stdcall`` on x86. Valid parameter values are "aapcs" and
 "aapcs-vfp".
   }];
 }
 
+def RegparmDocs : Documentation {
+  let Category = DocCatFunction;
+  let Content = [{
+On 32-bit x86 targets, the regparm attribute causes the compiler to pass
+the first three integer parameters in EAX, EDX, and ECX instead of on the
+stack. This attribute has no effect on variadic functions, and all parameters
+are passed via the stack as normal.
+}];
+}
+
+def SysVABIDocs : Documentation {
+  let Category = DocCatFunction;
+  let Content = [{
+On Windows x86_64 targets, this attribute changes the calling convention of a
+function to match the default convention used on Sys V targets such as Linux,
+Mac, and BSD. This attribute has no effect on other targets.
+}];
+}
+
+def MSABIDocs : Documentation {
+  let Category = DocCatFunction;
+  let Content = [{
+On non-Windows x86_64 targets, this attribute changes the calling convention of
+a function to match the default convention used on Windows x86_64. This
+attribute has no effect on Windows targets or non-x86_64 targets.
+}];
+}
+
+def StdCallDocs : Documentation {
+  let Category = DocCatFunction;
+  let Content = [{
+On 32-bit x86 targets, this attribute changes the calling convention of a
+function to clear parameters off of the stack on return. This convention does
+not support variadic calls or unprototyped functions in C, and has no effect on
+x86_64 targets. This calling convention is used widely by the Windows API and
+COM applications.  Documentation for the Visual C++ attribute is available on
+MSDN_.
+
+.. _MSDN: http://msdn.microsoft.com/en-us/library/zxk0tw93.aspx
+  }];
+}
+
+def FastCallDocs : Documentation {
+  let Category = DocCatFunction;
+  let Content = [{
+On 32-bit x86 targets, this attribute changes the calling convention of a
+function to use ECX and EDX as register parameters and clear parameters off of
+the stack on return. This convention does not support variadic calls or
+unprototyped functions in C, and has no effect on x86_64 targets. This calling
+convention is supported primarily for compatibility with existing code. Users
+seeking register parameters should use the ``regparm`` attribute, which does
+not require callee-cleanup.  Documentation for the Visual C++ attribute is
+available on MSDN_.
+
+.. _MSDN: http://msdn.microsoft.com/en-us/library/6xa169sk.aspx
+  }];
+}
+
+def ThisCallDocs : Documentation {
+  let Category = DocCatFunction;
+  let Content = [{
+On 32-bit x86 targets, this attribute changes the calling convention of a
+function to use ECX for the first parameter (typically the implicit ``this``
+parameter of C++ methods) and clear parameters off of the stack on return. This
+convention does not support variadic calls or unprototyped functions in C, and
+has no effect on x86_64 targets. Documentation for the Visual C++ attribute is
+available on MSDN_.
+
+.. _MSDN: http://msdn.microsoft.com/en-us/library/ek8tkfbw.aspx
+  }];
+}
+
 def DocCatConsumed : DocumentationCategory<"Consumed Annotation Checking"> {
   let Content = [{
 Clang supports additional attributes for checking basic resource management