Commit 1a711b16 authored by Reid Kleckner's avatar Reid Kleckner
Browse files

-fms-extensions: Implement half of #pragma init_seg 

Summary:
This pragma is very rare.  We could *hypothetically* lower some uses of
it down to @llvm.global_ctors, but given that GlobalOpt isn't able to
optimize prioritized global ctors today, there's really no point.

If we wanted to do this in the future, I would check if the section used
in the pragma started with ".CRT$XC" and had up to two characters after
it.  Those two characters could form the 16-bit initialization priority
that we support in @llvm.global_ctors.  We would have to teach LLVM to
lower prioritized global ctors on COFF as well.

This should let us compile some silly uses of this pragma in WebKit /
Blink.

Reviewers: rsmith, majnemer

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D4549

llvm-svn: 213593
parent e1aaced0

clang/include/clang/Basic/Attr.td

+12 −0
Original line number Diff line number Diff line
@@ -1767,6 +1767,18 @@ def MSVtorDisp : InheritableAttr { 
  let Documentation = [Undocumented];

}



def InitSeg : Attr {

  let Spellings = [Pragma<"", "init_seg">];

  let Args = [StringArgument<"Section">];

  let SemaHandler = 0;

  let Documentation = [InitSegDocs];

  let AdditionalMembers = [{

  void printPrettyPragma(raw_ostream &OS, const PrintingPolicy &Policy) const {

    OS << '(' << getSection() << ')';

  }

  }];

}



def Unaligned : IgnoredAttr {

  let Spellings = [Keyword<"__unaligned">];

}

clang/include/clang/Basic/AttrDocs.td

+16 −0
Original line number Diff line number Diff line
@@ -36,6 +36,22 @@ global variable or function should be in after translation. 
  let Heading = "section (gnu::section, __declspec(allocate))";

}



def InitSegDocs : Documentation {

  let Category = DocCatVariable;

  let Content = [{

The attribute applied by ``pragma init_seg()`` controls the section into

which global initialization function pointers are emitted.  It is only

available with ``-fms-extensions``.  Typically, this function pointer is

emitted into ``.CRT$XCU`` on Windows.  The user can change the order of

initialization by using a different section name with the same

``.CRT$XC`` prefix and a suffix that sorts lexicographically before or

after the standard ``.CRT$XCU`` sections.  See the init_seg_

documentation on MSDN for more information.



.. _init_seg: http://msdn.microsoft.com/en-us/library/7977wcck(v=vs.110).aspx

  }];

}



def TLSModelDocs : Documentation {

  let Category = DocCatVariable;

  let Content = [{

clang/include/clang/Basic/DiagnosticParseKinds.td

+3 −0
Original line number Diff line number Diff line
@@ -800,6 +800,9 @@ def warn_pragma_expected_section_push_pop_or_name : Warning< 
def warn_pragma_expected_section_label_or_name : Warning<

  "expected a stack label or a string literal for the section name in '#pragma %0' - ignored">,

  InGroup<IgnoredPragmas>;

def warn_pragma_expected_init_seg : Warning<

  "expected 'compiler', 'lib', 'user', or a string literal for the section name in '#pragma %0' - ignored">,

  InGroup<IgnoredPragmas>;

def warn_pragma_expected_integer : Warning<

  "expected integer between %0 and %1 inclusive in '#pragma %2' - ignored">,

  InGroup<IgnoredPragmas>;

clang/include/clang/Parse/Parser.h

+1 −1
Original line number Diff line number Diff line
@@ -725,7 +725,7 @@ private: 
  /// returned.

  bool ExpectAndConsume(tok::TokenKind ExpectedTok,

                        unsigned Diag = diag::err_expected,

                        const char *DiagMsg = "");

                        StringRef DiagMsg = "");



  /// \brief The parser expects a semicolon and, if present, will consume it.

  ///

clang/include/clang/Sema/Sema.h

+8 −0
Original line number Diff line number Diff line
@@ -330,6 +330,10 @@ public: 
  PragmaStack<StringLiteral *> ConstSegStack;

  PragmaStack<StringLiteral *> CodeSegStack;



  /// Last section used with #pragma init_seg.

  StringLiteral *CurInitSeg;

  SourceLocation CurInitSegLoc;



  /// VisContext - Manages the stack for \#pragma GCC visibility.

  void *VisContext; // Really a "PragmaVisStack*"
@@ -7179,6 +7183,10 @@ public: 
  void ActOnPragmaMSSection(SourceLocation PragmaLocation,

                            int SectionFlags, StringLiteral *SegmentName);



  /// \brief Called on well-formed \#pragma init_seg().

  void ActOnPragmaMSInitSeg(SourceLocation PragmaLocation,

                            StringLiteral *SegmentName);



  /// ActOnPragmaDetectMismatch - Call on well-formed \#pragma detect_mismatch

  void ActOnPragmaDetectMismatch(StringRef Name, StringRef Value);