r269670 - [OpenCL] Add supported OpenCL extensions to target info.

[Liu, Yaxun (Sam) via cfe-commits]

Sorry for the delay.

In ParsePragma.cpp:

void Parser::HandlePragmaOpenCLExtension() {
  assert(Tok.is(tok::annot_pragma_opencl_extension));
  OpenCLExtData data =
      OpenCLExtData::getFromOpaqueValue(Tok.getAnnotationValue());
  unsigned state = data.getInt();
  IdentifierInfo *ename = data.getPointer();
  SourceLocation NameLoc = Tok.getLocation();
  ConsumeToken(); // The annotation token.

  OpenCLOptions &f = Actions.getOpenCLOptions();
  auto CLVer = getLangOpts().OpenCLVersion;
  auto &Supp = getTargetInfo().getSupportedOpenCLOpts();
  // OpenCL 1.1 9.1: "The all variant sets the behavior for all extensions,
  // overriding all previously issued extension directives, but only if the
  // behavior is set to disable."
  if (state == 0 && ename->isStr("all")) {
#define OPENCLEXT(nm) \
    if (Supp.is_##nm##_supported_extension(CLVer)) \
      f.nm = 0;
#include "clang/Basic/OpenCLExtensions.def"
  }
#define OPENCLEXT(nm) else if (ename->isStr(#nm)) \
   if (Supp.is_##nm##_supported_extension(CLVer)) \
     f.nm = state; \
   else if (Supp.is_##nm##_supported_core(CLVer)) \
     PP.Diag(NameLoc, diag::warn_pragma_extension_is_core) << ename; \
   else \
     PP.Diag(NameLoc, diag::warn_pragma_unsupported_extension) << ename;
#include "clang/Basic/OpenCLExtensions.def"
  else {
    PP.Diag(NameLoc, diag::warn_pragma_unknown_extension) << ename;
    return;
  }
}

Whether an extension is supported is represented by getTargetInfo().getSupportedOpenCLOpts(), which does not change with pragma.

Whether an extension is enabled is reprented by Actions.getOpenCLOptions(), which changes with pragma.

test/SemaOpenCL/extensions.cl contains examples of unsupported extensions.

Sam

-----Original Message-----
From: Jeroen Ketema [mailto:j.ketema at imperial.ac.uk] 
Sent: Tuesday, May 31, 2016 6:07 PM
To: Liu, Yaxun (Sam) <Yaxun.Liu at amd.com>
Cc: Anastasia Stulova <Anastasia.Stulova at arm.com>; Clang Commits <cfe-commits at lists.llvm.org>; nd <nd at arm.com>
Subject: Re: r269670 - [OpenCL] Add supported OpenCL extensions to target info.

Hi Sam,

> This commit does not change the initial state of the extensions. An extension is supported is not the same as enabled. At the beginning all extensions are disabled.

I do not see this reflected in the code at all. Could you please:

a. Point me to the location where this distinction is made.

b. Convince me that I cannot enable an extension for a target if that target does not support the extension?

Jeroen