ARM: centralise SizeType, PtrDiffType, and IntPtrType

[compnerd]

Summary

Centralise the definitions of these compiler vended types to aid
inspection to ensure that they are defined similarly. The one case that
stands out is the Darwin case where the types do not match up. This
fixes the API conformance for APCS-GNU as well.

[fhahn]

Could you upload a diff with more context, as suggested in http://llvm.org/docs/Phabricator.html#requesting-a-review-via-the-web-interface? That would make it easier to review the patch.

[efriedma]

I think you missed a couple other places which still set SizeType and PtrDiffType?

[compnerd]

Catch a couple of missed instances, add more context

[compnerd]

lib/Basic/Targets/ARM.cpp

231

I changed this to:

if (Triple.isOSDarwin() && !Triple.isWatchABI())
  PtrDiffType = SignedInt;

[efriedma]

Are you sure the change to APCS is right? I mean, it looks like it's right if I compare to gcc with -mabi=gnu-apcs, but I'm not sure what, exactly, we're trying to be compatible with, so I'd prefer not to touch it, especially not in a patch with a bunch of changes which are supposed to be NFC.

[compnerd]

Well, without matching that ABI, I think that centralizing the logic isn't any cleaner, since we determine the ABI later. With this, we also match the ABI as GNU defines it, and we can move the logic to the same location. intptr_t on Darwin && !WatchOS has the one incompatibility.

[efriedma]

I guess... fine.

LGTM, assuming we have test coverage for all the different cases.

[compnerd]

Yeah, we have coverage for the various environments in test/Preprocessor/init.c. The one case that I didn't find was the APCS-GNU case, which I added a test for additional coverage.

[compnerd]

SVN r316810

lib/Basic/Targets/ARM.cpp

   DoubleAlign = LongLongAlign = LongDoubleAlign = SuitableAlign = 64;
   const llvm::Triple &T = getTriple();
 
-  // size_t is unsigned long on MachO-derived environments, NetBSD, and
-  // OpenBSD.
-  if (T.isOSBinFormatMachO() || T.getOS() == llvm::Triple::NetBSD ||
-      T.getOS() == llvm::Triple::OpenBSD)
-    SizeType = UnsignedLong;
-  else
-    SizeType = UnsignedInt;
-
   bool IsNetBSD = T.getOS() == llvm::Triple::NetBSD;
   bool IsOpenBSD = T.getOS() == llvm::Triple::OpenBSD;
   if (!T.isOSWindows() && !IsNetBSD && !IsOpenBSD)

   else
     DoubleAlign = LongLongAlign = LongDoubleAlign = SuitableAlign = 32;
 
-  // size_t is unsigned int on FreeBSD.
-  if (T.getOS() == llvm::Triple::FreeBSD)
-    SizeType = UnsignedInt;
-  else
-    SizeType = UnsignedLong;
-
   WCharType = SignedInt;
 
   // Do not respect the alignment of bit-field types when laying out

                              const TargetOptions &Opts)
     : TargetInfo(Triple), FPMath(FP_Default), IsAAPCS(true), LDREX(0),
       HW_FP(0) {
-
-  switch (getTriple().getOS()) {
-  case llvm::Triple::NetBSD:
-  case llvm::Triple::OpenBSD:
-    PtrDiffType = SignedLong;
-    break;
-  default:
-    PtrDiffType = SignedInt;
-    break;
-  }
-
   bool IsOpenBSD = Triple.getOS() == llvm::Triple::OpenBSD;
   bool IsNetBSD = Triple.getOS() == llvm::Triple::NetBSD;
-  IntPtrType =
+
+  PtrDiffType = IntPtrType =
       (Triple.isOSDarwin() || IsOpenBSD || IsNetBSD) ? SignedLong : SignedInt;
 
+  // FIXME: the isOSBinFormatMachO is a workaround for identifying a Darwin-like
+  // environment where size_t is `unsigned long` rather than `unsigned int`
+  SizeType = (Triple.isOSDarwin() || Triple.isOSBinFormatMachO() || IsOpenBSD ||
+              IsNetBSD)
+                 ? UnsignedLong
+                 : UnsignedInt;
+
+  // ptrdiff_t is inconsistent on Darwin
+  if (Triple.isOSDarwin())
+    PtrDiffType = SignedInt;
+
   // Cache arch related info.
   setArchInfo();
 

test/Preprocessor/init.c

 // ARM:#define __arm 1
 // ARM:#define __arm__ 1
 
+// RUN: %clang_cc1 -dM -ffreestanding -triple arm-none-none -target-abi apcs-gnu -E /dev/null -o - | FileCheck -match-full-lines -check-prefix ARM-APCS-GNU %s
+// ARM-APCS-GNU: #define __INTPTR_TYPE__ int
+// ARM-APCS-GNU: #define __PTRDIFF_TYPE__ int
+// ARM-APCS-GNU: #define __SIZE_TYPE__ unsigned int
+
 // RUN: %clang_cc1 -E -dM -ffreestanding -triple=armeb-none-none < /dev/null | FileCheck -match-full-lines -check-prefix ARM-BE %s
 //
 // ARM-BE-NOT:#define _LP64