[AArch64] Predefine __AARCH64_CMODEL_*__ as GCC does

[mcgrathr]

Summary

Make Clang on aarch64 targets predefine __AARCH64_CMODEL_SMALL__
or __AARCH64_CMODEL_TINY__, etc. These are the names that GCC
uses for its predefines.

[mcgrathr]

update log

[mcgrathr]

Thanks! Can you land it for me?

[MaskRay]

clang/lib/Basic/Targets/AArch64.cpp

200

This can be simplified. I'll do that.

[MaskRay]

Add tests

Rebase after -mcmodel cleanups (including fc6057e34fb3b1cfbbfcd5d71ae25ba24eb3ffa3)

clang/lib/Basic/Targets/AArch64.cpp

if (getTriple().getOS() == llvm::Triple::UnknownOS &&
     Builder.defineMacro("__ELF__");
 
   // Target properties.
   if (!getTriple().isOSWindows() && getTriple().isArch64Bit()) {
     Builder.defineMacro("_LP64");
     Builder.defineMacro("__LP64__");
   }
 
+  std::string CodeModel = getTargetOpts().CodeModel;
+  if (CodeModel == "default")
+    CodeModel = "small";
+  for (char &c : CodeModel)
+    c = toupper(c);
+  Builder.defineMacro("__AARCH64_CMODEL_" + CodeModel + "__");
+
   // ACLE predefines. Many can only have one possible value on v8 AArch64.
   Builder.defineMacro("__ARM_ACLE", "200");
   Builder.defineMacro("__ARM_ARCH", "8");
   Builder.defineMacro("__ARM_ARCH_PROFILE", "'A'");
 
   Builder.defineMacro("__ARM_64BIT_STATE", "1");
   Builder.defineMacro("__ARM_PCS_AAPCS64", "1");
   Builder.defineMacro("__ARM_ARCH_ISA_A64", "1");

clang/test/Preprocessor/init-aarch64.c

 // RUN: %clang_cc1 -E -dM -triple=aarch64 -xc /dev/null > %t.aarch64
 // RUN: FileCheck --check-prefixes=AARCH64,AARCH64_LE,AARCH64_C %s --match-full-lines < %t.aarch64
 // RUN: %clang_cc1 -E -dM -triple=arm64 -xc /dev/null > %t.arm64
 // RUN: cmp %t.aarch64 %t.arm64
 // RUN: %clang_cc1 -E -dM -triple=aarch64_be -xc /dev/null | FileCheck --check-prefixes=AARCH64,AARCH64_BE,AARCH64_C --match-full-lines %s
 // RUN: %clang_cc1 -E -dM -triple=arm64 -xc++ /dev/null | FileCheck --check-prefixes=AARCH64,AARCH64_LE,AARCH64_CXX --match-full-lines %s
 
 // AARCH64: #define _LP64 1
 // AARCH64_BE-NEXT: #define __AARCH64EB__ 1
+// AARCH64_BE-NEXT: #define __AARCH64_CMODEL_SMALL__ 1
 // AARCH64_BE-NEXT: #define __AARCH_BIG_ENDIAN 1
 // AARCH64_LE-NEXT: #define __AARCH64EL__ 1
+// AARCH64_LE-NEXT: #define __AARCH64_CMODEL_SMALL__ 1
 // AARCH64-NEXT: #define __ARM_64BIT_STATE 1
 // AARCH64-NEXT: #define __ARM_ACLE 200
 // AARCH64-NEXT: #define __ARM_ALIGN_MAX_STACK_PWR 4
 // AARCH64-NEXT: #define __ARM_ARCH 8
 // AARCH64-NEXT: #define __ARM_ARCH_ISA_A64 1
 // AARCH64-NEXT: #define __ARM_ARCH_PROFILE 'A'
 // AARCH64_BE-NEXT: #define __ARM_BIG_ENDIAN 1
 // AARCH64-NEXT: #define __ARM_FEATURE_CLZ 1

 // AARCH64-MSVC: #define __USER_LABEL_PREFIX__
 // AARCH64-MSVC: #define __WCHAR_MAX__ 65535
 // AARCH64-MSVC: #define __WCHAR_TYPE__ unsigned short
 // AARCH64-MSVC: #define __WCHAR_UNSIGNED__ 1
 // AARCH64-MSVC: #define __WCHAR_WIDTH__ 16
 // AARCH64-MSVC: #define __WINT_TYPE__ unsigned short
 // AARCH64-MSVC: #define __WINT_WIDTH__ 16
 // AARCH64-MSVC: #define __aarch64__ 1
+
+// RUN: %clang_cc1 -triple=aarch64 -E -dM -mcmodel=small -xc /dev/null | FileCheck --check-prefix=CMODEL_SMALL %s
+// RUN: %clang_cc1 -triple=aarch64 -E -dM -mcmodel=tiny -xc /dev/null | FileCheck --check-prefix=CMODEL_TINY %s
+// RUN: %clang_cc1 -triple=aarch64 -E -dM -mcmodel=large -xc /dev/null | FileCheck --check-prefix=CMODEL_LARGE %s
+
+// CMODEL_TINY: #define __AARCH64_CMODEL_TINY__ 1
+// CMODEL_SMALL: #define __AARCH64_CMODEL_SMALL__ 1
+// CMODEL_LARGE: #define __AARCH64_CMODEL_LARGE__ 1