Introduce code_model macros

[tamur]

Summary

gcc defines macros such as __code_model_small_ based on the user passed command line flag -mcmodel. clang accepts a flag with the same name and similar effects, but does not generate any macro that the user can use. This cl narrows the gap between gcc and clang behaviour.

However, achieving full compatibility with gcc is not trivial: The set of valid values for mcmodel in gcc and clang are not equal. Also, gcc defines different macros for different architectures. In this cl, we only tackle an easy part of the problem and define the macro only for x64 architecture. When the user does not specify a mcmodel, the macro for small code model is produced, as is the case with gcc.

[MaskRay]

include/clang/Basic/TargetOptions.h

72

Model -> CodeModel::Model because there are Model in other namespaces

namespace Reloc {
enum Model { Static, PIC_, DynamicNoPIC, ROPI, RWPI, ROPI_RWPI };
}

// Code model types.
namespace CodeModel {
  // Sync changes with CodeGenCWrappers.h.
enum Model { Tiny, Small, Kernel, Medium, Large };
}

lib/Basic/Targets/X86.cpp

866

The comment // For compatibility with gcc. needs changing.

Small code model is the fastest and expected to be suitable for vast majority of programs.

It is chosen here:

https://github.com/llvm-mirror/llvm/tree/master/lib/Target/X86/X86TargetMachine.cpp#L208

static CodeModel::Model getEffectiveCodeModel(Optional<CodeModel::Model> CM,

                                            bool JIT, bool Is64Bit) {
if (CM)
  return *CM;
if (JIT)
  return Is64Bit ? CodeModel::Large : CodeModel::Small;
return CodeModel::Small;

}

[MaskRay]

test/Preprocessor/init.c

7992

-dM here is better because it suppresses other CPP output (https://github.com/llvm-mirror/clang/tree/BindingDecl/lib/Frontend/CompilerInvocation.cpp#L2962)

[MaskRay]

lib/Basic/Targets/X86.cpp

865

I'm not sure if the comment is useful here... or you can comment that this piece of code should be consistent with X86TargetMachine.cpp#L208

[tamur]

lib/Basic/Targets/X86.cpp

865

I removed the comment, Done. What I had wanted was to explain why we have a code_model_small_ macro, not e.g. code_model_default_ macro, but maybe it will be obvious to future readers.

[echristo]

LGTM as well. Thanks!

include/clang/Basic/TargetOptions.h

public:
   std::vector<std::string> OpenCLExtensionsAsWritten;
 
   /// If given, enables support for __int128_t and __uint128_t types.
   bool ForceEnableInt128 = false;
 
   /// \brief If enabled, use 32-bit pointers for accessing const/local/shared
   /// address space.
   bool NVPTXUseShortPointers = false;
+
+  // The code model to be used as specified by the user. Corresponds to
+  // CodeModel::Model enum defined in include/llvm/Support/CodeGen.h, plus
+  // "default" for the case when the user has not explicitly specified a
+  // code model.
+  std::string CodeModel;
 };
 
 }  // end namespace clang
 
 #endif

lib/Basic/Targets/X86.cpp

SimdDefaultAlign =
       hasFeature("avx512f") ? 512 : hasFeature("avx") ? 256 : 128;
   return true;
 }
 
 /// X86TargetInfo::getTargetDefines - Return the set of the X86-specific macro
 /// definitions for this particular subtarget.
 void X86TargetInfo::getTargetDefines(const LangOptions &Opts,
                                      MacroBuilder &Builder) const {
+  std::string CodeModel = getTargetOpts().CodeModel;
+  if (CodeModel == "default")
+    CodeModel = "small";
+  Builder.defineMacro("__code_model_" + CodeModel + "_");
+
   // Target identification.
   if (getTriple().getArch() == llvm::Triple::x86_64) {
     Builder.defineMacro("__amd64__");
     Builder.defineMacro("__amd64");
     Builder.defineMacro("__x86_64");
     Builder.defineMacro("__x86_64__");
     if (getTriple().getArchName() == "x86_64h") {
       Builder.defineMacro("__x86_64h");

lib/Frontend/CompilerInvocation.cpp

static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
   Opts.AsmVerbose = Args.hasArg(OPT_masm_verbose);
   Opts.PreserveAsmComments = !Args.hasArg(OPT_fno_preserve_as_comments);
   Opts.AssumeSaneOperatorNew = !Args.hasArg(OPT_fno_assume_sane_operator_new);
   Opts.ObjCAutoRefCountExceptions = Args.hasArg(OPT_fobjc_arc_exceptions);
   Opts.CXAAtExit = !Args.hasArg(OPT_fno_use_cxa_atexit);
   Opts.RegisterGlobalDtorsWithAtExit =
       Args.hasArg(OPT_fregister_global_dtors_with_atexit);
   Opts.CXXCtorDtorAliases = Args.hasArg(OPT_mconstructor_aliases);
-  Opts.CodeModel = getCodeModel(Args, Diags);
+  Opts.CodeModel = TargetOpts.CodeModel;
   Opts.DebugPass = Args.getLastArgValue(OPT_mdebug_pass);
   Opts.DisableFPElim =
       (Args.hasArg(OPT_mdisable_fp_elim) || Args.hasArg(OPT_pg));
   Opts.DisableFree = Args.hasArg(OPT_disable_free);
   Opts.DiscardValueNames = Args.hasArg(OPT_discard_value_names);
   Opts.DisableTailCalls = Args.hasArg(OPT_mdisable_tail_calls);
   Opts.NoEscapingBlockTailCalls =
       Args.hasArg(OPT_fno_escaping_block_tail_calls);
static void ParsePreprocessorOutputArgs(PreprocessorOutputOptions &Opts,
   Opts.ShowIncludeDirectives = Args.hasArg(OPT_dI);
   Opts.RewriteIncludes = Args.hasArg(OPT_frewrite_includes);
   Opts.RewriteImports = Args.hasArg(OPT_frewrite_imports);
   Opts.UseLineDirectives = Args.hasArg(OPT_fuse_line_directives);
 }
 
 static void ParseTargetArgs(TargetOptions &Opts, ArgList &Args,
                             DiagnosticsEngine &Diags) {
+  Opts.CodeModel = getCodeModel(Args, Diags);
   Opts.ABI = Args.getLastArgValue(OPT_target_abi);
   if (Arg *A = Args.getLastArg(OPT_meabi)) {
     StringRef Value = A->getValue();
     llvm::EABI EABIVersion = llvm::StringSwitch<llvm::EABI>(Value)
                                  .Case("default", llvm::EABI::Default)
                                  .Case("4", llvm::EABI::EABI4)
                                  .Case("5", llvm::EABI::EABI5)
                                  .Case("gnu", llvm::EABI::GNU)

test/Preprocessor/init.c

 //
 // CXX11:#define __GNUG__ {{.*}}
 // CXX11:#define __GXX_EXPERIMENTAL_CXX0X__ 1
 // CXX11:#define __GXX_RTTI 1
 // CXX11:#define __GXX_WEAK__ 1
 // CXX11:#define __cplusplus 201103L
 // CXX11:#define __private_extern__ extern
 //
-// 
+//
 // RUN: %clang_cc1 -x c++ -std=c++98 -E -dM < /dev/null | FileCheck -match-full-lines -check-prefix CXX98 %s
-// 
+//
 // CXX98:#define __GNUG__ {{.*}}
 // CXX98:#define __GXX_RTTI 1
 // CXX98:#define __GXX_WEAK__ 1
 // CXX98:#define __cplusplus 199711L
 // CXX98:#define __private_extern__ extern
 //
-// 
+//
 // RUN: %clang_cc1 -fdeprecated-macro -E -dM < /dev/null | FileCheck -match-full-lines -check-prefix DEPRECATED %s
 //
 // DEPRECATED:#define __DEPRECATED 1
 //
-// 
+//
 // RUN: %clang_cc1 -std=c99 -E -dM < /dev/null | FileCheck -match-full-lines -check-prefix C99 %s
 //
 // C99:#define __STDC_VERSION__ 199901L
 // C99:#define __STRICT_ANSI__ 1
 // C99-NOT: __GXX_EXPERIMENTAL_CXX0X__
 // C99-NOT: __GXX_RTTI
 // C99-NOT: __GXX_WEAK__
 // C99-NOT: __cplusplus
 //
-// 
+//
 // RUN: %clang_cc1 -std=c11 -E -dM < /dev/null | FileCheck -match-full-lines -check-prefix C11 %s
 // RUN: %clang_cc1 -std=c1x -E -dM < /dev/null | FileCheck -match-full-lines -check-prefix C11 %s
 // RUN: %clang_cc1 -std=iso9899:2011 -E -dM < /dev/null | FileCheck -match-full-lines -check-prefix C11 %s
 // RUN: %clang_cc1 -std=iso9899:201x -E -dM < /dev/null | FileCheck -match-full-lines -check-prefix C11 %s
 //
 // C11:#define __STDC_UTF_16__ 1
 // C11:#define __STDC_UTF_32__ 1
 // C11:#define __STDC_VERSION__ 201112L
 // C11:#define __STRICT_ANSI__ 1
 // C11-NOT: __GXX_EXPERIMENTAL_CXX0X__
 // C11-NOT: __GXX_RTTI
 // C11-NOT: __GXX_WEAK__
 // C11-NOT: __cplusplus
 //
-// 
+//
 // RUN: %clang_cc1 -E -dM < /dev/null | FileCheck -match-full-lines -check-prefix COMMON %s
 //
 // COMMON:#define __CONSTANT_CFSTRINGS__ 1
 // COMMON:#define __FINITE_MATH_ONLY__ 0
 // COMMON:#define __GNUC_MINOR__ {{.*}}
 // COMMON:#define __GNUC_PATCHLEVEL__ {{.*}}
 // COMMON:#define __GNUC_STDC_INLINE__ 1
 // COMMON:#define __GNUC__ {{.*}}

 // COMMON:#define __clang_patchlevel__ {{[0-9]+}}
 // COMMON:#define __clang_version__ {{.*}}
 // COMMON:#define __llvm__ 1
 //
 // RUN: %clang_cc1 -E -dM -triple=x86_64-pc-win32 < /dev/null | FileCheck -match-full-lines -check-prefix C-DEFAULT %s
 // RUN: %clang_cc1 -E -dM -triple=x86_64-pc-linux-gnu < /dev/null | FileCheck -match-full-lines -check-prefix C-DEFAULT %s
 // RUN: %clang_cc1 -E -dM -triple=x86_64-apple-darwin < /dev/null | FileCheck -match-full-lines -check-prefix C-DEFAULT %s
 // RUN: %clang_cc1 -E -dM -triple=armv7a-apple-darwin < /dev/null | FileCheck -match-full-lines -check-prefix C-DEFAULT %s
-// 
+//
 // C-DEFAULT:#define __STDC_VERSION__ 201112L
 //
 // RUN: %clang_cc1 -ffreestanding -E -dM < /dev/null | FileCheck -match-full-lines -check-prefix FREESTANDING %s
 // FREESTANDING:#define __STDC_HOSTED__ 0
 //
 // RUN: %clang_cc1 -x c++ -std=gnu++2a -E -dM < /dev/null | FileCheck -match-full-lines -check-prefix GXX2A %s
 //
 // GXX2A:#define __GNUG__ {{.*}}

 //
 // RUN: %clang_cc1 -x c++ -std=gnu++98 -E -dM < /dev/null | FileCheck -match-full-lines -check-prefix GXX98 %s
 //
 // GXX98:#define __GNUG__ {{.*}}
 // GXX98:#define __GXX_WEAK__ 1
 // GXX98:#define __cplusplus 199711L
 // GXX98:#define __private_extern__ extern
 //
-// 
+//
 // RUN: %clang_cc1 -std=iso9899:199409 -E -dM < /dev/null | FileCheck -match-full-lines -check-prefix C94 %s
 //
 // C94:#define __STDC_VERSION__ 199409L
 //
-// 
+//
 // RUN: %clang_cc1 -fms-extensions -triple i686-pc-win32 -E -dM < /dev/null | FileCheck -match-full-lines -check-prefix MSEXT %s
 //
 // MSEXT-NOT:#define __STDC__
 // MSEXT:#define _INTEGRAL_MAX_BITS 64
 // MSEXT-NOT:#define _NATIVE_WCHAR_T_DEFINED 1
 // MSEXT-NOT:#define _WCHAR_T_DEFINED 1
 //
 //
 // RUN: %clang_cc1 -x c++ -fms-extensions -triple i686-pc-win32 -E -dM < /dev/null | FileCheck -match-full-lines -check-prefix MSEXT-CXX %s
 //
 // MSEXT-CXX:#define _NATIVE_WCHAR_T_DEFINED 1
 // MSEXT-CXX:#define _WCHAR_T_DEFINED 1
 // MSEXT-CXX:#define __BOOL_DEFINED 1
 //
 //
 // RUN: %clang_cc1 -x c++ -fno-wchar -fms-extensions -triple i686-pc-win32 -E -dM < /dev/null | FileCheck -match-full-lines -check-prefix MSEXT-CXX-NOWCHAR %s
 //
 // MSEXT-CXX-NOWCHAR-NOT:#define _NATIVE_WCHAR_T_DEFINED 1
 // MSEXT-CXX-NOWCHAR-NOT:#define _WCHAR_T_DEFINED 1
 // MSEXT-CXX-NOWCHAR:#define __BOOL_DEFINED 1
 //
-// 
+//
 // RUN: %clang_cc1 -x objective-c -E -dM < /dev/null | FileCheck -match-full-lines -check-prefix OBJC %s
 //
 // OBJC:#define OBJC_NEW_PROPERTIES 1
 // OBJC:#define __NEXT_RUNTIME__ 1
 // OBJC:#define __OBJC__ 1
 //
 //
 // RUN: %clang_cc1 -x objective-c -fobjc-gc -E -dM < /dev/null | FileCheck -match-full-lines -check-prefix OBJCGC %s
 //
 // OBJCGC:#define __OBJC_GC__ 1
 //
-// 
+//
 // RUN: %clang_cc1 -x objective-c -fobjc-exceptions -E -dM < /dev/null | FileCheck -match-full-lines -check-prefix NONFRAGILE %s
 //
 // NONFRAGILE:#define OBJC_ZEROCOST_EXCEPTIONS 1
 // NONFRAGILE:#define __OBJC2__ 1
 //
 //
 // RUN: %clang_cc1 -E -dM < /dev/null | FileCheck -match-full-lines -check-prefix O0 %s
 //

 // Oz:#define __OPTIMIZE_SIZE__ 1
 // Oz:#define __OPTIMIZE__ 1
 //
 //
 // RUN: %clang_cc1 -fpascal-strings -E -dM < /dev/null | FileCheck -match-full-lines -check-prefix PASCAL %s
 //
 // PASCAL:#define __PASCAL_STRINGS__ 1
 //
-// 
+//
 // RUN: %clang_cc1 -E -dM < /dev/null | FileCheck -match-full-lines -check-prefix SCHAR %s
-// 
+//
 // SCHAR:#define __STDC__ 1
 // SCHAR-NOT:#define __UNSIGNED_CHAR__
 // SCHAR:#define __clang__ 1
 //
 // RUN: %clang_cc1 -E -dM -fwchar-type=short -fno-signed-wchar < /dev/null | FileCheck -match-full-lines -check-prefix SHORTWCHAR %s
 // wchar_t is u16 for targeting Win32.
 // RUN: %clang_cc1 -E -dM -fwchar-type=short -fno-signed-wchar -triple=x86_64-w64-mingw32 < /dev/null | FileCheck -match-full-lines -check-prefix SHORTWCHAR %s
 // RUN: %clang_cc1 -dM -fwchar-type=short -fno-signed-wchar -triple=x86_64-unknown-windows-cygnus -E /dev/null | FileCheck -match-full-lines -check-prefix SHORTWCHAR %s

 // X86_64:#define __USER_LABEL_PREFIX__
 // X86_64:#define __WCHAR_MAX__ 2147483647
 // X86_64:#define __WCHAR_TYPE__ int
 // X86_64:#define __WCHAR_WIDTH__ 32
 // X86_64:#define __WINT_TYPE__ int
 // X86_64:#define __WINT_WIDTH__ 32
 // X86_64:#define __amd64 1
 // X86_64:#define __amd64__ 1
+// X86_64:#define __code_model_small_ 1
 // X86_64:#define __x86_64 1
 // X86_64:#define __x86_64__ 1
 //
 // RUN: %clang_cc1 -E -dM -ffreestanding -triple=x86_64h-none-none < /dev/null | FileCheck -match-full-lines -check-prefix X86_64H %s
 //
 // X86_64H:#define __x86_64 1
 // X86_64H:#define __x86_64__ 1
 // X86_64H:#define __x86_64h 1
 // X86_64H:#define __x86_64h__ 1
-
+//
+// RUN: %clang -xc - -E -dM -mcmodel=medium --target=i386-unknown-linux < /dev/null | FileCheck -match-full-lines -check-prefix X86_MEDIUM %s
+// X86_MEDIUM:#define __code_model_medium_ 1
+//
 // RUN: %clang_cc1 -E -dM -ffreestanding -triple=x86_64-none-none-gnux32 < /dev/null | FileCheck -match-full-lines -check-prefix X32 %s
 // RUN: %clang_cc1 -x c++ -E -dM -ffreestanding -triple=x86_64-none-none-gnux32 < /dev/null | FileCheck -match-full-lines -check-prefix X32 -check-prefix X32-CXX %s
 //
 // X32:#define _ILP32 1
 // X32-NOT:#define _LP64 1
 // X32:#define __BIGGEST_ALIGNMENT__ 16
 // X32:#define __BYTE_ORDER__ __ORDER_LITTLE_ENDIAN__
 // X32:#define __CHAR16_TYPE__ unsigned short

 // AVR:#define __GCC_ATOMIC_INT_LOCK_FREE 1
 // AVR:#define __GCC_ATOMIC_LLONG_LOCK_FREE 1
 // AVR:#define __GCC_ATOMIC_LONG_LOCK_FREE 1
 // AVR:#define __GCC_ATOMIC_POINTER_LOCK_FREE 1
 // AVR:#define __GCC_ATOMIC_SHORT_LOCK_FREE 1
 // AVR:#define __GCC_ATOMIC_TEST_AND_SET_TRUEVAL 1
 // AVR:#define __GCC_ATOMIC_WCHAR_T_LOCK_FREE 1
 // AVR:#define __GXX_ABI_VERSION 1002
-// AVR:#define __INT16_C_SUFFIX__ 
+// AVR:#define __INT16_C_SUFFIX__
 // AVR:#define __INT16_MAX__ 32767
 // AVR:#define __INT16_TYPE__ short
 // AVR:#define __INT32_C_SUFFIX__ L
 // AVR:#define __INT32_MAX__ 2147483647L
 // AVR:#define __INT32_TYPE__ long int
 // AVR:#define __INT64_C_SUFFIX__ LL
 // AVR:#define __INT64_MAX__ 9223372036854775807LL
 // AVR:#define __INT64_TYPE__ long long int
-// AVR:#define __INT8_C_SUFFIX__ 
+// AVR:#define __INT8_C_SUFFIX__
 // AVR:#define __INT8_MAX__ 127
 // AVR:#define __INT8_TYPE__ signed char
 // AVR:#define __INTMAX_C_SUFFIX__ LL
 // AVR:#define __INTMAX_MAX__ 9223372036854775807LL
 // AVR:#define __INTMAX_TYPE__ long long int
 // AVR:#define __INTPTR_MAX__ 32767
 // AVR:#define __INTPTR_TYPE__ int
 // AVR:#define __INT_FAST16_MAX__ 32767

 // AVR:#define __UINT16_MAX__ 65535U
 // AVR:#define __UINT16_TYPE__ unsigned short
 // AVR:#define __UINT32_C_SUFFIX__ UL
 // AVR:#define __UINT32_MAX__ 4294967295UL
 // AVR:#define __UINT32_TYPE__ long unsigned int
 // AVR:#define __UINT64_C_SUFFIX__ ULL
 // AVR:#define __UINT64_MAX__ 18446744073709551615ULL
 // AVR:#define __UINT64_TYPE__ long long unsigned int
-// AVR:#define __UINT8_C_SUFFIX__ 
+// AVR:#define __UINT8_C_SUFFIX__
 // AVR:#define __UINT8_MAX__ 255
 // AVR:#define __UINT8_TYPE__ unsigned char
 // AVR:#define __UINTMAX_C_SUFFIX__ ULL
 // AVR:#define __UINTMAX_MAX__ 18446744073709551615ULL
 // AVR:#define __UINTMAX_TYPE__ long long unsigned int
 // AVR:#define __UINTPTR_MAX__ 65535U
 // AVR:#define __UINTPTR_TYPE__ unsigned int
 // AVR:#define __UINT_FAST16_MAX__ 65535U
 // AVR:#define __UINT_FAST16_TYPE__ unsigned int
 // AVR:#define __UINT_FAST32_MAX__ 4294967295UL
 // AVR:#define __UINT_FAST32_TYPE__ long unsigned int
 // AVR:#define __UINT_FAST64_MAX__ 18446744073709551615ULL
 // AVR:#define __UINT_FAST64_TYPE__ long long unsigned int
 // AVR:#define __UINT_FAST8_MAX__ 255
 // AVR:#define __UINT_FAST8_TYPE__ unsigned char
 // AVR:#define __UINT_LEAST16_MAX__ 65535U
 // AVR:#define __UINT_LEAST16_TYPE__ unsigned int
 // AVR:#define __UINT_LEAST32_MAX__ 4294967295UL
 // AVR:#define __UINT_LEAST32_TYPE__ long unsigned int
 // AVR:#define __UINT_LEAST64_MAX__ 18446744073709551615ULL
 // AVR:#define __UINT_LEAST64_TYPE__ long long unsigned int
 // AVR:#define __UINT_LEAST8_MAX__ 255
 // AVR:#define __UINT_LEAST8_TYPE__ unsigned char
-// AVR:#define __USER_LABEL_PREFIX__ 
+// AVR:#define __USER_LABEL_PREFIX__
 // AVR:#define __WCHAR_MAX__ 32767
 // AVR:#define __WCHAR_TYPE__ int
 // AVR:#define __WINT_TYPE__ int
 
 
 // RUN: %clang_cc1 -E -dM -ffreestanding \
 // RUN:    -triple i686-windows-msvc -fms-compatibility -x c++ < /dev/null \
 // RUN:  | FileCheck -match-full-lines -check-prefix MSVC-X32 %s