[clang][AVR] Redefine some types to be compatible with avr-gcc

[benshi001]

Some key points,

1. This patch fixes the bug https://bugs.llvm.org/show_bug.cgi?id=31530 .

2. The test builtins.cpp failed on AVR and is disabled, due to uint16_t is defined to unsigned short. The underlying reason is that the system's libc/stdint.h is used instead of avr-libc's stdint.h.

In avr-libc's stdint, the correct definition is

typedef signed int int8_t attribute((mode(QI)));
typedef unsigned int uint8_t attribute((mode(QI)));
typedef signed int int16_t attribute ((mode (HI)));
typedef unsigned int uint16_t attribute ((mode (HI)));
typedef signed int int32_t attribute ((mode (SI)));
typedef unsigned int uint32_t attribute ((mode (SI)));

typedef signed int int64_t attribute((mode(DI)));
typedef unsigned int uint64_t attribute((mode(DI)));

[benshi001]

Though the disabled test builtins.cpp can pass after my another patch https://reviews.llvm.org/D97669, it will still fail on llvm build machines, since there are no avr-libc installed on them.

[efriedma]

clang/lib/Basic/Targets/AVR.cpp

313

Redefining __INT16_TYPE__ like this is unusual. The macro is normally defined in InitPreprocessor.cpp; if the logic there is wrong, I'd prefer to fix it there.

For specific types int16_t and uint16_t, I'm not sure if anything inside the compiler actually uses them at the moment, but I'd prefer to encode the type in the TargetInfo, along the lines of getInt64Type(), in case we need these types elsewhere in the future.

[benshi001]

clang/lib/Basic/Targets/AVR.cpp

313

Making changes to InitPreprocessor.cpp will affect all targets, and I not familar with other targets. Actually AVR is so special that it defines __INT16_TYPE__ to int.

[efriedma]

clang/lib/Basic/Targets/AVR.cpp

313

Making changes to InitPreprocessor.cpp will affect all targets, and I not familar with other targets.

That shouldn't be a problem as long as you have an appropriate reviewer; I volunteer. :)

You should be able to use getInt64Type() as a model for the necessary changes.

[benshi001]

clang/lib/Basic/Targets/AVR.cpp

313

Thanks for your suggestion. I have submitted a patch,

https://reviews.llvm.org/D102547, and you are appreciated to review it. ^_^

clang/lib/Basic/Targets/AVR.cpp

 
 void AVRTargetInfo::getTargetDefines(const LangOptions &Opts,
                                      MacroBuilder &Builder) const {
   Builder.defineMacro("AVR");
   Builder.defineMacro("__AVR");
   Builder.defineMacro("__AVR__");
   Builder.defineMacro("__ELF__");
   Builder.defineMacro("__flash", "__attribute__((address_space(1)))");
+  Builder.defineMacro("__UINT16_TYPE__", "unsigned int");
+  Builder.defineMacro("__INT16_TYPE__", "int");
 
   if (!this->CPU.empty()) {
     auto It = llvm::find_if(
         AVRMcus, [&](const MCUInfo &Info) { return Info.Name == this->CPU; });
 
     if (It != std::end(AVRMcus))
       Builder.defineMacro(It->DefineName);
   }
 }

clang/test/CodeGen/builtins.cpp

 // RUN: %clang_cc1 -std=c++11 -triple x86_64-linux-gnu -ffreestanding -verify %s
 // RUN: %clang_cc1 -std=c++11 -triple i686-pc-linux-gnu -ffreestanding -verify %s
-// RUN: %clang_cc1 -std=c++11 -triple avr-unknown-unknown -ffreestanding -verify %s
 
 // expected-no-diagnostics
 
 // Test that checks that the builtins return the same type as the stdint.h type
 // withe the same witdh. This is done by first declaring a variable of a stdint
 // type of the correct width and the redeclaring the variable with the type that
 // the builting return. If the types are different you should the an error from
 // clang of the form:

clang/test/Preprocessor/init.c

 // 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_MAX__ 32767
-// AVR:#define __INT16_TYPE__ short
+// AVR:#define __INT16_TYPE__ int
 // 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_MAX__ 127

 // AVR:#define __SIZEOF_SHORT__ 2
 // AVR:#define __SIZEOF_SIZE_T__ 2
 // AVR:#define __SIZEOF_WCHAR_T__ 2
 // AVR:#define __SIZEOF_WINT_T__ 2
 // AVR:#define __SIZE_MAX__ 65535U
 // AVR:#define __SIZE_TYPE__ unsigned int
 // AVR:#define __STDC__ 1
 // AVR:#define __UINT16_MAX__ 65535U
-// AVR:#define __UINT16_TYPE__ unsigned short
+// AVR:#define __UINT16_TYPE__ unsigned int
 // 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_MAX__ 255