clang++

clang++ とは、clangのC++コンパイラです。一部の環境では、c++コマンドの実体は、clang++コマンドです。c++コマンドについては、「c++」をご参照ください。

読み方

clang++: くらんぐぷらすぷらす、くらんぐぷらぷら

概要

FreeBSD 10.0-RELEASE以前のFreeBSD の場合、デフォルトで C++ コンパイラとして g++ がインストールされていました。FreeBSD の g++ コマンドと c++ コマンドは、同じものでした。FreeBSD 10.0-RELEASEからは、デフォルトのコンパイラがclang/clang++に変更されています。 FreeBSD は、標準でコンパイラが付属していますが、 ports コレクションを利用して clang (clang++が含まれます)をインストールすることで、システム標準のコンパイラよりも新しいコンパイラを導入できます。

インストール

Ubuntu/Debian系

clangを指定すると3.4がインストールされます。時期によって変更されるかもしれませんので、apt search などの結果をよく確認してください。

sudo apt install clang

sudo apt install clang-3.5

sudo apt install clang-3.4

FreeBSDにインストールする場合

ports コレクションからインストールする場合

cd /usr/ports/lang/clang34
sudo make install clean

pkgコマンドでインストールする場合

sudo pkg install clang34

portmasterコマンドでインストールする場合

sudo portmaster -y -d /usr/ports/lang/clang34

MacOS

Xcode から入れる場合には、以下の通りです。

Xcode を更新します。
Xcodeの Preferences の Downloads の Command Line Tools のインストールをクリックします。

FreeBSDへのインストール

FreeBSDでは、pkgコマンド、または、portsコレクションを使用してインストールできます。ベースシステムのコンパイラのコマンドは、/usr/binにありますが、pkg/portsでインストールしたコンパイラのコマンドやライブラリは、/usr/local に入ります。

パッケージの調べ方

$ pkg search clang
clang-cheri-3.4.20140528
clang-devel-3.5.r203994
clang32-3.2_3
clang33-3.3_7
clang34-3.4_2

clang 3.6 のインストール

sudo pkg install clang36

clang 3.6(開発版) のインストール

sudo pkg install clang-devel-3.6

clang 3.5 のインストール

C++14用の-std=c++14オプションがサポートされます。

sudo pkg install clang35

clang 3.5(開発版) のインストール

sudo pkg install clang-devel-3.5

clang 3.4 のインストール

sudo pkg install clang34

clang 3.3 のインストール

sudo pkg install clang33

clang 3.2 のインストール

sudo pkg install clang32

Ubuntu

apt/apt-cache でインストールできるパッケージが調べられます。

$ apt search 'clang' |grep ^clang
clang - C, C++ and Objective-C compiler (LLVM based)
clang-3.3 - C, C++ and Objective-C compiler (LLVM based)
clang-3.3-doc - C, C++ and Objective-C compiler (LLVM based) - Documentation
clang-3.3-examples - Clang examples
clang-3.4 - C, C++ and Objective-C compiler (LLVM based)
clang-3.4-doc - C, C++ and Objective-C compiler (LLVM based) - Documentation
clang-3.4-examples - Clang examples
clang-3.5 - C, C++ and Objective-C compiler (LLVM based)
clang-3.5-doc - C, C++ and Objective-C compiler (LLVM based) - Documentation
clang-3.5-examples - Clang examples
clang-format-3.3 - Tool to format C/C++/Obj-C code
clang-format-3.4 - Tool to format C/C++/Obj-C code
clang-format-3.5 - Tool to format C/C++/Obj-C code
clang-modernize-3.4 - Tool to convert C++98 and C++03 code to C++11
clang-modernize-3.5 - Tool to convert C++98 and C++03 code to C++11

$ apt-cache search 'clang' |grep ^clang

オプション

C++11系

clang++ -std=c++11 ...
clang++ -std=c++1y ...

C++14系

clang++ -std=c++14 ...

Abstract Syntax Tree(AST)

clang++ -cc1 -ast-print foo.cpp

詳細については、抽象構文木 (Abstract Syntax Tree, AST) をご参照ください。

コマンドラインオプション

OVERVIEW: clang LLVM compiler
 
USAGE: clang++ [options] <inputs>
 
OPTIONS:
  -###                    Print the commands to run for this compilation
  -E                      Only run the preprocessor
  -F <value>              Add directory to framework include search path
  -H                      Show header includes and nesting depth
  -I <value>              Add directory to include search path
  -MG                     Add missing headers to dependency list
  -MP                     Create phony target for each dependency (other than
			  main file)
  -MQ <value>             Specify target to quote for dependency
  -MT <value>             Specify target for dependency
  -ObjC++                 Treat source input files as Objective-C++ inputs
  -ObjC                   Treat source input files as Objective-C inputs
  -P                      Disable linemarker output in -E mode
  -Qunused-arguments      Don't emit warning for unused driver arguments
  -S                      Only run preprocess and compilation steps
  -Wa,<arg>               Pass the comma separated arguments in <arg> to the
			  assembler
  -Wl,<arg>               Pass the comma separated arguments in <arg> to the
			  linker
  -Wp,<arg>               Pass the comma separated arguments in <arg> to the
			  preprocessor
  -W<warning>             Enable the specified warning
  -Xanalyzer <arg>        Pass <arg> to the static analyzer
  -Xassembler <arg>       Pass <arg> to the assembler
  -Xclang <arg>           Pass <arg> to the clang compiler
  -Xlinker <arg>          Pass <arg> to the linker
  -Xpreprocessor <arg>    Pass <arg> to the preprocessor
  --analyze               Run the static analyzer
  -arcmt-migrate-emit-errors
                          Emit ARC errors even if the migrator can fix them
  -arcmt-migrate-report-output <value>
                          Output path for the plist report
  -cl-kernel-arg-info     OpenCL only. This option allows the compiler to store
			  information about the arguments of a kernel(s)
  -cxx-isystem <directory>
                          Add directory to the C++ SYSTEM include search path
  -c                      Only run preprocess, compile, and assemble steps
  -dD                     Print macro definitions in -E mode in addition to
			  normal output
  -dM                     Print macro definitions in -E mode instead of normal
			  output
  -dependency-dot <value> Filename to write DOT-formatted header dependencies to
  -dependency-file <value>
                          Filename (or -) to write dependency output to
  -emit-ast               Emit Clang AST files for source inputs
  -emit-llvm              Use the LLVM representation for assembler and object
			  files
  -faltivec               Enable AltiVec vector initializer syntax
  -fapple-kext            Use Apple's kernel extensions ABI
  -fapple-pragma-pack     Enable Apple gcc-compatible #pragma pack handling
  -fblocks                Enable the 'blocks' language feature
  -fborland-extensions    Accept non-standard constructs supported by the
			  Borland compiler
  -fbounds-checking       Enable run-time bounds checks
  -fcolor-diagnostics     Use colors in diagnostics
  -fcomment-block-commands=<arg>
			  Treat each comma separated argument in <arg> as a
			  documentation comment block command
  -fcxx-exceptions        Enable C++ exceptions
  -fdata-sections         Place each data in its own section (ELF Only)
  -fdelayed-template-parsing
			  Parse templated function definitions at the end of
			  the translation unit
  -fdiagnostics-parseable-fixits
                          Print fix-its in machine parseable form
  -fdiagnostics-print-source-range-info
                          Print source range spans in numeric form
  -fdiagnostics-show-name Print diagnostic name
  -fdiagnostics-show-note-include-stack
                          Display include stacks for diagnostic notes
  -fdiagnostics-show-option
                          Print option name with mappable diagnostics
  -fdiagnostics-show-template-tree
			  Print a template comparison tree for differing
			  templates
  -fdollars-in-identifiers
                          Allow '$' in identifiers
  -femit-all-decls        Emit all declarations, even if unused
  -fexceptions            Enable support for exception handling
  -ffast-math             Enable the *frontend*'s 'fast-math' mode. This has no
			  effect on optimizations, but provides a preprocessor
			  macro __FAST_MATH__ the same as GCC's -ffast-math flag
  -fformat-extensions     Enable FreeBSD kernel specific format string
			  extensions
  -ffp-contract=<value>   Form fused FP ops (e.g. FMAs): fast (everywhere) | on
			  (according to FP_CONTRACT pragma, default) | off
			  (never fuse)
  -ffreestanding          Assert that the compilation takes place in a
			  freestanding environment
  -ffunction-sections     Place each function in its own section (ELF Only)
  -fgnu-keywords          Allow GNU-extension keywords regardless of language
			  standard
  -fgnu-runtime           Generate output compatible with the standard GNU
			  Objective-C runtime
  -fgnu89-inline          Use the gnu89 inline semantics
  -finstrument-functions  Generate calls to instrument function entry and exit
  -flimit-debug-info      Limit debug information produced to reduce size of
			  debug binary
  -fmath-errno            Require math functions to indicate errors by setting
			  errno
  -fmodules-cache-path=<directory>
                          Specify the module cache path
  -fmodules-ignore-macro=<value>
			  Ignore the definition of the given macro when
			  building and loading modules
  -fmodules-prune-after=<seconds>
			  Specify the interval (in seconds) after which a
			  module file will be considered unused
  -fmodules-prune-interval=<seconds>
			  Specify the interval (in seconds) between attempts to
			  prune the module cache
  -fmodules               Enable the 'modules' language feature
  -fms-compatibility      Enable Microsoft compatibility mode
  -fms-extensions         Accept some non-standard constructs supported by the
			  Microsoft compiler
  -fmsc-version=<value>   Version of the Microsoft C/C++ compiler to report in
			  _MSC_VER (0 = don't define it (default))
  -fno-access-control     Disable C++ access control
  -fno-assume-sane-operator-new
                          Don't assume that C++'s global operator new can't alias any pointer
  -fno-autolink           Disable generation of linker directives for automatic library linking
  -fno-builtin            Disable implicit builtin knowledge of functions
  -fno-common             Compile common globals like normal definitions
  -fno-constant-cfstrings Disable creation of CodeFoundation-type constant strings
  -fno-diagnostics-fixit-info
                          Do not include fixit information in diagnostics
  -fno-diagnostics-show-note-include-stack
                          Display include stacks for diagnostic notes
  -fno-dollars-in-identifiers
                          Disallow '$' in identifiers
  -fno-elide-constructors Disable C++ copy constructor elision
  -fno-elide-type         Do not elide types when printing diagnostics
  -fno-lax-vector-conversions
			  Disallow implicit conversions between vectors with a
			  different number of elements or different element
			  types
  -fno-limit-debug-info   Do not limit debug information produced to reduce
			  size of debug binary
  -fno-merge-all-constants
                          Disallow merging of constants
  -fno-objc-infer-related-result-type
			  do not infer Objective-C related result type based on
			  method family
  -fno-operator-names     Do not treat C++ operator name keywords as synonyms
			  for operators
  -fno-rtti               Disable generation of rtti information
  -fno-sanitize-blacklist Don't use blacklist file for sanitizers
  -fno-sanitize-recover   Disable sanitizer check recovery
  -fno-show-column        Do not include column number on diagnostics
  -fno-show-source-location
			  Do not include source location information with
			  diagnostics
  -fno-spell-checking     Disable spell-checking
  -fno-threadsafe-statics Do not emit code to make initialization of local
			  statics thread safe
  -fno-use-cxa-atexit     Don't use __cxa_atexit for calling destructors
  -fno-use-init-array     Don't use .init_array instead of .ctors
  -fobjc-arc-exceptions   Use EH-safe code when synthesizing retains and
			  releases in -fobjc-arc
  -fobjc-arc              Synthesize retain and release calls for Objective-C
			  pointers
  -fobjc-exceptions       Enable Objective-C exceptions
  -fobjc-gc-only          Use GC exclusively for Objective-C related memory
			  management
  -fobjc-gc               Enable Objective-C garbage collection
  -fobjc-runtime=<value>  Specify the target Objective-C runtime kind and
			  version
  -fpack-struct=<value>   Specify the default maximum struct packing alignment
  -fpascal-strings        Recognize and construct Pascal-style string literals
  -fsanitize-address-zero-base-shadow
			  Make AddressSanitizer map shadow memory at zero
			  offset
  -fsanitize-blacklist=<value>
                          Path to blacklist file for sanitizers
  -fsanitize-memory-track-origins
                          Enable origins tracking in MemorySanitizer
  -fsanitize=<check>      Enable runtime instrumentation for bug detection:
			  address (memory errors) | thread (race detection) |
			  undefined (miscellaneous undefined behavior)
  -fshort-enums           Allocate to an enum type only as many bytes as it
			  needs for the declared range of possible values
  -fshort-wchar           Force wchar_t to be a short unsigned int
  -fshow-overloads=<value>
			  Which overload candidates to show when overload
			  resolution fails: best|all; defaults to all
  -fslp-vectorize-aggressive
                          Enable the BB vectorization passes
  -fslp-vectorize         Enable the superword-level parallelism vectorization
			  passes
  -fstrict-enums          Enable optimizations based on the strict definition
			  of an enum's value range
  -ftrap-function=<value> Issue call to specified function rather than a trap
			  instruction
  -ftrapv-handler=<function name>
                          Specify the function to be called on overflow
  -ftrapv                 Trap on integer overflow
  -funroll-loops          Turn on loop unroller
  -fuse-init-array        Use .init_array instead of .ctors
  -fvectorize             Enable the loop vectorization passes
  -fvisibility-inlines-hidden
			  Give inline C++ member functions default visibility
			  by default
  -fvisibility-ms-compat  Give global types 'default' visibility and global
			  functions and variables 'hidden' visibility by default
  -fvisibility=<value>    Set the default symbol visibility for all global
			  declarations
  -fwrapv                 Treat signed integer overflow as two's complement
  -fwritable-strings      Store string literals as writable data
  -gcc-toolchain <value>  Use the gcc toolchain at the given directory
  -gline-tables-only      Emit debug line number tables only
  -g                      Generate source level debug information
  -help                   Display available options
  -idirafter <value>      Add directory to AFTER include search path
  -iframework <value>     Add directory to SYSTEM framework search path
  -imacros <file>         Include macros from file before parsing
  -include-pch <file>     Include precompiled header file
  -include <file>         Include file before parsing
  -index-header-map       Make the next included directory (-I or -F) an
			  indexer header map
  -iprefix <dir>          Set the -iwithprefix/-iwithprefixbefore prefix
  -iquote <directory>     Add directory to QUOTE include search path
  -isysroot <dir>         Set the system root directory (usually /)
  -isystem <directory>    Add directory to SYSTEM include search path
  -iwithprefixbefore <dir>
                          Set directory to include search path with prefix
  -iwithprefix <dir>      Set directory to SYSTEM include search path with
			  prefix
  -iwithsysroot <directory>
			  Add directory to SYSTEM include search path, absolute
			  paths are relative to -isysroot
  --migrate               Run the migrator
  -mllvm <value>          Additional arguments to forward to LLVM's option
			  processing
  -mms-bitfields          Set the default structure layout to be compatible
			  with the Microsoft compiler standard
  -mno-global-merge       Disable merging of globals
  -mno-implicit-float     Don't generate implicit floating point instructions
  -momit-leaf-frame-pointer
                          Omit frame pointer setup for leaf functions
  -mqdsp6-compat          Enable hexagon-qdsp6 backward compatibility
  -mrelax-all             (integrated-as) Relax all machine instructions
  -mrtd                   Make StdCall calling convention the default
  -msoft-float            Use software floating point
  -mstack-alignment=<value>
                          Set the stack alignment
  -mstackrealign          Force realign the stack at entry to every function
  -mstrict-align          Force all memory accesses to be aligned (ARM only)
  -nobuiltininc           Disable builtin #include directories
  -nostdinc++             Disable standard #include directories for the C++
			  standard library
  -objcmt-migrate-literals
                          Enable migration to modern ObjC literals
  -objcmt-migrate-subscripting
                          Enable migration to modern ObjC subscripting
  -o <file>               Write output to <file>
  -pg                     Enable mcount instrumentation
  -pipe                   Use pipes between commands, when possible
  -print-file-name=<file> Print the full library path of <file>
  -print-ivar-layout      Enable Objective-C Ivar layout bitmap print trace
  -print-libgcc-file-name Print the library path for "libgcc.a"
  -print-prog-name=<name> Print the full program path of <name>
  -print-search-dirs      Print the paths used for finding libraries and
			  programs
  -pthread                Support POSIX threads in generated code
  -rewrite-legacy-objc    Rewrite Legacy Objective-C source to C++
  -rewrite-objc           Rewrite Objective-C source to C++
  -save-temps             Save intermediate compilation results
  -serialize-diagnostics <value>
                          Serialize compiler diagnostics to a file
  -std=<value>            Language standard to compile for
  -stdlib=<value>         C++ standard library to use
  -target <value>         Generate code for the given target
  -time                   Time individual commands
  -traditional-cpp        Enable some traditional CPP emulation
  -trigraphs              Process trigraph sequences
  -undef                  undef all system defines
  -verify                 Verify output using a verifier
  -v                      Show commands to run and use verbose output
  -working-directory <value>
			  Resolve file paths relative to the specified
			  directory
  -w                      Suppress all warnings
  -x <language>           Treat subsequent input files as having type <language>

コンパイル時の詳細を表示する例

コンパイル時のclang++コマンドの詳細は、-v オプションで表示できます。

掲載上の関係で「改行」を追加しています。

$ clang++ -v unnamed_namespace1.cpp
FreeBSD clang version 3.3 (tags/RELEASE_33/final 183502) 20130610
Target: x86_64-unknown-freebsd10.0
Thread model: posix
 "/usr/bin/clang++" -cc1 -triple x86_64-unknown-freebsd10.0 -emit-obj
 -mrelax-all -disable-free -disable-llvm-verifier -main-file-name
 unnamed_namespace1.cpp -mrelocation-model static -mdisable-fp-elim
 -masm-verbose -mconstructor-aliases -munwind-tables -target-cpu x86-64 -v
 -resource-dir /usr/bin/../lib/clang/3.3 -internal-isystem /usr/include/c++/v1
 -fdeprecated-macro -fdebug-compilation-dir
 /home/kaworu/p/cpp/std/namespace/unnamed_namespace -ferror-limit 19
 -fmessage-length 80 -mstackrealign -fobjc-runtime=gnustep
 -fobjc-default-synthesize-properties -fcxx-exceptions -fexceptions
 -fdiagnostics-show-option -fcolor-diagnostics -backend-option
 -vectorize-loops -o /tmp/unnamed_namespace1-GBn6GL.o -x c++
 unnamed_namespace1.cpp
 
clang -cc1 version 3.3 based upon LLVM 3.3 default target x86_64-unknown-freebsd10.0
ignoring nonexistent directory "/usr/include/c++/4.2/backward/backward"
ignoring nonexistent directory "/usr/bin/../lib/clang/3.3/include"
ignoring duplicate directory "/usr/include/c++/4.2"
ignoring duplicate directory "/usr/include/c++/4.2/backward"
ignoring duplicate directory "/usr/include/c++/4.2/backward"
#include "..." search starts here:
#include <...> search starts here:
 /usr/include/c++/v1
 /usr/include/c++/4.2
 /usr/include/c++/4.2/backward
 /usr/include/clang/3.3
 /usr/include
End of search list.
 
 "/usr/bin/ld" --eh-frame-hdr -dynamic-linker /libexec/ld-elf.so.1
 --hash-style=both --enable-new-dtags -o a.out /usr/lib/crt1.o /usr/lib/crti.o
 /usr/lib/crtbegin.o -L/usr/lib /tmp/unnamed_namespace1-GBn6GL.o -lc++ -lm
 -lgcc --as-needed -lgcc_s --no-as-needed -lc -lgcc --as-needed -lgcc_s
 --no-as-needed /usr/lib/crtend.o /usr/lib/crtn.o