C++ Support in Clang

Last updated: $Date: 2009-10-30 15:54:38 +0100 (Fri, 30 Oct 2009) $

This page tracks the status of C++ support in Clang.
Currently most of the C++ features are missing; here you can find features that are at least partially supported in Clang. If you are looking to get involved with Clang development to help work on support for C++, please also look at our Open Projects page for some specific ideas.

The following table is used to help track our implementation progress toward implementing the complete C++03 standard. We use a simple, somewhat arbitrary color-coding scheme to describe the relative completeness of features by section:

Not started/not evaluated Not Applicable Broken Some examples work Many examples work Nearly everything works Complete Complete (with tests for each paragraph)
N/A ✓

A feature is "complete" when the appropriate Clang component (Parse, AST, Sema, CodeGen) implements the behavior described in all of the paragraphs in the relevant C++ standard. Note that many C++ features are actually described in several different sections within the standard. The major components are:

Parse
Clang is able to parse the grammar of this feature (or the grammar described by this section), but does not necessarily do anything with the parsed result. Use Clang's -fsyntax-only option to parse C++ programs.
AST
Clang builds an abstract syntax tree (AST) for the feature, but does not necessarily perform any type-checking. Use Clang's -ast-print option to print the resulting ASTs.
Sema
Clang parses and type-checks this feature and provides a well-formed AST annotated with types. Use Clang's -fsyntax-only to type-check code.
CodeGen
Clang parses, type-checks, and generates code for this feature, allowing one to compile and execute programs.

Updates to this table are welcome! Since Clang already supports much of C, and therefore much C++, many of the currently-white cells could be filled in. If you wish to do so, please compare Clang's implementation against the C++ standard and provide a patch that updates the table accordingly. Tests for the various features are also welcome!

Section Parse AST Sema CodeGen Notes
2 [lex] N/A N/A N/A
  2.1 [lex.phases] N/A N/A N/A Extended characters aren't handled.
  2.2 [lex.charset] N/A N/A N/A No support for extended characters.
  2.3 [lex.trigraph] N/A N/A N/A
  2.4 [lex.pptoken] N/A N/A N/A
  2.5 [lex.digraph] N/A N/A N/A
  2.6 [lex.token] N/A N/A N/A
  2.7 [lex.comment] N/A N/A NDR "form feed or vtab in comment" is not diagnosed. No AST representation of comments.
  2.8 [lex.header] N/A N/A N/A
  2.9 [lex.ppnumber] N/A N/A N/A
  2.10 [lex.name] N/A N/A N/A No support for extended characters
  2.11 [lex.key] N/A N/A N/A
  2.12 [lex.operators] N/A N/A N/A
  2.13 [lex.literal] N/A N/A N/A
    2.13.1 [lex.icon] N/A N/A N/A
    2.13.2 [lex.ccon] N/A N/A N/A Poor support for extended characters
    2.13.3 [lex.fcon] N/A N/A N/A
    2.13.4 [lex.string] N/A N/A N/A Poor support for extended characters
    2.13.5 [lex.bool] N/A N/A N/A
3 [basic] N/A N/A N/A N/A
  3.1 [basic.def] N/A
  3.2 [basic.def.odr]
  3.3 [basic.scope] N/A N/A N/A
    3.3.1 [basic.scope.pdecl] N/A N/A N/A
    3.3.2 [basic.scope.local] N/A N/A N/A
    3.3.3 [basic.scope.proto] N/A N/A N/A
    3.3.4 [basic.funscope] N/A N/A N/A
    3.3.5 [basic.scope.namespace] N/A N/A N/A
    3.3.6 [basic.scope.class] N/A N/A N/A Does not check that reordering the members of a class maintains semantics.
    3.3.7 [basic.scope.hiding] N/A N/A N/A
  3.4 [basic.lookup] N/A N/A N/A
    3.4.1 [basic.lookup.unqual] N/A N/A N/A
    3.4.2 [basic.lookup.argdep] N/A N/A N/A
    3.4.3 [basic.lookup.qual] N/A N/A N/A
      3.4.3.1 [class.qual] N/A N/A N/A
      3.4.3.2 [namespace.qual] N/A N/A N/A
    3.4.4 [basic.lookup.elab]
    3.4.5 [basic.lookup.classref] N/A N/A N/A Missing ambiguity/consistency checks for paragraphs 3 (~type-name) and 7 (conversion-type-id)
    3.4.6 [basic.lookup.udir] N/A N/A N/A
  3.5 [basic.link]
  3.6 [basic.start]
    3.6.1 [basic.start.main]
    3.6.2 [basic.start.init]
    3.6.3 [basic.start.term]
  3.7 [basic.stc]
    3.7.1 [basic.stc.static]
    3.7.2 [basic.stc.auto]
    3.7.3 [basic.stc.dynamic]
      3.7.3.1 [basic.stc.dynamic.allocation]
      3.7.3.2 [basic.stc.dynamic.deallocation]
    3.7.4 [basic.stc.inherit]
  3.8 [basic.life]
  3.9 [basic.types]
    3.9.1 [basic.fundamental]
    3.9.2 [basic.compound]
    3.9.3 [basic.type.qualifier]
  3.10 [basic.lval]
4 [conv]
  4.1 [conv.lval]
  4.2 [conv.array]
  4.3 [conv.func]
  4.4 [conv.qual]
  4.5 [conv.prom]
  4.6 [conv.fpprom]
  4.7 [conv.integral]
  4.8 [conv.double]
  4.9 [conv.fpint]
  4.10 [conv.ptr]
  4.11 [conv.mem]
  4.12 [conv.bool]
5 [expr] N/A N/A ✓ N/A
  5.1 [expr.prim] cannot parse operator-function-ids that have explicit template argument lists
  5.2 [expr.post]
    5.2.1 [expr.sub]
    5.2.2 [expr.call]
    5.2.3 [expr.type.conv]
    5.2.4 [expr.pseudo]
    5.2.5 [expr.ref]
    5.2.6 [expr.post.incr]
    5.2.7 [expr.dynamic.cast]
    5.2.8 [expr.typeid]
    5.2.9 [expr.static.cast]
    5.2.10 [expr.reinterpret.cast]
    5.2.11 [expr.const.cast]
  5.3 [expr.unary]
    5.3.1 [expr.unary.op]
      5.3.1p1 Unary *
      5.3.1p2-5 Unary &
      5.3.1p6 Unary +
      5.3.1p7 Unary -
      5.3.1p8 Unary !
      5.3.1p9 Unary ~
    5.3.2 [expr.pre.incr]
    5.3.3 [expr.sizeof]
    5.3.4 [expr.new] operator delete is not looked up, initialization not quite correct
    5.3.5 [expr.delete]
  5.4 [expr.cast]
  5.5 [expr.mptr.oper] Dereferenced member function pointers have the wrong type(see FIXME in CheckPointerToMemberOperands).
  5.6 [expr.mul]
  5.7 [expr.add]
  5.8 [expr.shift]
  5.9 [expr.rel]
  5.10 [expr.eq]
  5.11 [expr.bit.and]
  5.12 [expr.xor]
  5.13 [expr.or]
  5.14 [expr.log.and]
  5.15 [expr.log.or]
  5.16 [expr.cond] some invalid hierarchy casts still accepted, but that's a general problem
  5.17 [expr.ass]
  5.18 [expr.comma]
  5.19 [expr.const] Uses C semantics
6 [stmt.stmt]
  6.1 [stmt.label]
  6.2 [stmt.expr]
  6.3 [stmt.block]
  6.4 [stmt.select] Conversion of declarations to required types not really supported.
    6.4.1 [stmt.if]
    6.4.2 [stmt.switch]
  6.5 [stmt.iter] Conversion of declarations to required types not really supported.
    6.5.1 [stmt.while]
    6.5.2 [stmt.do]
    6.5.3 [stmt.for]
  6.6 [stmt.jump]
    6.6.1 [stmt.break]
    6.6.2 [stmt.cont]
    6.6.3 [stmt.return]
    6.6.4 [stmt.goto]
  6.7 [stmt.dcl] Existence and accessibility of destructors is not tested for.
  6.8 [stmt.ambig]
7 [dcl.dcl]
  7.1 [dcl.spec]
    7.1.1 [dcl.stc] Linkage merging has some errors.
    7.1.2 [dcl.fct.spec]
    7.1.3 [dcl.typedef]
    7.1.4 [dcl.friend]
    7.1.5 [dcl.type]
      7.1.5.1 [dcl.type.cv]
      7.1.5.2 [dcl.type.simple]
      7.1.5.3 [dcl.type.elab]
  7.2 [dcl.enum]
  7.3 [basic.namespace]
    7.3.1 [namespace.def]
      7.3.1.1 [namespace.unnamed] Unnamed namespace members cannot be looked up.
      7.3.1.2 [namespace.memdef]
    7.3.2 [namespace.alias] N/A
    7.3.3 [namespace.udecl]
    7.3.4[namespace.udir] Example in p4 fails.
  7.4 [dcl.asm]
  7.5 [dcl.link]
8 [dcl.decl]
  8.1 [dcl.name] N/A
  8.2 [dcl.ambig.res] ✓ N/A ✓ N/A
  8.3 [dcl.meaning] N/A
    8.3.1 [dcl.ptr] N/A
    8.3.2 [dcl.ref] N/A
    8.3.3 [dcl.mptr] N/A
    8.3.4 [dcl.array] N/A
    8.3.5 [dcl.fct] N/A
    8.3.6 [dcl.fct.default] N/A Partial support for default arguments of templates.
  8.4 [dcl.fct.def]
  8.5 [dcl.init]
    8.5.1[dcl.init.aggr] No CodeGen for dynamic initialization.
    8.5.2[dcl.init.string]
    8.5.3 [dcl.init.ref]
9 [class]
  9.1 [class.name] N/A
  9.2 [class.mem] Basic parser support for using declarations.
  9.3 [class.mfct]
    9.3.1 [class.mfct.non-static]
    9.3.2 [class.this]
  9.4 [class.static]
    9.4.1 [class.static.mfct]
    9.4.2 [class.static.data]
  9.5 [class.union]
  9.6 [class.bit]
  9.7 [class.nest] N/A
  9.8 [class.local] ✓ ✓ ✓ N/A
  9.9 [class.nested.type] ✓ ✓ ✓ N/A
10 [class.derived]
  10.1 [class.mi]
  10.2 [class.member.lookup] N/A
  10.3 [class.virtual] Basic layout of classes with virtual functions.
  10.4 [class.abstract] N/A
11 [class.access] N/A
  11.1 [class.access.spec] N/A
  11.2 [class.access.base] N/A
  11.3 [class.access.dcl] N/A
  11.4 [class.friend] N/A
  11.5 [class.protected] N/A
  11.6 [class.access.virt] N/A
  11.7 [class.paths] N/A
  11.8 [class.access.nest] N/A
12 [special]
  12.1 [class.ctor] Most of the semantics of constructors are implemented.
  12.2 [class.temporary] N/A Implementation of temporary objects is in its initial stages.
  12.3 [class.conv]
    12.3.1 [class.conv.ctor]
    12.3.2 [class.conv.fct]
  12.4 [class.dtor] Most of the semantics of destructors are implemented.
  12.5 [class.free]
  12.6 [class.init]
    12.6.1 [class.expl.init]
    12.6.2 [class.base.init] Most of the semantics of base initializations are implemented.
  12.7 [class.cdtor]
  12.8 [class.copy] Most of the semantics of copy constructors are implemented.
13 [over]
  13.1 [over.load] N/A
  13.2 [over.dcl] N/A N/A
  13.3 [over.match] N/A N/A
    13.3.1 [over.match.funcs] N/A N/A
      13.3.1.1 [over.match.call] N/A N/A
        13.3.1.1.1 [over.call.func] N/A N/A
        13.3.1.1.2 [over.call.object] N/A N/A
      13.3.1.2 [over.match.oper] N/A N/A
      13.3.1.3 [over.match.ctor] N/A N/A
      13.3.1.4 [over.match.copy] N/A N/A
      13.3.1.5 [over.match.conv] N/A N/A
      13.3.1.6 [over.match.ref] N/A N/A
    13.3.2 [over.match.viable] N/A N/A
    13.3.3 [over.match.best] N/A N/A
      13.3.3.1 [over.best.ics] N/A N/A
        13.3.3.1.1 [over.ics.scs] N/A N/A
        13.3.3.1.2 [over.ics.user] N/A N/A
        13.3.3.1.3 [over.ics.ellipsis] N/A N/A
        13.3.3.1.4 [over.ics.ref] N/A N/A
      13.3.3.2 [over.ics.rank] N/A N/A
  13.4 [over.over] N/A N/A
  13.5 [over.oper] N/A
    13.5.1 [over.unary] N/A N/A
    13.5.2 [over.binary] N/A N/A
    13.5.3 [over.ass] N/A N/A
    13.5.4 [over.call] N/A N/A
    13.5.5 [over.sub] N/A N/A
    13.5.6 [over.ref] N/A N/A
    13.5.7 [over.inc] N/A N/A
  13.6 [over.built] N/A N/A Missing support for the ternary operator (p24, p25).
14 [temp]
  14.1 [temp.param] ✓ ✓ N/A Template template parameters cannot actually be used in templates
  14.2 [temp.names] N/A
  14.3 [temp.arg] N/A
    14.3.1 [temp.arg.type] ✓ ✓ N/A Paragraph 3 will be tested elsewhere
    14.3.2 [temp.arg.nontype] N/A
    14.3.3 [temp.arg.template] N/A
  14.4 [temp.type] N/A ✓ ✓ N/A
  14.5 [temp.decls]
    14.5.1 [temp.class]
      14.5.1.1 [temp.mem.func]
      14.5.1.2 [temp.mem.class]
      14.5.1.3 [temp.static]
    14.5.2 [temp.mem]
    14.5.3 [temp.friend] N/A
    14.5.4 [temp.class.spec] N/A
      14.5.4.1 [temp.class.spec.match] N/A N/A N/A
      14.5.4.2 [temp.class.order] N/A
      14.5.5.3 [temp.class.spec.mfunc] N/A
    14.5.5 [temp.fct]
      14.5.5.1 [temp.over.link] N/A
      14.5.5.2 [temp.func.order] N/A
  14.6 [temp.res]
    14.6.1 [temp.local]
    14.6.2 [temp.dep] N/A
      14.6.2.1 [temp.dep.type] N/A
      14.6.2.2 [temp.dep.expr] N/A
      14.6.2.3 [temp.dep.constexpr] N/A
      14.6.2.4 [temp.dep.temp] N/A
    14.6.3 [temp.nondep] N/A
    14.6.4 [temp.dep.res] N/A
      14.6.4.1 [temp.point] N/A
      14.6.4.2 [temp.dep.candidate] N/A Not restricted to functions with external linkage
    14.6.5 [temp.inject] N/A
  14.7 [temp.spec]
    14.7.1 [temp.inst] N/A
    14.7.2 [temp.explicit] Cannot test paragraph 11 until access control is implemented.
ASTs do not carry enough information to reproduce source code accurately.
    14.7.3 [temp.expl.spec] ✓ ✓ ASTs do not carry enough information to reproduce source code accurately
  14.8 [temp.fct.spec]
    14.8.1 [temp.arg.explicit]
    14.8.2 [temp.deduct] N/A N/A N/A
      14.8.2.1 [temp.deduct.call]
      14.8.2.2 [temp.deduct.funcaddr] N/A N/A
      14.8.2.3 [temp.deduct.conv]
      14.8.2.4 [temp.deduct.type] N/A N/A
    14.8.3 [temp.over]
15 [except]
  15.1 [except.throw] N/A N/A Does not check for existence of copy constructor and destructor, and some other details
  15.2 [except.ctor] N/A N/A N/A
  15.3 [except.handle] N/A N/A Not all constraints are checked
  15.4 [except.spec]
  15.5 [except.special] N/A N/A N/A N/A
    15.5.1 [except.terminate] N/A N/A N/A N/A
    15.5.2 [except.unexpected] N/A N/A N/A N/A
    15.5.3 [except.uncaught] N/A N/A N/A N/A
  15.6 [except.access] N/A N/A N/A N/A Redundant - struck from C++0x
16 [cpp]
  16.1 [cpp.cond]
  16.2 [cpp.include]
  16.3 [cpp.replace]
    16.3.1 [cpp.subst]
    16.3.2 [cpp.stringize]
    16.3.3 [cpp.concat]
    16.3.4 [cpp.rescan]
    16.3.5 [cpp.scope]
  16.4 [cpp.line]
  16.5 [cpp.error]
  16.6 [cpp.pragma]
  16.7 [cpp.null]
  16.8 [cpp.predefined]
A [gram]
  A.1 [gram.key]
  A.2 [gram.lex]
  A.3 [gram.basic]
  A.4 [gram.expr]
  A.5 [gram.stmt]
  A.6 [gram.dcl]
  A.7 [gram.decl]
  A.8 [gram.class]
  A.9 [gram.derived]
  A.10 [gram.special]
  A.11 [gram.over]
  A.12 [gram.temp]
  A.13 [gram.except]
  A.14 [gram.cpp]
B [implimits]
C [diff]
  C.1 [diff.iso]
    C.1.1 [diff.lex]
    C.1.2 [diff.basic]
    C.1.3 [diff.expr]
    C.1.4 [diff.stat]
    C.1.5 [diff.dcl]
    C.1.6 [diff.decl]
    C.1.7 [diff.class]
    C.1.8 [diff.special]
    C.1.9 [diff.cpp]
  C.2 [diff.library]
    C.2.1 [diff.mods.to.headers]
    C.2.2 [diff.mods.to.definitions]
      C.2.2.2 [diff.wchar.t]
      C.2.2.3 [diff.header.iso646.h]
      C.2.2.4 [diff.null]
    C.2.3 [diff.mods.to.declarations]
    C.2.4 [diff.mods.to.behavior]
      C.2.4.1 [diff.offsetof]
      C.2.4.2 [diff.malloc]
D [depr]
  D.1 [depr.incr.bool]
  D.2 [depr.static]
  D.3 [depr.access.dcl]
  D.4 [depr.string]
  D.5 [depr.c.headers]
E [extendid]
C++0x Features
Explicit conversion operators (N2437) No name mangling; ASTs don't contain calls to conversion operators
Static assertions (N1720) N/A
Deleted functions (N2346) N/A
Rvalue references (N2118 + N2831)
nullptr (N2431)
Right angle brackets (N1757) N/A N/A N/A
Decltype (N2343) ✓ ✓ ✓ N/A