[std] Add Annex for undefined and IFNDR behavior

Author: jensmaurer

source/basic.tex

@@ -645,7 +645,7 @@
 \pnum
 Every program shall contain at least one definition of every
 function or variable that is odr-used in that program
-outside of a discarded statement\iref{stmt.if}; no diagnostic required.
+outside of a discarded statement\iref{stmt.if}; no diagnostic required\ifndrdef{basic.def.odr.exact.one.def}.
 The definition can appear explicitly in the program, it can be found in
 the standard or a user-defined library, or (when appropriate) it is
 implicitly defined (see~\ref{class.default.ctor}, \ref{class.copy.ctor},
@@ -928,7 +928,7 @@
 reachable unnamed enumeration definition in the same scope
 that have the same first enumerator name and
 do not have typedef names for linkage purposes\iref{dcl.enum},
-those unnamed enumeration types shall be the same; no diagnostic required.
+those unnamed enumeration types shall be the same; no diagnostic required\ifndrdef{basic.def.odr.unnamed.enum.same.type}.
 \indextext{one-definition rule|)}
 
 \rSec1[basic.scope]{Scope}%
@@ -1803,7 +1803,7 @@
 If it is an invalid set, the program is ill-formed.
 If it differs from the result of a search in $T$ for $M$
 in a complete-class context\iref{class.mem} of $T$,
-the program is ill-formed, no diagnostic required.
+the program is ill-formed, no diagnostic required\ifndrdef{class.member.lookup.name.refers.diff.decl}.
 \begin{example}
 \begin{codeblock}
 struct A { int x; };                    // S(x,A) = \{ \{ \tcode{A::x} \}, \{ \tcode{A} \} \}
@@ -3662,7 +3662,7 @@
 zero or more objects of implicit-lifetime types\iref{term.implicit.lifetime.type}
 in its specified region of storage
 if doing so would result in the program having defined behavior.
-If no such set of objects would give the program defined behavior,
+If no such set of objects would give the program defined behavior\ubdef{intro.object.implicit.create},
 the behavior of the program is undefined.
 If multiple such sets of objects would give the program defined behavior,
 it is unspecified which such set of objects is created.
@@ -3924,7 +3924,7 @@
 if the pointer were of type \tcode{\keyword{void}*} is
 well-defined. Indirection through such a pointer is permitted but the resulting lvalue may only be used in
 limited ways, as described below. The
-program has undefined behavior if
+program has undefined behavior\ubdef{lifetime.outside.pointer} if:
 \begin{itemize}
 \item
   the pointer is used as the operand of a \grammarterm{delete-expression},
@@ -3987,7 +3987,7 @@
 a glvalue refers to
 allocated storage\iref{basic.stc.dynamic.allocation}, and using the
 properties of the glvalue that do not depend on its value is
-well-defined. The program has undefined behavior if
+well-defined. The program has undefined behavior\ubdef{lifetime.outside.glvalue} if:
 \begin{itemize}
 \item the glvalue is used to access the object, or
 \item the glvalue is used to call a non-static member function of the object, or
@@ -4077,7 +4077,7 @@
 \end{footnote}
 and another object of the original type does not occupy
 that same storage location when the implicit destructor call takes
-place, the behavior of the program is undefined. This is true
+place, the behavior of the program is undefined\ubdef{original.type.implicit.destructor}. This is true
 even if the block is exited with an exception.
 \begin{example}
 \begin{codeblock}
@@ -4097,7 +4097,7 @@
 Creating a new object within the storage that a const, complete
 object with static, thread, or automatic storage duration occupies,
 or within the storage that such a const object used to occupy before
-its lifetime ended, results in undefined behavior.
+its lifetime ended, results in undefined behavior\ubdef{creating.within.const.complete.obj}.
 \begin{example}
 \begin{codeblock}
 struct B {
@@ -4436,7 +4436,7 @@
 does not satisfy the semantic constraints
 specified in~\ref{basic.stc.dynamic.allocation}
 and~\ref{basic.stc.dynamic.deallocation},
-the behavior is undefined.
+the behavior is undefined\ubdef{basic.stc.alloc.dealloc.constraint}.
 
 \indextext{storage duration!dynamic|)}
 
@@ -6445,7 +6445,7 @@
 The value computations of the operands of an
 operator are sequenced before the value computation of the result of the
 operator.
-The behavior is undefined if
+The behavior is undefined\iref{intro.multithread}\ubdef{intro.execution.unsequenced.modification} if
 \begin{itemize}
 \item
 \indextext{side effects}%
@@ -6853,7 +6853,7 @@
 and neither happens before the other,
 except for the special case for signal handlers described below.
 Any such data race results in undefined
-behavior.
+behavior\ubdef{intro.races.data}.
 \begin{note}
 It can be shown that programs that correctly use mutexes
 and \tcode{memory_order::seq_cst} operations to prevent all data races and use no
@@ -7219,7 +7219,7 @@
 objects with automatic storage duration\iref{class.dtor}. If
 \tcode{std::exit} is invoked during the destruction of
 an object with static or thread storage duration, the program has undefined
-behavior.
+behavior\ubdef{basic.start.main.exit.during.destruction}.
 
 \pnum
 \indextext{termination!program}%
@@ -7513,7 +7513,7 @@
 \pnum
 If a function contains a block variable of static or thread storage duration that has been
 destroyed and the function is called during the destruction of an object with static or
-thread storage duration, the program has undefined behavior if the flow of control
+thread storage duration, the program has undefined behavior\ubdef{basic.start.term.use.after.destruction} if the flow of control
 passes through the definition of the previously destroyed block variable.
 \begin{note}
 Likewise, the behavior is undefined
@@ -7540,7 +7540,7 @@
 handlers\iref{support.runtime} that does not happen before\iref{intro.multithread}
 completion of destruction of objects with static storage duration and execution of
 \tcode{std::atexit} registered functions\iref{support.start.term}, the program has
-undefined behavior.
+undefined behavior\ubdef{basic.start.term.signal.handler}.
 \begin{note}
 If there is a use of an object with static storage
 duration that does not happen before the object's destruction, the program has undefined

source/classes.tex

@@ -2341,7 +2341,7 @@
 that is, if the object is not of the destructor's class type and
 not of a class derived from the destructor's class type (including when
 the destructor is invoked via a null pointer value), the program has
-undefined behavior.
+undefined behavior\ubdef{class.dtor.not.class.type}.
 \begin{note}
 Invoking \keyword{delete} on a null pointer does not call the
 destructor; see \ref{expr.delete}.
@@ -2408,7 +2408,7 @@
 
 \pnum
 Once a destructor is invoked for an object, the object's lifetime ends;
-the behavior is undefined if the destructor is invoked
+the behavior is undefined\ubdef{class.dtor.no.longer.exists} if the destructor is invoked
 for an object whose lifetime has ended\iref{basic.life}.
 \begin{example}
 If the destructor for an object with automatic storage duration is explicitly invoked,
@@ -3289,7 +3289,7 @@
 each anonymous union member \tcode{X}\iref{class.union.anon} that
 is a member of a union and
 has such an element as an immediate subobject (recursively),
-if modification of \tcode{X} would have undefined behavior under~\ref{basic.life},
+if modification of \tcode{X} would have undefined behavior\ubdef{class.union.assignment.not.start.lifetime} under~\ref{basic.life},
 an object of the type of \tcode{X} is implicitly created
 in the nominated storage;
 no initialization is performed and
@@ -4076,7 +4076,7 @@
 \indextext{definition!virtual function}%
 A virtual function declared in a class shall be defined, or declared
 pure\iref{class.abstract} in that class, or both; no diagnostic is
-required\iref{basic.def.odr}.
+required\iref{basic.def.odr}\ifndrdef{class.virtual.pure.or.defined}.
 \indextext{friend!\tcode{virtual} and}%
 
 \pnum
@@ -4309,7 +4309,7 @@
 \indextext{virtual function call!undefined pure}%
 the effect of making a virtual call\iref{class.virtual} to a pure
 virtual function directly or indirectly for the object being created (or
-destroyed) from such a constructor (or destructor) is undefined.%
+destroyed) from such a constructor (or destructor) is undefined\ubdef{class.abstract.pure.virtual}.%
 \indextext{derived class|)}
 
 \rSec1[class.access]{Member access control}%
@@ -5591,7 +5591,7 @@
 The target constructor is selected by overload resolution.
 Once the target constructor returns, the body of the delegating constructor
 is executed. If a constructor delegates to itself directly or indirectly,
-the program is ill-formed, no diagnostic required.
+the program is ill-formed, no diagnostic required\ifndrdef{class.base.init.delegate.itself}.
 \begin{example}
 \begin{codeblock}
 struct C {
@@ -5906,7 +5906,7 @@
 \item
 a postcondition assertion of a destructor\iref{dcl.contract.func},
 \end{itemize}
-the program has undefined behavior.
+the program has undefined behavior\ubdef{class.base.init.mem.fun}.
 \begin{example}
 \begin{codeblock}
 class A {
@@ -6103,9 +6103,9 @@
 \indextext{destruction!member access}%
 For an object with a non-trivial constructor, referring to any non-static member
 or base class of the object before the constructor begins execution results in
-undefined behavior. For an object with a non-trivial destructor, referring to
+undefined behavior\ubdef{class.cdtor.before.ctor.after.dtor}. For an object with a non-trivial destructor, referring to
 any non-static member or base class of the object after the destructor finishes
-execution results in undefined behavior.
+execution results in undefined behavior\ubdef{class.cdtor.before.ctor.after.dtor}.
 \begin{example}
 \begin{codeblock}
 struct X { int i; };
@@ -6190,15 +6190,15 @@
 indirectly derive from
 \tcode{B}
 shall have started and the destruction of these classes shall not have
-completed, otherwise the conversion results in undefined behavior.
+completed, otherwise the conversion results in undefined behavior\ubdef{class.cdtor.convert.or.form.pointer}.
 To form a pointer to (or access the value of) a direct non-static member of
 an object
 \tcode{obj},
 the construction of
 \tcode{obj}
 shall have started and its destruction shall not have completed,
 otherwise the computation of the pointer value (or accessing the member
-value) results in undefined behavior.
+value) results in undefined behavior\ubdef{class.cdtor.convert.or.form.pointer}.
 \begin{example}
 \begin{codeblock}
 struct A { };
@@ -6242,7 +6242,7 @@
 and the object expression refers to
 the complete object of \tcode{x} or one of that object's base class subobjects
 but not \tcode{x} or one of its base class subobjects, the behavior
-is undefined.
+is undefined\ubdef{class.cdtor.virtual.not.x}.
 \begin{example}
 \begin{codeblock}
 struct V {
@@ -6299,7 +6299,7 @@
 \tcode{typeid}
 refers to the object under construction or destruction and the static type of
 the operand is neither the constructor or destructor's class nor one of its
-bases, the behavior is undefined.
+bases, the behavior is undefined\ubdef{class.cdtor.typeid}.
 
 \pnum
 \indextext{construction!dynamic cast and}%
@@ -6324,7 +6324,7 @@
 the operand is not a pointer to or object of the constructor or destructor's
 own class or one of its bases, the
 \keyword{dynamic_cast}
-results in undefined behavior.
+results in undefined behavior\ubdef{class.cdtor.dynamic.cast}.
 \begin{example}
 \begin{codeblock}
 struct V {

source/declarations.tex

@@ -1304,7 +1304,7 @@
 \indextext{const object!undefined change to}%
 Any attempt to modify\iref{expr.assign,expr.post.incr,expr.pre.incr} a
 const object\iref{basic.type.qualifier} during its
-lifetime\iref{basic.life} results in undefined behavior.
+lifetime\iref{basic.life} results in undefined behavior\ubdef{dcl.type.cv.modify.const.obj}.
 \begin{example}
 \begin{codeblock}
 const int ci = 3;                       // cv-qualified (initialized as required)
@@ -1348,7 +1348,7 @@
 \impldef{semantics of an access through a volatile glvalue}.
 If an attempt is made to access an object defined with a
 volatile-qualified type through the use of a non-volatile glvalue,
-the behavior is undefined.
+the behavior is undefined\ubdef{dcl.type.cv.access.volatile}.
 
 \pnum
 \indextext{type specifier!\idxcode{volatile}}%
@@ -7379,7 +7379,7 @@
 The evaluation that invoked a resumption member function is
 called the \defnx{resumer}{coroutine!resumer}.
 Invoking a resumption member function for a coroutine
-that is not suspended results in undefined behavior.
+that is not suspended results in undefined behavior\ubdef{dcl.fct.def.coroutine.resume.not.suspended}.
 
 \pnum
 An implementation may need to allocate additional storage for a coroutine.
@@ -7473,7 +7473,7 @@
 The storage for the coroutine state is released by calling a
 non-array deallocation function\iref{basic.stc.dynamic.deallocation}.
 If \tcode{destroy} is called for a coroutine that is not suspended, the
-program has undefined behavior.
+program has undefined behavior\ubdef{dcl.fct.def.coroutine.destroy.not.suspended}.
 
 \pnum
 The deallocation function's name is looked up by searching for it in the scope of the promise type.
@@ -9630,7 +9630,7 @@
 \grammarterm{alignment-specifier}{},
 every defining
 declaration of that entity shall specify an equivalent alignment.
-No diagnostic is required if declarations of an entity have
+No diagnostic is required\ifndrdef{dcl.align.diff.translation.units} if declarations of an entity have
 different \grammarterm{alignment-specifier}{s}
 in different translation units.
 \begin{example}
@@ -9684,7 +9684,7 @@
 at the point where the assumption appears,
 the assumption has no effect.
 Otherwise,
-evaluation of the assumption has runtime-undefined behavior.
+evaluation of the assumption has runtime-undefined behavior\ubdef{dcl.attr.assume.false}.
 
 \pnum
 \begin{note}
@@ -10114,12 +10114,12 @@
 specify the \tcode{noreturn} attribute if any declaration of that function specifies the
 \tcode{noreturn} attribute. If a function is declared with the \tcode{noreturn} attribute in one
 translation unit and the same function is declared without the \tcode{noreturn} attribute in another
-translation unit, the program is ill-formed, no diagnostic required.
+translation unit, the program is ill-formed, no diagnostic required\ifndrdef{dcl.attr.noreturn.trans.unit.mismatch}.
 
 \pnum
 If a function \tcode{f} is invoked where \tcode{f} was previously declared with the \tcode{noreturn}
 attribute and that invocation eventually returns,
-the behavior is runtime-undefined.
+the behavior is runtime-undefined\ubdef{dcl.attr.noreturn.eventually.returns}.
 \begin{note}
 The function can
 terminate by throwing an exception.

source/exceptions.tex

@@ -690,7 +690,7 @@
 Referring to any non-static member or base class of an object
 in the handler for a
 \grammarterm{function-try-block}
-of a constructor or destructor for that object results in undefined behavior.
+of a constructor or destructor for that object results in undefined behavior\ubdef{except.handle.handler.ctor.dtor}.
 
 \pnum
 Exceptions thrown in destructors of objects with static storage duration or in