Changed dartLangSpec errors to warnings
Partially resolves issue #34349.
Also note that #34365 and #34319 are affected by this change.
Change-Id: I1d9023464090ff2c07f9dc062353202ddb82ba25
Reviewed-on: https://dart-review.googlesource.com/c/78121
Reviewed-by: Leaf Petersen <leafp@google.com>
diff --git a/docs/language/dartLangSpec.tex b/docs/language/dartLangSpec.tex
index 374d59a..5b453a0 100644
--- a/docs/language/dartLangSpec.tex
+++ b/docs/language/dartLangSpec.tex
@@ -606,8 +606,8 @@
Isolates are created by spawning (\ref{spawningAnIsolate}).
-\section{Errors}
-\LMLabel{errors}
+\section{Errors and Warnings}
+\LMLabel{errorsAndWarnings}
\LMHash{}
This specification distinguishes between several kinds of errors.
@@ -649,6 +649,12 @@
}
\LMHash{}
+{\em Compile-time warnings} are situations that do not preclude execution,
+but which are unlikely to be intended,
+and likely to cause bugs or inconveniences.
+A compile-time warning must be reported by a Dart compiler before the associated code is executed.
+
+\LMHash{}
When this specification says that a {\em run-time error} occurs,
it means that a corresponding error object is thrown.
When it says that a {\em dynamic type error} occurs,
@@ -699,11 +705,11 @@
with the same type and modifiers.
\LMHash{}
-An initialized variable declaration that contains one or more terms of the form
+An \syntax{<initializedVariableDeclaration>} that contains one or more terms of the form
\syntax{<initializedIdentifier>}
-(\commentary{a declaration that declares two or more initialized variables})
+(\commentary{that is, a declaration that declares two or more initialized variables})
is equivalent to multiple variable declarations declaring
-the same set of variable names in the same order,
+the same set of variable names, in the same order,
with the same initialization, type, and modifiers.
\commentary{
@@ -737,7 +743,8 @@
}
\LMHash{}
-An {\em initialized variable} is a variable whose declaring identifier is
+An {\em initializing variable declaration}
+is a variable declaration whose declaring identifier is
immediately followed by `\code{=}' and an {\em initializing expression}.
\LMHash{}
@@ -832,7 +839,8 @@
A mutable instance variable introduces an instance setter into the immediately enclosing class.
\LMHash{}
-Let $v$ be an initialized variable and let $e$ be the associated initializing expression.
+Let $v$ be variable declared in an initializing variable declaration,
+and let $e$ be the associated initializing expression.
It is a compile-time error if the static type of $e$ is not assignable to the declared type of $v$.
It is a compile-time error if a final instance variable whose declaration has an initializer expression
is also initialized by a constructor, either by an initializing formal or an initializer list entry.
@@ -1499,7 +1507,7 @@
\LMHash{}
%% TODO(eernst): We need to use the concept of 'correctly overrides' rather than 'is a subtype of', e.g., to treat `void` correctly.
It is a compile-time error if an instance method $m_1$ overrides an instance member $m_2$ and the type of $m_1$ is not a subtype of the type of $m_2$.
-It is a compile-time error if an instance method $m_1$ overrides an instance member $m_2$, the signature of $m_2$ explicitly specifies a default value for a formal parameter $p$, and the signature of $m_1$ implies a different default value for $p$.
+It is a compile-time warning if an instance method $m_1$ overrides an instance member $m_2$, the signature of $m_2$ explicitly specifies a default value for a formal parameter $p$, and the signature of $m_1$ implies a different default value for $p$.
\commentary{
A method declaration may conflict with other declarations
@@ -1605,7 +1613,7 @@
It is a compile-time error to declare an optional parameter in an operator.
\LMHash{}
-It is a compile-time error if the return type of a user-declared operator
+It is a compile-time warning if the return type of a user-declared operator
\syntax{`[]='}
is explicitly declared and not \VOID{}.
@@ -1993,10 +2001,12 @@
}
\LMHash{}
-It is a compile-time error if a setter declares a return type other than \VOID{}.
+It is a compile-time warning if a setter declares a return type other than \VOID{}.
It is a compile-time error if a setter $m_1$ overrides (\ref{inheritanceAndOverriding}) a setter $m_2$
and the parameter type of $m_1$ is not a supertype of the parameter type of $m_2$.
-It is a compile-time error if a class has a setter named $v=$ with argument type $T$ and a getter named $v$ with return type $S$,
+It is a compile-time warning if a class has
+a setter named $v=$ with argument type $T$ and
+a getter named $v$ with return type $S$,
and $S$ may not be assigned to $T$.
\commentary{
@@ -2358,13 +2368,17 @@
It is a compile-time error if $k$ includes an initializing formal for a final variable $f$ whose declaration includes an initialization expression.
\LMHash{}
-Each final instance variable $f$ declared in the immediately enclosing class must have an initializer in $k$'s initializer list unless it has already been initialized by one of the following means:
+Let $f$ be a final instance variable declared in
+the immediately enclosing class.
+A compile-time error occurs unless $f$ is initialized
+by one of the following means:
\begin{itemize}
-\item Initialization at the declaration of $f$.
-\item Initialization by means of an initializing formal of $k$.
+\item $f$ is declared by an initializing variable declaration.
+\item $f$ is initialized by means of an initializing formal of $k$.
+\item $f$ has an initializer in $k$'s initializer list.
\end{itemize}
-or a compile-time error occurs.
+\LMHash{}
It is a compile-time error if $k$'s initializer list contains an initializer for a variable that is not an instance variable declared in the immediately surrounding class.
\commentary{
@@ -5832,7 +5846,7 @@
It is possible for a running isolate to exhaust its memory or stack, resulting in a run-time error that cannot be effectively caught, which will force the isolate to be suspended.
\commentary{
-As discussed in section \ref{errors}, the handling of a suspended isolate is the responsibility of the embedder.
+As discussed in section \ref{errorsAndWarnings}, the handling of a suspended isolate is the responsibility of the embedder.
}
@@ -7384,8 +7398,8 @@
If no error occurs, the value of the assignment expression is $o$.
\commentary{
-If $v$ is a final variable, a compile-time error has occurred,
-but a type check may cause a dynamic error.
+If $v$ is a final variable, a compile-time error has occurred and execution is unspecified.
+But a program with no compile-time errors may incur a dynamic type error.
}
% add local functions per bug 23218
@@ -8815,9 +8829,11 @@
is \DYNAMIC{}.
\LMHash{}
-Let $v$ be an initialized local variable and let $e$ be the associated initializing expression.
+Let $v$ be a local variable declared by an initializing variable declaration,
+and let $e$ be the associated initializing expression.
It is a compile-time error if the static type of $e$ is not assignable to the type of $v$.
-It is a compile-time error if a local variable $v$ is final and $v$ is not an initialized variable.
+It is a compile-time error if a local variable $v$ is final,
+and the declaration of $v$ is not an initializing variable declaration.
\commentary{
It is also a compile-time error to assign to a final local variable
@@ -9493,7 +9509,7 @@
}
\LMHash{}
-It is a compile-time error if all of the following conditions hold:
+It is a compile-time warning if all of the following conditions hold:
\begin{itemize}
\item The switch statement does not have a default clause.
\item The static type of $e$ is an enumerated type with elements $\id_1, \ldots, \id_n$.
@@ -9501,7 +9517,7 @@
\end{itemize}
\commentary{
-In other words, an error will be raised if a switch statement over an enum is not exhaustive.
+In other words, a warning will be emitted if a switch statement over an enum is not exhaustive.
}
@@ -9736,8 +9752,8 @@
}
\LMHash{}
-Let $f$ be the function immediately enclosing a return statement of the form \RETURN{};.
-It is a compile-time error if $f$ is neither a generator nor a generative constructor and either:
+Let $f$ be the function immediately enclosing a return statement of the form \code{\RETURN{};}.
+It is a compile-time warning if $f$ is neither a generator nor a generative constructor and either:
\begin{itemize}
%% TODO(eernst): Integrating generalized-void.md, "may not be assigned
%% to void" is useless. Update, also considering invalid_returns.md.
@@ -9747,7 +9763,8 @@
\end{itemize}
\commentary{
-Hence, a compile-time error will not be raised if $f$ has no declared return type,
+Hence, a compile-time warning will not be raised if $f$ has no declared return type,
+%% TODO(eernst): Update when integrating generalized-void.md!
since the return type would be \DYNAMIC{} and \DYNAMIC{} may be assigned to \VOID{} and to \code{Future<Null>}.
However, any synchronous non-generator function that declares a return type must return an expression explicitly.
}
@@ -10436,7 +10453,7 @@
}
\LMHash{}
-It is a compile-time error to import two different libraries with the same name unless their name is the empty string.
+It is a compile-time warning to import two different libraries with the same name unless their name is the empty string.
\commentary{
A widely disseminated library should be given a name that will not conflict with other such libraries.
