Hi,
Von: Markus Schaber
> Von: Dino Viehland [mailto:di...@microsoft.com]
> > So you want to warn if the file contains a print statement w/o from
> > __future__ import print_function? What if it's a call to print such
> > as
> > print('foo') which is valid in both 2.x and 3.x?
>
> Considering our user base, I could ignore this corner case, as the user can
> simply get rid of the warning by adding the import statement.
>
> > Either way you should be able to just update ParsePrintStmt in Parser.cs.
> > But dealing w/ the case of the parens would be a little more difficult
> > - but I think you can just peek at the next token after print and see
> > if it's a parenthesis right after we eat the print keyword.
>
> Ok, I'll see whether I can do that.
The patch below emits a warning during Compilation for print statements whose
argument list does not start with a '(' if Py3k warnings are enabled.
Best regards
Markus Schaber
944eab0d7da3660001f1dabf473f48d5ddd4ee25
Languages/IronPython/IronPython/Compiler/Parser.cs | 18 ++++++++++++++++--
.../IronPython/IronPython/Resources.Designer.cs | 9 +++++++++
Languages/IronPython/IronPython/Resources.resx | 3 +++
3 files changed, 28 insertions(+), 2 deletions(-)
diff --git a/Languages/IronPython/IronPython/Compiler/Parser.cs
b/Languages/IronPython/IronPython/Compiler/Parser.cs
index bdef897..d756593 100644
--- a/Languages/IronPython/IronPython/Compiler/Parser.cs
+++ b/Languages/IronPython/IronPython/Compiler/Parser.cs
@@ -38,6 +38,7 @@ namespace IronPython.Compiler {
public class Parser : IDisposable { // TODO: remove IDisposable
// immutable properties:
private readonly Tokenizer _tokenizer;
+ private readonly bool _warnPython30;
// mutable properties:
private ErrorSink _errors;
@@ -70,7 +71,7 @@ namespace IronPython.Compiler {
#region Construction
- private Parser(CompilerContext context, Tokenizer tokenizer, ErrorSink
errorSink, ParserSink parserSink, ModuleOptions languageFeatures) {
+ private Parser(CompilerContext context, Tokenizer tokenizer, ErrorSink
errorSink, ParserSink parserSink, ModuleOptions languageFeatures, bool
warnPython30) {
ContractUtils.RequiresNotNull(tokenizer, "tokenizer");
ContractUtils.RequiresNotNull(errorSink, "errorSink");
ContractUtils.RequiresNotNull(parserSink, "parserSink");
@@ -79,6 +80,7 @@ namespace IronPython.Compiler {
_tokenizer = tokenizer;
_errors = errorSink;
+ _warnPython30 = warnPython30;
if (parserSink != ParserSink.Null) {
_sink = parserSink;
}
@@ -123,7 +125,7 @@ namespace IronPython.Compiler {
tokenizer.Initialize(null, reader, context.SourceUnit,
SourceLocation.MinValue);
tokenizer.IndentationInconsistencySeverity =
options.IndentationInconsistencySeverity;
- Parser result = new Parser(context, tokenizer, context.Errors,
context.ParserSink, compilerOptions.Module);
+ Parser result = new Parser(context, tokenizer, context.Errors,
context.ParserSink, compilerOptions.Module, options.WarnPython30);
result._sourceReader = reader;
return result;
}
@@ -379,6 +381,13 @@ namespace IronPython.Compiler {
Severity.FatalError);
}
+ private void ReportWarning(string message)
+ {
+ SourceLocation start =
_tokenizer.IndexToLocation(_lookahead.Span.Start);
+ SourceLocation end =
_tokenizer.IndexToLocation(_lookahead.Span.End);
+ _errors.Add(_sourceUnit, message, new SourceSpan(start, end), 0,
Severity.Warning);
+ }
+
#endregion
#region LL(1) Parsing
@@ -1017,6 +1026,11 @@ namespace IronPython.Compiler {
//print_stmt: 'print' ( [ expression (',' expression)* [','] ] | '>>'
expression [ (',' expression)+ [','] ] )
private PrintStatement ParsePrintStmt() {
Eat(TokenKind.KeywordPrint);
+
+ if (_warnPython30 && PeekToken().Kind !=
TokenKind.LeftParenthesis) {
+ ReportWarning(Resources.UsingPrintStatementWarning);
+ }
+
var start = GetStart();
Expression dest = null;
PrintStatement ret;
diff --git a/Languages/IronPython/IronPython/Resources.Designer.cs
b/Languages/IronPython/IronPython/Resources.Designer.cs
index b564a8e..4a5d5fe 100644
--- a/Languages/IronPython/IronPython/Resources.Designer.cs
+++ b/Languages/IronPython/IronPython/Resources.Designer.cs
@@ -419,5 +419,14 @@ namespace IronPython {
return ResourceManager.GetString("UnknownFutureFeature",
resourceCulture);
}
}
+
+ /// <summary>
+ /// Looks up a localized string similar to Python 2 print statement
found. For Python 3 compatibility, use "from __future__ import
print_function" and the print() function instead..
+ /// </summary>
+ internal static string UsingPrintStatementWarning {
+ get {
+ return ResourceManager.GetString("UsingPrintStatementWarning",
resourceCulture);
+ }
+ }
}
}
diff --git a/Languages/IronPython/IronPython/Resources.resx
b/Languages/IronPython/IronPython/Resources.resx
index 3d89b3d..f666b1f 100644
--- a/Languages/IronPython/IronPython/Resources.resx
+++ b/Languages/IronPython/IronPython/Resources.resx
@@ -238,4 +238,7 @@
<data name="UnknownFutureFeature" xml:space="preserve">
<value>future feature is not defined:</value>
</data>
+ <data name="UsingPrintStatementWarning" xml:space="preserve">
+ <value>Python 2 print statement found. For Python 3 compatibility, use
"from __future__ import print_function" and the print() function
instead.</value>
+ </data>
</root>
\ No newline at end of file
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