[cfe-commits] PATCH: teach clang -fixit to fix what it can

[Douglas Gregor]

On Aug 12, 2010, at 9:04 PM, Nick Lewycky wrote:

> The attached patch adds a new feature to clang -fixit, labelled "-fix-what-you-can". By default, fix-it will refuse to make any fixes in a file that contains unfixable errors. This is undesirable behaviour much of the time, so the new -fix-what-you-can flag applies all fixits in each file.
> 
> It's implemented by extending the existing FixItPathRewriter to include a bool FixWhatYouCan, and then renaming it to FixItOptions since it's no longer just for rewriting paths.
> 
> Please review!

Index: lib/Frontend/CompilerInvocation.cpp
===================================================================
--- lib/Frontend/CompilerInvocation.cpp	(revision 110945)
+++ lib/Frontend/CompilerInvocation.cpp	(working copy)
@@ -1050,6 +1050,7 @@
   Opts.ViewClassInheritance = Args.getLastArgValue(OPT_cxx_inheritance_view);
   Opts.ASTMergeFiles = Args.getAllArgValues(OPT_ast_merge);
   Opts.LLVMArgs = Args.getAllArgValues(OPT_mllvm);
+  Opts.FixWhatYouCan = Args.hasArg(OPT_fix_what_you_can);
 
   InputKind DashX = IK_None;
   if (const Arg *A = Args.getLastArg(OPT_x)) {


Shouldn't you also update FrontendOptsToArgs?

Index: lib/Rewrite/FixItRewriter.cpp
===================================================================
--- lib/Rewrite/FixItRewriter.cpp	(revision 110945)
+++ lib/Rewrite/FixItRewriter.cpp	(working copy)
@@ -27,10 +27,10 @@
 
 FixItRewriter::FixItRewriter(Diagnostic &Diags, SourceManager &SourceMgr,
                              const LangOptions &LangOpts,
-                             FixItPathRewriter *PathRewriter)
+                             FixItOptions *FixItOpts)
   : Diags(Diags),
     Rewrite(SourceMgr, LangOpts),
-    PathRewriter(PathRewriter),
+    FixItOpts(FixItOpts),
     NumFailures(0) {
   Client = Diags.getClient();
   Diags.setClient(this);
@@ -49,7 +49,7 @@
 }
 
 bool FixItRewriter::WriteFixedFiles() {
-  if (NumFailures > 0) {
+  if (NumFailures > 0 && !FixItOpts->FixWhatYouCan) {
     Diag(FullSourceLoc(), diag::warn_fixit_no_changes);
     return true;
   }

In general, this is pretty dangerous, since a wrong Fix-It (e.g., typo-correcting to the wrong thing) can mean that you're mangling the user's source code. But, I guess that's what you want... so the patch is fine.

	- Doug


> 
> Nick
> 
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