clang-format: Add support for SEH __try / __except / __finally blocks.

This lets clang-format format

    __try {
    } __except(0) {
    }

and

    __try {
    } __finally {
    }

correctly. __try and __finally are keywords if `LangOpts.MicrosoftExt` is set,
so this turns this on.  This also enables a few other keywords, but it
shouldn't overly perturb regular clang-format operation.  __except is a
context-sensitive keyword, so `AdditionalKeywords` needs to be passed around to
a few more places.

Fixes PR22321.

llvm-svn: 228148

1 files changed, 12 insertions, 4 deletions

diff --git a/clang/lib/Format/UnwrappedLineFormatter.cpp b/clang/lib/Format/UnwrappedLineFormatter.cpp
index 4844b66f9fd..0c744e493f0 100644
--- a/clang/lib/Format/UnwrappedLineFormatter.cpp
+++ b/clang/lib/Format/UnwrappedLineFormatter.cpp
@@ -27,7 +27,8 @@ bool startsExternCBlock(const AnnotatedLine &Line) {
 
 class LineJoiner {
 public:
-  LineJoiner(const FormatStyle &Style) : Style(Style) {}
+  LineJoiner(const FormatStyle &Style, const AdditionalKeywords &Keywords)
+      : Style(Style), Keywords(Keywords) {}
 
   /// \brief Calculates how many lines can be merged into 1 starting at \p I.
   unsigned
@@ -200,7 +201,9 @@ private:
     if (Line.First->isOneOf(tok::kw_else, tok::kw_case))
       return 0;
     if (Line.First->isOneOf(tok::kw_if, tok::kw_while, tok::kw_do, tok::kw_try,
-                            tok::kw_catch, tok::kw_for, tok::r_brace)) {
+                            tok::kw___try, tok::kw_catch, tok::kw___finally,
+                            tok::kw_for, tok::r_brace) ||
+        Line.First->is(Keywords.kw___except)) {
       if (!Style.AllowShortBlocksOnASingleLine)
         return 0;
       if (!Style.AllowShortIfStatementsOnASingleLine &&
@@ -211,7 +214,11 @@ private:
         return 0;
       // FIXME: Consider an option to allow short exception handling clauses on
       // a single line.
-      if (Line.First->isOneOf(tok::kw_try, tok::kw_catch))
+      // FIXME: This isn't covered by tests.
+      // FIXME: For catch, __except, __finally the first token on the line
+      // is '}', so this isn't correct here.
+      if (Line.First->isOneOf(tok::kw_try, tok::kw___try, tok::kw_catch,
+                              Keywords.kw___except, tok::kw___finally))
         return 0;
     }
 
@@ -286,6 +293,7 @@ private:
   }
 
   const FormatStyle &Style;
+  const AdditionalKeywords &Keywords;
 };
 
 class NoColumnLimitFormatter {
@@ -324,7 +332,7 @@ unsigned
 UnwrappedLineFormatter::format(const SmallVectorImpl<AnnotatedLine *> &Lines,
                                bool DryRun, int AdditionalIndent,
                                bool FixBadIndentation) {
-  LineJoiner Joiner(Style);
+  LineJoiner Joiner(Style, Keywords);
 
   // Try to look up already computed penalty in DryRun-mode.
   std::pair<const SmallVectorImpl<AnnotatedLine *> *, unsigned> CacheKey(