[PATCH] Fix bug in clang-format while merging short function (PR19461)

[Dinesh Dwivedi]

Hi djasper, chapuni, klimek,

if Style.AllowShortFunctionsOnASingleLine == FormatStyle::SFS_All, clang-format tries to join short functions and prints in single line.
This code was not taking care of cases where there is something in between function header and body e.g. attached test cases where
there are preprocessor directives in between function header and body.

Attached patch fixes this issue by checking if we have both header and body and nothing between them while trying to merge functions.

Please let me know if this is ok.

TEST PLAN
  Added testcases for different BreakBeforeBraces styles.

http://reviews.llvm.org/D3439

Files:
  lib/Format/Format.cpp
  unittests/Format/FormatTest.cpp

Index: lib/Format/Format.cpp
===================================================================
--- lib/Format/Format.cpp
+++ lib/Format/Format.cpp
@@ -559,7 +559,7 @@
       Limit -= 2;
 
       unsigned MergedLines = 0;
-      if (MergeShortFunctions) {
+      if (MergeShortFunctions && TheLine->MustBeDeclaration) {
         MergedLines = tryMergeSimpleBlock(I + 1, E, Limit);
         // If we managed to merge the block, count the function header, which is
         // on a separate line.
Index: unittests/Format/FormatTest.cpp
===================================================================
--- unittests/Format/FormatTest.cpp
+++ unittests/Format/FormatTest.cpp
@@ -7336,6 +7336,26 @@
                "}\n"
                "}",
                BreakBeforeBrace);
+
+  verifyFormat("#ifdef _DEBUG\n"
+               "int foo(int i = 0)\n"
+               "#else\n"
+               "int foo(int i = 5)\n"
+               "#endif\n"
+               "{\n"
+               "  return i;\n"
+               "}\n"
+               "void foo1()\n"
+               "#ifdef _DEBUG\n"
+               "{\n"
+               "  return 0;\n"
+               "}\n"
+               "#else\n"
+               "{\n"
+               "  return 5;\n"
+               "}\n"
+               "#endif",
+               BreakBeforeBrace);
 }
 
 TEST_F(FormatTest, AllmanBraceBreaking) {
@@ -7418,6 +7438,26 @@
                "}\n",
                BreakBeforeBrace);
 
+  verifyFormat("#ifdef _DEBUG\n"
+               "int foo(int i = 0)\n"
+               "#else\n"
+               "int foo(int i = 5)\n"
+               "#endif\n"
+               "{\n"
+               "  return i;\n"
+               "}\n"
+               "void foo1()\n"
+               "#ifdef _DEBUG\n"
+               "{\n"
+               "  return 0;\n"
+               "}\n"
+               "#else\n"
+               "{\n"
+               "  return 5;\n"
+               "}\n"
+               "#endif",
+               BreakBeforeBrace);
+
   BreakBeforeBrace.ColumnLimit = 19;
   verifyFormat("void f() { int i; }", BreakBeforeBrace);
   BreakBeforeBrace.ColumnLimit = 18;
@@ -7538,6 +7578,26 @@
                "  Y = 0,\n"
                "}\n",
                GNUBraceStyle);
+
+  verifyFormat("#ifdef _DEBUG\n"
+               "int foo(int i = 0)\n"
+               "#else\n"
+               "int foo(int i = 5)\n"
+               "#endif\n"
+               "{\n"
+               "  return i;\n"
+               "}\n"
+               "void foo1()\n"
+               "#ifdef _DEBUG\n"
+               "{\n"
+               "  return 0;\n"
+               "}\n"
+               "#else\n"
+               "{\n"
+               "  return 5;\n"
+               "}\n"
+               "#endif",
+               GNUBraceStyle);
 }
 TEST_F(FormatTest, CatchExceptionReferenceBinding) {
   verifyFormat("void f() {\n"
-------------- next part --------------
A non-text attachment was scrubbed...
Name: D3439.1.patch
Type: text/x-patch
Size: 2877 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20140421/de437671/attachment.bin>