clang-format: Fix access to uninitialized memory.

With incomplete code, we aren't guaranteed to generated changes for
every token. In that case, we need to assume that even the very first
change can continue a preprocessor directive and initialize values
accordingly.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@231066 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Format/WhitespaceManager.cpp b/lib/Format/WhitespaceManager.cpp
index 44e5f690a2630aa13d6f29c89aca2d23cbf3477f..fd5dd5991da0835b6a249f4d33919c279578c86c 100644 (file)
--- a/lib/Format/WhitespaceManager.cpp
+++ b/lib/Format/WhitespaceManager.cpp
@@ -232,6 +232,7 @@ void WhitespaceManager::alignEscapedNewlines() {
   unsigned MaxEndOfLine =
       Style.AlignEscapedNewlinesLeft ? 0 : Style.ColumnLimit;
   unsigned StartOfMacro = 0;
+  Changes[0].EscapedNewlineColumn = 0;
   for (unsigned i = 1, e = Changes.size(); i < e; ++i) {
     Change &C = Changes[i];
     if (C.NewlinesBefore > 0) {

diff --git a/unittests/Format/FormatTest.cpp b/unittests/Format/FormatTest.cpp
index bfc601fb2035935c3a888620225591905cc18f43..d49250391c5028101edfb52c941e5dfaeef8f1f5 100644 (file)
--- a/unittests/Format/FormatTest.cpp
+++ b/unittests/Format/FormatTest.cpp
@@ -2656,6 +2656,10 @@ TEST_F(FormatTest, MacroDefinitionsWithIncompleteCode) {
                getLLVMStyleWithColumns(28));
   verifyFormat("#d, = };");
   verifyFormat("#if \"a");
+  verifyFormat("({\n"
+               "#define b }\\\n"
+               "  a\n"
+               "a");
 
   verifyNoCrash("#if a\na(\n#else\n#endif\n{a");
   verifyNoCrash("a={0,1\n#if a\n#else\n;\n#endif\n}");