[clang-format] Fix consecutive alignments in #else blocks

Since 3.8 or earlier, clang-format has been lumping all #else, #elif,
etc blocks together when doing whitespace replacements and causing
consecutive alignments across #else blocks.

Commit c077975 partially addressed the problem but also triggered
"regressions".

This patch fixes the root cause of the problem and "reverts" c077975
(except for the unit tests).

Fixes #36070.
Fixes #55265.
Fixes #60721.
Fixes #61498.

Differential Revision: https://reviews.llvm.org/D150057

2 files changed, 47 insertions, 2 deletions

diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 099a5cb91364..dc673934a3f1 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -6367,6 +6367,51 @@ TEST_F(FormatTest, FormatAlignInsidePreprocessorElseBlock) {
                "#endif\n"
                "}",
                Style);
+
+  verifyFormat("#if FOO\n"
+               "int a = 1;\n"
+               "#else\n"
+               "int ab = 2;\n"
+               "#endif\n"
+               "#ifdef BAR\n"
+               "int abc = 3;\n"
+               "#elifdef BAZ\n"
+               "int abcd = 4;\n"
+               "#endif",
+               Style);
+
+  verifyFormat("void f() {\n"
+               "  if (foo) {\n"
+               "#if FOO\n"
+               "    int a = 1;\n"
+               "#else\n"
+               "    bool a = true;\n"
+               "#endif\n"
+               "    int abc = 3;\n"
+               "#ifndef BAR\n"
+               "    int abcd = 4;\n"
+               "#elif BAZ\n"
+               "    bool abcd = true;\n"
+               "#endif\n"
+               "  }\n"
+               "}",
+               Style);
+
+  verifyFormat("void f() {\n"
+               "#if FOO\n"
+               "  a = 1;\n"
+               "#else\n"
+               "  ab = 2;\n"
+               "#endif\n"
+               "}\n"
+               "void g() {\n"
+               "#if BAR\n"
+               "  abc = 3;\n"
+               "#elifndef BAZ\n"
+               "  abcd = 4;\n"
+               "#endif\n"
+               "}",
+               Style);
 }
 
 TEST_F(FormatTest, FormatHashIfNotAtStartOfLine) {
diff --git a/clang/unittests/Format/FormatTestComments.cpp b/clang/unittests/Format/FormatTestComments.cpp
index 60e045059be8..6e5b5b2d68d8 100644
--- a/clang/unittests/Format/FormatTestComments.cpp
+++ b/clang/unittests/Format/FormatTestComments.cpp
@@ -2759,7 +2759,7 @@ TEST_F(FormatTestComments, AlignTrailingComments) {
 
   // Checks an edge case in preprocessor handling.
   // These comments should *not* be aligned
-  EXPECT_NE( // change for EQ when fixed
+  EXPECT_EQ(
       "#if FOO\n"
       "#else\n"
       "long a; // Line about a\n"
@@ -4316,7 +4316,7 @@ TEST_F(FormatTestComments, SplitCommentIntroducers) {
 )",
             format(R"(//
 /\
-/ 
+/
   )",
                    getLLVMStyleWithColumns(10)));
 }