[clang-format] [PR25010] AllowShortIfStatementsOnASingleLine not working if an "else" statement is present

Summary:
Addressing: PR25010 - https://bugs.llvm.org/show_bug.cgi?id=25010

Code like:

```
    if(true) var++;
    else  {
        var--;
    }
```

is reformatted to be

```
  if (true)
    var++;
  else {
    var--;
  }
```

Even when `AllowShortIfStatementsOnASingleLine` is true

The following revision comes from a +1'd suggestion in the PR to support AllowShortIfElseStatementsOnASingleLine

This suppresses the clause prevents the merging of the if when there is a compound else

Reviewers: klimek, djasper, JonasToth, alexfh, krasimir, reuk
Reviewed By: reuk
Subscribers: reuk, Higuoxing, jdoerfert, cfe-commits
Tags: #clang-tools-extra
Differential Revision: https://reviews.llvm.org/D59087

llvm-svn: 356029

1 files changed, 65 insertions, 10 deletions

diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 650636b7633..7fcff46f581 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -439,7 +439,8 @@ TEST_F(FormatTest, FormatIfWithoutCompoundStatement) {
 
   FormatStyle AllowsMergedIf = getLLVMStyle();
   AllowsMergedIf.AlignEscapedNewlines = FormatStyle::ENAS_Left;
-  AllowsMergedIf.AllowShortIfStatementsOnASingleLine = true;
+  AllowsMergedIf.AllowShortIfStatementsOnASingleLine =
+      FormatStyle::SIS_WithoutElse;
   verifyFormat("if (a)\n"
                "  // comment\n"
                "  f();",
@@ -487,6 +488,41 @@ TEST_F(FormatTest, FormatIfWithoutCompoundStatement) {
   verifyFormat("if (a)\n  return;", AllowsMergedIf);
 }
 
+TEST_F(FormatTest, FormatIfWithoutCompoundStatementButElseWith) {
+  FormatStyle AllowsMergedIf = getLLVMStyle();
+  AllowsMergedIf.AlignEscapedNewlines = FormatStyle::ENAS_Left;
+  AllowsMergedIf.AllowShortIfStatementsOnASingleLine =
+      FormatStyle::SIS_WithoutElse;
+  verifyFormat("if (a)\n"
+               "  f();\n"
+               "else {\n"
+               "  g();\n"
+               "}",
+               AllowsMergedIf);
+  verifyFormat("if (a)\n"
+               "  f();\n"
+               "else\n"
+               "  g();\n",
+               AllowsMergedIf);
+
+  AllowsMergedIf.AllowShortIfStatementsOnASingleLine = FormatStyle::SIS_Always;
+
+  verifyFormat("if (a) f();\n"
+               "else {\n"
+               "  g();\n"
+               "}",
+               AllowsMergedIf);
+  verifyFormat("if (a) f();\n"
+               "else {\n"
+               "  if (a) f();\n"
+               "  else {\n"
+               "    g();\n"
+               "  }\n"
+               "  g();\n"
+               "}",
+               AllowsMergedIf);
+}
+
 TEST_F(FormatTest, FormatLoopsWithoutCompoundStatement) {
   FormatStyle AllowsMergedLoops = getLLVMStyle();
   AllowsMergedLoops.AllowShortLoopsOnASingleLine = true;
@@ -515,7 +551,8 @@ TEST_F(FormatTest, FormatShortBracedStatements) {
   AllowSimpleBracedStatements.ColumnLimit = 40;
   AllowSimpleBracedStatements.AllowShortBlocksOnASingleLine = true;
 
-  AllowSimpleBracedStatements.AllowShortIfStatementsOnASingleLine = true;
+  AllowSimpleBracedStatements.AllowShortIfStatementsOnASingleLine =
+      FormatStyle::SIS_WithoutElse;
   AllowSimpleBracedStatements.AllowShortLoopsOnASingleLine = true;
 
   AllowSimpleBracedStatements.BreakBeforeBraces = FormatStyle::BS_Custom;
@@ -563,7 +600,8 @@ TEST_F(FormatTest, FormatShortBracedStatements) {
                "};",
                AllowSimpleBracedStatements);
 
-  AllowSimpleBracedStatements.AllowShortIfStatementsOnASingleLine = false;
+  AllowSimpleBracedStatements.AllowShortIfStatementsOnASingleLine =
+      FormatStyle::SIS_Never;
   verifyFormat("if (true) {}", AllowSimpleBracedStatements);
   verifyFormat("if (true) {\n"
                "  f();\n"
@@ -588,7 +626,8 @@ TEST_F(FormatTest, FormatShortBracedStatements) {
                "}",
                AllowSimpleBracedStatements);
 
-  AllowSimpleBracedStatements.AllowShortIfStatementsOnASingleLine = true;
+  AllowSimpleBracedStatements.AllowShortIfStatementsOnASingleLine =
+      FormatStyle::SIS_WithoutElse;
   AllowSimpleBracedStatements.AllowShortLoopsOnASingleLine = true;
   AllowSimpleBracedStatements.BraceWrapping.AfterControlStatement = true;
 
@@ -625,7 +664,8 @@ TEST_F(FormatTest, FormatShortBracedStatements) {
                "}",
                AllowSimpleBracedStatements);
 
-  AllowSimpleBracedStatements.AllowShortIfStatementsOnASingleLine = false;
+  AllowSimpleBracedStatements.AllowShortIfStatementsOnASingleLine =
+      FormatStyle::SIS_Never;
   verifyFormat("if (true) {}", AllowSimpleBracedStatements);
   verifyFormat("if (true)\n"
                "{\n"
@@ -659,7 +699,7 @@ TEST_F(FormatTest, FormatShortBracedStatements) {
 TEST_F(FormatTest, ShortBlocksInMacrosDontMergeWithCodeAfterMacro) {
   FormatStyle Style = getLLVMStyleWithColumns(60);
   Style.AllowShortBlocksOnASingleLine = true;
-  Style.AllowShortIfStatementsOnASingleLine = true;
+  Style.AllowShortIfStatementsOnASingleLine = FormatStyle::SIS_WithoutElse;
   Style.BreakBeforeBraces = FormatStyle::BS_Allman;
   EXPECT_EQ("#define A                                                  \\\n"
             "  if (HANDLEwernufrnuLwrmviferuvnierv)                     \\\n"
@@ -3157,7 +3197,7 @@ TEST_F(FormatTest, GraciouslyHandleIncorrectPreprocessorConditions) {
 
 TEST_F(FormatTest, FormatsJoinedLinesOnSubsequentRuns) {
   FormatStyle SingleLine = getLLVMStyle();
-  SingleLine.AllowShortIfStatementsOnASingleLine = true;
+  SingleLine.AllowShortIfStatementsOnASingleLine = FormatStyle::SIS_WithoutElse;
   verifyFormat("#if 0\n"
                "#elif 1\n"
                "#endif\n"
@@ -8000,7 +8040,8 @@ TEST_F(FormatTest, FormatHashIfExpressions) {
 
 TEST_F(FormatTest, MergeHandlingInTheFaceOfPreprocessorDirectives) {
   FormatStyle AllowsMergedIf = getGoogleStyle();
-  AllowsMergedIf.AllowShortIfStatementsOnASingleLine = true;
+  AllowsMergedIf.AllowShortIfStatementsOnASingleLine =
+      FormatStyle::SIS_WithoutElse;
   verifyFormat("void f() { f(); }\n#error E", AllowsMergedIf);
   verifyFormat("if (true) return 42;\n#error E", AllowsMergedIf);
   verifyFormat("if (true)\n#error E\n  return 42;", AllowsMergedIf);
@@ -10425,7 +10466,8 @@ TEST_F(FormatTest, AllmanBraceBreaking) {
   AllmanBraceStyle.ColumnLimit = 80;
 
   FormatStyle BreakBeforeBraceShortIfs = AllmanBraceStyle;
-  BreakBeforeBraceShortIfs.AllowShortIfStatementsOnASingleLine = true;
+  BreakBeforeBraceShortIfs.AllowShortIfStatementsOnASingleLine =
+      FormatStyle::SIS_WithoutElse;
   BreakBeforeBraceShortIfs.AllowShortLoopsOnASingleLine = true;
   verifyFormat("void f(bool b)\n"
                "{\n"
@@ -10887,7 +10929,6 @@ TEST_F(FormatTest, ParsesConfigurationBools) {
   CHECK_PARSE_BOOL(AllowAllParametersOfDeclarationOnNextLine);
   CHECK_PARSE_BOOL(AllowShortBlocksOnASingleLine);
   CHECK_PARSE_BOOL(AllowShortCaseLabelsOnASingleLine);
-  CHECK_PARSE_BOOL(AllowShortIfStatementsOnASingleLine);
   CHECK_PARSE_BOOL(AllowShortLoopsOnASingleLine);
   CHECK_PARSE_BOOL(BinPackArguments);
   CHECK_PARSE_BOOL(BinPackParameters);
@@ -11150,6 +11191,20 @@ TEST_F(FormatTest, ParsesConfiguration) {
   CHECK_PARSE("NamespaceIndentation: All", NamespaceIndentation,
               FormatStyle::NI_All);
 
+  Style.AllowShortIfStatementsOnASingleLine = FormatStyle::SIS_Always;
+  CHECK_PARSE("AllowShortIfStatementsOnASingleLine: Never",
+              AllowShortIfStatementsOnASingleLine, FormatStyle::SIS_Never);
+  CHECK_PARSE("AllowShortIfStatementsOnASingleLine: WithoutElse",
+              AllowShortIfStatementsOnASingleLine,
+              FormatStyle::SIS_WithoutElse);
+  CHECK_PARSE("AllowShortIfStatementsOnASingleLine: Always",
+              AllowShortIfStatementsOnASingleLine, FormatStyle::SIS_Always);
+  CHECK_PARSE("AllowShortIfStatementsOnASingleLine: false",
+              AllowShortIfStatementsOnASingleLine, FormatStyle::SIS_Never);
+  CHECK_PARSE("AllowShortIfStatementsOnASingleLine: true",
+              AllowShortIfStatementsOnASingleLine,
+              FormatStyle::SIS_WithoutElse);
+
   // FIXME: This is required because parsing a configuration simply overwrites
   // the first N elements of the list instead of resetting it.
   Style.ForEachMacros.clear();