From 26c0945309f5e3fa62cfc38713dbadcb0d6e25de Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <daniel.marjamaki@gmail.com>
Date: Thu, 22 Apr 2021 19:15:22 +0200
Subject: [PATCH] Handle c++20 spaceship operator

---
 lib/token.cpp         |  2 ++
 lib/tokenize.cpp      | 14 ++++++++++++++
 lib/tokenize.h        |  3 +++
 lib/tokenlist.cpp     | 14 ++++++++++++--
 test/testtokenize.cpp | 18 ++++++++++++++++++
 5 files changed, 49 insertions(+), 2 deletions(-)

diff --git a/lib/token.cpp b/lib/token.cpp
index 205bfaf53..16879c204 100644
--- a/lib/token.cpp
+++ b/lib/token.cpp
@@ -111,6 +111,8 @@ void Token::update_property_info()
                   mStr == ">"  ||
                   mStr == ">="))
             tokType(eComparisonOp);
+        else if (mStr == "<=>")
+            tokType(eComparisonOp);
         else if (mStr.size() == 2 &&
                  (mStr == "++" ||
                   mStr == "--"))
diff --git a/lib/tokenize.cpp b/lib/tokenize.cpp
index 7a4947361..91934ee16 100644
--- a/lib/tokenize.cpp
+++ b/lib/tokenize.cpp
@@ -4783,6 +4783,8 @@ bool Tokenizer::simplifyTokenList1(const char FileName[])
 
     removeAlignas();
 
+    simplifySpaceshipOperator();
+
     // Bail out if code is garbage
     if (mTimerResults) {
         Timer t("Tokenizer::tokenize::findGarbageCode", mSettings->showtime, mTimerResults);
@@ -10923,6 +10925,18 @@ void Tokenizer::removeAlignas()
     }
 }
 
+void Tokenizer::simplifySpaceshipOperator()
+{
+    if (isCPP() && mSettings->standards.cpp >= Standards::CPP20) {
+        for (Token *tok = list.front(); tok && tok->next(); tok = tok->next()) {
+            if (Token::simpleMatch(tok, "<= >")) {
+                tok->str("<=>");
+                tok->deleteNext();
+            }
+        }
+    }
+}
+
 static const std::unordered_set<std::string> keywords = {
     "inline"
     , "_inline"
diff --git a/lib/tokenize.h b/lib/tokenize.h
index af92bfc82..27754efbf 100644
--- a/lib/tokenize.h
+++ b/lib/tokenize.h
@@ -695,6 +695,9 @@ private:
     /** Remove alignas */
     void removeAlignas();
 
+    /** Simplify c++20 spaceship operator */
+    void simplifySpaceshipOperator();
+
     /**
      * Remove keywords "volatile", "inline", "register", and "restrict"
      */
diff --git a/lib/tokenlist.cpp b/lib/tokenlist.cpp
index e6a55903a..00033f0c1 100644
--- a/lib/tokenlist.cpp
+++ b/lib/tokenlist.cpp
@@ -1152,16 +1152,26 @@ static void compileShift(Token *&tok, AST_state& state)
     }
 }
 
-static void compileRelComp(Token *&tok, AST_state& state)
+static void compileThreewayComp(Token *&tok, AST_state& state)
 {
     compileShift(tok, state);
     while (tok) {
-        if (Token::Match(tok, "<|<=|>=|>") && !tok->link()) {
+        if (tok->str() == "<=>") {
             compileBinOp(tok, state, compileShift);
         } else break;
     }
 }
 
+static void compileRelComp(Token *&tok, AST_state& state)
+{
+    compileThreewayComp(tok, state);
+    while (tok) {
+        if (Token::Match(tok, "<|<=|>=|>") && !tok->link()) {
+            compileBinOp(tok, state, compileThreewayComp);
+        } else break;
+    }
+}
+
 static void compileEqComp(Token *&tok, AST_state& state)
 {
     compileRelComp(tok, state);
diff --git a/test/testtokenize.cpp b/test/testtokenize.cpp
index ee8612a26..50fea13e9 100644
--- a/test/testtokenize.cpp
+++ b/test/testtokenize.cpp
@@ -327,6 +327,7 @@ private:
         TEST_CASE(simplifyOperatorName26);
         TEST_CASE(simplifyOperatorName27);
         TEST_CASE(simplifyOperatorName28);
+        TEST_CASE(simplifyOperatorName29); // spaceship operator
 
         TEST_CASE(simplifyOverloadedOperators1);
         TEST_CASE(simplifyOverloadedOperators2); // (*this)(123)
@@ -418,6 +419,8 @@ private:
         TEST_CASE(removeAlignas);
 
         TEST_CASE(simplifyCoroutines);
+
+        TEST_CASE(simplifySpaceshipOperator);
     }
 
     std::string tokenizeAndStringify(const char code[], bool expand = true, Settings::PlatformType platform = Settings::Native, const char* filename = "test.cpp", bool cpp11 = true) {
@@ -4707,6 +4710,12 @@ private:
                       tokenizeAndStringify(code));
     }
 
+    void simplifyOperatorName29() {
+        Settings settings;
+        settings.standards.cpp = Standards::CPP20;
+        ASSERT_EQUALS("auto operator<=> ( ) ;", tokenizeAndStringify("auto operator<=>();", settings));
+    }
+
     void simplifyOverloadedOperators1() {
         const char code[] = "struct S { void operator()(int); };\n"
                             "\n"
@@ -5309,6 +5318,7 @@ private:
 
         tokenList.combineStringAndCharLiterals();
         tokenList.combineOperators();
+        tokenList.simplifySpaceshipOperator();
         tokenList.createLinks();
         tokenList.createLinks2();
         tokenList.list.front()->assignIndexes();
@@ -5363,6 +5373,7 @@ private:
         ASSERT_EQUALS("abc=,", testAst("a,b=c"));
         ASSERT_EQUALS("a-1+", testAst("-a+1"));
         ASSERT_EQUALS("ab++-c-", testAst("a-b++-c"));
+        ASSERT_EQUALS("ab<=>", testAst("a<=>b"));
 
         // sizeof
         ASSERT_EQUALS("ab.sizeof", testAst("sizeof a.b"));
@@ -6526,6 +6537,13 @@ private:
         const char expected3[] = "generator < int > f ( ) { co_return ( 7 ) ; }";
         ASSERT_EQUALS(expected3, tokenizeAndStringify(code3, settings));
     }
+
+    void simplifySpaceshipOperator() {
+        Settings settings;
+        settings.standards.cpp = Standards::CPP20;
+
+        ASSERT_EQUALS("; x <=> y ;", tokenizeAndStringify(";x<=>y;", settings));
+    }
 };
 
 REGISTER_TEST(TestTokenizer)