Support case ranges (gcc extension, #6490)

lib/tokenize.cpp

@@ -2380,6 +2380,27 @@ void Tokenizer::simplifyLabelsCaseDefault()
 }
 
 
+void Tokenizer::simplifyCaseRange()
+{
+    for (Token* tok = list.front(); tok; tok = tok->next()) {
+        if (Token::Match(tok, "case %num% . . . %num% :")) {
+            MathLib::bigint start = MathLib::toLongNumber(tok->strAt(1));
+            MathLib::bigint end = MathLib::toLongNumber(tok->strAt(5));
+            if (start < end) {
+                tok = tok->tokAt(2);
+                tok->str(":");
+                tok->deleteNext();
+                tok->next()->str("case");
+                for (MathLib::bigint i = end-1; i > start; i--) {
+                    tok->insertToken(":");
+                    tok->insertToken(MathLib::toString(i));
+                    tok->insertToken("case");
+                }
+            }
+        }
+    }
+}
+
 
 
 void Tokenizer::simplifyTemplates()
@@ -3373,6 +3394,9 @@ bool Tokenizer::simplifyTokenList1(const char FileName[])
     simplifyVarDecl(true);
     simplifyFunctionParameters();
 
+    // simplify case ranges (gcc extension)
+    simplifyCaseRange();
+
     // simplify labels and 'case|default'-like syntaxes
     simplifyLabelsCaseDefault();
 

lib/tokenize.h

@@ -209,6 +209,10 @@ public:
       */
     void simplifyLabelsCaseDefault();
 
+    /** simplify case ranges (gcc extension)
+      */
+    void simplifyCaseRange();
+
     /** Remove macros in global scope */
     void removeMacrosInGlobalScope();
 

test/testtokenize.cpp

@@ -443,6 +443,8 @@ private:
 
         TEST_CASE(simplifyDeprecated);
 
+        TEST_CASE(simplifyCaseRange);
+
         TEST_CASE(compileLimits); // #5592 crash: gcc: testsuit: gcc.c-torture/compile/limits-declparen.c
 
         TEST_CASE(prepareTernaryOpForAST);
@@ -7991,6 +7993,11 @@ private:
                       tokenizeAndStringify("[[deprecated]] int f();", false, true, Settings::Unspecified, "test.c", true));
     }
 
+    void simplifyCaseRange() {
+        ASSERT_EQUALS("void f ( ) { case 1 : ; case 2 : ; case 3 : ; case 4 : ; }", tokenizeAndStringify("void f() { case 1 ... 4: }"));
+        ASSERT_EQUALS("void f ( ) { case 4 . . . 1 : ; }", tokenizeAndStringify("void f() { case 4 ... 1: }"));
+    }
+
     void prepareTernaryOpForAST() {
         ASSERT_EQUALS("a ? b : c ;", tokenizeAndStringify("a ? b : c;"));