Formatter breaks code containing macros

[iloveeclipse]

Using C/C++ Development Tools SDK 10.7.1.202208222120.

• With the file in editor below
• select all lines
• trigger formatting via Ctrl+Shift+F

/*
 * CodeFormatTest.cpp
 */
#define s
#define ms *1.0
class CodeFormatTest{
public:
        void methodWithParam(double d){

        }

        void test(){
                methodWithParam(1 s);
                methodWithParam(1 ms);
        }

};

This will produce this (broken, not compilable) code (note missing space between 1 and ms inside methodWithParam(1ms);)

/*
 * CodeFormatTest.cpp
 */
#define s
#define ms *1.0
class CodeFormatTest {
public:
  void methodWithParam(double d)
  {

  }

  void test()
  {
    methodWithParam(1 s);
    methodWithParam(1ms);
  }

};

[jonahgraham]

Here is a test to add to CodeFormatterTest for anyone planning on working on this:

Test code

```java //#define s //#define ms *1.0 //class CodeFormatTest{ //public: // void methodWithParam(double d){ // // } // // void test(){ // methodWithParam(1 s); // methodWithParam(1 ms); // } // //}; //#define s //#define ms *1.0 //class CodeFormatTest { //public: // void methodWithParam(double d) { // // } // // void test() { // methodWithParam(1 s); // methodWithParam(1 ms); // } // //}; public void testIssue121() throws Exception { assertFormatterResult(); } ```

The above test fails with this stack trace

```java junit.framework.ComparisonFailure: expected:<... methodWithParam(1[ ]ms); } }; > but was:<... methodWithParam(1[]ms); } }; > at junit.framework.Assert.assertEquals(Assert.java:100) at junit.framework.Assert.assertEquals(Assert.java:107) at junit.framework.TestCase.assertEquals(TestCase.java:260) at org.eclipse.cdt.ui.tests.text.CodeFormatterTest.assertFormatterResult(CodeFormatterTest.java:75) at org.eclipse.cdt.ui.tests.text.CodeFormatterTest.assertFormatterResult(CodeFormatterTest.java:66) at org.eclipse.cdt.ui.tests.text.CodeFormatterTest.testIssue121(CodeFormatterTest.java:4851) ```

This may be a good fix to work on for someone new to the CDT code base as this code is reasonably well tested and well contained. See these packages for the main part of the code formatter code:

• org.eclipse.cdt.core.formatter
• org.eclipse.cdt.internal.formatter

[jonahgraham]

Some more useful reference - Bug 268962 is a similar class of bug and at the time Anton who was very familiar with the code base, said:

Macros can easily pose a problem for the formatter, esp. when they span only parts of a syntactic element. There are some heuristics in place, but a general solution is difficult.