[Issue 15302] New: DMD -O optimizing out meaningful code

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=15302

          Issue ID: 15302
           Summary: DMD -O optimizing out meaningful code
           Product: D
           Version: D2
          Hardware: x86
                OS: All
            Status: NEW
          Severity: major
          Priority: P1
         Component: dmd
          Assignee: nobody at puremagic.com
          Reporter: ketmar at ketmar.no-ip.org

compiling the following code with "dmd -O" leading to failed assert. seems that
dmd optimized out "lineNumber++;", failing to see that it is used in "catch"
part.

===

class XException : Exception {
  this (string msg, size_t lineNumber, string file=__FILE__, size_t
line=__LINE__, Throwable next=null) pure nothrow @safe {
    super(msg, file, line, next);
    _lineNumber = lineNumber;
  }
  @nogc @safe size_t lineNumber() const nothrow {
        return _lineNumber;
    }
  private:
  size_t _lineNumber;
}


void foo (string[] lines) {
  size_t lineNumber = 0;
  try {
    foreach (line; lines) {
      lineNumber++;
      if (line == "Line3") throw new Exception("!");
    }
  } catch (Exception e) {
    throw new XException(e.msg, lineNumber, e.file, e.line, e.next);
  }
}


void main () {
  try {
    foo(["Line", "AnotherLine", "Line3"]);
  } catch (XException e) {
    assert(e.lineNumber == 3);
  }
}

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