[cfe-dev] Clang AST: how to get more precise debug information in certain cases?

[Stanislav Pankevich via cfe-dev]

Hi all,

I would like to obtain the correct source locations from the Clang AST
information but I am having some difficulties in doing that.

The attached screenshot example-1 demonstrates running clang -Xclang
-ast-dump foo.c on the following code:

int foo(int aaaaa, int bbbbb) {
  if (aaaaa == bbbbb) {
    return 1;
  } else {
    return 0;
  }
}

The source locations for the BinaryOperator only cover the "aaaaa =="
part, not the full expression "aaaaa == bbbbb".

In other cases (see the example-2) only the part of the second operand
is covered but never the whole expression.

My questions are:

1) Is there a specific reason for this behavior?
2) Which API should I use to obtain more precise information about the
source locations? I have tried using getExpansionColumnNumber() and
getColumnNumber() functions of the SourceManager class but they both
give me the results similar to those of -ast-dump and I never get the
precise information.

Thanks in advance.

Stanislav Pankevich
-------------- next part --------------
A non-text attachment was scrubbed...
Name: example-2-binary-operator-debug-info-other-examples.png
Type: image/png
Size: 32265 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-dev/attachments/20190601/d51d9f88/attachment.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: example-1-binary-operator-debug-info.png
Type: image/png
Size: 441893 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-dev/attachments/20190601/d51d9f88/attachment-0001.png>