Fix bpf_dins_pkt rewrite in BinaryOperator #1006
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Binary operator expressions where the left hand-side expression is a reference to the packet are replaced by a call to the bpf_dins_pkt helper. When replacing text, the Clang Rewriter tries to maintain a list of offsets between the original and the new position of tokens. Replacing the whole binary operator expression with the call to bpf_dins_pkt confuses the Rewriter and it is unable to track the new position of the right hand-side expression. Rewriting the binary operator expression in two times without rewriting the right hand-side expression itself solves the issue.
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This pull request fixes #537 by changing the way
BinaryOperatorexpressions are rewritten.
Binary operator expressions where the left hand-side expression is a
reference to the packet are replaced by a call to the
bpf_dins_pkthelper. When replacing text, the Clang Rewriter tries to maintain a
list of offsets between the original and the new position of tokens.
However, replacing the whole binary operator expression with the call
to
bpf_dins_pktconfuses the Rewriter and it is unable to track thenew position of the right hand-side expression. Rewriting the binary
operator expression in two times without rewriting the right
hand-side expression itself solves the issue.
I believe the second issue reported in #537 by @mvbpolito is a
different bug. It's specific to the use of a constant in a rewritten
expression. The constant seems "invisible" to the Clang rewriter.
I haven't found a proper way to fix it yet.See #1008./cc @drzaeus77 @valkum