cl: loadMacro

[xushiwei]

No description provided.

[fennoai]

Review: macro constant-expression evaluation

Nice, compact operator-precedence evaluator, and the presumedFiles set + Config.PresumedFiles removal cleanly internalizes file filtering. The Tokenize/dispose lifecycle is correct and presumedFiles is properly nil-guarded in loadFiles. I did find one definite correctness bug (unary -/~ are no-ops) plus a cluster of panic-on-malformed-input risks worth addressing before merge — macro bodies come from arbitrary headers and none of the compiles closures run under recover(), so a panic aborts the whole generation.

Also worth considering (no reliable inline anchor):

• Unknown binary operators silently truncate. parseExpr (const_expr.go:71-78) exits the loop on any operator not in opPrecs (==, &&, ||, ?:, etc.) and, unless needRParen, returns ok=true with only the left-hand value. So #define X (1 && 0) would emit 1. Encountering an unknown operator mid-expression should force ok=false rather than returning the truncated prefix. evalConstExpr also discards left; asserting len(left)==0 at the top level would catch trailing garbage.
• Scientific-notation float misclassified. parseOperand distinguishes int vs float by scanning for . (const_expr.go:186), so 1e10 takes the ParseInt path, fails, and the constant is silently dropped. Consider also checking for e/E/p/P.
• Performance: PresumedFile now returns a Go string (clang.go:238), allocating + copying a C string for every visited cursor in loadFiles/cppdump purely to do a map/== test on a path where most cursors are filtered out. Consider comparing without materializing a Go string, or caching by clang.File.