Remove trailing semicolon from EIGEN_UNUSED_VARIABLE macro

Pavel Guzenfeldrequested to merge
PavelGuzenfeld/eigen:fix-unused-variable-semi into master

Summary

The EIGEN_UNUSED_VARIABLE() macro included a trailing semicolon in its expansion, causing double-semicolons (;;) at the ~360 call sites that also had a semicolon. This triggers -Wextra-semi-stmt warnings (Clang) and -Wextra-semi (GCC).

Fix

Remove the semicolon from the macro definition (standard C/C++ macro convention: callers provide the semicolon) and add missing semicolons to the ~100 call sites that relied on the macro providing one.

Changed files

  • Eigen/src/Core/util/Macros.h — macro definition (1 char removed)
  • 20 other files — added missing semicolons at call sites

Testing

  • basicstuff, sparse_basic, cxx11_tensor_scan — all pass (GCC 15.2.0, C++20)

Closes #3007 (closed)

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