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Guard all malloc, realloc and free() fonctions with check_that_malloc_is_allowed()

Antoine Hoaraurequested to merge
ahoarau/eigen:add-more-checks-mallocs into master

Context

Checking dynamic allocation at runtime for a specific check of code, using Eigen::internal::set_is_malloc_allowed(true|false)

Changing eigen_assert to throw instead of aborting the program, (most unit c++ unit testing framework do not support std::abort())

#include <stdexcept>
#define eigen_assert(x) if(!(x)) throw(std::runtime_error("Assertion failed"));
#include <Eigen/Core>

ref: https://eigen.tuxfamily.org/dox/TopicAssertions.html

After #1055 (closed), the following code (using catch2) crashes on windows, due to the fact that memory has been reallocated successfully, but not returned due to the throw.

        Eigen::VectorXd q(50);
        REQUIRE_FALSE(Eigen::internal::set_is_malloc_allowed(false));
        CHECK_THROWS(q.conservativeResizeLike(Eigen::VectorXd::Zero(350)));   /// calls aligned_realloc(), next line crashes while trying to free the q variable.
        REQUIRE(Eigen::internal::set_is_malloc_allowed(true)); /// next instruction is a crash as it is trying to free the reallocated-not-really q variable.

What does this implement/fix?

  • The change introduced in !1055 (merged) only check after the memory was actually allocated, causing the free() function to behave unexpectedly (heap crashes on windows)
  • Add guards for all malloc, realloc and free function, so user can detect ANY unwanted call in their application

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