$ opt -stats -mypassname < program.bc > /dev/null
... statistics output ...
+Note that in order to use the '``-stats``' option, LLVM must be
+compiled with assertions enabled.
+
When running ``opt`` on a C file from the SPEC benchmark suite, it gives a
report that looks like this:
Function *F = ...;
- for (User *U : GV->users()) {
+ for (User *U : F->users()) {
if (Instruction *Inst = dyn_cast<Instruction>(U)) {
errs() << "F is used in instruction:\n";
errs() << *Inst << "\n";
<HowToSetUpLLVMStyleRTTI>` which describes how you can implement this
pattern for use with the LLVM helpers.
+.. _abi_breaking_checks:
+
+ABI Breaking Checks
+-------------------
+
+Checks and asserts that alter the LLVM C++ ABI are predicated on the
+preprocessor symbol `LLVM_ENABLE_ABI_BREAKING_CHECKS` -- LLVM
+libraries built with `LLVM_ENABLE_ABI_BREAKING_CHECKS` are not ABI
+compatible LLVM libraries built without it defined. By default,
+turning on assertions also turns on `LLVM_ENABLE_ABI_BREAKING_CHECKS`
+so a default +Asserts build is not ABI compatible with a
+default -Asserts build. Clients that want ABI compatibility
+between +Asserts and -Asserts builds should use the CMake or autoconf
+build systems to set `LLVM_ENABLE_ABI_BREAKING_CHECKS` independently
+of `LLVM_ENABLE_ASSERTIONS`.
+
.. _coreclasses:
The Core LLVM Class Hierarchy Reference