-D__cpp_deduction_guides=0 -Wno-macro-redefined

FAQ.md

@@ -42,6 +42,18 @@ Play with your `-isystem` options until you get a group of options that you can
 
 If you want the ccls binary at a specific location use a symlink - do not move the binary itself.
 
+### `-std=c++1z` `-std=c++17` `bits/unordered_map.h`
+
+In C++17 mode, it is likely to cause libclang to crash when `bits/unordered_map.h` is indexed.
+See https://bugs.llvm.org/show_bug.cgi?id=37695 for details.
+The workaround is to add `-D__cpp_deduction_guides=0 -Wno-macro-redefined` to the initialization option `clang.extraArgs`
+
+In Emacs, it is:
+```elisp
+(setq ccls-extra-init-params
+  '(:clang (:extraArgs ("-D__cpp_deduction_guides=0" "-Wno-macro-redefined"))))
+```
+
 ### Project root detection
 
 [emacs-ccls](https://github.com/MaskRay/emacs-cquery/) locates the project root with `ccls-project-root-matchers`:

Getting-started.md

@@ -59,6 +59,10 @@ Note:
 `.ccls` does not do *word splitting* or *command substitution* for you,
 you cannot use space-separated arguments like `%cpp -std=gnu++14 -pthread`
 
+### Linux
+
+If your project uses `-std=c++1z` `-std=c++17`, you likely need to add `-D__cpp_deduction_guides=0 -Wno-macro-redefined` to the initialization option `clang.extraArgs`. See [[FAQ]] for details.
+
 ### Windows
 
 If your project is compiled with MSVC, you may change the compiler driver (`%clang` above) to `clang-cl`, and use the initialization option `extraClangArguments` to pass three options: