llvm.md

LLDB

lldb a.out
lldb -- a.out args

r   # run
c   # continue
n   # next line
s   # step into
bt  # backtrace

(lldb) break set -f test.cpp -l 30
(lldb) br set -f test.cpp -l 30
(lldb) b test.cpp : l
(lldb) br list
(lldb) br del
(lldb) p varname

... frame / fr var
... fr select/frame no
... watchpoint set variable global variable
... watchpoint set variable -w read | write | read_write global variable

• gcc & llvm are toolchain
  • Preprocess
  • Syntax mistake
  • Assemble object
  • Link into executable

Precompiled Headers

• Precompiled headers are a general approach employed by many compilers to reduce compilation time.
• Consequently, compile times can often be greatly improved by caching some of the (redundant) work done by a compiler to process headers.
• Precompiled header files, which represent one of many ways to implement this optimization, are files that represent an on-disk cache that contains the vital information necessary to reduce some of the work needed to process a corresponding header file.
• While details of precompiled headers vary between compilers, precompiled headers are highly effective at speeding up program compilation on systems with very large system headers (e.g., macOS).

References

• LLVM User Manual
• LLVM Grad Student
• LLVM Warning
  • Wall and -Werror at a minimum on any new code you are developing. Warnings are added for good reasons, they find bugs.