# Reference

LLVM and API reference documentation.

- API Reference
- LLVM Reference
  - Command Line Utilities
  - Garbage Collection
  - LibFuzzer
  - LLVM IR
  - Testing and Debugging
  - XRay
  - Additional Topics

## API Reference

Doxygen generated documentation
  (classes)
How To Use Attributes
  Answers some questions about the new Attributes infrastructure.

Documentation for Go bindings

ORC Design and Implementation
  Describes the design and implementation of the ORC APIs, including some usage examples, and a guide for users transitioning from ORCv1 to ORCv2.

## LLVM Reference

### Command Line Utilities

LLVM Command Guide
  A reference manual for the LLVM command line utilities (“man” pages for LLVM tools).
LLVM bugpoint tool: design and usage
  Automatic bug finder and test-case reducer description and usage information.
Using -opt-bisect-limit to debug optimization errors
  A command line option for debugging optimization-induced failures.
The Microsoft PDB File Format
  A detailed description of the Microsoft PDB (Program Database) file format.

### Garbage Collection

Garbage Collection with LLVM
  The interfaces source-language compilers should use for compiling GC’d programs.
Garbage Collection Safepoints in LLVM
  This describes a set of experimental extensions for garbage collection support.

### LibFuzzer

libFuzzer – a library for coverage-guided fuzz testing.
  A library for writing in-process guided fuzzers.
Fuzzing LLVM libraries and tools
  Information on writing and using Fuzzers to find bugs in LLVM.

### LLVM IR

LLVM Language Reference Manual
  Defines the LLVM intermediate representation and the assembly form of the different nodes.
Design and Usage of the InAlloca Attribute
  Description of the `inalloca` argument attribute.
LLVM Bitcode File Format
  This describes the file format and encoding used for LLVM “bc” files.
Machine IR (MIR) Format Reference Manual
  A reference manual for the MIR serialization format, which is used to test LLVM’s code generation passes.
Global Instruction Selection
  This describes the prototype instruction selection replacement, GlobalISel.

### Testing and Debugging

LLVM Testing Infrastructure Guide
  A reference manual for using the LLVM testing infrastructure.
test-suite Guide
  Describes how to compile and run the test-suite benchmarks.
GWP-ASan
  A sampled heap memory error detection toolkit designed for production use.

### XRay

XRay Instrumentation
  High-level documentation of how to use XRay in LLVM.
Debugging with XRay
  An example of how to debug an application with XRay.

### Additional Topics

FaultMaps and implicit checks
  LLVM support for folding control flow into faulting machine instructions.
LLVM Atomic Instructions and Concurrency Guide
  Information about LLVM’s concurrency model.
Exception Handling in LLVM
  This document describes the design and implementation of exception handling in LLVM.
LLVM Extensions
  LLVM-specific extensions to tools and formats LLVM seeks compatibility with.
How to set up LLVM-style RTTI for your class hierarchy
  How to make `isa<>`, `dyn_cast<>`, etc. available for clients of your class hierarchy.
LLVM Block Frequency Terminology
  Provides information about terminology used in the `BlockFrequencyInfo` analysis pass.
LLVM Branch Weight Metadata
  Provides information about Branch Prediction Information.
The Often Misunderstood GEP Instruction
  Answers to some very frequent questions about LLVM’s most frequently misunderstood instruction.
Scudo Hardened Allocator
  A library that implements a security-hardened malloc().
MemTagSanitizer
  Security hardening for production code aiming to mitigate memory related vulnerabilities. Based on the Armv8.5-A Memory Tagging Extension.
Dependence Graphs
  A description of the design of the various dependence graphs such as the DDG (Data Dependence Graph).
Speculative Load Hardening
  A description of the Speculative Load Hardening mitigation for Spectre v1.
Segmented Stacks in LLVM
  This document describes segmented stacks and how they are used in LLVM.
LLVM’s Optional Rich Disassembly Output
  This document describes the optional rich disassembly output syntax.
Stack maps and patch points in LLVM
  LLVM support for mapping instruction addresses to the location of values and allowing code to be patched.
Coroutines in LLVM
  LLVM support for coroutines.
YAML I/O
  A reference guide for using LLVM’s YAML I/O library.