llvm-core-lib-examples

Examples described in Getting started with LLVM core libraries book. Build using Visual studio 2017 (v15). Assumes LLVM to be installed at 'C:\LLVM'

• llvm-func-pass

  Consists of source code for a tool that would list all function names present in bit code file being passed as an argument.

  >> llvm-func-pass.exe hello.bc
  ?fib@@YAHH@Z has 5 basic block(s) and accepts 1 arguments
  

• clang-read-diagnostics

  Consists of source code for a tool that would list out all clang diagnostic messages for a source file being passed as an argument

  >> clang-read-diagnostics.exe hello_with_errors.c
  Severity: 3 File: ..\hello_with_error.c
  Line: 7 Col: 12 Category: "Parse Issue" Message: expected ';' at end of declaration
  

• llvm-clang-lexer

  Consists of source code for a tool that would use clang lexer to emit tokens from given c/cpp source file passed as an argument

  Source file: min.c
  int min(int a, int b)
  {
      if (a < b)
          return a;
      return b;
  }
  

  >> llvm-clang-lexer.exe min.c
  Number of token: 20
  KEYWORD(int) IDENTIFIER(min) PUNCTUATION(() KEYWORD(int) IDENTIFIER(a) PUNCTUATION(,) KEYWORD(int) IDENTIFIER(b) PUNCTUATION())
  PUNCTUATION({) KEYWORD(if) PUNCTUATION(() IDENTIFIER(a) PUNCTUATION(<) IDENTIFIER(b)PUNCTUATION()) KEYWORD(return) IDENTIFIER(a)
  PUNCTUATION(;) KEYWORD(return)
  ``
  
  

• llvm-clang-traverse-ast

  Tool to parse provided source code and print function names using its declaraion. Function name is obtained by tranversing the AST (abstract syntax tree) provided by clang

  >> llvm-clang-traverse-ast.exe min.c
  min.c:1:5 declares min
  

• llvm-clang-ast-stats

  Tool to print out abstract syntax tree statisitics. This tool attempst to perform actions performed by clang driver in a simplified manner (not handling all use cases).

  //Input Source: fib.cpp
  #define MAX_INPUT 1000
  
  int fib(int n)
  {
      if (n > MAX_INPUT)
      {
          return 0;
      }
  
      if (n == 0 || n == 1)
      {
          return 1;
      }
      else
      {
          return fib(n - 1) + fib(n - 2);
      }
  }
  

  >>llvm-clang-ast-stats.exe fib.cpp
  int fib(int n) {
      if (n > 1000) {
          return 0;
      }
      if (n == 0 || n == 1) {
          return 1;
      } else {
          return fib(n - 1) + fib(n - 2);
      }
  }
  
  *** AST Context Stats:
    69 types total.
      58 Builtin types, 24 each (1392 bytes)
      4 Complex types, 40 each (160 bytes)
      1 FunctionProto types, 40 each (40 bytes)
      5 Pointer types, 40 each (200 bytes)
      1 Record types, 32 each (32 bytes)
  Total bytes = 1824
  0/0 implicit default constructors created
  0/0 implicit copy constructors created
  0/0 implicit copy assignment operators created
  0/0 implicit destructors created
  
  Number of memory regions: 2
  Bytes used: 4636
  Bytes allocated: 8192
  Bytes wasted: 3556 (includes alignment, etc)