The document discusses the phases of a compiler including lexical analysis, syntax analysis, intermediate code generation, code optimization, and target code generation. It also covers bootstrapping, which is the process of using a simple language to translate a more complex program, allowing the creation of self-hosting compilers. Finally, it defines a cross compiler as one that compiles code for a different platform than the one it is running on, providing the example of a Linux/x86 compiler building code for an Arduino/ARM system.

1. Topic – Phases of compiler, Bootstrapping, Cross Compiler
Subject – Compiler Design
Course – B.Tech CSE
Aditya Malkani Miss Shalini

2. • The compiler is software that converts a program written in a high-level language (Source Language)
to low-level language (Object/Target/Machine Language).
• The source code is typically written in a high-level, human-readable language such as Java or C++.

4. Lexical Analyzer – It is also called a scanner. It takes the output of the preprocessor as the input which is in a
pure high-level language. It reads the characters from the source program and groups them into lexemes. Each
lexeme corresponds to a token.
SYNTAX ANALYZER It is sometimes called a parser. It constructs the parse tree. It takes all the tokens one by
one and uses Context-Free Grammar to construct the parse tree.
It verifies the parse tree, whether it’s meaningful or not. It furthermore produces a
verified parse tree
INTERMEDIATE CODE GENERATOR It generates intermediate code, which is a form that can be readily executed
by a machine We have many popular intermediate codes.
CODE OPTIMIZER It transforms the code so that it consumes fewer resources and produces more speed.
The main purpose of the Target Code generator is to write a code that the machine
can understand and also register allocation, instruction selection, etc.The output is dependent on the type of
assembler.

5. • Bootstrapping is a process in which simple language is used to translate more complicated program
which in turn may handle for more complicated program.
• This complicated program can further handle even more complicated program and so on.
• Bootstrapping is widely used in the compilation development.
• Bootstrapping is used to produce a self-hosting compiler. Self-hosting compiler is a type of compiler that
can compile its own source code.

6. • A Cross compiler is a compiler that generates executable code for a platform other than one on which
the compiler is running.
• For example a compiler that running on Linux/x86 box is building a program which will run on a
separate Arduino/ARM.
• It is independent of System/machine and OS.
• Keil is a cross compiler.