cc

C compiler

The C language grammar (c.y and c.l files) have been taken from:

Instructions on how to use this library

Open the terminal and cd into the source code directory
type make to compile all the source code
run the binary cc which has the following usage (<outfile.ll> is optional and if not provided default filename would be a.ll)
```
 Usage: ./cc <prog.c>  -dumpast
        ./cc <prog.c>  -scopechk
        ./cc <prog.c>  -emit-ir [<outfile.ll>]
```
NOTE : this program doesn't exhaustively support all C constructs but supports most of them and you'll get appropriate warnings/error for invalid/unsupported programs
some sample programs are also provided (in examples directory) to test the AST implementation
their corresponding sample output is in out/ directory

Example : emit code for hello_world.c program in examples dir into out/ dir

./cc examples/hello_world.c -emit-ir out/a.ll

resulting a.ll can be compiled using llc and run using lli

All the integer types (i.e int, long int, short int etc.) are supported, if some combination of type specifiers is not supported you'll get the appropriate error message
Floating point types are also supported (i.e float and double)
Implicit type conversion among int types, float types and across int and float types are supported (using llvm instructions such as sitofp or fptoui etc.)
Storage type specifiers are not supported (they're not part of the language)
Type qualifiers are not supported (they're just ignored)

All the declarations/expressions are supported
Among the control-flow statements, except for-loop all the C statements are supported (i.e. if-else, while, do-while, switch statements, case and default statements, labeled statements and gotos, break, continue, return etc.)
old C style for loop is supported for scope checking
Gracefull exiting of invalid C program is supported (i.e. proper error mentioning during codegen/scope checking)
Any construct that is not supported you'll get an appropriate error message for it

Some basic local optimizations like local-constant-folding, local-deadcode removal are supported
local-constant folding is supported for logical and/or operations only
dead-code removal is supported for if-else, while statements (removal of statement code that is unreachable)
REMARK on deadcode removal :
- for example : if condition of if stmt is true but else block has a label inside it then both then as well as else statement codes are generated, this is because there can be a goto in the program that branches to those labels, similarly for while statements

Name		Name	Last commit message	Last commit date
Latest commit History 49 Commits
.gitignore		.gitignore
Makefile		Makefile
README.md		README.md
ast.cpp		ast.cpp
ast.hpp		ast.hpp
blockitem_codegen.hpp		blockitem_codegen.hpp
c.l		c.l
c.y		c.y
cc.cpp		cc.cpp
codegen.cpp		codegen.cpp
declaration_codegen.hpp		declaration_codegen.hpp
declarator_codgen.hpp		declarator_codgen.hpp
expression_codegen.hpp		expression_codegen.hpp
scope_check.cpp		scope_check.cpp
scope_check.hpp		scope_check.hpp
statement_codegen.hpp		statement_codegen.hpp