program :=
<function \n> (NOTE: angular braces are used for grouping)
function :=
type ident() stmtblock
type ident(type ident <, type ident>*) stmtblock
type :=
bool
int
array
void
stmtblock :=
{\n <stmt \n>* }
stmt :=
stmtblock
type ident <, ident>*
array ident\[expr\] <, ident\[expr\]>*
print(<string|expr> <, <string|expr> >*
if (expr) stmtblock [else stmtblock]
while (expr) stmtblock
for (ident : expr) stmtblock
ident := expr
ident\[expr\] := expr
expr
;[^\n]*
return [expr]
abort(<string|expr> <, <string|expr> >*
expr :=
true
false
-?[0-9]
ident
(expr ? expr : expr)
sizeof(ident)
input()
ident\[expr\]
ident()
ident(expr <, expr>*)
(expr binop expr)
(unaryop expr)
binop :=
- * ^ / % & | == != > >= < <=
(caret is exponentiation, we have no xor operator)
unaryop :=
- !
(bang is Boolean not)
string :=
" ('\\' ["nt\\] | [^\\\n"])* "
ident :=
[a-zA-Z_][a-zA-Z0-9_]*
- All variables are initialized to 0 by default, including array elements.
- Any attempt to access or assign an array element out of bounds traps.
Create a buid directory for yourself and do:
cmake .. (assuming you created builddir in the root directory)
make
It will create binary called lilang. You can check for various options with lilang --help
Files that should be parsed by this compiler are in passing-tests/ and files that should not be parsed are in failing-tests/ directory.
You can do:
ctest to run the tests.
Use the compiler driver (called little) that calls the frontend (called lilang) automatically and creates an executable a.out in the current directory.
Eg:
./little lil.lil
The above compiler driver basically does following:
Say you have a file, lil.lil. It compiles to LLVM IR like follows:
./lilang lil.lil --print-ir=a.bc
The file a.bc now contains the LLVM IR in textual form. If you want to execute it, you need to link it with the runtime file as follows:
clang runtime.c a.bc -o file.out