Exercise from Dmitry Soshnikov's course on YouTube
On the root folder, compile with following command:
clang -o eva-llvm `llvm-config --cxxflags --ldflags --system-libs --libs core` src/eva-llvm.cpp
It should print the name of module and generate out.ll with the same contents
saankhya@araj:~/eva-llvm$ ./eva-llvm
; ModuleID = 'EvaLLVM'
source_filename = "EvaLLVM"
This chapter adds infrastructure to generate functions (main function in this case). Script to run and test the implementation is added (compile-run.sh)
The output of the script should give the following:
saankhya@araj:~/eva-llvm$ compile-run.sh
; ModuleID = 'EvaLLVM'
source_filename = "EvaLLVM"
define i32 @main() {
entry:
ret i32 42
}
42
Here we learn how to use strings in LLVM language and create extern function calls. In the last commit we see how to invoke these extern functions referenced in the code. printf is used as exemplary function. Towards the end you should see the following output on executing the script compile-run.sh
aankhya@araj:~/eva-llvm$ compile-run.sh
; ModuleID = 'EvaLLVM'
source_filename = "EvaLLVM"
@0 = private unnamed_addr constant [15 x i8] c"Hello, world!\0A\00", align 1
declare i32 @printf(i8*, ...)
define i32 @main() {
entry:
%0 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([15 x i8], [15 x i8]* @0, i32 0, i32 0))
ret i32 %0
}
Hello, world!
14
Notice the getelementptr call, this will be discussed in the next chapters
In this chapter we add basic parser for the grammar of Eva and parse the following program using the same
(
(printf "Value : %d" 42)
)
This demonstrates how to add global variables in the generated code from the S-expressions. At the end, one should get the following IR generated
; ModuleID = 'EvaLLVM'
source_filename = "EvaLLVM"
@VERSION = global i32 42, align 4
@0 = private unnamed_addr constant [16 x i8] c"Version: %d\\n\\n\00", align 1
declare i32 @printf(i8*, ...)
define i32 @main() {
entry:
%0 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([16 x i8], [16 x i8]* @0, i32 0, i32 0), i32* @VERSION)
ret i32 %0
}