base on A x86_64 C99 compiler written in Rust from scratch <div> <p align="left"> <img src="https://i.ibb.co/1bfxpbb/wreckage-mj.jpg" width="800"> </p> </div> [](https://github.com/PhilippRados/wrecc/actions/workflows/test.yml)    `wrecc` is a small,lean x86-64 C99 compiler written from scratch. The name is a play on the word _wreck_ which describes a rusting ship on the sea floor. The compiler emits [x86-64](https://en.wikipedia.org/wiki/X86-64) assembly in [AT&T syntax](https://staffwww.fullcoll.edu/aclifton/courses/cs241/syntax.html), it adheres to the [System V ABI](https://wiki.osdev.org/System_V_ABI) which I could only test for Ubuntu and Macos. There are no dependencies you only need your assembler and linker which the compiler then invokes to create the final binary. ### Table of contents * [Installation](#installation) + [Pre-built binaries](#binaries) + [Cargo](#cargo) * [Features](#features) + [Preprocessor](#preprocessor) + [Compiler](#compiler) + [Supported keywords](#keywords) + [Unimplemented features](#unimplemented) + [Error messages](#errors) + [Ast pretty-printer](#ast) * [Testing](#testing) * [Troubleshooting](#troubleshooting) * [Contribution](#contribution) * [Project goals](#goals) * [Resources](#resources) ## Installation ### Pre-built binaries <a name="binaries"></a> If you don't have the rust toolchain installed on your system you can install the latest binary (MacOs, Linux) from the releases directly: ``` curl --proto '=https' --tlsv1.2 -LsSf https://github.com/PhilippRados/wrecc/releases/download/v0.2.0/wrecc-installer.sh | sh ``` ### Cargo Using `cargo binstall` ``` cargo binstall wrecc ``` or building from source ``` cargo install wrecc ``` ## Features Since not all keywords are currently implemented wrecc uses [custom standard-headers](https://github.com/PhilippRados/wrecc/tree/master/include) which are built directly into the binary ### Preprocessor The preprocessor implements all [C99 preprocessor directives](https://en.cppreference.com/w/c/keyword), except `#line` and `#pragma`. Most prominently it currently also misses function-like macros which are on the agenda though. ### Compiler #### Supported Keywords <a name="keywords"></a> <img width="481" alt="keywords" src="https://github.com/PhilippRados/wrecc/assets/60818062/492cdf56-ee83-4333-9084-02fcd8a08356"> #### Other than that it even supports: <details> <summary>Aggregate initialization with designated initializers</summary> ```C struct { union { int foo; long baz; } nested; int array[16]; } bar = { .nested.foo = 3, .array[6] = 1}; ``` </details> <details> <summary>Function pointers</summary> ```C #include <stdio.h> typedef int (*BinaryOperation)(int, int); typedef struct { BinaryOperation add; BinaryOperation subtract; } Calculator; int add(int a, int b) { return a + b; } int subtract(int a, int b) { return a - b; } int main() { Calculator calc = {add, subtract}; printf("Result of addition: %d\n", calc.add(10, 5)); printf("Result of subtraction: %d\n", calc.subtract(10, 5)); } ``` </details> <details> <summary>Constant folding</summary> ```C char **string_offset = (char **)&"hello" + (int)(3 * 1); int array[(long)3 * 2 - 1]; ``` </details> #### Unimplemented Features <a name="unimplemented"></a> Aside from the missing keywords these are the main missing features: - [x] Arrays with unspecified size - [x] Compiling multiple files at once - [ ] Raw structs/unions as function argument-/return-types - [ ] Floating point types<br> Here is a list of all the stuff still missing: [todo](https://placid-eris-c19.notion.site/check-all-errors-from-c-testsuite-6f3fa2a3c24a4711b5e89f45354db540?pvs=4) ### Error messages <a name="errors"></a> Wrecc also has nice looking messages. Error reporting doesn't stop after the first error. Using the `--no-color` option you can switch off color-highlighting in errors. Currently there are only errors and no warnings. <table> <tr> <th>C code</th> <th>Errors</th> </tr> <tr> <td> ```C int foo(void); int main() { int a = foo(1); long *p = a; return p * 2; } ``` </td> <td> <img width="535" alt="error" src="https://github.com/PhilippRados/wrecc/assets/60818062/0b0e0c9f-3600-460c-9da5-1705ef0f83d9"> </td> </tr> </table> ### Ast pretty-printer <a name="ast"></a> When compiling using the `--dump-ast` option it prints the parse-tree <table> <tr> <th>C code</th> <th>AST</th> </tr> <tr> <td> ```C #define SIZE 16 void foo(char); int main() { int arr[SIZE] = {1, 2}; char p = (char)(*arr + 3); switch (p) { case 'c': foo(p); } } ``` </td> <td> ``` Declaration: -Decl: 'foo' FuncDef: 'main' -Declaration: --Init: 'arr' ---Aggregate: ----Scalar: -----Literal: 1 ----Scalar: -----Literal: 2 -Declaration: --Init: 'p' ---Scalar: ----Cast: 'char' -----Grouping: ------Binary: '+' -------Unary: '*' --------Ident: 'arr' -------Literal: 3 -Switch: --Ident: 'p' --Block: ---Case: ----Literal: 99 ----Expr: -----FuncCall: ------Ident: 'foo' ------Ident: 'p' ``` </td> </tr> </table> #### Inspect all options by running `wrecc --help` ## Testing Run different types of tests with `make <target>`. Available targets can be inspected using `make help` as shown below. ```console $ make help Usage: make <target> help Display this help unit-tests Run rust unit-tests snapshot-tests Run snapshot-tests located in tests/ c-testsuite Requires c-testsuite (https://github.com/c-testsuite/c-testsuite) and env-var C_TESTSUITE set to its path fuzzer Launch afl.rs fuzzer ``` ## Troubleshooting Reasons for `wrecc` not working properly on your machine: - Unsupported architecture/OS - Cannot find libc in standard library search paths (can be fixed by passing custom search path using `-L <path>` option) - If it's not mentioned in the [unimplemented features](#unimplemented) section then please raise an issue ## Contribution If you want to help me with this compiler I would really welcome it. The easiest place to start is probably by implementing one of the missing keywords/types mentioned in the [unimplemented features](#unimplemented) section. Make sure all tests still pass and implement your own if it's something new that is not already being tested.<br> Have a look at the [documentation](https://docs.rs/wrecc_compiler/latest/wrecc_compiler/) to get a high level overview of the compiler pipeline. ## Project goals <a name="goals"></a> - Not relying on custom headers - Passing all C99 tests in [c-testsuite](https://github.com/c-testsuite/c-testsuite) - Compiling real-world C projects like [Git](https://github.com/git/git/tree/master) ## Resources The following resources helped me in building this compiler: - [Crafting Interpreters](https://craftinginterpreters.com/) - Engineering a Compiler (Book) - [acwj](https://github.com/DoctorWkt/acwj) - [saltwater](https://github.com/jyn514/saltwater) - [chibicc](https://github.com/rui314/chibicc) ", Assign "at most 3 tags" to the expected json: {"id":"9156","tags":[]} "only from the tags list I provide: [{"id":77,"name":"3d"},{"id":89,"name":"agent"},{"id":17,"name":"ai"},{"id":54,"name":"algorithm"},{"id":24,"name":"api"},{"id":44,"name":"authentication"},{"id":3,"name":"aws"},{"id":27,"name":"backend"},{"id":60,"name":"benchmark"},{"id":72,"name":"best-practices"},{"id":39,"name":"bitcoin"},{"id":37,"name":"blockchain"},{"id":1,"name":"blog"},{"id":45,"name":"bundler"},{"id":58,"name":"cache"},{"id":21,"name":"chat"},{"id":49,"name":"cicd"},{"id":4,"name":"cli"},{"id":64,"name":"cloud-native"},{"id":48,"name":"cms"},{"id":61,"name":"compiler"},{"id":68,"name":"containerization"},{"id":92,"name":"crm"},{"id":34,"name":"data"},{"id":47,"name":"database"},{"id":8,"name":"declarative-gui "},{"id":9,"name":"deploy-tool"},{"id":53,"name":"desktop-app"},{"id":6,"name":"dev-exp-lib"},{"id":59,"name":"dev-tool"},{"id":13,"name":"ecommerce"},{"id":26,"name":"editor"},{"id":66,"name":"emulator"},{"id":62,"name":"filesystem"},{"id":80,"name":"finance"},{"id":15,"name":"firmware"},{"id":73,"name":"for-fun"},{"id":2,"name":"framework"},{"id":11,"name":"frontend"},{"id":22,"name":"game"},{"id":81,"name":"game-engine "},{"id":23,"name":"graphql"},{"id":84,"name":"gui"},{"id":91,"name":"http"},{"id":5,"name":"http-client"},{"id":51,"name":"iac"},{"id":30,"name":"ide"},{"id":78,"name":"iot"},{"id":40,"name":"json"},{"id":83,"name":"julian"},{"id":38,"name":"k8s"},{"id":31,"name":"language"},{"id":10,"name":"learning-resource"},{"id":33,"name":"lib"},{"id":41,"name":"linter"},{"id":28,"name":"lms"},{"id":16,"name":"logging"},{"id":76,"name":"low-code"},{"id":90,"name":"message-queue"},{"id":42,"name":"mobile-app"},{"id":18,"name":"monitoring"},{"id":36,"name":"networking"},{"id":7,"name":"node-version"},{"id":55,"name":"nosql"},{"id":57,"name":"observability"},{"id":46,"name":"orm"},{"id":52,"name":"os"},{"id":14,"name":"parser"},{"id":74,"name":"react"},{"id":82,"name":"real-time"},{"id":56,"name":"robot"},{"id":65,"name":"runtime"},{"id":32,"name":"sdk"},{"id":71,"name":"search"},{"id":63,"name":"secrets"},{"id":25,"name":"security"},{"id":85,"name":"server"},{"id":86,"name":"serverless"},{"id":70,"name":"storage"},{"id":75,"name":"system-design"},{"id":79,"name":"terminal"},{"id":29,"name":"testing"},{"id":12,"name":"ui"},{"id":50,"name":"ux"},{"id":88,"name":"video"},{"id":20,"name":"web-app"},{"id":35,"name":"web-server"},{"id":43,"name":"webassembly"},{"id":69,"name":"workflow"},{"id":87,"name":"yaml"}]" returns me the "expected json"