Chibicc Patch Enabling File Inclusion via HTTPS using CURL

Make-chibicc-possible-to-include-files-over-https.patch

From 80dc44045e764fcd438971fde323f2207165f091 Mon Sep 17 00:00:00 2001
From: 13m0n4de <[email protected]>
Date: Sat, 17 Feb 2024 22:08:56 +0800
Subject: [PATCH] Make it possible to include files over https

---
 Makefile     |  2 +-
 main.c       |  7 +++++++
 preprocess.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 55 insertions(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index c22748c..49b553d 100644
--- a/Makefile
+++ b/Makefile
@@ -9,7 +9,7 @@ TESTS=$(TEST_SRCS:.c=.exe)
 # Stage 1
 
 chibicc: $(OBJS)
-	$(CC) $(CFLAGS) -o $@ $^ $(LDFLAGS)
+	$(CC) $(CFLAGS) -o $@ $^ $(LDFLAGS) -lcurl
 
 $(OBJS): chibicc.h
 
diff --git a/main.c b/main.c
index ffaabf4..d850c56 100644
--- a/main.c
+++ b/main.c
@@ -1,4 +1,5 @@
 #include "chibicc.h"
+#include <curl/curl.h>
 
 typedef enum {
   FILE_NONE, FILE_C, FILE_ASM, FILE_OBJ, FILE_AR, FILE_DSO,
@@ -702,6 +703,10 @@ int main(int argc, char **argv) {
   init_macros();
   parse_args(argc, argv);
 
+  if (curl_global_init(CURL_GLOBAL_DEFAULT) != 0) {
+    error("Could not initialize Global cURL context. (Yes, your C compiler is using curl Kappa)");
+  }
+
   if (opt_cc1) {
     add_default_include_paths(argv[0]);
     cc1();
@@ -785,6 +790,8 @@ int main(int argc, char **argv) {
     continue;
   }
 
+  curl_global_cleanup();
+
   if (ld_args.len > 0)
     run_linker(&ld_args, opt_o ? opt_o : "a.out");
   return 0;
diff --git a/preprocess.c b/preprocess.c
index 2bef487..66332d4 100644
--- a/preprocess.c
+++ b/preprocess.c
@@ -23,6 +23,7 @@
 // https://github.com/rui314/chibicc/wiki/cpp.algo.pdf
 
 #include "chibicc.h"
+#include <curl/curl.h>
 
 typedef struct MacroParam MacroParam;
 struct MacroParam {
@@ -861,6 +862,52 @@ static Token *preprocess2(Token *tok) {
       bool is_dquote;
       char *filename = read_include_filename(&tok, tok->next, &is_dquote);
 
+      // Hacked by https://github.com/13m0n4de
+      // Available to everyone under Public Domain
+      if (strncmp("https://", filename, 8) == 0 && is_dquote) {
+        CURLU *url = curl_url();
+        if (curl_url_set(url, CURLUPART_URL, filename, 0)) {
+          error("Could not parse the include URL '%s'", filename);
+        }
+
+        char *path;
+        if (curl_url_get(url, CURLUPART_PATH, &path, 0)) {
+          error("Could not extract path from the include URL '%s'", filename);
+        }
+
+        curl_url_cleanup(url);
+        
+        char *dir = dirname(tok->filename);
+        char *base = basename(path);
+        char download_path[strlen(dir) + strlen(base) + 2];
+        sprintf(download_path, "%s/%s", dir, base);
+
+        curl_free(path);
+
+        CURL *curl = curl_easy_init();
+        if (curl == NULL) {
+          error("Could not initialize cURL context");
+        }
+
+        FILE *download_file = fopen(download_path, "w");
+        if (download_file == NULL) {
+          error("Could not open file '%s': %s", download_path, strerror(errno));
+        }
+
+        curl_easy_setopt(curl, CURLOPT_URL, filename);
+        curl_easy_setopt(curl, CURLOPT_WRITEDATA, download_file);
+        CURLcode res = curl_easy_perform(curl);
+        if (res != CURLE_OK) {
+          error("Could not download '%s': %s", filename, curl_easy_strerror(res));
+        }
+
+        curl_easy_cleanup(curl);
+        fclose(download_file);
+
+        tok = include_file(tok, download_path, start->next->next);
+        continue;
+      }
+
       if (filename[0] != '/' && is_dquote) {
         char *path = format("%s/%s", dirname(strdup(start->file->name)), filename);
         if (file_exists(path)) {
-- 
2.43.0

The idea comes from: youtube.com/watch?v=4vSyqK3SK-0
This is the patch made for TinyCC, as seen in the video: rexim/a6636976d12f67ea530ece118a700317
Here is my new patch designed to support the latest version of TinyCC: https://gist.github.com/13m0n4de/84912522cce6db31da069baf1add04f8

This patch does the same job, only it's for Chibicc instead.

In this patch, it's necessary to use double quotes to enclose the HTTPS links instead of angle brackets.
This is because when chibicc tokenizes, it treats "//" and everything following it as a comment and removes it.
However, when parsed as a string, there's no issue.

Example:

#define STB_SPRINTF_IMPLEMENTATION
#include "https://raw.githubusercontent.com/nothings/stb/master/stb_sprintf.h"
#include <stdio.h>

int main() {
    char buffer[20];

    // Using functions defined by stb_sprintf.h
    stbsp_sprintf(buffer, "Hello %s", "NAVI");
    puts(buffer);

    return 0;
}