From 76b80dd7f4423b37753031a6ef061ef08c570c06 Mon Sep 17 00:00:00 2001
From: Mustafa Quraish <mustafaq9@gmail.com>
Date: Sat, 29 Jan 2022 22:26:17 -0500
Subject: Make the compiler / scripts work on Linux too (yay!)

---
 assemble.sh     | 17 ++++++++++++++---
 cup/generator.c | 12 ++++++++++++
 tests/common.sh | 17 ++++++++++++++---
 3 files changed, 40 insertions(+), 6 deletions(-)

diff --git a/assemble.sh b/assemble.sh
index 90f945f..ed9b46e 100755
--- a/assemble.sh
+++ b/assemble.sh
@@ -8,7 +8,18 @@ then
     exit 1
 fi
 
-set -xe
 
-nasm -f macho64 -o $1.o $1
-ld -lSystem $1.o
+case "$(uname -s)" in
+   Darwin)
+        set -xe
+        nasm -f macho64 -o $1.o $1
+        ld -lSystem $1.o
+        set +xe
+        ;;
+   Linux)
+        set -xe
+        nasm -f elf64 -o $1.o $1
+        ld $1.o
+        set +xe
+        ;;
+esac
\ No newline at end of file
diff --git a/cup/generator.c b/cup/generator.c
index d7b252d..61e8c69 100644
--- a/cup/generator.c
+++ b/cup/generator.c
@@ -307,10 +307,22 @@ void generate_asm(Node *root, FILE *out)
     }
 
     // Call `main` from `_main` and return
+#if __APPLE__
     fprintf(out, "global _main\n");
     fprintf(out, "_main:\n");
+#else
+    fprintf(out, "global _start\n");
+    fprintf(out, "_start:\n");
+#endif
     fprintf(out, "    call main\n");
+
+#if __APPLE__
     fprintf(out, "    ret\n");
+#else
+    fprintf(out, "    mov rdi, rax\n");
+    fprintf(out, "    mov rax, %d\n", SYS_exit);
+    fprintf(out, "    syscall\n");
+#endif
 
     // TODO: Add implementations of some primitives?
 }
\ No newline at end of file
diff --git a/tests/common.sh b/tests/common.sh
index 80e0bea..f863826 100644
--- a/tests/common.sh
+++ b/tests/common.sh
@@ -1,9 +1,20 @@
 #!/bin/bash
 
 function assemble() {
-    # Note: macOS only for now, abstract this out later
-    nasm -f macho64 -o output.o output.nasm
-    ld -lSystem output.o
+    case "$(uname -s)" in
+        Darwin)
+                set -e
+                nasm -f macho64 -o output.nasm.o output.nasm
+                ld -lSystem output.nasm.o
+                set +e
+                ;;
+        Linux)
+                set -e
+                nasm -f elf64 -o output.nasm.o output.nasm
+                ld output.nasm.o
+                set +e
+                ;;
+    esac
 }
 
 function assert_exit_status() {
-- 
cgit v1.2.3