Auto merge of #44906 - dkl:main-signature, r=nagisa

Fix native main() signature on 64bit

Hello,

in LLVM-IR produced by rustc on x86_64-linux-gnu, the native main() function had incorrect types for the function result and argc parameter: i64, while it should be i32 (really c_int). See also #20064, #29633.

So I've attempted a fix here. I tested it by checking the LLVM IR produced with --target x86_64-unknown-linux-gnu and i686-unknown-linux-gnu. Also I tried running the tests (`./x.py test`), however I'm getting two failures with and without the patch, which I'm guessing is unrelated.

Author: bors

src/librustc_back/target/aarch64_apple_ios.rs

@@ -18,6 +18,7 @@ pub fn target() -> TargetResult {
         llvm_target: "arm64-apple-ios".to_string(),
         target_endian: "little".to_string(),
         target_pointer_width: "64".to_string(),
+        target_c_int_width: "32".to_string(),
         data_layout: "e-m:o-i64:64-i128:128-n32:64-S128".to_string(),
         arch: "aarch64".to_string(),
         target_os: "ios".to_string(),

src/librustc_back/target/aarch64_linux_android.rs

@@ -24,6 +24,7 @@ pub fn target() -> TargetResult {
         llvm_target: "aarch64-linux-android".to_string(),
         target_endian: "little".to_string(),
         target_pointer_width: "64".to_string(),
+        target_c_int_width: "32".to_string(),
         data_layout: "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128".to_string(),
         arch: "aarch64".to_string(),
         target_os: "android".to_string(),

src/librustc_back/target/aarch64_unknown_freebsd.rs

@@ -22,6 +22,7 @@ pub fn target() -> TargetResult {
         llvm_target: "aarch64-unknown-freebsd".to_string(),
         target_endian: "little".to_string(),
         target_pointer_width: "64".to_string(),
+        target_c_int_width: "32".to_string(),
         data_layout: "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128".to_string(),
         arch: "aarch64".to_string(),
         target_os: "freebsd".to_string(),

src/librustc_back/target/aarch64_unknown_fuchsia.rs

@@ -19,6 +19,7 @@ pub fn target() -> TargetResult {
         llvm_target: "aarch64-unknown-fuchsia".to_string(),
         target_endian: "little".to_string(),
         target_pointer_width: "64".to_string(),
+        target_c_int_width: "32".to_string(),
         data_layout: "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128".to_string(),
         arch: "aarch64".to_string(),
         target_os: "fuchsia".to_string(),

src/librustc_back/target/aarch64_unknown_linux_gnu.rs

@@ -22,6 +22,7 @@ pub fn target() -> TargetResult {
         llvm_target: "aarch64-unknown-linux-gnu".to_string(),
         target_endian: "little".to_string(),
         target_pointer_width: "64".to_string(),
+        target_c_int_width: "32".to_string(),
         target_env: "gnu".to_string(),
         data_layout: "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128".to_string(),
         arch: "aarch64".to_string(),

src/librustc_back/target/aarch64_unknown_linux_musl.rs

@@ -22,6 +22,7 @@ pub fn target() -> TargetResult {
         llvm_target: "aarch64-unknown-linux-musl".to_string(),
         target_endian: "little".to_string(),
         target_pointer_width: "64".to_string(),
+        target_c_int_width: "32".to_string(),
         target_env: "musl".to_string(),
         data_layout: "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128".to_string(),
         arch: "aarch64".to_string(),

src/librustc_back/target/arm_linux_androideabi.rs

@@ -21,6 +21,7 @@ pub fn target() -> TargetResult {
         llvm_target: "arm-linux-androideabi".to_string(),
         target_endian: "little".to_string(),
         target_pointer_width: "32".to_string(),
+        target_c_int_width: "32".to_string(),
         data_layout: "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64".to_string(),
         arch: "arm".to_string(),
         target_os: "android".to_string(),

src/librustc_back/target/arm_unknown_linux_gnueabi.rs

@@ -18,6 +18,7 @@ pub fn target() -> TargetResult {
         llvm_target: "arm-unknown-linux-gnueabi".to_string(),
         target_endian: "little".to_string(),
         target_pointer_width: "32".to_string(),
+        target_c_int_width: "32".to_string(),
         data_layout: "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64".to_string(),
         arch: "arm".to_string(),
         target_os: "linux".to_string(),

src/librustc_back/target/arm_unknown_linux_gnueabihf.rs

@@ -18,6 +18,7 @@ pub fn target() -> TargetResult {
         llvm_target: "arm-unknown-linux-gnueabihf".to_string(),
         target_endian: "little".to_string(),
         target_pointer_width: "32".to_string(),
+        target_c_int_width: "32".to_string(),
         data_layout: "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64".to_string(),
         arch: "arm".to_string(),
         target_os: "linux".to_string(),

src/librustc_back/target/arm_unknown_linux_musleabi.rs

@@ -25,6 +25,7 @@ pub fn target() -> TargetResult {
         llvm_target: "arm-unknown-linux-gnueabi".to_string(),
         target_endian: "little".to_string(),
         target_pointer_width: "32".to_string(),
+        target_c_int_width: "32".to_string(),
         data_layout: "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64".to_string(),
         arch: "arm".to_string(),
         target_os: "linux".to_string(),