Implement desired functionality

src/aro/Diagnostics/messages.def

@@ -1294,15 +1294,11 @@ invalid_utf8
     .msg = "source file is not valid UTF-8"
     .kind = .@"error"
 
-implicitly_unsigned_literal_clang
+implicitly_unsigned_literal
     .msg = "integer literal is too large to be represented in a signed integer type, interpreting as unsigned"
     .opt = W("implicitly-unsigned-literal")
     .kind = .warning
 
-implicitly_unsigned_literal_gcc
-    .msg = "integer constant is so large that it is unsigned"
-    .kind = .warning
-
 invalid_preproc_operator
     .msg = "token is not a valid binary operator in a preprocessor subexpression"
     .kind = .@"error"

src/aro/Parser.zig

@@ -29,6 +29,7 @@ const StringId = StrInt.StringId;
 const Builtins = @import("Builtins.zig");
 const Builtin = Builtins.Builtin;
 const evalBuiltin = @import("Builtins/eval.zig").eval;
+const target_util = @import("target.zig");
 
 const Switch = struct {
     default: ?TokenIndex = null,
@@ -8418,7 +8419,7 @@ fn fixedSizeInt(p: *Parser, base: u8, buf: []const u8, suffix: NumberSuffix, tok
     if (suffix.isSignedInteger()) {
         const max_int = try Value.maxInt(p.comp.types.intmax, p.comp);
         if (interned_val.compare(.gt, max_int, p.comp)) {
-            try p.errTok(if (p.comp.langopts.emulate == .gcc) .implicitly_unsigned_literal_gcc else .implicitly_unsigned_literal_clang, tok_i);
+            try p.errTok(.implicitly_unsigned_literal, tok_i);
         }
     }
 
@@ -8448,7 +8449,17 @@ fn fixedSizeInt(p: *Parser, base: u8, buf: []const u8, suffix: NumberSuffix, tok
         const max_int = try Value.maxInt(res.ty, p.comp);
         if (interned_val.compare(.lte, max_int, p.comp)) break;
     } else {
-        res.ty = .{ .specifier = if (p.comp.langopts.emulate == .gcc) .int128 else .ulong_long };
+        res.ty = .{ .specifier = spec: {
+            if (p.comp.langopts.emulate == .gcc) {
+                if (target_util.hasInt128(p.comp.target)) {
+                    break :spec .int128;
+                } else {
+                    break :spec .long_long;
+                }
+            } else {
+                break :spec .ulong_long;
+            }
+        } };
     }
 
     res.node = try p.addNode(.{ .tag = .int_literal, .ty = res.ty, .data = undefined });

test/cases/integer literal promotion warning clang.c

@@ -1,8 +1,5 @@
 //aro-args --emulate=clang
 
-_Static_assert(__builtin_types_compatible_p(typeof(18446744073709550592), __int128), "");
 _Static_assert(__builtin_types_compatible_p(typeof(18446744073709550592), unsigned long long), "");
 
-#define EXPECTED_ERRORS "integer literal promotion warning clang.c:3:52: warning: integer literal is too large to be represented in a signed integer type, interpreting as unsigned [-Wimplicitly-unsigned-literal]" \
-                        "integer literal promotion warning clang.c:3:1: error: static assertion failed '__builtin_types_compatible_p(unsigned long long, __int128)' \"\"" \
-                        "integer literal promotion warning clang.c:4:52: warning: integer literal is too large to be represented in a signed integer type, interpreting as unsigned [-Wimplicitly-unsigned-literal]"
+#define EXPECTED_ERRORS "integer literal promotion warning clang.c:3:52: warning: integer literal is too large to be represented in a signed integer type, interpreting as unsigned [-Wimplicitly-unsigned-literal]"

test/cases/integer literal promotion warning gcc 32.c

@@ -0,0 +1,6 @@
+//aro-args --emulate=gcc --target=riscv32-linux-gnu
+
+_Static_assert(__builtin_types_compatible_p(typeof(18446744073709550592), long long int), "");
+
+#define EXPECTED_ERRORS "integer literal promotion warning gcc 32.c:3:52: warning: integer literal is too large to be represented in a signed integer type, interpreting as unsigned [-Wimplicitly-unsigned-literal]"
+

test/cases/integer literal promotion warning gcc 64.c

@@ -0,0 +1,6 @@
+//aro-args --emulate=gcc --target=x86_64-linux-gnu
+
+_Static_assert(__builtin_types_compatible_p(typeof(18446744073709550592), __int128), "");
+
+#define EXPECTED_ERRORS "integer literal promotion warning gcc 64.c:3:52: warning: integer literal is too large to be represented in a signed integer type, interpreting as unsigned [-Wimplicitly-unsigned-literal]"
+