zig cc: support reading from non-files

    echo 'some C program' | $CC -x c -

Is a common pattern to test for compiler or linker features. This patch
adds support for reading from non-regular files.

This will make at least one more Go test to pass.

1 files changed, 9 insertions, 11 deletions

diff --git a/src/Compilation.zig b/src/Compilation.zig
index 1b6d805bb3..3ae43773e3 100644
--- a/src/Compilation.zig
+++ b/src/Compilation.zig
@@ -3981,7 +3981,7 @@ fn updateCObject(comp: *Compilation, c_object: *CObject, c_obj_prog_node: *std.P
 
         // We can't know the digest until we do the C compiler invocation,
         // so we need a temporary filename.
-        const out_obj_path = try comp.tmpFilePath(arena, o_basename);
+        const out_obj_path = try comp.local_cache_directory.tmpFilePath(arena, o_basename);
         var zig_cache_tmp_dir = try comp.local_cache_directory.handle.makeOpenPath("tmp", .{});
         defer zig_cache_tmp_dir.close();
 
@@ -4129,16 +4129,6 @@ fn updateCObject(comp: *Compilation, c_object: *CObject, c_obj_prog_node: *std.P
     };
 }
 
-pub fn tmpFilePath(comp: *Compilation, ally: Allocator, suffix: []const u8) error{OutOfMemory}![]const u8 {
-    const s = std.fs.path.sep_str;
-    const rand_int = std.crypto.random.int(u64);
-    if (comp.local_cache_directory.path) |p| {
-        return std.fmt.allocPrint(ally, "{s}" ++ s ++ "tmp" ++ s ++ "{x}-{s}", .{ p, rand_int, suffix });
-    } else {
-        return std.fmt.allocPrint(ally, "tmp" ++ s ++ "{x}-{s}", .{ rand_int, suffix });
-    }
-}
-
 pub fn addTranslateCCArgs(
     comp: *Compilation,
     arena: Allocator,
@@ -4597,6 +4587,14 @@ pub const FileExt = enum {
             => false,
         };
     }
+
+    // maximum length of @tagName(ext: FileExt)
+    pub const max_len = blk: {
+        var max: u16 = 0;
+        inline for (std.meta.tags(FileExt)) |ext|
+            max = std.math.max(@tagName(ext).len, max);
+        break :blk max;
+    };
 };
 
 pub fn hasObjectExt(filename: []const u8) bool {