csharpcomp: Reduce number of read() system calls.

* lib/csharpcomp.c: Include <stddef.h>.
(compile_csharp_using_dotnet): Read bytes into a buffer, not one-by-one.

ChangeLog

@@ -1,3 +1,9 @@
+2025-02-25  Bruno Haible  <[email protected]>
+
+	csharpcomp: Reduce number of read() system calls.
+	* lib/csharpcomp.c: Include <stddef.h>.
+	(compile_csharp_using_dotnet): Read bytes into a buffer, not one-by-one.
+
 2025-02-25  Bruno Haible  <[email protected]>
 
 	vc-mtime: Reduce number of read() system calls.

lib/csharpcomp.c

@@ -23,6 +23,7 @@
 
 #include <dirent.h>
 #include <errno.h>
+#include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -311,11 +312,17 @@ compile_csharp_using_dotnet (const char * const *sources,
             {
               /* Read the subprocess output, and test whether it is
                  non-empty.  */
-              size_t count = 0;
-              char c;
+              ptrdiff_t count = 0;
 
-              while (safe_read (fd[0], &c, 1) > 0)
-                count++;
+              for (;;)
+                {
+                  char buf[1024];
+                  ptrdiff_t n = safe_read (fd[0], buf, sizeof (buf));
+                  if (n > 0)
+                    count += n;
+                  else
+                    break;
+                }
 
               close (fd[0]);