Fix fread() with 2gb+ sizes

test/libc/stdio/freopen_test.c

@@ -16,53 +16,67 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/stdio/stdio.h"
-#include "libc/testlib/testlib.h"
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
 
 /*
  * This test was contributed by @ahgamut
  * https://github.com/jart/cosmopolitan/issues/61#issuecomment-792214575
  */
 
-void SetUpOnce(void) {
-  testlib_enable_tmp_setup_teardown();
+char path[PATH_MAX];
+
+void teardown(void) {
+  unlink(path);
 }
 
-int writefile(const char* filename) {
-  int stat = 0;
-  FILE* fp = fopen(filename, "w");
-  stat = fputs("cosmopolitan libc\n", fp);
-  fclose(fp);
-  return stat;
-}
-
-int readfile(const char* filename) {
-  int stat = 0;
-  char buf1[30];
-  char buf2[30];
-  FILE *fp1, *fp2;
-  fp1 = fopen(filename, "r");
-  if (!fp1) {
-    printf("failed to read %s in r\n", filename);
+int setup(void) {
+  int fd;
+  const char* tmpdir;
+  if ((tmpdir = getenv("TMPDIR")))
+    strlcpy(path, tmpdir, sizeof(path));
+  else
+    strlcpy(path, "/tmp", sizeof(path));
+  strlcat(path, "/freopen_test.XXXXXX", sizeof(path));
+  if ((fd = mkstemp(path)) == -1)
     return 1;
-  }
-  buf1[0] = fgetc(fp1);
-  buf1[1] = '\0';
-  fp2 = freopen(filename, "rb", fp1);
-  if (!fp2) {
-    printf("failed to read %s in rb\n", filename);
-    return 1;
-  }
-  stat = fread(buf2, sizeof(buf2[0]), 20, fp2);
-  ASSERT_EQ(18, stat);
-  buf2[stat] = '\0';
-  fclose(fp2);
-  ASSERT_STREQ("c", buf1);
-  ASSERT_STREQ("cosmopolitan libc\n", buf2);
+  if (write(fd, "cosmopolitan libc\n", 18) != 18)
+    return 2;
+  if (close(fd))
+    return 3;
   return 0;
 }
 
-TEST(freopen, test) {
-  writefile("file.txt");
-  readfile("file.txt");
+int test(void) {
+  FILE* fp;
+  char buf[20];
+  if (!(fp = fopen(path, "r")))
+    return 4;
+  if (fgetc(fp) != 'c')
+    return 5;
+  if (!(fp = freopen(path, "rb", fp)))
+    return 6;
+  if (fread(buf, 1, 20, fp) != 18)
+    return 7;
+  if (memcmp(buf, "cosmopolitan libc\n", 18))
+    return 8;
+  if (fclose(fp))
+    return 9;
+  return 0;
+}
+
+int main(int argc, char* argv[]) {
+  int rc;
+  if ((rc = setup())) {
+    perror(path);
+    teardown();
+    return rc;
+  }
+  rc = test();
+  teardown();
+  return rc;
 }

test/posix/BUILD.mk

@@ -52,6 +52,9 @@ o/$(MODE)/test/posix/%.dbg:			\
 		$(APE_NO_MODIFY_SELF)
 	@$(APELINK)
 
+o/$(MODE)/test/posix/fread3gb_test.runs:	\
+		private QUOTA += -F5gb -M5gb
+
 .PHONY: o/$(MODE)/test/posix
 o/$(MODE)/test/posix:				\
 		$(TEST_POSIX_BINS)		\

test/posix/fread3gb_test.c

@@ -0,0 +1,73 @@
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#define SIZE ((size_t)2 * 1024 * 1024 * 1024 + 13)
+
+char path[PATH_MAX];
+
+void teardown(void) {
+  unlink(path);
+}
+
+int setup(void) {
+  int fd;
+  struct stat st;
+  const char *tmpdir;
+  if (!stat("/dev/shm", &st))
+    strlcpy(path, "/dev/shm", sizeof(path));
+  else if ((tmpdir = getenv("TMPDIR")))
+    strlcpy(path, tmpdir, sizeof(path));
+  else
+    strlcpy(path, "/tmp", sizeof(path));
+  strlcat(path, "/fread3gb.XXXXXX", sizeof(path));
+  if ((fd = mkstemp(path)) == -1)
+    return 1;
+  if (ftruncate(fd, SIZE))
+    return 2;
+  if (pwrite(fd, "a", 1, 0) != 1)
+    return 3;
+  if (pwrite(fd, "z", 1, SIZE - 1) != 1)
+    return 4;
+  if (close(fd))
+    return 5;
+  return 0;
+}
+
+int test(void) {
+  FILE *f;
+  char *buf;
+  size_t rc;
+  if (!(f = fopen(path, "r")))
+    return 6;
+  if (!(buf = malloc(SIZE)))
+    return 7;
+  if ((rc = fread(buf, SIZE, 1, f)) != 1) {
+    fprintf(stderr, "tell = %zu\n", ftello(f));
+    fprintf(stderr, "rc = %zu\n", rc);
+    perror("fread");
+    return 8;
+  }
+  if (buf[0] != 'a')
+    return 9;
+  if (buf[SIZE - 1] != 'z')
+    return 10;
+  if (fclose(f))
+    return 11;
+  return 0;
+}
+
+int main(int argc, char *argv[]) {
+  int rc;
+  if ((rc = setup())) {
+    perror(path);
+    teardown();
+    return rc;
+  }
+  rc = test();
+  teardown();
+  return rc;
+}