[libc] Fix missing UINTMAX_WIDTH

[michaelrj-google]

In patch #82461 the sprintf tests were made to use UINTMAX_WIDTH which
isn't defined on all systems. This patch changes it to
sizeof(uintmax_t)*CHAR_BIT which is more portable.

[llvmbot]

@llvm/pr-subscribers-libc

Author: Michael Jones (michaelrj-google)

Changes

In patch #82461 the sprintf tests were made to use UINTMAX_WIDTH which
isn't defined on all systems. This patch changes it to
sizeof(uintmax_t)*CHAR_BIT which is more portable.

---

Full diff: https://github.com/llvm/llvm-project/pull/87092.diff

1 Files Affected:

• (modified) libc/test/src/stdio/sprintf_test.cpp (+4-3)

diff --git a/libc/test/src/stdio/sprintf_test.cpp b/libc/test/src/stdio/sprintf_test.cpp
index ba31034146fedf..8e9870f71a9595 100644
--- a/libc/test/src/stdio/sprintf_test.cpp
+++ b/libc/test/src/stdio/sprintf_test.cpp
@@ -203,9 +203,10 @@ TEST(LlvmLibcSPrintfTest, IntConv) {
 
   char format[64];
   char uintmax[128];
-  LIBC_NAMESPACE::sprintf(format, "%%w%du", UINTMAX_WIDTH);
-  const int uintmax_len = LIBC_NAMESPACE::sprintf(uintmax, "%ju", UINTMAX_MAX);
-  written = LIBC_NAMESPACE::sprintf(buff, format, UINTMAX_MAX);
+  LIBC_NAMESPACE::sprintf(format, "%%w%du", sizeof(uintmax_t) * CHAR_BIT);
+  const int uintmax_len =
+      LIBC_NAMESPACE::sprintf(uintmax, "%ju", sizeof(uintmax_t) * CHAR_BIT);
+  written = LIBC_NAMESPACE::sprintf(buff, format, sizeof(uintmax_t) * CHAR_BIT);
   EXPECT_EQ(written, uintmax_len);
   ASSERT_STREQ(buff, uintmax);
 

[nickdesaulniers]

Could also do something like:

#ifndef UINTMAX_WIDTH
#define UINTMAX_WIDTH sizeof(uintmax_t) * CHAR_BIT
#endif

But happy to take this to unbreak builds.

[nickdesaulniers]

See also bf7d997

[nickdesaulniers]

More context:

$ git branch -a --contains bf7d997 | grep origin/release
  remotes/origin/release/14.x
  remotes/origin/release/15.x
  remotes/origin/release/16.x
  remotes/origin/release/17.x
  remotes/origin/release/18.x

shows that bf7d997 first landed in 14.x (or exists there, don't know if it was backported earlier). So clang's <stdint.h> did not define UINTMAX_WIDTH until clang-14, which is the clang version the failed buildbots are running.