[llvm-branch-commits] [libcxx] release/18.x: [libcxx] coerce formatter precision to int (#87738) (PR #87801)

[via llvm-branch-commits]

https://github.com/llvmbot created https://github.com/llvm/llvm-project/pull/87801

Backport e1830f586ac4c504f632bdb69aab49234256e899

Requested by: @androm3da

>From 0b39e23a5a34957fa31a3180dcaf18df0bec9e95 Mon Sep 17 00:00:00 2001
From: Brian Cain <bcain at quicinc.com>
Date: Fri, 5 Apr 2024 11:06:37 -0500
Subject: [PATCH] [libcxx] coerce formatter precision to int (#87738)

__precision_ is declared as an int32_t which on some hexagon platforms
is defined as a long.

This change fixes errors like the ones below:

In file included from
/local/mnt/workspace/hex/llvm-project/libcxx/test/libcxx/diagnostics/format.nodiscard_extensions.compile.pass.cpp:19:
In file included from
/local/mnt/workspace/hex/obj_runtimes_hex88_qurt_v75_ON_ON_shared/include/c++/v1/format:202:
In file included from
/local/mnt/workspace/hex/obj_runtimes_hex88_qurt_v75_ON_ON_shared/include/c++/v1/__format/format_functions.h:29:

/local/mnt/workspace/hex/obj_runtimes_hex88_qurt_v75_ON_ON_shared/include/c++/v1/__format/formatter_floating_point.h:700:17:
error: no matching function for call to 'max'
700 | int __p = std::max(1, (__specs.__has_precision() ?
__specs.__precision_ : 6));
          |                 ^~~~~~~~

/local/mnt/workspace/hex/obj_runtimes_hex88_qurt_v75_ON_ON_shared/include/c++/v1/__format/formatter_floating_point.h:771:25:
note: in instantiation of function template specialization
'std::__formatter::__format_floating_point<float, char,
std::format_context>' requested here
771 | return __formatter::__format_floating_point(__value, __ctx,
__parser_.__get_parsed_std_specifications(__ctx));
          |                         ^

/local/mnt/workspace/hex/obj_runtimes_hex88_qurt_v75_ON_ON_shared/include/c++/v1/__format/format_functions.h:284:42:
note: in instantiation of function template specialization
'std::__formatter_floating_point<char>::format<float,
std::format_context>' requested here
284 | __ctx.advance_to(__formatter.format(__arg, __ctx));
          |                                          ^

/local/mnt/workspace/hex/obj_runtimes_hex88_qurt_v75_ON_ON_shared/include/c++/v1/__format/format_functions.h:429:15:
note: in instantiation of function template specialization
'std::__vformat_to<std::back_insert_iterator<std::string>, char,
std::back_insert_iterator<std::__format::__output_buffer<char>>>'
requested here
429 | return std::__vformat_to(std::move(__out_it), __fmt, __args);
          |               ^

/local/mnt/workspace/hex/obj_runtimes_hex88_qurt_v75_ON_ON_shared/include/c++/v1/__format/format_functions.h:462:8:
note: in instantiation of function template specialization
'std::vformat_to<std::back_insert_iterator<std::string>>' requested here
      462 |   std::vformat_to(std::back_inserter(__res), __fmt, __args);
          |        ^

/local/mnt/workspace/hex/llvm-project/libcxx/test/libcxx/diagnostics/format.nodiscard_extensions.compile.pass.cpp:29:8:
note: in instantiation of function template specialization
'std::vformat<void>' requested here
       29 |   std::vformat("", std::make_format_args());
          |        ^

/local/mnt/workspace/hex/obj_runtimes_hex88_qurt_v75_ON_ON_shared/include/c++/v1/__algorithm/max.h:35:1:
note: candidate template ignored: deduced conflicting types for
parameter '_Tp' ('int' vs. 'int32_t' (aka 'long'))
35 | max(_LIBCPP_LIFETIMEBOUND const _Tp& __a, _LIBCPP_LIFETIMEBOUND
const _Tp& __b) {
          | ^

/local/mnt/workspace/hex/obj_runtimes_hex88_qurt_v75_ON_ON_shared/include/c++/v1/__algorithm/max.h:43:1:
note: candidate template ignored: could not match
'initializer_list<_Tp>' against 'int'
       43 | max(initializer_list<_Tp> __t, _Compare __comp) {
          | ^

/local/mnt/workspace/hex/obj_runtimes_hex88_qurt_v75_ON_ON_shared/include/c++/v1/__algorithm/max.h:48:86:
note: candidate function template not viable: requires single argument
'__t', but 2 arguments were provided
48 | _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI
_LIBCPP_CONSTEXPR_SINCE_CXX14 _Tp max(initializer_list<_Tp> __t) {
| ^ ~~~~~~~~~~~~~~~~~~~~~~~~~

/local/mnt/workspace/hex/obj_runtimes_hex88_qurt_v75_ON_ON_shared/include/c++/v1/__algorithm/max.h:29:1:
note: candidate function template not viable: requires 3 arguments, but
2 were provided
29 | max(_LIBCPP_LIFETIMEBOUND const _Tp& __a, _LIBCPP_LIFETIMEBOUND
const _Tp& __b, _Compare __comp) {
| ^
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

(cherry picked from commit e1830f586ac4c504f632bdb69aab49234256e899)
---
 libcxx/include/__format/formatter_floating_point.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libcxx/include/__format/formatter_floating_point.h b/libcxx/include/__format/formatter_floating_point.h
index 6802a8b7bd4ca3..46a090a787ae28 100644
--- a/libcxx/include/__format/formatter_floating_point.h
+++ b/libcxx/include/__format/formatter_floating_point.h
@@ -689,7 +689,7 @@ __format_floating_point(_Tp __value, _FormatContext& __ctx, __format_spec::__par
       // Let P equal the precision if nonzero, 6 if the precision is not
       // specified, or 1 if the precision is 0. Then, if a conversion with
       // style E would have an exponent of X:
-      int __p = std::max(1, (__specs.__has_precision() ? __specs.__precision_ : 6));
+      int __p = std::max<int>(1, (__specs.__has_precision() ? __specs.__precision_ : 6));
       if (__result.__exponent == __result.__last)
         // if P > X >= -4, the conversion is with style f or F and precision P - 1 - X.
         // By including the radix point it calculates P - (1 + X)