[flang-commits] [flang] 4a10b4c - [flang] fix flang builds with clang 20 after #100692 (#106718)

[via flang-commits]

Author: jeanPerier
Date: 2024-08-30T15:43:20+02:00
New Revision: 4a10b4c0bd241f3a2d7162fe29f520af7da6840c

URL: https://github.com/llvm/llvm-project/commit/4a10b4c0bd241f3a2d7162fe29f520af7da6840c
DIFF: https://github.com/llvm/llvm-project/commit/4a10b4c0bd241f3a2d7162fe29f520af7da6840c.diff

LOG: [flang] fix flang builds with clang 20 after #100692 (#106718)

#100692 changes clang template deduction, and an error was now emitted
when building flang with top of the tree clang when mapping std::pow in
intrinsics-library.cpp for constant folding `error: address of
overloaded function 'pow' is ambiguous`

See https://lab.llvm.org/buildbot/#/builders/4/builds/1670

I I am not expert enough to understand if the new error is justified or
not here, but it is easy to help the compiler here with explicit
wrappers to fix the builds.

Added: 
    

Modified: 
    flang/lib/Evaluate/intrinsics-library.cpp

Removed: 
    


################################################################################
diff  --git a/flang/lib/Evaluate/intrinsics-library.cpp b/flang/lib/Evaluate/intrinsics-library.cpp
index 65636b9956e780..ed28d8130808fa 100644
--- a/flang/lib/Evaluate/intrinsics-library.cpp
+++ b/flang/lib/Evaluate/intrinsics-library.cpp
@@ -255,6 +255,25 @@ struct HostRuntimeLibrary<HostT, LibraryVersion::Libm> {
   static constexpr HostRuntimeMap map{table};
   static_assert(map.Verify(), "map must be sorted");
 };
+
+// Helpers to map complex std::pow whose resolution in F2{std::pow} is
+// ambiguous as of clang++ 20.
+template <typename HostT>
+static std::complex<HostT> StdPowF2(
+    const std::complex<HostT> &x, const std::complex<HostT> &y) {
+  return std::pow(x, y);
+}
+template <typename HostT>
+static std::complex<HostT> StdPowF2A(
+    const HostT &x, const std::complex<HostT> &y) {
+  return std::pow(x, y);
+}
+template <typename HostT>
+static std::complex<HostT> StdPowF2B(
+    const std::complex<HostT> &x, const HostT &y) {
+  return std::pow(x, y);
+}
+
 template <typename HostT>
 struct HostRuntimeLibrary<std::complex<HostT>, LibraryVersion::Libm> {
   using F = FuncPointer<std::complex<HostT>, const std::complex<HostT> &>;
@@ -275,9 +294,9 @@ struct HostRuntimeLibrary<std::complex<HostT>, LibraryVersion::Libm> {
       FolderFactory<F, F{std::cosh}>::Create("cosh"),
       FolderFactory<F, F{std::exp}>::Create("exp"),
       FolderFactory<F, F{std::log}>::Create("log"),
-      FolderFactory<F2, F2{std::pow}>::Create("pow"),
-      FolderFactory<F2A, F2A{std::pow}>::Create("pow"),
-      FolderFactory<F2B, F2B{std::pow}>::Create("pow"),
+      FolderFactory<F2, F2{StdPowF2}>::Create("pow"),
+      FolderFactory<F2A, F2A{StdPowF2A}>::Create("pow"),
+      FolderFactory<F2B, F2B{StdPowF2B}>::Create("pow"),
       FolderFactory<F, F{std::sin}>::Create("sin"),
       FolderFactory<F, F{std::sinh}>::Create("sinh"),
       FolderFactory<F, F{std::sqrt}>::Create("sqrt"),