build: Bump fmt minimum 7.0, fix fmt+gcc bugs

.github/workflows/ci.yml

@@ -39,7 +39,7 @@ jobs:
             openexr_ver: v2.4.3
             python_ver: 2.7
             simd: sse4.2
-            fmt_ver: 6.1.2
+            fmt_ver: 7.0.1
             pybind11_ver: v2.4.2
             setenvs: export PUGIXML_VERSION=v1.9 CMAKE_VERSION=3.15.5
           - desc: gcc6/C++14 py3.7 boost1.70 exr2.4 ocio1.1
@@ -96,7 +96,7 @@ jobs:
             cxx_std: 17
             python_ver: 3.9
             simd: "avx2,f16c"
-            fmt_ver: 8.1.1
+            fmt_ver: 9.1.0
             pybind11_ver: v2.8.1
           - desc: icc/C++17 py3.9 boost1.76 exr3.1 ocio2.1 qt5.15
             nametag: linux-vfx2022-icc
@@ -147,7 +147,7 @@ jobs:
             cxx_std: 17
             python_ver: "3.10"
             simd: "avx2,f16c"
-            fmt_ver: 9.1.0
+            fmt_ver: 10.1.1
             pybind11_ver: v2.10.0
           - desc: oldest/hobbled gcc6.3/C++14 py2.7 boost-1.66 exr-2.4 no-sse no-ocio
             # Oldest versions of the dependencies that we can muster, and various
@@ -157,7 +157,7 @@ jobs:
             container: aswf/ci-osl:2019
             vfxyear: 2019
             cxx_std: 14
-            fmt_ver: 6.1.2
+            fmt_ver: 7.0.1
             openexr_ver: v2.4.0
             pybind11_ver: v2.4.2
             python_ver: 2.7
@@ -255,7 +255,7 @@ jobs:
             cc_compiler: gcc-11
             cxx_compiler: g++-11
             cxx_std: 17
-            fmt_ver: 9.1.0
+            fmt_ver: 10.1.1
             openexr_ver: v3.2.0
             pybind11_ver: v2.11.1
             python_ver: "3.10"
@@ -275,7 +275,7 @@ jobs:
             cc_compiler: gcc-12
             cxx_compiler: g++-12
             cxx_std: 20
-            fmt_ver: 10.0.0
+            fmt_ver: master
             openexr_ver: main
             pybind11_ver: master
             python_ver: "3.10"
@@ -296,7 +296,7 @@ jobs:
             cxx_compiler: clang++
             cc_compiler: clang
             cxx_std: 20
-            fmt_ver: 9.0.0
+            fmt_ver: 10.1.1
             openexr_ver: v3.1.11
             pybind11_ver: v2.9.2
             python_ver: 3.8

INSTALL.md

@@ -27,9 +27,9 @@ NEW or CHANGED MINIMUM dependencies since the last major release are **bold**.
  * libjpeg >= 8, or libjpeg-turbo >= 1.1 (tested through jpeg9d and jpeg-turbo
    2.1)
  * Boost >= 1.53 (recommended: at least 1.66; tested through 1.81)
- * [fmtlib](https://github.com/fmtlib/fmt) >= 6.1.2 (tested through 10.0). If
-   not found at build time, this will be automatically downloaded unless the
-   build sets `-DBUILD_MISSING_FMT=OFF`.
+ * **[fmtlib](https://github.com/fmtlib/fmt) >= 7.0** (tested through 10.1).
+   If not found at build time, this will be automatically downloaded unless
+   the build sets `-DBUILD_MISSING_FMT=OFF`.
 
 ### Optional dependencies -- features may be disabled if not found
  * If you are building the `iv` viewer (which will be disabled if any of

src/cmake/externalpackages.cmake

@@ -317,7 +317,7 @@ endmacro()
 option (BUILD_FMT_FORCE "Force local download/build of fmt even if installed" OFF)
 option (BUILD_MISSING_FMT "Local download/build of fmt if not installed" ON)
 option (INTERNALIZE_FMT "Copy fmt headers into <install>/include/OpenImageIO/detail/fmt" ON)
-set (BUILD_FMT_VERSION "9.0.0" CACHE STRING "Preferred fmtlib/fmt version, when downloading/building our own")
+set (BUILD_FMT_VERSION "10.0.0" CACHE STRING "Preferred fmtlib/fmt version, when downloading/building our own")
 
 macro (find_or_download_fmt)
     # If we weren't told to force our own download/build of fmt, look
@@ -350,7 +350,8 @@ macro (find_or_download_fmt)
     else ()
         set (OIIO_USING_FMT_LOCAL FALSE)
     endif ()
-    checked_find_package (fmt REQUIRED)
+    checked_find_package (fmt REQUIRED
+                          VERSION_MIN 7.0)
 endmacro()
 
 find_or_download_fmt()

src/include/OpenImageIO/detail/fmt.h

@@ -5,6 +5,7 @@
 #pragma once
 #define OIIO_FMT_H
 
+#include <OpenImageIO/dassert.h>
 #include <OpenImageIO/platform.h>
 #include <OpenImageIO/type_traits.h>
 
@@ -18,6 +19,14 @@
 #    define FMT_EXCEPTIONS 0
 #endif
 
+// Redefining FMT_THROW to something benign seems to avoid some UB or possibly
+// gcc 11+ compiler bug triggered by the definition of FMT_THROW in fmt 10.1+
+// when FMT_EXCEPTIONS=0, which results in mangling SIMD math. This nugget
+// below works around the problems for hard to understand reasons.
+#if !defined(FMT_THROW) && OIIO_GNUC_VERSION >= 110000
+#    define FMT_THROW(x) OIIO_ASSERT_MSG(0, "fmt exception: %s", (x).what())
+#endif
+
 // Use the grisu fast floating point formatting for old fmt versions
 // (irrelevant for >= 7.1).
 #ifndef FMT_USE_GRISU

src/include/OpenImageIO/strutil.h

@@ -127,11 +127,7 @@ template<typename Str, typename... Args>
 OIIO_NODISCARD
 inline std::string format(const Str& fmt, Args&&... args)
 {
-#if FMT_VERSION >= 70000
     return ::fmt::vformat(fmt, ::fmt::make_format_args(args...));
-#else
-    return ::fmt::format(fmt, args...);
-#endif
 }
 } // namespace fmt