8314488: Compiling the JDK with C++17

Reviewed-by: dholmes, stefank, ayang, kvn, iwalulya, jsjolen, ihse

Author: Kim Barrett

doc/hotspot-style.html

@@ -597,11 +597,11 @@ AC_DEFUN([FLAGS_SETUP_CFLAGS_HELPER],
 
   # CXXFLAGS C++ language level for all of JDK, including Hotspot.
   if test "x$TOOLCHAIN_TYPE" = xgcc || test "x$TOOLCHAIN_TYPE" = xclang; then
-    LANGSTD_CXXFLAGS="-std=c++14"
+    LANGSTD_CXXFLAGS="-std=c++17"
   elif test "x$TOOLCHAIN_TYPE" = xmicrosoft; then
-    LANGSTD_CXXFLAGS="-std:c++14"
+    LANGSTD_CXXFLAGS="-std:c++17"
   else
-    AC_MSG_ERROR([Cannot enable C++14 for this toolchain])
+    AC_MSG_ERROR([Cannot enable C++17 for this toolchain])
   fi
   TOOLCHAIN_CFLAGS_JDK_CXXONLY="$TOOLCHAIN_CFLAGS_JDK_CXXONLY $LANGSTD_CXXFLAGS"
   TOOLCHAIN_CFLAGS_JVM="$TOOLCHAIN_CFLAGS_JVM $LANGSTD_CXXFLAGS"

doc/hotspot-style.md

@@ -1,7 +1,7 @@
 		// Configure cpptools IntelliSense
 		"C_Cpp.intelliSenseCachePath": "{{OUTPUTDIR}}/.vscode",
 		"C_Cpp.default.compileCommands": "{{OUTPUTDIR}}/compile_commands.json",
-		"C_Cpp.default.cppStandard": "c++14",
+		"C_Cpp.default.cppStandard": "c++17",
 		"C_Cpp.default.compilerPath": "{{COMPILER}}",
 
 		// Configure ccls

make/autoconf/flags-cflags.m4

@@ -1,7 +1,7 @@
 		// Configure cpptools IntelliSense
 		"C_Cpp.intelliSenseCachePath": "{{OUTPUTDIR}}/.vscode",
 		"C_Cpp.default.compileCommands": "{{OUTPUTDIR}}/compile_commands.json",
-		"C_Cpp.default.cppStandard": "c++14",
+		"C_Cpp.default.cppStandard": "c++17",
 		"C_Cpp.default.compilerPath": "{{COMPILER}}",
 
 		// Configure clangd

make/ide/vscode/hotspot/indexers/ccls-settings.txt

@@ -1,5 +1,5 @@
 		// Configure cpptools IntelliSense
 		"C_Cpp.intelliSenseCachePath": "{{OUTPUTDIR}}/.vscode",
 		"C_Cpp.default.compileCommands": "{{OUTPUTDIR}}/compile_commands.json",
-		"C_Cpp.default.cppStandard": "c++14",
+		"C_Cpp.default.cppStandard": "c++17",
 		"C_Cpp.default.compilerPath": "{{COMPILER}}",

make/ide/vscode/hotspot/indexers/clangd-settings.txt

@@ -1,7 +1,7 @@
 		// Configure cpptools IntelliSense
 		"C_Cpp.intelliSenseCachePath": "{{OUTPUTDIR}}/.vscode",
 		"C_Cpp.default.compileCommands": "{{OUTPUTDIR}}/compile_commands.json",
-		"C_Cpp.default.cppStandard": "c++14",
+		"C_Cpp.default.cppStandard": "c++17",
 		"C_Cpp.default.compilerPath": "{{COMPILER}}",
 
 		// Configure RTags