Merge for issue #24915

configure

@@ -667,6 +667,12 @@ UNIVERSAL_ARCH_FLAGS
 CFLAGS_NODIST
 BASECFLAGS
 OPT
+LLVM_PROF_FOUND
+LLVM_PROF_ERR
+LLVM_PROF_FILE
+LLVM_PROF_MERGER
+PGO_PROF_USE_FLAG
+PGO_PROF_GEN_FLAG
 ABIFLAGS
 LN
 MKDIR_P
@@ -6431,6 +6437,80 @@ $as_echo "no" >&6; }
 fi
 
 
+# Enable PGO flags.
+# Extract the first word of "llvm-profdata", so it can be a program name with args.
+set dummy llvm-profdata; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if ${ac_cv_prog_LLVM_PROF_FOUND+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  if test -n "$LLVM_PROF_FOUND"; then
+  ac_cv_prog_LLVM_PROF_FOUND="$LLVM_PROF_FOUND" # Let the user override the test.
+else
+as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+    ac_cv_prog_LLVM_PROF_FOUND="found"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+  test -z "$ac_cv_prog_LLVM_PROF_FOUND" && ac_cv_prog_LLVM_PROF_FOUND="not-found"
+fi
+fi
+LLVM_PROF_FOUND=$ac_cv_prog_LLVM_PROF_FOUND
+if test -n "$LLVM_PROF_FOUND"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $LLVM_PROF_FOUND" >&5
+$as_echo "$LLVM_PROF_FOUND" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
+LLVM_PROF_ERR=no
+case $CC in
+  *clang*)
+    # Any changes made here should be reflected in the GCC+Darwin case below
+    PGO_PROF_GEN_FLAG="-fprofile-instr-generate"
+    PGO_PROF_USE_FLAG="-fprofile-instr-use=code.profclangd"
+    LLVM_PROF_MERGER="llvm-profdata merge -output=code.profclangd *.profclangr"
+    LLVM_PROF_FILE="LLVM_PROFILE_FILE=\"code-%p.profclangr\""
+    if test $LLVM_PROF_FOUND = not-found
+    then
+      LLVM_PROF_ERR=yes
+    fi
+    ;;
+  *gcc*)
+    case $ac_sys_system in
+      Darwin*)
+        PGO_PROF_GEN_FLAG="-fprofile-instr-generate"
+        PGO_PROF_USE_FLAG="-fprofile-instr-use=code.profclangd"
+        LLVM_PROF_MERGER="llvm-profdata merge -output=code.profclangd *.profclangr"
+        LLVM_PROF_FILE="LLVM_PROFILE_FILE=\"code-%p.profclangr\""
+        if test $LLVM_PROF_FOUND = not-found
+        then
+          LLVM_PROF_ERR=yes
+        fi
+        ;;
+      *)
+        PGO_PROF_GEN_FLAG="-fprofile-generate"
+        PGO_PROF_USE_FLAG="-fprofile-use -fprofile-correction"
+        LLVM_PROF_MERGER="true"
+        LLVM_PROF_FILE=""
+        ;;
+    esac
+    ;;
+esac
+
 # XXX Shouldn't the code above that fiddles with BASECFLAGS and OPT be
 # merged with this chunk of code?