[3.15] gh-148294: Make configure find g++ correctly (GH-150212)

The `AC_PATH_TOOL` calls had included a duplicated argument, causing a "`PATH`"
consisting of `notfound` to be searched instead of `$PATH`.
(cherry picked from commit c613f72eeef83340cb369287f7c1a195e086d1d5)

Co-authored-by: sendaoYan <yansendao@126.com>

diff --git a/Misc/NEWS.d/next/Build/2026-05-21-15-14-59.gh-issue-148294.VtFaW4.rst b/Misc/NEWS.d/next/Build/2026-05-21-15-14-59.gh-issue-148294.VtFaW4.rst
new file mode 100644 (file)
index 0000000..861261d
--- /dev/null
+++ b/Misc/NEWS.d/next/Build/2026-05-21-15-14-59.gh-issue-148294.VtFaW4.rst
@@ -0,0 +1,2 @@
+Corrected the use of ``AC_PATH_TOOL`` in ``configure.ac`` to allow a C++
+compiler to be found on :envvar:`!PATH`.

diff --git a/configure b/configure
index acba294d55de8f2c8f82725ee41f8181a6a547bc..9ad2171460f7ace4865bbc5dc4b0881346f4933f 100755 (executable)
--- a/configure
+++ b/configure
@@ -6645,7 +6645,7 @@ else case e in #(
   ;;
   *)
   as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
-for as_dir in notfound
+for as_dir in $PATH
 do
   IFS=$as_save_IFS
   case $as_dir in #(((
@@ -6694,7 +6694,7 @@ else case e in #(
   ;;
   *)
   as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
-for as_dir in notfound
+for as_dir in $PATH
 do
   IFS=$as_save_IFS
   case $as_dir in #(((
@@ -6726,7 +6726,7 @@ printf "%s\n" "no" >&6; }
 fi
 
   if test "x$ac_pt_CXX" = x; then
-    CXX="g++"
+    CXX="notfound"
   else
     case $cross_compiling:$ac_tool_warned in
 yes:)
@@ -6755,7 +6755,7 @@ else case e in #(
   ;;
   *)
   as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
-for as_dir in notfound
+for as_dir in $PATH
 do
   IFS=$as_save_IFS
   case $as_dir in #(((
@@ -6804,7 +6804,7 @@ else case e in #(
   ;;
   *)
   as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
-for as_dir in notfound
+for as_dir in $PATH
 do
   IFS=$as_save_IFS
   case $as_dir in #(((
@@ -6836,7 +6836,7 @@ printf "%s\n" "no" >&6; }
 fi
 
   if test "x$ac_pt_CXX" = x; then
-    CXX="c++"
+    CXX="notfound"
   else
     case $cross_compiling:$ac_tool_warned in
 yes:)
@@ -6865,7 +6865,7 @@ else case e in #(
   ;;
   *)
   as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
-for as_dir in notfound
+for as_dir in $PATH
 do
   IFS=$as_save_IFS
   case $as_dir in #(((
@@ -6914,7 +6914,7 @@ else case e in #(
   ;;
   *)
   as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
-for as_dir in notfound
+for as_dir in $PATH
 do
   IFS=$as_save_IFS
   case $as_dir in #(((
@@ -6946,7 +6946,7 @@ printf "%s\n" "no" >&6; }
 fi
 
   if test "x$ac_pt_CXX" = x; then
-    CXX="clang++"
+    CXX="notfound"
   else
     case $cross_compiling:$ac_tool_warned in
 yes:)
@@ -6975,7 +6975,7 @@ else case e in #(
   ;;
   *)
   as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
-for as_dir in notfound
+for as_dir in $PATH
 do
   IFS=$as_save_IFS
   case $as_dir in #(((
@@ -7024,7 +7024,7 @@ else case e in #(
   ;;
   *)
   as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
-for as_dir in notfound
+for as_dir in $PATH
 do
   IFS=$as_save_IFS
   case $as_dir in #(((
@@ -7056,7 +7056,7 @@ printf "%s\n" "no" >&6; }
 fi
 
   if test "x$ac_pt_CXX" = x; then
-    CXX="icpc"
+    CXX="notfound"
   else
     case $cross_compiling:$ac_tool_warned in
 yes:)

diff --git a/configure.ac b/configure.ac
index d909c2fc92894ef9376573c20fe3a724483f32c8..a51e173e5293f2d4e8e576e03ba89bc22078c89b 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -1137,10 +1137,10 @@ preset_cxx="$CXX"
 if test -z "$CXX"
 then
         case "$ac_cv_cc_name" in
-        gcc)    AC_PATH_TOOL([CXX], [g++], [g++], [notfound]) ;;
-        cc)     AC_PATH_TOOL([CXX], [c++], [c++], [notfound]) ;;
-        clang)             AC_PATH_TOOL([CXX], [clang++], [clang++], [notfound]) ;;
-        icc)               AC_PATH_TOOL([CXX], [icpc], [icpc], [notfound]) ;;
+        gcc)    AC_PATH_TOOL([CXX], [g++], [notfound]) ;;
+        cc)     AC_PATH_TOOL([CXX], [c++], [notfound]) ;;
+        clang)             AC_PATH_TOOL([CXX], [clang++], [notfound]) ;;
+        icc)               AC_PATH_TOOL([CXX], [icpc], [notfound]) ;;
         esac
        if test "$CXX" = "notfound"
        then