gh-148294: Make configure find g++ correctly (GH-148298)

The `AC_PATH_TOOL` calls had included a duplicated argument, causing a "`PATH`"
consisting of `notfound` to be searched instead of `$PATH`.

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 a320a397fe10d6ff543a9e7094a9cbea5162549e..a1b635ffd15c4a38fcd428cf20902af82200ede7 100755 (executable)
--- a/configure
+++ b/configure
@@ -6640,7 +6640,7 @@ 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 $as_dir in #(((
@@ -6689,7 +6689,7 @@ else case e in #(
   ;;
   *)
   as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
-for as_dir in notfound
+for as_dir in $PATH
 do
   IFS=$as_save_IFS
   case $as_dir in #(((
@@ -6721,7 +6721,7 @@ 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:)
@@ -6750,7 +6750,7 @@ 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 $as_dir in #(((
@@ -6799,7 +6799,7 @@ else case e in #(
   ;;
   *)
   as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
-for as_dir in notfound
+for as_dir in $PATH
 do
   IFS=$as_save_IFS
   case $as_dir in #(((
@@ -6831,7 +6831,7 @@ 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:)
@@ -6860,7 +6860,7 @@ 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 $as_dir in #(((
@@ -6909,7 +6909,7 @@ else case e in #(
   ;;
   *)
   as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
-for as_dir in notfound
+for as_dir in $PATH
 do
   IFS=$as_save_IFS
   case $as_dir in #(((
@@ -6941,7 +6941,7 @@ 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:)
@@ -6970,7 +6970,7 @@ 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 $as_dir in #(((
@@ -7019,7 +7019,7 @@ else case e in #(
   ;;
   *)
   as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
-for as_dir in notfound
+for as_dir in $PATH
 do
   IFS=$as_save_IFS
   case $as_dir in #(((
@@ -7051,7 +7051,7 @@ 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 d975d9685caa7d61f39feeb0526d1fed9bc91bfc..082c6c2d756cdcaf42ce22facf113bbb5468cd9d 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