Revert use of libuv for process execution for 3.28

Wide use of CMake 3.28.{1,0[-rcN]} has uncovered some hangs and crashes
in libuv SIGCHLD handling on some platforms, particularly in virtualization
environments on macOS hosts.  Although the bug does not seem to be in CMake,
we can restore stability in the CMake 3.28 release series for users of such
platforms by reverting our new uses of libuv for process execution.

Revert implementation changes merged by commit 4771544386 (Merge topic
'replace-cmsysprocess-with-cmuvprocesschain', 2023-09-06, v3.28.0-rc1~138),
but keep test suite updates.

Issue: #25414, #25500, #25562, #25589

1 files changed, 31 insertions, 51 deletions

diff --git a/Source/cmProcessTools.cxx b/Source/cmProcessTools.cxx
index 1dd1dce..9e7854b 100644
--- a/Source/cmProcessTools.cxx
+++ b/Source/cmProcessTools.cxx
@@ -2,68 +2,48 @@
    file Copyright.txt or https://cmake.org/licensing for details.  */
 #include "cmProcessTools.h"
 
-#include <algorithm>
-#include <iterator>
 #include <ostream>
 
-#include <cm3p/uv.h>
+#include "cmsys/Process.h"
 
 #include "cmProcessOutput.h"
-#include "cmUVHandlePtr.h"
-#include "cmUVStream.h"
 
-std::vector<cmUVProcessChain::Status> cmProcessTools::RunProcess(
-  cmUVProcessChainBuilder& builder, OutputParser* out, OutputParser* err,
-  Encoding encoding)
+void cmProcessTools::RunProcess(struct cmsysProcess_s* cp, OutputParser* out,
+                                OutputParser* err, Encoding encoding)
 {
+  cmsysProcess_Execute(cp);
+  char* data = nullptr;
+  int length = 0;
+  int p;
   cmProcessOutput processOutput(encoding);
-
-  builder.SetBuiltinStream(cmUVProcessChainBuilder::Stream_OUTPUT)
-    .SetBuiltinStream(cmUVProcessChainBuilder::Stream_ERROR);
-
-  auto chain = builder.Start();
-
   std::string strdata;
-  cm::uv_pipe_ptr outputPipe;
-  outputPipe.init(chain.GetLoop(), 0);
-  uv_pipe_open(outputPipe, chain.OutputStream());
-  auto outputHandle = cmUVStreamRead(
-    outputPipe,
-    [&out, &processOutput, &strdata](std::vector<char> data) {
-      if (out) {
-        processOutput.DecodeText(data.data(), data.size(), strdata, 1);
-        if (!out->Process(strdata.c_str(), static_cast<int>(strdata.size()))) {
-          out = nullptr;
-        }
+  while ((out || err) &&
+         (p = cmsysProcess_WaitForData(cp, &data, &length, nullptr))) {
+    if (out && p == cmsysProcess_Pipe_STDOUT) {
+      processOutput.DecodeText(data, length, strdata, 1);
+      if (!out->Process(strdata.c_str(), static_cast<int>(strdata.size()))) {
+        out = nullptr;
       }
-    },
-    [&out]() { out = nullptr; });
-  cm::uv_pipe_ptr errorPipe;
-  errorPipe.init(chain.GetLoop(), 0);
-  uv_pipe_open(errorPipe, chain.ErrorStream());
-  auto errorHandle = cmUVStreamRead(
-    errorPipe,
-    [&err, &processOutput, &strdata](std::vector<char> data) {
-      if (err) {
-        processOutput.DecodeText(data.data(), data.size(), strdata, 2);
-        if (!err->Process(strdata.c_str(), static_cast<int>(strdata.size()))) {
-          err = nullptr;
-        }
+    } else if (err && p == cmsysProcess_Pipe_STDERR) {
+      processOutput.DecodeText(data, length, strdata, 2);
+      if (!err->Process(strdata.c_str(), static_cast<int>(strdata.size()))) {
+        err = nullptr;
       }
-    },
-    [&err]() { err = nullptr; });
-  while (out || err || !chain.Finished()) {
-    uv_run(&chain.GetLoop(), UV_RUN_ONCE);
+    }
   }
-
-  std::vector<cmUVProcessChain::Status> result;
-  auto status = chain.GetStatus();
-  std::transform(
-    status.begin(), status.end(), std::back_inserter(result),
-    [](const cmUVProcessChain::Status* s) -> cmUVProcessChain::Status {
-      return *s;
-    });
-  return result;
+  if (out) {
+    processOutput.DecodeText(std::string(), strdata, 1);
+    if (!strdata.empty()) {
+      out->Process(strdata.c_str(), static_cast<int>(strdata.size()));
+    }
+  }
+  if (err) {
+    processOutput.DecodeText(std::string(), strdata, 2);
+    if (!strdata.empty()) {
+      err->Process(strdata.c_str(), static_cast<int>(strdata.size()));
+    }
+  }
+  cmsysProcess_WaitForExit(cp, nullptr);
 }
 
 cmProcessTools::LineParser::LineParser(char sep, bool ignoreCR)