From 4678b7b34a7150803377e02e1229dac9b783ab64 Mon Sep 17 00:00:00 2001
From: Tyler Yankee <tyler.yankee@kitware.com>
Date: Sat, 1 Aug 2026 11:43:09 -0400
Subject: [PATCH] string(JSON): Use cmJSONState to read input

This approach will be more portable.
---
 Source/cmStringCommand.cxx                   | 17 +++++++----------
 Tests/RunCMake/string/JSONBadJson-stderr.txt | 16 ++++++++++++----
 2 files changed, 19 insertions(+), 14 deletions(-)

diff --git a/Source/cmStringCommand.cxx b/Source/cmStringCommand.cxx
index f67b074fe2..acda83e42d 100644
--- a/Source/cmStringCommand.cxx
+++ b/Source/cmStringCommand.cxx
@@ -10,7 +10,7 @@
 #include <cstdlib>
 #include <exception>
 #include <limits>
-#include <memory>
+#include <sstream>
 #include <stdexcept>
 #include <utility>
 
@@ -19,12 +19,12 @@
 #include <cm/string_view>
 #include <cmext/string_view>
 
-#include <cm3p/json/reader.h>
 #include <cm3p/json/value.h>
 #include <cm3p/json/writer.h>
 
 #include "cmCMakeString.hxx"
 #include "cmExecutionStatus.h"
+#include "cmJSONState.h"
 #include "cmList.h"
 #include "cmMakefile.h"
 #include "cmMessageType.h"
@@ -909,15 +909,12 @@ Json::Value& ResolvePath(Json::Value& json, Args path)
 
 Json::Value ReadJson(std::string const& jsonstr)
 {
-  Json::CharReaderBuilder builder;
-  builder["collectComments"] = false;
-  auto jsonReader = std::unique_ptr<Json::CharReader>(builder.newCharReader());
+  std::istringstream iss(jsonstr);
   Json::Value json;
-  std::string error;
-  if (!jsonReader->parse(jsonstr.data(), jsonstr.data() + jsonstr.size(),
-                         &json, &error)) {
-    throw json_error(
-      cmStrCat("failed parsing json string:\n"_s, jsonstr, '\n', error));
+  cmJSONState parseState(iss, &json, cmJSONState::StrictMode::Relaxed);
+  if (!parseState.errors.empty()) {
+    throw json_error(cmStrCat("failed parsing json string:\n"_s,
+                              parseState.GetErrorMessage()));
   }
   return json;
 }
diff --git a/Tests/RunCMake/string/JSONBadJson-stderr.txt b/Tests/RunCMake/string/JSONBadJson-stderr.txt
index 812ef88494..c6052f5ffc 100644
--- a/Tests/RunCMake/string/JSONBadJson-stderr.txt
+++ b/Tests/RunCMake/string/JSONBadJson-stderr.txt
@@ -1,26 +1,34 @@
 CMake Error at JSONBadJson\.cmake:1 \(string\):
   string sub-command JSON failed parsing json string:
+(
+  Syntax error: value, object or array expected\.
 
   invalid
 
-  \* Line 1, Column 1
+  \^\.|
+  JSON Parse Error:
 
+   \* Line 1, Column 1
     Syntax error: value, object or array expected\.
 
-  \.
+  \.)
 Call Stack \(most recent call first\):
   CMakeLists\.txt:[0-9]+ \(include\)
 
 
 CMake Error at JSONBadJson\.cmake:2 \(string\):
   string sub-command JSON failed parsing json string:
+(
+  Syntax error: value, object or array expected\.
 
   value
 
-  \* Line 1, Column 1
+  \^\.|
+  JSON Parse Error:
 
+   \* Line 1, Column 1
     Syntax error: value, object or array expected\.
 
-  \.
+  \.)
 Call Stack \(most recent call first\):
   CMakeLists\.txt:[0-9]+ \(include\)