server: Report backtraces in codemodel response

Report the source locations (e.g. in `CMakeLists.txt`) for all targets
and target-related statements.  This allows IDEs to locate the
statements and automatically edit them when the user adds or removes
files or changes target properties via GUI.

Increment the protocol minor version number to tell clients that the new
information is available.

1 files changed, 51 insertions, 1 deletions

diff --git a/Source/cmServerProtocol.cxx b/Source/cmServerProtocol.cxx
index 54ee109..21b69cf 100644
--- a/Source/cmServerProtocol.cxx
+++ b/Source/cmServerProtocol.cxx
@@ -2,12 +2,14 @@
    file Copyright.txt or https://cmake.org/licensing for details.  */
 #include "cmServerProtocol.h"
 
+#include "cmAlgorithms.h"
 #include "cmExternalMakefileProjectGenerator.h"
 #include "cmFileMonitor.h"
 #include "cmGeneratorExpression.h"
 #include "cmGeneratorTarget.h"
 #include "cmGlobalGenerator.h"
 #include "cmLinkLineComputer.h"
+#include "cmListFileCache.h"
 #include "cmLocalGenerator.h"
 #include "cmMakefile.h"
 #include "cmServer.h"
@@ -18,6 +20,7 @@
 #include "cmStateSnapshot.h"
 #include "cmStateTypes.h"
 #include "cmSystemTools.h"
+#include "cmTarget.h"
 #include "cm_uv.h"
 #include "cmake.h"
 
@@ -249,7 +252,7 @@ bool cmServerProtocol::DoActivate(const cmServerRequest& /*request*/,
 
 std::pair<int, int> cmServerProtocol1::ProtocolVersion() const
 {
-  return std::make_pair(1, 0);
+  return std::make_pair(1, 1);
 }
 
 static void setErrorMessage(std::string* errorMessage, const std::string& text)
@@ -729,6 +732,37 @@ static Json::Value DumpSourceFilesList(
   return result;
 }
 
+static Json::Value DumpBacktrace(const cmListFileBacktrace& backtrace)
+{
+  Json::Value result = Json::arrayValue;
+
+  cmListFileBacktrace backtraceCopy = backtrace;
+  while (!backtraceCopy.Top().FilePath.empty()) {
+    Json::Value entry = Json::objectValue;
+    entry[kPATH_KEY] = backtraceCopy.Top().FilePath;
+    if (backtraceCopy.Top().Line) {
+      entry[kLINE_NUMBER_KEY] = (int)backtraceCopy.Top().Line;
+    }
+    if (!backtraceCopy.Top().Name.empty()) {
+      entry[kNAME_KEY] = backtraceCopy.Top().Name;
+    }
+    result.append(std::move(entry));
+    backtraceCopy = backtraceCopy.Pop();
+  }
+  return result;
+}
+
+static void DumpBacktraceRange(Json::Value& result, const std::string& type,
+                               const cmBacktraceRange& range)
+{
+  for (const auto& bt : range) {
+    Json::Value obj = Json::objectValue;
+    obj[kTYPE_KEY] = type;
+    obj[kBACKTRACE_KEY] = DumpBacktrace(bt);
+    result.append(obj);
+  }
+}
+
 static Json::Value DumpTarget(cmGeneratorTarget* target,
                               const std::string& config)
 {
@@ -763,6 +797,22 @@ static Json::Value DumpTarget(cmGeneratorTarget* target,
 
   result[kFULL_NAME_KEY] = target->GetFullName(config);
 
+  Json::Value crossRefs = Json::objectValue;
+  crossRefs[kBACKTRACE_KEY] = DumpBacktrace(target->Target->GetBacktrace());
+
+  Json::Value statements = Json::arrayValue;
+  DumpBacktraceRange(statements, "target_compile_definitions",
+                     target->Target->GetCompileDefinitionsBacktraces());
+  DumpBacktraceRange(statements, "target_include_directories",
+                     target->Target->GetIncludeDirectoriesBacktraces());
+  DumpBacktraceRange(statements, "target_compile_options",
+                     target->Target->GetCompileOptionsBacktraces());
+  DumpBacktraceRange(statements, "target_link_libraries",
+                     target->Target->GetLinkImplementationBacktraces());
+
+  crossRefs[kRELATED_STATEMENTS_KEY] = std::move(statements);
+  result[kTARGET_CROSS_REFERENCES_KEY] = std::move(crossRefs);
+
   if (target->HaveWellDefinedOutputFiles()) {
     Json::Value artifacts = Json::arrayValue;
     artifacts.append(