Index: docs/CommandGuide/llvm-cov.rst
===================================================================
--- docs/CommandGuide/llvm-cov.rst
+++ docs/CommandGuide/llvm-cov.rst
@@ -382,3 +382,10 @@
  It is an error to specify an architecture that is not included in the
  universal binary or to use an architecture that does not match a
  non-universal binary.
+
+.. option:: -summary-only
+
+ Export only summary information for each file in the coverage data. This mode
+ will not export coverage information for smaller units such as individual
+ functions or regions. The result will be the same as produced by :program:
+ `llvm-cov report` command, but presented in JSON format rather than text.
Index: tools/llvm-cov/CodeCoverage.cpp
===================================================================
--- tools/llvm-cov/CodeCoverage.cpp
+++ tools/llvm-cov/CodeCoverage.cpp
@@ -631,6 +631,10 @@
       "show-instantiation-summary", cl::Optional,
       cl::desc("Show instantiation statistics in summary table"));
 
+  cl::opt<bool> SummaryOnly(
+      "summary-only", cl::Optional,
+      cl::desc("Export only summary information for each source file"));
+
   auto commandLineParser = [&, this](int argc, const char **argv) -> int {
     cl::ParseCommandLineOptions(argc, argv, "LLVM code coverage tool\n");
     ViewOpts.Debug = DebugDump;
@@ -743,6 +747,7 @@
 
     ViewOpts.ShowRegionSummary = RegionSummary;
     ViewOpts.ShowInstantiationSummary = InstantiationSummary;
+    ViewOpts.ExportSummaryOnly = SummaryOnly;
 
     return 0;
   };
Index: tools/llvm-cov/CoverageExporterJson.cpp
===================================================================
--- tools/llvm-cov/CoverageExporterJson.cpp
+++ tools/llvm-cov/CoverageExporterJson.cpp
@@ -177,8 +177,11 @@
                                                           SourceFiles, Options);
     renderFiles(SourceFiles, FileReports);
 
-    emitDictKey("functions");
-    renderFunctions(Coverage.getCoveredFunctions());
+    // Skip functions-level information for summary-only export mode.
+    if (!Options.ExportSummaryOnly) {
+      emitDictKey("functions");
+      renderFunctions(Coverage.getCoveredFunctions());
+    }
 
     emitDictKey("totals");
     renderSummary(Totals);
@@ -254,27 +257,31 @@
     emitDictStart();
 
     emitDictElement("filename", FileCoverage.getFilename());
-    emitDictKey("segments");
 
-    // Start List of Segments.
-    emitArrayStart();
+    // Skip segments and expansions for summary-only export mode.
+    if (!Options.ExportSummaryOnly) {
+      emitDictKey("segments");
 
-    for (const auto &Segment : FileCoverage)
-      renderSegment(Segment);
+      // Start List of Segments.
+      emitArrayStart();
 
-    // End List of Segments.
-    emitArrayEnd();
+      for (const auto &Segment : FileCoverage)
+        renderSegment(Segment);
+
+      // End List of Segments.
+      emitArrayEnd();
 
-    emitDictKey("expansions");
+      emitDictKey("expansions");
 
-    // Start List of Expansions.
-    emitArrayStart();
+      // Start List of Expansions.
+      emitArrayStart();
 
-    for (const auto &Expansion : FileCoverage.getExpansions())
-      renderExpansion(Expansion);
+      for (const auto &Expansion : FileCoverage.getExpansions())
+        renderExpansion(Expansion);
 
-    // End List of Expansions.
-    emitArrayEnd();
+      // End List of Expansions.
+      emitArrayEnd();
+    }
 
     emitDictKey("summary");
     renderSummary(FileReport);
Index: tools/llvm-cov/CoverageViewOptions.h
===================================================================
--- tools/llvm-cov/CoverageViewOptions.h
+++ tools/llvm-cov/CoverageViewOptions.h
@@ -32,6 +32,7 @@
   bool ShowFullFilenames;
   bool ShowRegionSummary;
   bool ShowInstantiationSummary;
+  bool ExportSummaryOnly;
   OutputFormat Format;
   std::string ShowOutputDirectory;
   std::vector<std::string> DemanglerOpts;