[llvm] [llvm-cov] Add a SourcesFile flag (PR #80646)

[Farzon Lotfi via llvm-commits]

https://github.com/farzonl updated https://github.com/llvm/llvm-project/pull/80646

>From 61e18316ba4ca9810a96269141ba3f1705a3c667 Mon Sep 17 00:00:00 2001
From: Farzon Lotfi <farzon at farzon.com>
Date: Mon, 5 Feb 2024 03:38:25 -0500
Subject: [PATCH] [llvm-cov] Add a SourcesFile for providing sources on
 character limited terminals

---
 llvm/docs/CommandGuide/llvm-cov.rst  | 15 ++++++++++
 llvm/tools/llvm-cov/CodeCoverage.cpp | 41 ++++++++++++++++++++++++++++
 2 files changed, 56 insertions(+)

diff --git a/llvm/docs/CommandGuide/llvm-cov.rst b/llvm/docs/CommandGuide/llvm-cov.rst
index 968f3c452f558..ba592eb5404bf 100644
--- a/llvm/docs/CommandGuide/llvm-cov.rst
+++ b/llvm/docs/CommandGuide/llvm-cov.rst
@@ -380,6 +380,11 @@ OPTIONS
  Fail if an object file cannot be found for a binary ID present in the profile,
  neither on the command line nor via binary ID lookup.
 
+.. option:: -sourcesFile
+
+ A json file of source files used as an alternative to -sources for 
+ terminals with character limits.
+
 .. program:: llvm-cov report
 
 .. _llvm-cov-report:
@@ -470,6 +475,11 @@ OPTIONS
  Fail if an object file cannot be found for a binary ID present in the profile,
  neither on the command line nor via binary ID lookup.
 
+.. option:: -sourcesFile
+
+ A json file of source files used as an alternative to -sources for 
+ terminals with character limits.
+
 .. program:: llvm-cov export
 
 .. _llvm-cov-export:
@@ -562,6 +572,11 @@ OPTIONS
  Fail if an object file cannot be found for a binary ID present in the profile,
  neither on the command line nor via binary ID lookup.
 
+.. option:: -sourcesFile
+
+ A json file of source files used as an alternative to -sources for 
+ terminals with character limits.
+
 CONVERT-FOR-TESTING COMMAND
 ---------------------------
 
diff --git a/llvm/tools/llvm-cov/CodeCoverage.cpp b/llvm/tools/llvm-cov/CodeCoverage.cpp
index 049e89d1a2300..7d2d8fba9ab6d 100644
--- a/llvm/tools/llvm-cov/CodeCoverage.cpp
+++ b/llvm/tools/llvm-cov/CodeCoverage.cpp
@@ -31,6 +31,7 @@
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Format.h"
+#include "llvm/Support/JSON.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/Process.h"
@@ -685,6 +686,9 @@ int CodeCoverageTool::run(Command Cmd, int argc, const char **argv) {
   cl::list<std::string> InputSourceFiles("sources", cl::Positional,
                                          cl::desc("<Source files>"));
 
+  cl::opt<std::string> InputSourcesFile(
+      "sourcesFile", cl::Positional, cl::desc("<A json file of source files>"));
+
   cl::opt<bool> DebugDumpCollectedPaths(
       "dump-collected-paths", cl::Optional, cl::Hidden,
       cl::desc("Show the collected paths to source files"));
@@ -958,6 +962,43 @@ int CodeCoverageTool::run(Command Cmd, int argc, const char **argv) {
     for (const std::string &File : InputSourceFiles)
       collectPaths(File);
 
+    if (!InputSourcesFile.empty()) {
+      ErrorOr<std::unique_ptr<MemoryBuffer>> Buf =
+          MemoryBuffer::getFile(InputSourcesFile);
+
+      if (!Buf)
+        return 1;
+
+      // Parse the JSON document
+      llvm::Expected<llvm::json::Value> jsonDocument =
+          llvm::json::parse(Buf.get()->getBuffer());
+
+      if (!jsonDocument) {
+        error("Error parsing Sources JSON File: ",
+              llvm::toString(jsonDocument.takeError()));
+        return 1;
+      }
+
+      // Access the JSON data
+      const llvm::json::Object *jsonObject = jsonDocument->getAsObject();
+      if (!jsonObject) {
+        error("Expected Sources JSON to be inclosed in an object");
+        return 1;
+      }
+      auto jsonArray = jsonObject->getArray("sourcesFile");
+      if (!jsonArray) {
+        error("Expected Sources JSON to list sources under the 'sourcesFile' "
+              "key.");
+        return 1;
+      }
+      for (size_t i = 0; i < jsonArray->size(); ++i) {
+        std::optional<llvm::StringRef> File =
+            jsonArray[i].data()->getAsString();
+        if (File)
+          collectPaths(File->str());
+      }
+    }
+
     if (DebugDumpCollectedPaths) {
       for (const std::string &SF : SourceFiles)
         outs() << SF << '\n';