From 05052d7cccf8f69f877746fa0c35484ac2d41b52 Mon Sep 17 00:00:00 2001
From: firewave <firewave@users.noreply.github.com>
Date: Tue, 14 Jan 2025 12:35:06 +0100
Subject: [PATCH] added CLI option `--debug-ipc` to log `ProcessExecutor` IPC
 communication [skip ci]

---
 cli/cmdlineparser.cpp      |  3 +++
 cli/processexecutor.cpp    | 11 +++++++++--
 lib/check.cpp              |  1 +
 lib/settings.h             |  3 +++
 test/cli/other_test.py     | 26 +++++++++++++++++++++++++-
 test/testcmdlineparser.cpp |  8 ++++++++
 6 files changed, 49 insertions(+), 3 deletions(-)

diff --git a/cli/cmdlineparser.cpp b/cli/cmdlineparser.cpp
index 2069c89579c..865580f049d 100644
--- a/cli/cmdlineparser.cpp
+++ b/cli/cmdlineparser.cpp
@@ -631,6 +631,9 @@ CmdLineParser::Result CmdLineParser::parseFromArgs(int argc, const char* const a
         else if (std::strcmp(argv[i], "--debug-ignore") == 0)
             mSettings.debugignore = true;
 
+        else if (std::strcmp(argv[i], "--debug-ipc") == 0)
+            mSettings.debugipc = true;
+
         // Show --debug output after the first simplifications
         else if (std::strcmp(argv[i], "--debug") == 0 ||
                  std::strcmp(argv[i], "--debug-normal") == 0)
diff --git a/cli/processexecutor.cpp b/cli/processexecutor.cpp
index cc6c7baf214..18f4a822192 100644
--- a/cli/processexecutor.cpp
+++ b/cli/processexecutor.cpp
@@ -80,7 +80,7 @@ namespace {
     public:
         enum PipeSignal : std::uint8_t {REPORT_OUT='1',REPORT_ERROR='2',REPORT_SUPPR_INLINE='3',REPORT_SUPPR='4',CHILD_END='5',REPORT_METRIC='6',REPORT_TIMER='7'};
 
-        explicit PipeWriter(int pipe) : mWpipe(pipe) {}
+        explicit PipeWriter(int pipe, bool debug) : mWpipe(pipe), mDebug(debug) {}
 
         void reportOut(const std::string &outmsg, Color c) override {
             writeToPipe(REPORT_OUT, static_cast<char>(c) + outmsg);
@@ -153,6 +153,9 @@ namespace {
 
         void writeToPipe(PipeSignal type, const std::string &data) const
         {
+            if (mDebug)
+                std::cout << "writeToPipe - " << type << " - " << data << std::endl;
+
             {
                 const auto t = static_cast<char>(type);
                 writeToPipeInternal(type, &t, 1);
@@ -169,6 +172,7 @@ namespace {
         }
 
         const int mWpipe;
+        const bool mDebug;
     };
 }
 
@@ -235,6 +239,9 @@ bool ProcessExecutor::handleRead(int rpipe, unsigned int &result, const std::str
         } while (bytes_to_read != 0);
     }
 
+    if (mSettings.debugipc)
+        std::cout << "handleRead - " << type << " - " << buf << std::endl;
+
     bool res = true;
     if (type == PipeWriter::REPORT_OUT) {
         // the first character is the color
@@ -378,7 +385,7 @@ unsigned int ProcessExecutor::check()
                     mTimerResults->reset();
                 // TODO: how to "reset" mSuppressions?
 
-                PipeWriter pipewriter(pipes[1]);
+                PipeWriter pipewriter(pipes[1], mSettings.debugipc);
                 CppCheck fileChecker(mSettings, mSuppressions, pipewriter, mTimerResults, false, mExecuteCommand);
                 unsigned int resultOfCheck = 0;
 
diff --git a/lib/check.cpp b/lib/check.cpp
index 58b8dbfe0e1..1d0cfe61792 100644
--- a/lib/check.cpp
+++ b/lib/check.cpp
@@ -130,6 +130,7 @@ ErrorPath Check::getErrorPath(const Token* errtok, const ValueFlow::Value* value
 
 void Check::logChecker(const char id[])
 {
+    // TODO: only issue when we would actually use it later on
     reportError(nullptr, Severity::internal, "logChecker", id);
 }
 
diff --git a/lib/settings.h b/lib/settings.h
index b7b23675aae..8e0881562ed 100644
--- a/lib/settings.h
+++ b/lib/settings.h
@@ -202,6 +202,9 @@ class CPPCHECKLIB WARN_UNUSED Settings {
     /** @brief Is --debug-ignore given? */
     bool debugignore{};
 
+    /** @brief Is --debug-ipc given? */
+    bool debugipc{};
+
     /** @brief Internal: Is --debug-lookup or --debug-lookup=all given? */
     bool debuglookup{};
 
diff --git a/test/cli/other_test.py b/test/cli/other_test.py
index 4aaddc3572d..72f0a7a00bd 100644
--- a/test/cli/other_test.py
+++ b/test/cli/other_test.py
@@ -4633,4 +4633,28 @@ def test_dui_include_absolute_missing(tmp_path):  # #14675
     assert stdout == ''
     assert stderr.splitlines() == [
         f"{test_file}:0:0: error: Can not open include file '/share/include/missing.h' that is explicitly included. [missingIncludeExplicit]"
-    ]
\ No newline at end of file
+    ]
+
+
+@pytest.mark.xfail(strict=True)  # TODO: should not report logChecker when not required
+@pytest.mark.skipif(sys.platform == 'win32', reason="requires ProcessExecutor")
+def test_ipc_log_checker(tmp_path):
+    test_file = tmp_path / 'test.c'
+    with open(test_file, "w") as f:
+        f.write('void f() {}')
+
+    args = [
+        '-q',
+        '--debug-ipc',
+        '-j2',
+        '--executor=process',
+        str(test_file)
+    ]
+
+    exitcode, stdout, stderr = cppcheck(args)
+    assert exitcode == 0
+    assert stdout.splitlines() == [
+        'writeToPipe - 5 - 0',
+        'handleRead - 5 - 0'
+    ]
+    assert stderr.splitlines() == []
\ No newline at end of file
diff --git a/test/testcmdlineparser.cpp b/test/testcmdlineparser.cpp
index e5d231d47ed..250faaf8d1f 100644
--- a/test/testcmdlineparser.cpp
+++ b/test/testcmdlineparser.cpp
@@ -498,6 +498,7 @@ class TestCmdlineParser : public TestFixture {
         TEST_CASE(noSafety);
         TEST_CASE(noSafetyOverride);
         TEST_CASE(debugAnalyzerinfo);
+        TEST_CASE(debugIpc);
 
         TEST_CASE(ignorepaths1);
         TEST_CASE(ignorepaths2);
@@ -3479,6 +3480,13 @@ class TestCmdlineParser : public TestFixture {
         ASSERT_EQUALS(true, settings->debugainfo);
     }
 
+    void debugIpc() {
+        REDIRECT;
+        const char * const argv[] = {"cppcheck", "--debug-ipc", "file.cpp"};
+        ASSERT_EQUALS_ENUM(CmdLineParser::Result::Success, parseFromArgs(argv));
+        ASSERT_EQUALS(true, settings->debugipc);
+    }
+
     void ignorepaths1() {
         REDIRECT;
         const char * const argv[] = {"cppcheck", "-isrc", "file.cpp"};