From 002f12bf05a8ed977e2fec582d03039ab0bb11ca Mon Sep 17 00:00:00 2001
From: Thiago Macieira <thiago.macieira@intel.com>
Date: Sun, 29 Dec 2024 12:30:58 -0300
Subject: [PATCH] tracegen: Remove the use of QUuid and therefore
 QCryptographicHash

By bypassing the two completely and just using the SHA1 algorithm
directly. This removes the only use of either class in bootstrapped
tools.

The use of the null UUID as a namespace is non-standard, so I've
scheduled it for removal in Qt 7, which will also simplify the code. It
will be closer to Microsoft's suggestion in [1]. Until then, this keeps
the exact same algorithm as Qt 6.8's tracegen so the two versions
generate the same IDs.

[1] https://learn.microsoft.com/en-us/windows/win32/api/traceloggingprovider/nf-traceloggingprovider-tracelogging_define_provider#provider-name-and-id

Change-Id: I5056b93971c9b03d7d82fffd53bf27228074d9f4
Reviewed-by: Ahmad Samir <a.samirh78@gmail.com>
---
 src/tools/tracegen/etw.cpp | 52 +++++++++++++++++++++++++-------------
 1 file changed, 35 insertions(+), 17 deletions(-)

diff --git a/src/tools/tracegen/etw.cpp b/src/tools/tracegen/etw.cpp
index f54a7896ea4..8859fbeb916 100644
--- a/src/tools/tracegen/etw.cpp
+++ b/src/tools/tracegen/etw.cpp
@@ -9,7 +9,10 @@
 #include <qfile.h>
 #include <qfileinfo.h>
 #include <qtextstream.h>
-#include <quuid.h>
+
+// This is a bootstrapped tool, so we can't rely on QCryptographicHash for the
+// faster SHA1 implementations from OpenSSL.
+#include "../../3rdparty/sha1/sha1.cpp"
 
 using namespace Qt::StringLiterals;
 
@@ -77,26 +80,44 @@ static void writeEtwMacro(QTextStream &stream, const Tracepoint::Field &field)
     stream << "TraceLoggingValue(" << name << ", \"" << name << "\")";
 }
 
-static QString createGuid(const QUuid &uuid)
+static QString createGuid(QByteArrayView name)
 {
+    quint8 uuid[20] = {};   // SHA1 produces 160 bits of data
+
+    Sha1State state;
+    sha1InitState(&state);
+#if QT_VERSION < QT_VERSION_CHECK(7, 0, 0)
+    // namespace {00000000-0000-0000-0000-000000000000} for compatibility
+    sha1Update(&state, uuid, 16);
+#endif
+    sha1Update(&state, reinterpret_cast<const uchar *>(name.data()), name.size());
+    sha1FinalizeState(&state);
+
+    sha1ToHash(&state, uuid);
+
+    // set UUID OSF DCE version 5 (SHA1)
+    uuid[6] = (uuid[6] & 0xF) | 0x50;   // version 5
+    uuid[8] = (uuid[8] & 0x3F) | 0x80;  // OSF DCE variant
+
     QString guid;
 
     QTextStream stream(&guid);
 
     Qt::hex(stream);
+    Qt::showbase(stream);
 
     stream << "("
-           << "0x" << uuid.data1    << ", "
-           << "0x" << uuid.data2    << ", "
-           << "0x" << uuid.data3    << ", "
-           << "0x" << uuid.data4[0] << ", "
-           << "0x" << uuid.data4[1] << ", "
-           << "0x" << uuid.data4[2] << ", "
-           << "0x" << uuid.data4[3] << ", "
-           << "0x" << uuid.data4[4] << ", "
-           << "0x" << uuid.data4[5] << ", "
-           << "0x" << uuid.data4[6] << ", "
-           << "0x" << uuid.data4[7]
+           << qFromBigEndian<quint32>(uuid + 0) << ", "
+           << qFromBigEndian<quint16>(uuid + 4) << ", "
+           << qFromBigEndian<quint16>(uuid + 6) << ", "
+           << uuid[8] << ", "
+           << uuid[9] << ", "
+           << uuid[10] << ", "
+           << uuid[11] << ", "
+           << uuid[12] << ", "
+           << uuid[13] << ", "
+           << uuid[14] << ", "
+           << uuid[15]
            << ")";
 
     return guid;
@@ -105,12 +126,10 @@ static QString createGuid(const QUuid &uuid)
 static void writePrologue(QTextStream &stream, const QString &fileName, const Provider &provider)
 {
     writeCommonPrologue(stream);
-    QUuid uuid = QUuid::createUuidV5(QUuid(), provider.name.toLocal8Bit());
 
     const QString providerV = providerVar(provider.name);
     const QString guard = includeGuard(fileName);
-    const QString guid = createGuid(uuid);
-    const QString guidString = uuid.toString();
+    const QString guid = createGuid(provider.name.toLocal8Bit());
 
     stream << "#ifndef " << guard << "\n"
            << "#define " << guard << "\n"
@@ -135,7 +154,6 @@ static void writePrologue(QTextStream &stream, const QString &fileName, const Pr
         stream << provider.prefixText.join(u'\n') << "\n\n";
 
     stream << "#ifdef TRACEPOINT_DEFINE\n"
-           << "/* " << guidString << " */\n"
            << "TRACELOGGING_DEFINE_PROVIDER(" << providerV << ", \""
            << provider.name <<"\", " << guid << ");\n\n";