Move the header checking into ExecutableCompilationUnit

We don't need to verify the header unless we want to execute the code.

Change-Id: Ieac51c47faafcd7047228b4264aa7750ba3d8889
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>
 
 
 

4 files changed, 65 insertions, 4 deletions

diff --git a/src/qml/jsruntime/qv4compilationunitmapper_unix.cpp b/src/qml/jsruntime/qv4compilationunitmapper_unix.cpp
index 6768bc9596..a9ab2f5ccb 100644
--- a/src/qml/jsruntime/qv4compilationunitmapper_unix.cpp
+++ b/src/qml/jsruntime/qv4compilationunitmapper_unix.cpp
@@ -45,7 +45,7 @@
 #include <QScopeGuard>
 #include <QDateTime>
 
-#include "qv4compileddata_p.h"
+#include "qv4executablecompilationunit_p.h"
 
 QT_BEGIN_NAMESPACE
 
@@ -73,7 +73,7 @@ CompiledData::Unit *CompilationUnitMapper::open(const QString &cacheFileName, co
         return nullptr;
     }
 
-    if (!header.verifyHeader(sourceTimeStamp, errorString))
+    if (!ExecutableCompilationUnit::verifyHeader(&header, sourceTimeStamp, errorString))
         return nullptr;
 
     // Data structure and qt version matched, so now we can access the rest of the file safely.
diff --git a/src/qml/jsruntime/qv4compilationunitmapper_win.cpp b/src/qml/jsruntime/qv4compilationunitmapper_win.cpp
index 779c1288fe..9e8babc5e6 100644
--- a/src/qml/jsruntime/qv4compilationunitmapper_win.cpp
+++ b/src/qml/jsruntime/qv4compilationunitmapper_win.cpp
@@ -39,7 +39,7 @@
 
 #include "qv4compilationunitmapper_p.h"
 
-#include "qv4compileddata_p.h"
+#include "qv4executablecompilationunit_p.h"
 #include <QScopeGuard>
 #include <QFileInfo>
 #include <QDateTime>
@@ -87,7 +87,7 @@ CompiledData::Unit *CompilationUnitMapper::open(const QString &cacheFileName, co
         return nullptr;
     }
 
-    if (!header.verifyHeader(sourceTimeStamp, errorString))
+    if (!ExecutableCompilationUnit::verifyHeader(&header, sourceTimeStamp, errorString))
         return nullptr;
 
     // Data structure and qt version matched, so now we can access the rest of the file safely.
diff --git a/src/qml/jsruntime/qv4executablecompilationunit.cpp b/src/qml/jsruntime/qv4executablecompilationunit.cpp
index 58f6735008..7867dff769 100644
--- a/src/qml/jsruntime/qv4executablecompilationunit.cpp
+++ b/src/qml/jsruntime/qv4executablecompilationunit.cpp
@@ -51,6 +51,7 @@
 #include <private/qqmlvaluetypewrapper_p.h>
 #include <private/qv4module_p.h>
 #include <private/qv4compilationunitmapper_p.h>
+#include <private/qml_compile_hash_p.h>
 
 #include <QtQml/qqmlfile.h>
 #include <QtQml/qqmlpropertymap.h>
@@ -60,6 +61,19 @@
 #include <QtCore/qfileinfo.h>
 #include <QtCore/qscopeguard.h>
 
+#if defined(QML_COMPILE_HASH)
+#  ifdef Q_OS_LINUX
+// Place on a separate section on Linux so it's easier to check from outside
+// what the hash version is.
+__attribute__((section(".qml_compile_hash")))
+#  endif
+const char qml_compile_hash[48 + 1] = QML_COMPILE_HASH;
+static_assert(sizeof(QV4::CompiledData::Unit::libraryVersionHash) >= QML_COMPILE_HASH_LENGTH + 1,
+              "Compile hash length exceeds reserved size in data structure. Please adjust and bump the format version");
+#else
+#  error "QML_COMPILE_HASH must be defined for the build of QtDeclarative to ensure version checking for cache files"
+#endif
+
 QT_BEGIN_NAMESPACE
 
 namespace QV4 {
@@ -804,6 +818,50 @@ QString ExecutableCompilationUnit::bindingValueAsScriptString(
             : bindingValueAsString(binding);
 }
 
+bool ExecutableCompilationUnit::verifyHeader(
+        const CompiledData::Unit *unit, QDateTime expectedSourceTimeStamp, QString *errorString)
+{
+    if (strncmp(unit->magic, CompiledData::magic_str, sizeof(unit->magic))) {
+        *errorString = QStringLiteral("Magic bytes in the header do not match");
+        return false;
+    }
+
+    if (unit->version != quint32(QV4_DATA_STRUCTURE_VERSION)) {
+        *errorString = QString::fromUtf8("V4 data structure version mismatch. Found %1 expected %2")
+                               .arg(unit->version, 0, 16).arg(QV4_DATA_STRUCTURE_VERSION, 0, 16);
+        return false;
+    }
+
+    if (unit->qtVersion != quint32(QT_VERSION)) {
+        *errorString = QString::fromUtf8("Qt version mismatch. Found %1 expected %2")
+                               .arg(unit->qtVersion, 0, 16).arg(QT_VERSION, 0, 16);
+        return false;
+    }
+
+    if (unit->sourceTimeStamp) {
+        // Files from the resource system do not have any time stamps, so fall back to the application
+        // executable.
+        if (!expectedSourceTimeStamp.isValid())
+            expectedSourceTimeStamp = QFileInfo(QCoreApplication::applicationFilePath()).lastModified();
+
+        if (expectedSourceTimeStamp.isValid()
+                && expectedSourceTimeStamp.toMSecsSinceEpoch() != unit->sourceTimeStamp) {
+            *errorString = QStringLiteral("QML source file has a different time stamp than cached file.");
+            return false;
+        }
+    }
+
+#if defined(QML_COMPILE_HASH)
+    if (qstrcmp(qml_compile_hash, unit->libraryVersionHash) != 0) {
+        *errorString = QStringLiteral("QML library version mismatch. Expected compile hash does not match");
+        return false;
+    }
+#else
+#error "QML_COMPILE_HASH must be defined for the build of QtDeclarative to ensure version checking for cache files"
+#endif
+    return true;
+}
+
 } // namespace QV4
 
 QT_END_NAMESPACE
diff --git a/src/qml/jsruntime/qv4executablecompilationunit_p.h b/src/qml/jsruntime/qv4executablecompilationunit_p.h
index 4e3aadf28a..1823a3663c 100644
--- a/src/qml/jsruntime/qv4executablecompilationunit_p.h
+++ b/src/qml/jsruntime/qv4executablecompilationunit_p.h
@@ -251,6 +251,9 @@ public:
         return constants[binding->value.constantValueIndex].doubleValue();
     }
 
+    static bool verifyHeader(const CompiledData::Unit *unit, QDateTime expectedSourceTimeStamp,
+                             QString *errorString);
+
 protected:
     quint32 totalStringCount() const
     { return data->stringTableSize; }