PHP-CPP now checks whether an already compiled extension is still compatible with the PHP-CPP library. This prevents weird crashes when users update their PHP-CPP library, without recompiling their extensions

7 files changed, 116 insertions, 7 deletions

diff --git a/include/extension.h b/include/extension.h
index 562fceb..15ad5e1 100644
--- a/include/extension.h
+++ b/include/extension.h
@@ -38,10 +38,19 @@ class Extension : public Namespace
 public:
     /**
      *  Constructor that defines a number of functions right away
+     *
+     *  The first two parameters should be filled by the extension programmer with the
+     *  name of the extension, and the version number of the extension (like "1.0").
+     *  The third parameter, apiversion, does not have to be supplied and is best kept
+     *  to the default value. This third parameter checks whether the PHP-CPP version
+     *  that is currently installed on the server is the same as the PHP-CPP version
+     *  that was used to compile the extension with.
+     *
      *  @param  name        Extension name
      *  @param  version     Extension version string
+     *  @param  apiversion  PHP API version (this should always be PHPCPP_API_VERSION, so you better not supply it)
      */
-    Extension(const char *name, const char *version = "1.0");
+    Extension(const char *name, const char *version = "1.0", int apiversion = PHPCPP_API_VERSION);
     
     /**
      *  No copy'ing and no moving
diff --git a/include/version.h b/include/version.h
new file mode 100644
index 0000000..85d2b66
--- /dev/null
+++ b/include/version.h
@@ -0,0 +1,17 @@
+/**
+ *  Version.h
+ *
+ *  Macro with API version. The API version number prevents that 
+ *  extensions are loaded that are incompatible with the libphpcpp.so
+ *  library
+ *
+ *  @author Emiel Bruijntjes <emiel.bruijntjes@copernica.com>
+ *  @copyright 2015 Copernica BV
+ */
+
+/**
+ *  Macro with version number (this is incremented with every release)
+ */
+#define PHPCPP_API_VERSION  20150120
+
+
diff --git a/phpcpp.h b/phpcpp.h
index 231e112..b5216ff 100644
--- a/phpcpp.h
+++ b/phpcpp.h
@@ -27,6 +27,7 @@
 /**
  *  Include all headers files that are related to this library
  */
+#include <phpcpp/version.h>
 #include <phpcpp/inivalue.h>
 #include <phpcpp/ini.h>
 #include <phpcpp/exception.h>
diff --git a/zend/extension.cpp b/zend/extension.cpp
index 1545f89..4ad54a3 100644
--- a/zend/extension.cpp
+++ b/zend/extension.cpp
@@ -15,9 +15,10 @@ namespace Php {
  *  Constructor that defines a number of functions right away
  *  @param  name        Extension name
  *  @param  version     Extension version string
+ *  @param  apiversion  API version number
  */
-Extension::Extension(const char *name, const char *version) :
-    Namespace(""), _impl(new ExtensionImpl(this, name, version)) {}
+Extension::Extension(const char *name, const char *version, int apiversion) :
+    Namespace(""), _impl(new ExtensionImpl(this, name, version, apiversion)) {}
     
 /**
  *  Destructor
diff --git a/zend/extensionimpl.cpp b/zend/extensionimpl.cpp
index 262ecdb..fd97a76 100644
--- a/zend/extensionimpl.cpp
+++ b/zend/extensionimpl.cpp
@@ -220,12 +220,34 @@ int ExtensionImpl::processIdle(int type, int module_number TSRMLS_DC)
 }
 
 /**
+ *  Function that is called when the PHP engine initializes with a different PHP-CPP
+ *  version for the libphpcpp.so file than the version the extension was compiled for
+ *  @param  type        Module type
+ *  @param  number      Module number
+ *  @param  tsrm_ls
+ *  @return int         0 on success
+ */
+int ExtensionImpl::processMismatch(int type, int module_number TSRMLS_DC)
+{
+    // get the extension
+    auto *extension = find(module_number TSRMLS_CC);
+    
+    // report a warning
+    warning << "Version mismatch between PHP-CPP and extension " << extension->name() << " " << extension->version() << " (recompile needed?)" << std::endl;
+    
+    // done
+    return BOOL2SUCCESS(true);
+}
+
+/**
  *  Constructor
  *  @param  data        Pointer to the extension object created by the extension programmer
  *  @param  name        Name of the extension
  *  @param  version     Version number
+ *  @param  apiversion  API version number
  */
-ExtensionImpl::ExtensionImpl(Extension *data, const char *name, const char *version) : ExtensionBase(data)
+ExtensionImpl::ExtensionImpl(Extension *data, const char *name, const char *version, int apiversion) : 
+    ExtensionBase(data)
 {
     // keep extension pointer based on the name
     name2extension[name] = this;
@@ -262,6 +284,17 @@ ExtensionImpl::ExtensionImpl(Extension *data, const char *name, const char *vers
     _entry.globals_ptr = NULL;
 #endif
 
+    // everything is ok if the api versions match
+    if (apiversion == PHPCPP_API_VERSION) return;
+    
+    // mismatch between api versions, the extension is invalid, we use a 
+    // different startup function to report to the user
+    _entry.module_startup_func = &ExtensionImpl::processMismatch;
+
+    // the other callback functions are no longer necessary
+    _entry.module_shutdown_func = nullptr;
+    _entry.request_startup_func = nullptr;
+    _entry.request_shutdown_func = nullptr;
 }
 
 /**
@@ -277,6 +310,26 @@ ExtensionImpl::~ExtensionImpl()
 }
 
 /**
+ *  The extension name
+ *  @return const char *
+ */
+const char *ExtensionImpl::name() const
+{
+    // name is stored in the struct
+    return _entry.name;
+}
+
+/**
+ *  The extension version
+ *  @return const char *
+ */
+const char *ExtensionImpl::version() const
+{
+    // version is stored in the struct
+    return _entry.version;
+}
+
+/**
  *  Retrieve the module entry
  *  @return zend_module_entry
  */
@@ -285,6 +338,10 @@ zend_module_entry *ExtensionImpl::module()
     // check if functions were already defined
     if (_entry.functions) return &_entry;
 
+    // if the 'processMismatch' function is installed, the API version is wrong,
+    // and nothing should be initialized
+    if (_entry.module_startup_func == &ExtensionImpl::processMismatch) return &_entry;
+
     // the number of functions
     int count = _data->functions();
     
diff --git a/zend/extensionimpl.h b/zend/extensionimpl.h
index 0e9a289..0a366ba 100644
--- a/zend/extensionimpl.h
+++ b/zend/extensionimpl.h
@@ -37,15 +37,16 @@ protected:
      *  @var zend_ini_entry
      */
     zend_ini_entry *_ini = nullptr;
-        
+    
 public:
     /**
      *  Constructor
      *  @param  data        Extension object created by the extension programmer
      *  @param  name        Name of the extension
      *  @param  version     Version number
+     *  @param  apiversion  API version number
      */
-    ExtensionImpl(Extension *data, const char *name, const char *version);
+    ExtensionImpl(Extension *data, const char *name, const char *version, int apiversion);
     
     /**
      *  No copy'ing and no moving
@@ -58,6 +59,18 @@ public:
      */
     virtual ~ExtensionImpl();
     
+    /**
+     *  The extension name
+     *  @return const char *
+     */
+    const char *name() const;
+    
+    /**
+     *  The extension version
+     *  @return const char *
+     */
+    const char *version() const;
+    
     /** 
      *  Is the object locked (true) or is it still possible to add more functions,
      *  classes and other elements to it?
@@ -94,7 +107,7 @@ private:
      *  @param  tsrm_ls
      */
     void initialize(TSRMLS_D);
-
+    
     /**
      *  Function that is called when the extension initializes
      *  @param  type        Module type
@@ -130,6 +143,16 @@ private:
      *  @return int         0 on success
      */
     static int processIdle(int type, int module_number TSRMLS_DC);
+
+    /**
+     *  Function that is called when the PHP engine initializes with a different PHP-CPP
+     *  version for the libphpcpp.so file than the version the extension was compiled for
+     *  @param  type        Module type
+     *  @param  number      Module number
+     *  @param  tsrm_ls
+     *  @return int         0 on success
+     */
+    static int processMismatch(int type, int module_number TSRMLS_DC);
 };
 
 /**
diff --git a/zend/includes.h b/zend/includes.h
index 83b1086..fb14b87 100644
--- a/zend/includes.h
+++ b/zend/includes.h
@@ -46,6 +46,7 @@
 /**
  *  Include other files from this library
  */
+#include "../include/version.h"
 #include "../include/inivalue.h"
 #include "../include/ini.h"
 #include "../include/exception.h"