Fix the compile and run execution session in Python (#2373)

Signed-off-by: Alexandre Eichenberger <[email protected]>
Co-authored-by: Tung D. Le <[email protected]>

docs/doc_example/main.cpp

@@ -18,8 +18,8 @@ std::string readArgs(int argc, char *argv[]) {
 int main(int argc, char *argv[]) {
   // Read compiler options from command line and compile the doc example into a
   // model library.
-  const char *errorMessage = NULL;
-  const char *compiledFilename;
+  char *errorMessage = nullptr;
+  char *compiledFilename = nullptr;
   std::string flags = readArgs(argc, argv);
   flags += "-o add-cpp-interface";
   std::cout << "Compile with options \"" << flags << "\"\n";
@@ -30,11 +30,15 @@ int main(int argc, char *argv[]) {
     if (errorMessage)
       std::cerr << " and message \"" << errorMessage << "\"";
     std::cerr << "." << std::endl;
+    free(compiledFilename);
+    free(errorMessage);
     return rc;
   }
   std::string libFilename(compiledFilename);
   std::cout << "Compiled succeeded with results in file: " << libFilename
             << std::endl;
+  free(compiledFilename);
+  free(errorMessage);
 
   // Prepare the execution session.
   onnx_mlir::ExecutionSession *session;

docs/mnist_example/README.md

@@ -279,8 +279,7 @@ The runtime use an `OMExecutionSession` object to hold a specific model and entr
 
 ```Python
 #Load the model mnist.so compiled with onnx-mlir.
-model = 'mnist.so'
-session = OMExecutionSession(model)
+session = OMExecutionSession('mnist.so')
 #Print the models input / output signature, for display.
 #If there are problems with the signature functions,                           \
     they can be simply commented out.
@@ -295,10 +294,10 @@ outputs = session.run([input])
 
 The outputs can then be analyzed by inspecting the values inside the `output` list of numpy arrays.
 
-The full code is available [here](mnist.py). It finds that `0` is the most likely digit for the given input. The command is:
+The full code is available [here](mnist-runPyRuntime.py). It finds that `0` is the most likely digit for the given input. The command is:
 
 ```shell
-./mnist.py
+./mnist-runPyRuntime.py
 ```
 
 and produces an output similar to the following (you may see slightly different prediction numbers if you train the model yourself):
@@ -321,6 +320,22 @@ prediction  9 = 8.650948e-15
 The digit is 0
 ```
 
+We provide two additional Python interfaces. 
+The second interface extends the above execution session by simply compiling a model before loading it for execution (see [here](mnist-runPyCompileAndRuntime.py)). 
+The user simply passes the `.onnx` model and the flags needed to compile the model.
+Unless explicitly disabled by the `reuse_compiled_model=0`, the execution session will reuse a previously compiled model whose name matches the name the output file generated by the compiler. 
+Note that the execution session does not check if the cached version was compiled using identical compiler flags; it is the responsibility of the user to then clear the cached version, or disable the reuse using the provided optional flag.
+
+For example, the code below will compile and load the `mnist.onnx` model, compiling only when the `mnist2.so` binary file cannot be located. Model inference can then proceed using the `session.run(...)` command.
+
+```Python
+# Load onnx model and create CompileExecutionSession object,
+# by first compiling the mnist.onnx model with the "-O3" options.
+session = OMCompileExecutionSession("./mnist.onnx" ,"-O3 -o=mnist2")
+```
+
+The third interface provides a simple interface to explicitly compile an onnx model (see [here](mnist-compile.py)). 
+
 ## Write a Java Driver Code
 
 Inference APIs and data structures for Java closely mirror those for C/C++. Documentation of the APIs are found [here](https://onnx.ai/onnx-mlir/doxygen_html/OMModel_java/classcom_1_1ibm_1_1onnxmlir_1_1_o_m_model.html), with the Java interface for Tensor [here](https://onnx.ai/onnx-mlir/doxygen_html/OMTensor_java/classcom_1_1ibm_1_1onnxmlir_1_1_o_m_tensor.html) and TensorList [here](https://onnx.ai/onnx-mlir/doxygen_html/OMTensorList_java/classcom_1_1ibm_1_1onnxmlir_1_1_o_m_tensor_list.html).

docs/mnist_example/mnist-compile.py

@@ -7,7 +7,7 @@
 file = './mnist.onnx'
 compiler = OMCompileSession(file)
 # Generate the library file. Success when rc == 0 while set the opt as "-O3"
-rc = compiler.compile("-O3")
+rc = compiler.compile("-O3 -o mnist")
 # Get the output file name
 model = compiler.get_compiled_file_name()
 if rc:

docs/mnist_example/mnist-runPyCompileAndRuntime.py

@@ -3,13 +3,13 @@
 import numpy as np
 from PyCompileAndRuntime import OMCompileExecutionSession
 
-# Load onnx model and create CompileExecutionSession object.
-inputFileName = './mnist.onnx'
-# Set the full name of compiled model
-sharedLibPath = './mnist.so'
-# Set the compile option as "-O3"
-session = OMCompileExecutionSession(inputFileName,sharedLibPath,"-O3")
-
+# Load onnx model and create CompileExecutionSession object,
+# by first compiling the mnist.onnx model with the "-O3" options.
+session = OMCompileExecutionSession("./mnist.onnx" ,"-O3 -o=mnist2",
+                                    reuse_compiled_model=1)
+if session.get_compiled_result():
+    print("error with :" + session.get_error_message())
+    exit(1)
 # Print the models input/output signature, for display.
 # Signature functions for info only, commented out if they cause problems.
 print("input signature in json", session.input_signature())

docs/mnist_example/mnist-runPyRuntime.py

@@ -4,8 +4,7 @@
 from PyRuntime import OMExecutionSession
 
 # Load the model mnist.so compiled with onnx-mlir.
-model = './mnist.so'
-session = OMExecutionSession(model)
+session = OMExecutionSession('./mnist.so')
 # Print the models input/output signature, for display.
 # Signature functions for info only, commented out if they cause problems.
 print("input signature in json", session.input_signature())

include/OnnxMlirCompiler.h

@@ -60,18 +60,18 @@ namespace onnx_mlir {
  *  Name may include a path, and must include the file name and its extention.
  *
  *  @param outputFilename Output file name of the compiled output for the given
- * emission target. User is responsible for freeing the string.
+ *  emission target. User is responsible for freeing the string.
  *
  *  @param flags A char * contains all the options provided to compile the
- * model.
+ *  model.
  *
  *  @param errorMessage Output error message, if any. User is responsible for
- * freeing the string.
+ *  freeing the string.
  *
  *  @return 0 on success or OnnxMlirCompilerErrorCodes on failure.
  */
 ONNX_MLIR_EXPORT int64_t omCompileFromFile(const char *inputFilename,
-    const char *flags, const char **outputFilename, const char **errorMessage);
+    const char *flags, char **outputFilename, char **errorMessage);
 
 /*!
  *  Compile an onnx model from an ONNX protobuf array. This method is not thread
@@ -85,18 +85,33 @@ ONNX_MLIR_EXPORT int64_t omCompileFromFile(const char *inputFilename,
  *  @param bufferSize Size of ONNX protobuf array.
  *  @param outputBaseName File name without extension to write output.
  *  Name may include a path, must include the file name, and should not include
- * an extention.
+ *  an extention.
  *  @param emissionTarget Target format to compile to.
  *  @param outputFilename Output file name of the compiled output for the given
- * emission target. User is responsible for freeing the string.
- *  @param errorMessage Error message.
+ *  emission target. User is responsible for freeing the string.
+ *  @param errorMessage Error message, if any. User is responsible for freeing
+ *  the string.
  *  @return 0 on success or OnnxMlirCompilerErrorCodes failure. User is
- * responsible for freeing the string.
+ *  responsible for freeing the string.
  */
 ONNX_MLIR_EXPORT int64_t omCompileFromArray(const void *inputBuffer,
     int64_t bufferSize, const char *outputBaseName,
-    EmissionTargetType emissionTarget, const char **outputFilename,
-    const char **errorMessage);
+    EmissionTargetType emissionTarget, char **outputFilename,
+    char **errorMessage);
+
+/*!
+ * Compute the file name of the compiled output for the given
+ * emission target. User is responsible for freeing the string.
+ *
+ *  @param inputFilename File name pointing onnx model protobuf or MLIR.
+ *  Name may include a path, and must include the file name and its extention.
+ *  @param flags A char * contains all the options provided to compile the
+ *  model.
+ *  @return string containing the file name. User is responsible for freeing the
+ *  string.
+ */
+ONNX_MLIR_EXPORT char *omCompileOutputFileName(
+    const char *inputFilename, const char *flags);
 
 #ifdef __cplusplus
 } // namespace onnx_mlir

src/Compiler/OnnxMlirCompiler.cpp

@@ -18,16 +18,27 @@ using namespace onnx_mlir;
 
 namespace onnx_mlir {
 
+// Derive the name; base name is either given by a "-o" option, or is taken as
+// the model name. The extention depends on the target; e.g. -EmitLib will
+// generate a .so, other targets may generate a .mlir.
 static std::string deriveOutputFileName(
     std::vector<std::string> &flagVect, std::string inputFilename) {
   // Get output file name.
   std::string outputBasename;
   int num = flagVect.size();
-  for (int i = 0; i < num - 1;
-       ++i) { // Skip last as need 2 consecutive entries.
-    if (flagVect[i].find("-o") == 0) {
-      outputBasename = flagVect[i + 1];
-      break;
+  for (int i = 0; i < num; ++i) {
+    if (flagVect[i].find("-o=", 0, 3) == 0) {
+      if (flagVect[i].length() > 3) {
+        outputBasename = flagVect[i].substr(3);
+        break;
+      } else
+        llvm::errs() << "Parsing `-o=` option, expected a name. Use default.\n";
+    } else if (flagVect[i].find("-o") == 0) {
+      if (i < num - 1) {
+        outputBasename = flagVect[i + 1];
+        break;
+      } else
+        llvm::errs() << "Parsing `-o` option, expected a name. Use default.\n";
     }
   }
   // If no output file name, derive it from input file name
@@ -56,12 +67,7 @@ static std::string deriveOutputFileName(
   return getTargetFilename(outputBasename, emissionTarget);
 }
 
-extern "C" {
-
-ONNX_MLIR_EXPORT int64_t omCompileFromFile(const char *inputFilename,
-    const char *flags, const char **outputFilename, const char **errorMessage) {
-  // Process the flags, saving each space-separated text in a separate
-  // entry in the string vector flagVect.
+static std::vector<std::string> parseFlags(const char *flags) {
   std::vector<std::string> flagVect;
   const char *str = flags;
   do {
@@ -76,6 +82,23 @@ ONNX_MLIR_EXPORT int64_t omCompileFromFile(const char *inputFilename,
     if (begin != str)
       flagVect.push_back(std::string(begin, str));
   } while (*str);
+  return flagVect;
+}
+
+extern "C" {
+
+ONNX_MLIR_EXPORT int64_t omCompileFromFile(const char *inputFilename,
+    const char *flags, char **outputFilename, char **errorMessage) {
+  // Ensure known values in filename and error message if provided.
+  if (outputFilename)
+    *outputFilename = nullptr;
+  if (errorMessage)
+    *errorMessage = nullptr;
+
+  // Process the flags, saving each space-separated text in a separate
+  // entry in the string vector flagVect.
+  std::vector<std::string> flagVect = parseFlags(flags);
+
   // Use 'onnx-mlir' command to compile the model.
   std::string onnxMlirPath;
   const auto &envDir = getEnvVar("ONNX_MLIR_BIN_PATH");
@@ -90,17 +113,33 @@ ONNX_MLIR_EXPORT int64_t omCompileFromFile(const char *inputFilename,
   onnxMlirCompile.appendStr(inputFilenameStr);
   // Run command.
   int rc = onnxMlirCompile.exec();
-  if (rc == CompilerSuccess && outputFilename) {
+  if (rc != CompilerSuccess) {
+    // Failure to compile.
+    if (errorMessage) {
+      std::string errorStr =
+          "Compiler failed with error code " + std::to_string(rc);
+      *errorMessage = strdup(errorStr.c_str());
+    }
+    return CompilerFailureInLLVMOpt;
+  }
+  // Success.
+  if (outputFilename) {
     std::string name = deriveOutputFileName(flagVect, inputFilenameStr);
     *outputFilename = strdup(name.c_str());
   }
-  return rc != 0 ? CompilerFailureInLLVMOpt : CompilerSuccess;
+  return CompilerSuccess;
 }
 
 ONNX_MLIR_EXPORT int64_t omCompileFromArray(const void *inputBuffer,
     int64_t bufferSize, const char *outputBaseName,
-    EmissionTargetType emissionTarget, const char **outputFilename,
-    const char **errorMessage) {
+    EmissionTargetType emissionTarget, char **outputFilename,
+    char **errorMessage) {
+  // Ensure known values in filename and error message if provided.
+  if (outputFilename)
+    *outputFilename = nullptr;
+  if (errorMessage)
+    *errorMessage = nullptr;
+
   mlir::OwningOpRef<mlir::ModuleOp> module;
   mlir::MLIRContext context;
   registerDialects(context);
@@ -124,5 +163,13 @@ ONNX_MLIR_EXPORT int64_t omCompileFromArray(const void *inputBuffer,
   return rc;
 }
 
+ONNX_MLIR_EXPORT char *omCompileOutputFileName(
+    const char *inputFilename, const char *flags) {
+  std::vector<std::string> flagVect = parseFlags(flags);
+  std::string inputFilenameStr(inputFilename);
+  std::string name = deriveOutputFileName(flagVect, inputFilenameStr);
+  return strdup(name.c_str());
+}
+
 } // extern C
 } // namespace onnx_mlir

src/Compiler/PyOMCompileSession.cpp

@@ -35,7 +35,8 @@ int64_t PyOMCompileSession::pyCompileFromFile(std::string flags) {
         "No OMCompileSession was created with the input file name specified.";
     return -1;
   }
-  const char *outputName, *errorMsg;
+  char *outputName = nullptr;
+  char *errorMsg = nullptr;
   int64_t rc;
   rc = omCompileFromFile(
       inputFileName.c_str(), flags.c_str(), &outputName, &errorMsg);
@@ -50,6 +51,8 @@ int64_t PyOMCompileSession::pyCompileFromFile(std::string flags) {
     // Empty output file name.
     outputFileName = std::string();
   }
+  free(outputName);
+  free(errorMsg);
   return rc;
 }
 
@@ -60,7 +63,8 @@ int64_t PyOMCompileSession::pyCompileFromArray(
         "No OMCompileSession was created with the input buffer specified.";
     return -1;
   }
-  const char *outputName, *errorMsg;
+  char *outputName = nullptr;
+  char *errorMsg = nullptr;
   int64_t rc;
   rc = omCompileFromArray(inputBuffer, inputBufferSize, outputBaseName.c_str(),
       emissionTarget, &outputName, &errorMsg);
@@ -75,6 +79,8 @@ int64_t PyOMCompileSession::pyCompileFromArray(
     // Empty output file name.
     outputFileName = std::string();
   }
+  free(outputName);
+  free(errorMsg);
   return rc;
 }