Byte code instrumentation

A method of instrumenting a computer program, comprising:

• (a) examining an initial intermediate representation of the program;
• (b) selecting portions of the initial intermediate representation for instrumentation;
• (c) instrumenting the portions to provide instrumented portions;
• (d) converting the instrumented portions into byte code;
• and
• (e) prior to converting the instrumented portions to byte code, creating an intermediate representation tree of nodes corresponding to intermediate representation operations and operands of the initial intermediate representation, the nodes being interconnected according to a logical relationship between the operators and the operands, wherein instrumenting the portions includes modifying the intermediate representation tree.

A method of instrumenting a computer program, comprising:

• (a) examining an initial intermediate representation of the program;
• (b) selecting portions of the initial intermediate representation for instrumentation;
• (c) instrumenting the portions to provide instrumented portions;
• (d) converting the instrumented portions into byte code;
• (e) prior to converting the instrumented portions, creating an effective scope table that correlates a unique scope identifier for each block of intermediate representation code contained within the initial intermediate representation to an effective scope identifier that indicates whether new program variables are defined within a each block of intermediate representation code;
• and
• (f) in response to a first block of the intermediate representation code having a first effective scope identifier not equal to a second effective scope identifier of a second block of the intermediate representation code that precedes the first block of the intermediate representation code, selecting for instrumentation a portion of the intermediate representation code corresponding to a transition between the first and second blocks.

A method of instrumenting a computer program, comprising:

• (a) examining an initial intermediate representation of the program;
• (b) selecting portions of the initial intermediate representation for instrumentation;
• (c) instrumenting the portions to provide instrumented portions;
• (d) converting the instrumented portions into byte code;
• (e) prior to converting the instrumented portions, creating an effective scope table that correlates a unique scope identifier for each block of intermediate representation code contained within the initial intermediate representation to an effective scope identifier that indicates whether new program variables are defined within a each block of intermediate representation code;
• and
• (f) in response to a first block of the intermediate representation code containing a label and having associated therewith a first effective scope identifier not equal to a second effective scope identifier of a second block of the intermediate representation code containing a control flow instruction to the label, selecting for instrumentation a portion of the intermediate representation code corresponding to a transition between the control flow instruction and the label.

A method of instrumenting a computer program, comprising:

• (a) examining an initial intermediate representation of the program;
• (b) creating an intermediate representation tree of nodes corresponding to intermediate representation operations and operands of the initial intermediate representation, the nodes being interconnected according to a logical relationship between the operations and the operands;
• (c) selecting portions of the initial intermediate representation for instrumentations;
• (d) instrumenting the portions by modifying the intermediate representation tree with run time instrumentation code;
• (e) using the intermediate representation tree to create an instrumented intermediate representation that is structurally equivalent to the initial intermediate representation;
• and
• (f) converting the instrumented intermediate representation to byte code.

A computer program instrumenter, comprising:

• (a) examining means for examining an initial intermediate representation of the program;
• (b) creating means, coupled to the examining means, for creating an intermediate representation tree of nodes corresponding to intermediate representation operations and operands of the initial intermediate representation, the nodes being interconnected according to a logical relationship between the operations and the operands;
• (c) selecting means, coupled to the examining means, for selecting portions of the initial intermediate representation for instrumentations;
• (d) instrumenting means, coupled to the creating means and the selecting means, for instrumenting the portions by modifying the intermediate representation tree with run time instrumentation code;
• (e) tree means, coupled to the instrumenting means, for using the intermediate representation tree to create an instrumented intermediate representation that is structurally equivalent to the initial intermediate representation;
• and
• (f) means, coupled to the tree means, for converting the instrumented intermediate representation to byte code.