HP OpenVMS systems documentation

Chapter 5
5	Signature Information and Translated Images (Alpha and I64 Systems Only)
5.1	Overview
5.1.1	Translated VAX Images on Alpha Systems
5.1.1.1	Direct Calls From Translated to Native Code
5.1.1.2	Direct Calls From Native to Translated Code
5.1.1.3	Indirect Calls From Native to Translated Code
5.1.2	Translated Images on I64 Systems
5.1.2.1	Calls From Translated to Native I64 Code
5.1.2.2	Direct Calls From Native I64 Code to Translated Code
5.1.2.3	Indirect Calls From Native to Translated Code
5.1.3	Signature Information Fields in Function Descriptors
5.2	Signature Information Blocks
5.2.1	Signature Information on Alpha Systems
5.2.2	Signature Information on I64 Systems
5.2.3	Signature Information Block Content
5.2.4	Call Parameter PSIG Conversions
5.2.4.1	Native-Alpha-to-Translated-VAX PSIG Conversions
5.2.4.2	Translated-VAX-to-Native-Alpha PSIG Conversions
5.2.4.3	Native-I64-to-Translated-Alpha PSIG Conversions
5.2.4.4	Translated-Alpha-to-Native-I64 PSIG Conversions
5.2.5	Default Signature Information
Chapter 6
6	OpenVMS Argument Data Types
6.1	Atomic Data Types
6.2	String Data Types
6.3	Miscellaneous Data Types
6.4	Reserved Data-Type Codes
6.4.1	Facility-Specific Data-Type Codes
6.5	Varying Character String Data Type (DSC$K_DTYPE_VT)
Chapter 7
7	OpenVMS Argument Descriptors
7.1	Descriptor Prototype
7.2	Fixed-Length Descriptor (CLASS_S)
7.3	Dynamic String Descriptor (CLASS_D)
7.4	Array Descriptor (CLASS_A)
7.5	Procedure Argument Descriptor (CLASS_P)
7.6	Decimal String Descriptor (CLASS_SD)
7.7	Noncontiguous Array Descriptor (CLASS_NCA)
7.8	Varying String Descriptor (CLASS_VS)
7.9	Varying String Array Descriptor (CLASS_VSA)
7.10	Unaligned Bit String Descriptor (CLASS_UBS)
7.11	Unaligned Bit Array Descriptor (CLASS_UBA)
7.12	String with Bounds Descriptor (CLASS_SB)
7.13	Unaligned Bit String with Bounds Descriptor (CLASS_UBSB)
7.14	Reserved Descriptor Class Codes
7.14.1	Facility-Specific Descriptor Class Codes
Chapter 8
8	OpenVMS Conditions
8.1	Condition Values
8.1.1	Interpretation of Severity Codes
8.1.2	Use of Condition Values
8.2	Condition Handlers
8.3	Condition Handler Options
8.4	Operations Involving Condition Handlers
8.4.1	Establishing a Condition Handler
8.4.2	Reverting to the Caller's Handling
8.4.3	Signaling a Condition
8.4.4	Signaling a Condition Using GENTRAP (Alpha and I64 Systems Only)
8.4.5	Signaling a Condition Using BREAK (I64 Only)
8.4.6	Condition Handler Search
8.5	Properties of Condition Handlers
8.5.1	Condition Handler Parameters and Invocation
8.5.1.1	Signal Argument Vector
8.5.1.2	Mechanism Argument Vector
8.5.1.2.1	VAX Mechanism Vector Format
8.5.1.2.2	Alpha Mechanism Vector Format
8.5.1.2.3	I64 Mechanism Vector Format
8.5.1.3	Mechanism Depth
8.5.2	System Default Condition Handlers
8.5.3	Coordinating the Handler and Establisher
8.5.3.1	Use of Memory
8.5.3.2	Exception Synchronization (Alpha Only)
8.5.3.3	Continuation from Exceptions (Alpha Only)
8.5.3.4	Floating-Point Control Status (I64 Only)
8.6	Returning from a Condition Handler
8.7	Request to Unwind from a Signal
8.7.1	Signaler's Registers
8.7.2	Unwind Completion
8.8	GOTO Unwind Operations (Alpha and I64 Systems Only)
8.8.1	Handler Invocation During a GOTO Unwind
8.8.2	Unwind Completion
8.9	Multiple Active Signals
8.10	Multiple Active Unwind Operations
Appendix A
Appendix A	Stack Unwinding and Exception Handling on OpenVMS I64
A.1	Unwinding the Stack
A.1.1	Initial Context
A.1.2	Step to Previous Frame
A.2	Exception Handling Framework
A.3	Coding Conventions for Reliable Unwinding
A.3.1	Requirements for Unwinding the Stack
A.3.2	Conventions for Prologue Regions
A.3.3	Conventions for Body Regions
A.3.4	Conventions for Epilogues
A.3.5	Conventions for the Spill Area in the Memory Stack Frame
A.4	Data Structures
A.4.1	Unwind Table and Unwind Information Block
A.4.1.1	Unwind Descriptor Area
A.4.1.2	Region Header Records
A.4.1.3	Descriptor Records for Prologue Regions
A.4.1.4	Descriptor Records for Body Regions
A.4.1.5	Descriptor Records for Body or Prologue Regions
A.4.1.6	Rules for Using Unwind Descriptors
A.4.1.7	Processing Unwind Descriptors
A.4.2	Condition Handler
A.4.3	Operating System-Specific Data Area
A.4.3.1	General Information Segment
A.4.3.2	Caller Spill Register Information
A.4.4	Language-Specific Data Area
A.5	Default Unwind Information
A.6	System Unwind Routines