Guardian Procedure Calls Reference Manual

limit
input
INT:value
specifies the maximum length (in bytes) of the output line. This value must not be less than the
minimum width specified by the HIST_MinWidth literal in the HHISTRY file; otherwise, an error
occurs.
Returned Value
INT
If the procedure is successful, the length of the output text in bytes or zero (0) if there is no more
text for the current context. If the procedure is unsuccessful, ret-val contains a negative value
as follows:
HIST_BAD_WIDTH-2
The value of the limit parameter is less than the minimum width for output defined by the HIST_MinWidth
literal in the HHISTRY header file.
HIST_BAD_WORKSPACE-9
The workspace structure has an invalid version identifier. This error can occur if HIST_FORMAT_ is called
without first calling the HIST_INIT_ procedure or if the workspace structure has become corrupted.
HIST_BAD_FORMAT_CALL-10
Nothing to format. This error can occur if you call HIST_FORMAT_ again after a previous call returned zero
indicating no more text for the current context.
workspace.FormatSelect Field
The workspace.FormatSelect field determines what information is reported back by
HIST_FORMAT_ to the caller. This field is initialized to a default value by the HIST_INIT_ procedure,
but it can be changed by the caller before the first HIST_FORMAT_ call for any stack frame.
Changing FormatSelect between successive calls to HIST_FORMAT_ without an intervening
call to HIST_GETPRIOR_ has an undefined effect. The field is a bit mask formed by combining these
literals:
Shows the code space in which the procedure resides; for example, user code (UC), user code
RISC (UCr), accelerated system library (acc SL), system code RISC (SCr), system library RISC
HF_CodeSpace.
(SLr), or millicode (milli). For TNS code, it shows the code segment index (for example, UL.00).
For named native shared run-time libraries (SRLs), it shows the SRL name (not its object file
name)
Shows the RISC register contents whenever a full context is available (for example, when a
signal is generated). If a full context is available for a frame in TNS or accelerated mode when
the emulated TNS registers R0 through R7 are available, they are also shown
HF_Context.
Shows the emulated TNS registers R0 through R7 when available. This option is redundant if
the HF_Context option is set.
HF_Context_TNS
Shows discontinuities. Three hyphens (---) denote a discontinuity in the calling sequence; for
example, when a trap or system-generated nondeferrable signal occurred. An ellipsis (...)
HF_Gaps
denotes missing procedure activation records in the chain of events. See "Protected Contexts"
later under Protected Context Considerations.
For procedures executing in TNS/E native mode, shows the program counter (pc), previous
stack pointer (PSP), and stack pointer (sp), when relevant, in hexadecimal 64-bit values.
HF_LocLineRISC is the TNS/R equivalent for HF_LocLineIPF.
HF_LocLineIPF
The PSP is defined as FP plus the frame offset (the size of the stack frame). Compiler-listed
variable offsets are relative to PSP.
If a larger set of IPF registers is being displayed because of the HF_Context or HF_Registers
options, the HF_LocLineIPF information is redundant and is not shown.
HIST_FORMAT_ Procedure 699