mach-stack(3) - Plan 9 from User Space

From adc93f6097615f16d57e8a24a256302f2144ec4e Mon Sep 17 00:00:00 2001 From: rsc Date: Fri, 14 Jan 2005 17:37:50 +0000 Subject: cut out the html - they're going to cause diffing problems. --- man/man3/mach-stack.html | 232 ----------------------------------------------- 1 file changed, 232 deletions(-) delete mode 100644 man/man3/mach-stack.html (limited to 'man/man3/mach-stack.html') diff --git a/man/man3/mach-stack.html b/man/man3/mach-stack.html deleted file mode 100644 index d08258bd..00000000 --- a/man/man3/mach-stack.html +++ /dev/null @@ -1,232 +0,0 @@ - -mach-stack(3) - Plan 9 from User Space - - - - -

MACH-STACK(3) MACH-STACK(3) -

-
-

NAME
- -
- - stacktrace, localaddr, unwindframe, windindex, windreglocs – stack - traces
- -
-

SYNOPSIS
- -
- - #include <u.h> - #include <libc.h> - #include <mach.h> - - - int     stacktrace(Map *map, Rgetter rget, Tracer trace) -
- - int     localaddr(Map *map, Regs *regs, char *fn, char *val, ulong - *val) -
- - int     unwindframe(Map *map, Regs *regs, ulong *next, Symbol *sym) - -
- - int     windindex(char *regname) -
- - Loc*    windreglocs(void)
- -
-

DESCRIPTION
- -
- - Stacktrace provides machine-independent implementations of process - stack traces. They must retrieve data and register contents from - an executing image. Sometimes the desired registers are not the - current registers but rather a set of saved registers stored elsewhere - in memory. The caller may specify an initial - register set in the form of an Rgetter function, of the form -
- - -
- - ulong rget(Map *map, char *name) - - - - -
- It returns the contents of a register when given a map and a register - name. It is usually sufficient for the register function to return - meaningful values only for SP and PC, and for the link register - (usually LR) on CISC machines. -
- - Given the map and the rgetter, stacktrace unwinds the stack starting - at the innermost function. At each level in the trace, it calls - the tracer function, which has the form -
- - -
- - int trace(Map *map, ulong pc, ulong callerpc, - - - - Rgetter rget, Symbol *s) - - - - - -
- - - -
- -
- The tracer is passed the map, the current program counter, the - program counter of the caller (zero if the caller is unknown), - a new rget function, and a symbol (see mach-symbol(3)) describing - the current function (nil if no symbol is known). The value returned - by the tracer controls whether the stack trace continues: a - zero or negative return value stops the trace, while a positive - return value continues it. -
- - The rgetter passed to the tracer is not the rgetter passed to - stacktrace itself. Instead, it is a function returning the register - values at the time of the call, to the extent that they can be - reconstructed. The most common use for this rgetter is as an argument - to lget4, etc., when evaluating the locations of local - variables. -
- - Localaddr uses stacktrace to walk up the stack looking for the - innermost instance of a function named fn ; once it finds the - function, it looks for the parameter or local variable var, storing - the address of the variable in val. -
- - Unwindframe is the low-level function on which stacktrace is built. - Given the current memory image in map and the current register - set in regs , unwindframe fills in next with the values of the - register set at the time of the call to the function in the current - program counter. Sym should be the symbol corresponding to - the current function, if available. -
- - The next array holds only the winding registers, typically the - caller-save registers and the program counter and stack pointer. - The order of registers in the array is called the winding order. - The winding set can be found in the array mach−>windreg, which - has mach−>nwindreg entries. Windindex returns the index of - the named register in the winding order. Windreglocs returns an - array of Loc structures corresponding to the winding registers, - in the winding order.
- -
-

EXAMPLE
- -
- - The following code writes a simple stack trace to standard output, - stopping after at most 20 stack frames.
- -
- - static int
- trace(Map *map, ulong pc, ulong callerpc,
- -
- - Rgetter rget, Symbol *s, int depth)
- -
- {
- -
- - char buf[512];
- int i, first;
- u32int v;
- Symbol s2;
- if(sym)
- print("%s+%lx", s->name, pc - loceval(s->loc));
- else
- print("%lux", pc);
- print("(");
- first = 0;
- for(i=0; indexlsym(s, &i, &s2)>=0; i++){
- if(s.class != CPARAM)
- continue;
- if(first++)
- print(", ");
- if(lget4(map, rget, s->loc, &v) >= 0)
- print("%s=%#lux", s->name, (ulong)v);
- else
- print("%s=???", s->name);
- }
- print(") called from ");
- symoff(buf, sizeof buf, callerpc, CTEXT);
- print("%s\n", buf);
- return depth < 20;
- -
- }
- -
- - if(stacktrace(map, nil, trace) <= 0)
- print("no stack frame0);
- -
- -
- -
-

SOURCE
- -
- - /usr/local/plan9/src/libmach - -
-

SEE ALSO
- -
- - mach(3)
- -
-

BUGS
- -
- - Need to talk about Regs
- -
- -

- - -

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	- - - -

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