dwarfpc.c File Reference

#include <precomp.h>
#include <debug.h>

Include dependency graph for dwarfpc.c:

Go to the source code of this file.

Classes
struct	State

Macros
#define	NDEBUG
#define	trace   0

Typedefs
typedef struct State	State

Enumerations
enum	{   Isstmt = 1<<0, BasicDwarfBlock = 1<<1, EndSequence = 1<<2, PrologueEnd = 1<<3,   EpilogueBegin = 1<<4 }

Functions
int	dwarfpctoline (Dwarf *d, DwarfSym *proc, ulong pc, char **file, char **function, ulong *line)
VOID	RosSymFreeInfo (PROSSYM_LINEINFO LineInfo)

Macro Definition Documentation

NDEBUG

#define NDEBUG

Definition at line 16 of file dwarfpc.c.

trace

#define trace   0

Definition at line 18 of file dwarfpc.c.

Typedef Documentation

State

typedef struct State State

Definition at line 29 of file dwarfpc.c.

Enumeration Type Documentation

anonymous enum

anonymous enum

Enumerator
Isstmt
BasicDwarfBlock
EndSequence
PrologueEnd
EpilogueBegin

Definition at line 20 of file dwarfpc.c.

{
    Isstmt = 1<<0,
    BasicDwarfBlock = 1<<1,
    EndSequence = 1<<2,
    PrologueEnd = 1<<3,
    EpilogueBegin = 1<<4
};

Function Documentation

dwarfpctoline()

int dwarfpctoline	(	Dwarf *	d,
		DwarfSym *	proc,
		ulong	pc,
		char **	file,
		char **	function,
		ulong *	line
	)

Definition at line 41 of file dwarfpc.c.

{
    char *cdir;
    uchar *prog, *opcount, *end, *dirs;
    ulong off, unit, len, vers, x, start, lastline;
    int i, first, firstline, op, a, l, quantum, isstmt, linebase, linerange, opcodebase, nf;
    char *files, *s;
    DwarfBuf b;
    DwarfSym sym;
    State emit, cur, reset;
    char **f, **newf;

    f = nil;
    memset(proc, 0, sizeof(*proc));

    int runit = dwarfaddrtounit(d, pc, &unit);
    if (runit < 0)
        return -1;
    int rtag = dwarflookuptag(d, unit, TagCompileUnit, &sym);
    if (rtag < 0)
        return -1;

    if(!sym.attrs.have.stmtlist){
        werrstr("no line mapping information for 0x%x", pc);
        return -1;
    }
    off = sym.attrs.stmtlist;
    if(off >= d->line.len){
        werrstr("bad stmtlist");
        goto bad;
    }

    if(trace) werrstr("unit 0x%x stmtlist 0x%x", unit, sym.attrs.stmtlist);

    memset(&b, 0, sizeof b);
    b.d = d;
    b.p = d->line.data + off;
    b.ep = b.p + d->line.len;
    b.addrsize = sym.b.addrsize;    /* should i get this from somewhere else? */

    len = dwarfget4(&b);
    if(b.p==nil || b.p+len > b.ep || b.p+len < b.p){
        werrstr("bad len");
        goto bad;
    }

    b.ep = b.p+len;
    vers = dwarfget2(&b);
    if(vers != 2){
        werrstr("bad dwarf version 0x%x", vers);
        return -1;
    }

    len = dwarfget4(&b);
    if(b.p==nil || b.p+len > b.ep || b.p+len < b.p){
        werrstr("another bad len");
        goto bad;
    }
    prog = b.p+len;

    quantum = dwarfget1(&b);
    isstmt = dwarfget1(&b);
    linebase = (schar)dwarfget1(&b);
    linerange = (schar)dwarfget1(&b);
    opcodebase = dwarfget1(&b);

    opcount = b.p-1;
    dwarfgetnref(&b, opcodebase-1);
    if(b.p == nil){
        werrstr("bad opcode chart");
        goto bad;
    }

    /* just skip the files and dirs for now; we'll come back */
    dirs = b.p;
    while (b.p && *b.p)
        dwarfgetstring(&b);
    dwarfget1(&b);

    files = (char*)b.p;
    while(b.p!=nil && *b.p!=0){
        dwarfgetstring(&b);
        dwarfget128(&b);
        dwarfget128(&b);
        dwarfget128(&b);
    }
    dwarfget1(&b);

    /* move on to the program */
    if(b.p == nil || b.p > prog){
        werrstr("bad header");
        goto bad;
    }
    b.p = prog;

    reset.addr = 0;
    reset.file = 1;
    reset.line = 1;
    reset.column = 0;
    reset.flags = isstmt ? Isstmt : 0;
    reset.isa = 0;

    cur = reset;
    emit = reset;
    nf = 0;
    start = 0;
    if(trace) werrstr("program @ %lu ... %.*H opbase = %d", b.p - d->line.data, b.ep-b.p, b.p, opcodebase);
    first = 1;
    while(b.p != nil){
        firstline = 0;
        op = dwarfget1(&b);
        if(trace) werrstr("\tline %lu, addr 0x%x, op %d %.10H", cur.line, cur.addr, op, b.p);
        if(op >= opcodebase){
            a = (op - opcodebase) / linerange;
            l = (op - opcodebase) % linerange + linebase;
            cur.line += l;
            cur.addr += a * quantum;
            if(trace) werrstr(" +%d,%d", a, l);
        emit:
            if(first){
                if(cur.addr > pc){
                    werrstr("found wrong line mapping 0x%x for pc 0x%x", cur.addr, pc);
                    /* This is an overzealous check.  gcc can produce discontiguous ranges
                       and reorder statements, so it's possible for a future line to start
                       ahead of pc and still find a matching one. */
                    /*goto out;*/
                    firstline = 1;
                }
                first = 0;
                start = cur.addr;
            }
            if(cur.addr > pc && !firstline)
                break;
            if(b.p == nil){
                werrstr("buffer underflow in line mapping");
                goto out;
            }
            emit = cur;
            if(emit.flags & EndSequence){
                werrstr("found wrong line mapping 0x%x-0x%x for pc 0x%x", start, cur.addr, pc);
                goto out;
            }
            cur.flags &= ~(BasicDwarfBlock|PrologueEnd|EpilogueBegin);
        }else{
            switch(op){
            case 0: /* extended op code */
                if(trace) werrstr(" ext");
                len = dwarfget128(&b);
                end = b.p+len;
                if(b.p == nil || end > b.ep || end < b.p || len < 1)
                    goto bad;
                switch(dwarfget1(&b)){
                case 1: /* end sequence */
                    if(trace) werrstr(" end");
                    cur.flags |= EndSequence;
                    goto emit;
                case 2: /* set address */
                    cur.addr = dwarfgetaddr(&b);
                    if(trace) werrstr(" set pc 0x%x", cur.addr);
                    break;
                case 3: /* define file */
                    newf = malloc(nf+1*sizeof(f[0]));
                    if (newf)
                        RtlMoveMemory(newf, f, nf*sizeof(f[0]));
                    if(newf == nil)
                        goto out;
                    free(f);
                    f = newf;
                    f[nf++] = s = dwarfgetstring(&b);
                    DPRINT1("str %s", s);
                    dwarfget128(&b);
                    dwarfget128(&b);
                    dwarfget128(&b);
                    if(trace) werrstr(" def file %s", s);
                    break;
                }
                if(b.p == nil || b.p > end)
                    goto bad;
                b.p = end;
                break;
            case 1: /* emit */
                if(trace) werrstr(" emit");
                goto emit;
            case 2: /* advance pc */
                a = dwarfget128(&b);
                if(trace) werrstr(" advance pc + %lu", a*quantum);
                cur.addr += a * quantum;
                break;
            case 3: /* advance line */
                l = dwarfget128s(&b);
                if(trace) werrstr(" advance line + %ld", l);
                cur.line += l;
                break;
            case 4: /* set file */
                if(trace) werrstr(" set file");
                cur.file = dwarfget128s(&b);
                break;
            case 5: /* set column */
                if(trace) werrstr(" set column");
                cur.column = dwarfget128(&b);
                break;
            case 6: /* negate stmt */
                if(trace) werrstr(" negate stmt");
                cur.flags ^= Isstmt;
                break;
            case 7: /* set basic block */
                if(trace) werrstr(" set basic block");
                cur.flags |= BasicDwarfBlock;
                break;
            case 8: /* const add pc */
                a = (255 - opcodebase) / linerange * quantum;
                if(trace) werrstr(" const add pc + %d", a);
                cur.addr += a;
                break;
            case 9: /* fixed advance pc */
                a = dwarfget2(&b);
                if(trace) werrstr(" fixed advance pc + %d", a);
                cur.addr += a;
                break;
            case 10:    /* set prologue end */
                if(trace) werrstr(" set prologue end");
                cur.flags |= PrologueEnd;
                break;
            case 11:    /* set epilogue begin */
                if(trace) werrstr(" set epilogue begin");
                cur.flags |= EpilogueBegin;
                break;
            case 12:    /* set isa */
                if(trace) werrstr(" set isa");
                cur.isa = dwarfget128(&b);
                break;
            default:    /* something new - skip it */
                if(trace) werrstr(" unknown %d", opcount[op]);
                for(i=0; i<opcount[op]; i++)
                    dwarfget128(&b);
                break;
            }
        }
    }
    if(b.p == nil)
        goto bad;

    /* finally!  the data we seek is in "emit" */

    if(emit.file == 0){
        werrstr("invalid file index in mapping data");
        goto out;
    }
    if(line)
        *line = emit.line;

    /* skip over first emit.file-2 guys */
    b.p = (uchar*)files;
    for(i=emit.file-1; i > 0 && b.p!=nil && *b.p!=0; i--){
        dwarfgetstring(&b);
        dwarfget128(&b);
        dwarfget128(&b);
        dwarfget128(&b);
    }
    if(b.p == nil){
        werrstr("problem parsing file data second time (cannot happen)");
        goto bad;
    }
    if(*b.p == 0){
        if(i >= nf){
            werrstr("bad file index in mapping data");
            goto bad;
        }
        b.p = (uchar*)f[i];
    }
    s = dwarfgetstring(&b);
    *file = s;
    i = dwarfget128(&b);        /* directory */
    x = dwarfget128(&b);
    x = dwarfget128(&b);

    /* fetch dir name */
    cdir = sym.attrs.have.compdir ? sym.attrs.compdir : 0;

    char *dwarfdir;
    dwarfdir = nil;
    b.p = dirs;
    for (x = 1; b.p && *b.p; x++) {
        dwarfdir = dwarfgetstring(&b);
        if (x == i) break;
    }

    if (!cdir && dwarfdir)
        cdir = dwarfdir;

    char *filefull = malloc(strlen(cdir) + strlen(*file) + 2);
    strcpy(filefull, cdir);
    strcat(filefull, "/");
    strcat(filefull, *file);
    *file = filefull;

    *function = nil;
    lastline = 0;

    runit = dwarfaddrtounit(d, pc, &unit);
    if (runit == 0) {
        DwarfSym compunit = { };
        int renum = dwarfenumunit(d, unit, &compunit);
        if (renum < 0)
            return -1;
        renum = dwarfnextsymat(d, &compunit, proc);
        while (renum == 0) {
            if (proc->attrs.tag == TagSubprogram &&
                proc->attrs.have.name)
            {
                if (proc->attrs.lowpc <= pc && proc->attrs.highpc > pc) {
                    *function = malloc(strlen(proc->attrs.name)+1);
                    strcpy(*function, proc->attrs.name);
                    goto done;
                }
            }
            renum = dwarfnextsym(d, proc);
        }
    }

    // Next search by declaration
    runit = dwarfaddrtounit(d, pc, &unit);
    if (runit == 0) {
        DwarfSym compunit = { };
        int renum = dwarfenumunit(d, unit, &compunit);
        if (renum < 0)
            return -1;
        renum = dwarfnextsymat(d, &compunit, proc);
        while (renum == 0) {
            if (proc->attrs.tag == TagSubprogram &&
                proc->attrs.have.name &&
                proc->attrs.declfile == emit.file)
            {
                if (proc->attrs.declline <= *line &&
                    proc->attrs.declline > lastline) {
                    free(*function);
                    *function = malloc(strlen(proc->attrs.name)+1);
                    strcpy(*function, proc->attrs.name);
                    goto done;
                }
                lastline = proc->attrs.declline;
            }
            renum = dwarfnextsym(d, proc);
        }
    }

    /* free at last, free at last */
done:
    free(f);
    return 0;
bad:
    werrstr("corrupted line mapping for 0x%x", pc);
out:
    free(f);
    return -1;
}

RosSymFreeInfo()

VOID RosSymFreeInfo

(

PROSSYM_LINEINFO

LineInfo

)

Definition at line 398 of file dwarfpc.c.

{
    int i;
    free(LineInfo->FileName);
    LineInfo->FileName = NULL;
    free(LineInfo->FunctionName);
    LineInfo->FunctionName = NULL;
    for (i = 0; i < sizeof(LineInfo->Parameters)/sizeof(LineInfo->Parameters[0]); i++)
        free(LineInfo->Parameters[i].ValueName);
}