dwarfinfo.c

Go to the documentation of this file.

/*
 * Dwarf info parse and search.
 */

#define NTOSAPI
#include <ntifs.h>
#include <ndk/ntndk.h>
#include <reactos/rossym.h>
#include "rossympriv.h"
#include <ntimage.h>

#define NDEBUG
#include <debug.h>

#include "dwarf.h"
#include <windef.h>

enum
{
    DwarfAttrSibling = 0x01,
    DwarfAttrLocation = 0x02,
    DwarfAttrName = 0x03,
    DwarfAttrOrdering = 0x09,
    DwarfAttrByteSize = 0x0B,
    DwarfAttrBitOffset = 0x0C,
    DwarfAttrBitSize = 0x0D,
    DwarfAttrStmtList = 0x10,
    DwarfAttrLowpc = 0x11,
    DwarfAttrHighpc = 0x12,
    DwarfAttrLanguage = 0x13,
    DwarfAttrDiscr = 0x15,
    DwarfAttrDiscrValue = 0x16,
    DwarfAttrVisibility = 0x17,
    DwarfAttrImport = 0x18,
    DwarfAttrStringLength = 0x19,
    DwarfAttrCommonRef = 0x1A,
    DwarfAttrCompDir = 0x1B,
    DwarfAttrConstValue = 0x1C,
    DwarfAttrContainingType = 0x1D,
    DwarfAttrDefaultValue = 0x1E,
    DwarfAttrInline = 0x20,
    DwarfAttrIsOptional = 0x21,
    DwarfAttrLowerBound = 0x22,
    DwarfAttrProducer = 0x25,
    DwarfAttrPrototyped = 0x27,
    DwarfAttrReturnAddr = 0x2A,
    DwarfAttrStartScope = 0x2C,
    DwarfAttrStrideSize = 0x2E,
    DwarfAttrUpperBound = 0x2F,
    DwarfAttrAbstractOrigin = 0x31,
    DwarfAttrAccessibility = 0x32,
    DwarfAttrAddrClass = 0x33,
    DwarfAttrArtificial = 0x34,
    DwarfAttrBaseTypes = 0x35,
    DwarfAttrCalling = 0x36,
    DwarfAttrCount = 0x37,
    DwarfAttrDataMemberLoc = 0x38,
    DwarfAttrDeclColumn = 0x39,
    DwarfAttrDeclFile = 0x3A,
    DwarfAttrDeclLine = 0x3B,
    DwarfAttrDeclaration = 0x3C,
    DwarfAttrDiscrList = 0x3D,
    DwarfAttrEncoding = 0x3E,
    DwarfAttrExternal = 0x3F,
    DwarfAttrFrameBase = 0x40,
    DwarfAttrFriend = 0x41,
    DwarfAttrIdentifierCase = 0x42,
    DwarfAttrMacroInfo = 0x43,
    DwarfAttrNamelistItem = 0x44,
    DwarfAttrPriority = 0x45,
    DwarfAttrSegment = 0x46,
    DwarfAttrSpecification = 0x47,
    DwarfAttrStaticLink = 0x48,
    DwarfAttrType = 0x49,
    DwarfAttrUseLocation = 0x4A,
    DwarfAttrVarParam = 0x4B,
    DwarfAttrVirtuality = 0x4C,
    DwarfAttrVtableElemLoc = 0x4D,
    DwarfAttrAllocated = 0x4E,
    DwarfAttrAssociated = 0x4F,
    DwarfAttrDataLocation = 0x50,
    DwarfAttrStride = 0x51,
    DwarfAttrEntrypc = 0x52,
    DwarfAttrUseUTF8 = 0x53,
    DwarfAttrExtension = 0x54,
    DwarfAttrRanges = 0x55,
    DwarfAttrTrampoline = 0x56,
    DwarfAttrCallColumn = 0x57,
    DwarfAttrCallFile = 0x58,
    DwarfAttrCallLine = 0x59,
    DwarfAttrDescription = 0x5A,
    DwarfAttrMax,

    FormAddr = 0x01,
    FormDwarfBlock2 = 0x03,
    FormDwarfBlock4 = 0x04,
    FormData2 = 0x05,
    FormData4 = 0x06,
    FormData8 = 0x07,
    FormString = 0x08,
    FormDwarfBlock = 0x09,
    FormDwarfBlock1 = 0x0A,
    FormData1 = 0x0B,
    FormFlag = 0x0C,
    FormSdata = 0x0D,
    FormStrp = 0x0E,
    FormUdata = 0x0F,
    FormRefAddr = 0x10,
    FormRef1 = 0x11,
    FormRef2 = 0x12,
    FormRef4 = 0x13,
    FormRef8 = 0x14,
    FormRefUdata = 0x15,
    FormIndirect = 0x16
};

static int parseattrs(DwarfBuf*, ulong, DwarfAbbrev*, DwarfAttrs*);
static int getulong(DwarfBuf*, int, ulong, ulong*, int*);
static int getuchar(DwarfBuf*, int, uchar*);
static int getstring(DwarfBuf*, int, char**);
static int getblock(DwarfBuf*, int, DwarfBlock*);
static int skipform(DwarfBuf*, int);
static int constblock(Dwarf*, DwarfBlock*, ulong*);

int
dwarflookupnameinunit(Dwarf *d, ulong unit, char *name, DwarfSym *s)
{
    if(dwarfenumunit(d, unit, s) < 0)
        return -1;

    dwarfnextsymat(d, s, 0);    /* s is now the CompileUnit */
    while(dwarfnextsymat(d, s, 1) == 1)
        if(s->attrs.name && strcmp(s->attrs.name, name) == 0)
            return 0;
    werrstr("symbol '%s' not found", name);
    return -1;
}


int
dwarflookupsubname(Dwarf *d, DwarfSym *parent, char *name, DwarfSym *s)
{
    *s = *parent;
    while(dwarfnextsymat(d, s, parent->depth+1))
        if(s->attrs.name && strcmp(s->attrs.name, name) == 0)
            return 0;
    werrstr("symbol '%s' not found", name);
    return -1;
}

int
dwarflookuptag(Dwarf *d, ulong unit, ulong tag, DwarfSym *s)
{
    if(dwarfenumunit(d, unit, s) < 0) {
        return -1;
    }

    dwarfnextsymat(d, s, 0);    /* s is now the CompileUnit */
    if(s->attrs.tag == tag) {
        return 0;
    }
    while(dwarfnextsymat(d, s, 1) == 1)
        if(s->attrs.tag == tag) {
            return 0;
        }
    werrstr("symbol with tag 0x%lux not found", tag);
    return -1;
}

int
dwarfseeksym(Dwarf *d, ulong unit, ulong off, DwarfSym *s)
{
    if(dwarfenumunit(d, unit, s) < 0)
        return -1;
    s->b.p = d->info.data + unit + off;
    if(dwarfnextsymat(d, s, 0) != 1)
        return -1;
    return 0;
}

int
dwarflookupfn(Dwarf *d, ulong unit, ulong pc, DwarfSym *s)
{
    if(dwarfenumunit(d, unit, s) < 0)
        return -1;

    if(dwarfnextsymat(d, s, 0) != 1)
        return -1;
    /* s is now the CompileUnit */

    while(dwarfnextsymat(d, s, 1) == 1){
        if(s->attrs.tag != TagSubprogram)
            continue;
        if(s->attrs.lowpc <= pc && pc < s->attrs.highpc)
            return 0;
    }
    werrstr("fn containing pc 0x%lux not found", pc);
    return -1;
}

int
dwarfenumunit(Dwarf *d, ulong unit, DwarfSym *s)
{
    int i;
    ulong aoff, len;

    if(unit >= d->info.len){
        werrstr("dwarf unit address 0x%x >= 0x%x out of range", unit, d->info.len);
        return -1;
    }
    memset(s, 0, sizeof *s);
    memset(&s->b, 0, sizeof s->b);

    s->b.d = d;
    s->b.p = d->info.data + unit;
    s->b.ep = d->info.data + d->info.len;
    len = dwarfget4(&s->b);
    s->nextunit = unit + 4 + len;

    if(s->b.ep - s->b.p < len){
    badheader:
        werrstr("bad dwarf unit header at unit 0x%lux", unit);
        return -1;
    }
    s->b.ep = s->b.p+len;
    if((i=dwarfget2(&s->b)) != 2)
        goto badheader;
    aoff = dwarfget4(&s->b);
    s->b.addrsize = dwarfget1(&s->b);
    if(d->addrsize == 0)
        d->addrsize = s->b.addrsize;
    if(s->b.p == nil)
        goto badheader;

    s->aoff = aoff;
    s->unit = unit;
    s->depth = 0;
    return 0;
}

int
dwarfenum(Dwarf *d, DwarfSym *s)
{
    if(dwarfenumunit(d, 0, s) < 0)
        return -1;
    s->allunits = 1;
    return 0;
}

int
dwarfnextsym(Dwarf *d, DwarfSym *s)
{
    ulong num;
    DwarfAbbrev *a;

    if(s->attrs.haskids)
        s->depth++;
top:
    if(s->b.p >= s->b.ep){
        if(s->allunits && s->nextunit < d->info.len){
            if(dwarfenumunit(d, s->nextunit, s) < 0) {
                return -1;
            }
            s->allunits = 1;
            goto top;
        }
        return 0;
    }

    s->uoff = s->b.p - (d->info.data+s->unit);
    num = dwarfget128(&s->b);
    if(num == 0){
        if(s->depth == 0) {
            return 0;
        }
        if(s->depth > 0)
            s->depth--;
        goto top;
    }

    a = dwarfgetabbrev(d, s->aoff, num);
    if(a == nil){
        werrstr("getabbrev %ud %ud for %ud,%ud: %r\n", s->aoff, num, s->unit, s->uoff);
        return -1;
    }
    if(parseattrs(&s->b, s->unit, a, &s->attrs) < 0) {
        return -1;
    }
    return 1;
}

int
dwarfnextsymat(Dwarf *d, DwarfSym *s, int depth)
{
    int r;
    DwarfSym t;
    uint sib;

    if(s->depth == depth && s->attrs.have.sibling){
        sib = s->attrs.sibling;
        if(sib < d->info.len && d->info.data+sib >= s->b.p)
            s->b.p = d->info.data+sib;
        s->attrs.haskids = 0;
    }

    /*
     * The funny game with t and s make sure that
     * if we get to the end of a run of a particular
     * depth, we leave s so that a call to nextsymat with depth-1
     * will actually produce the desired guy.  We could change
     * the interface to dwarfnextsym instead, but I'm scared
     * to touch it.
     */
    t = *s;
    for(;;){
        if((r = dwarfnextsym(d, &t)) != 1) {
            return r;
        }
        if(t.depth < depth){
            /* went too far - nothing to see */
            return 0;
        }
        *s = t;
        if(t.depth == depth) {
            return 1;
        }
    }
}

typedef struct Parse Parse;
struct Parse {
    int name;
    int off;
    int haveoff;
    int type;
};

#define OFFSET(x) offsetof(DwarfAttrs, x), offsetof(DwarfAttrs, have.x)

static Parse plist[] = {    /* Font Tab 4 */
    { DwarfAttrAbstractOrigin,  OFFSET(abstractorigin),     TReference },
    { DwarfAttrAccessibility,   OFFSET(accessibility),      TConstant },
    { DwarfAttrAddrClass,       OFFSET(addrclass),          TConstant },
    { DwarfAttrArtificial,      OFFSET(isartificial),       TFlag },
    { DwarfAttrBaseTypes,       OFFSET(basetypes),          TReference },
    { DwarfAttrBitOffset,       OFFSET(bitoffset),          TConstant },
    { DwarfAttrBitSize,     OFFSET(bitsize),            TConstant },
    { DwarfAttrByteSize,        OFFSET(bytesize),           TConstant },
    { DwarfAttrCalling,     OFFSET(calling),            TConstant },
    { DwarfAttrCommonRef,       OFFSET(commonref),          TReference },
    { DwarfAttrCompDir,     OFFSET(compdir),            TString },
    { DwarfAttrConstValue,      OFFSET(constvalue),         TString|TConstant|TBlock },
    { DwarfAttrContainingType,  OFFSET(containingtype),     TReference },
    { DwarfAttrCount,           OFFSET(count),              TConstant|TReference },
    { DwarfAttrDataMemberLoc,   OFFSET(datamemberloc),      TBlock|TConstant|TReference },
    { DwarfAttrDeclColumn,      OFFSET(declcolumn),         TConstant },
    { DwarfAttrDeclFile,        OFFSET(declfile),           TConstant },
    { DwarfAttrDeclLine,        OFFSET(declline),           TConstant },
    { DwarfAttrDeclaration, OFFSET(isdeclaration),      TFlag },
    { DwarfAttrDefaultValue,    OFFSET(defaultvalue),       TReference },
    { DwarfAttrDiscr,           OFFSET(discr),              TReference },
    { DwarfAttrDiscrList,       OFFSET(discrlist),          TBlock },
    { DwarfAttrDiscrValue,      OFFSET(discrvalue),         TConstant },
    { DwarfAttrEncoding,        OFFSET(encoding),           TConstant },
    { DwarfAttrExternal,        OFFSET(isexternal),         TFlag },
    { DwarfAttrFrameBase,       OFFSET(framebase),          TBlock|TConstant },
    { DwarfAttrFriend,          OFFSET(friend),             TReference },
    { DwarfAttrHighpc,          OFFSET(highpc),             TAddress },
    { DwarfAttrEntrypc,         OFFSET(entrypc),            TAddress },
    { DwarfAttrIdentifierCase,  OFFSET(identifiercase),     TConstant },
    { DwarfAttrImport,          OFFSET(import),             TReference },
    { DwarfAttrInline,          OFFSET(inlined),            TConstant },
    { DwarfAttrIsOptional,      OFFSET(isoptional),         TFlag },
    { DwarfAttrLanguage,        OFFSET(language),           TConstant },
    { DwarfAttrLocation,        OFFSET(location),           TBlock|TConstant },
    { DwarfAttrLowerBound,      OFFSET(lowerbound),         TConstant|TReference },
    { DwarfAttrLowpc,           OFFSET(lowpc),              TAddress },
    { DwarfAttrMacroInfo,       OFFSET(macroinfo),          TConstant },
    { DwarfAttrName,            OFFSET(name),               TString },
    { DwarfAttrNamelistItem,    OFFSET(namelistitem),       TBlock },
    { DwarfAttrOrdering,        OFFSET(ordering),           TConstant },
    { DwarfAttrPriority,        OFFSET(priority),           TReference },
    { DwarfAttrProducer,        OFFSET(producer),           TString },
    { DwarfAttrPrototyped,      OFFSET(isprototyped),       TFlag },
    { DwarfAttrRanges,          OFFSET(ranges),             TReference },
    { DwarfAttrReturnAddr,      OFFSET(returnaddr),         TBlock|TConstant },
    { DwarfAttrSegment,     OFFSET(segment),            TBlock|TConstant },
    { DwarfAttrSibling,     OFFSET(sibling),            TReference },
    { DwarfAttrSpecification,   OFFSET(specification),      TReference },
    { DwarfAttrStartScope,      OFFSET(startscope),         TConstant },
    { DwarfAttrStaticLink,      OFFSET(staticlink),         TBlock|TConstant },
    { DwarfAttrStmtList,        OFFSET(stmtlist),           TConstant },
    { DwarfAttrStrideSize,      OFFSET(stridesize),         TConstant },
    { DwarfAttrStringLength,    OFFSET(stringlength),       TBlock|TConstant },
    { DwarfAttrType,            OFFSET(type),               TReference },
    { DwarfAttrUpperBound,      OFFSET(upperbound),         TConstant|TReference },
    { DwarfAttrUseLocation, OFFSET(uselocation),        TBlock|TConstant },
    { DwarfAttrVarParam,        OFFSET(isvarparam),         TFlag },
    { DwarfAttrVirtuality,      OFFSET(virtuality),         TConstant },
    { DwarfAttrVisibility,      OFFSET(visibility),         TConstant },
    { DwarfAttrVtableElemLoc,   OFFSET(vtableelemloc),      TBlock|TReference },
    { }
};

static Parse ptab[DwarfAttrMax];

static int
parseattrs(DwarfBuf *b, ulong unit, DwarfAbbrev *a, DwarfAttrs *attrs)
{
    int i, f, n, got;
    static int nbad;
    void *v;

    /* initialize ptab first time through for quick access */
    if(ptab[DwarfAttrName].name != DwarfAttrName)
        for(i=0; plist[i].name; i++)
            ptab[plist[i].name] = plist[i];

    memset(attrs, 0, sizeof *attrs);
    attrs->tag = a->tag;
    attrs->haskids = a->haskids;

    for(i=0; i<a->nattr; i++){
        n = a->attr[i].name;
        f = a->attr[i].form;
        if(n < 0 || n >= DwarfAttrMax || ptab[n].name==0){
            if(++nbad == 1)
                werrstr("dwarf parse attrs: unexpected attribute name 0x%x", n);
            continue; //return -1;
        }
        v = (char*)attrs + ptab[n].off;
        got = 0;
        if(f == FormIndirect)
            f = dwarfget128(b);
        if((ptab[n].type&(TConstant|TReference|TAddress))
        && getulong(b, f, unit, v, &got) >= 0)
            ;
        else if((ptab[n].type&TFlag) && getuchar(b, f, v) >= 0)
            got = TFlag;
        else if((ptab[n].type&TString) && getstring(b, f, v) >= 0)
            got = TString;
        else if((ptab[n].type&TBlock) && getblock(b, f, v) >= 0)
            got = TBlock;
        else{
            if(skipform(b, f) < 0){
                if(++nbad == 1)
                    werrstr("dwarf parse attrs: cannot skip form %d", f);
                return -1;
            }
        }
        if(got == TBlock && (ptab[n].type&TConstant))
            got = constblock(b->d, v, v);
        *((uchar*)attrs+ptab[n].haveoff) = got;
    }
    return 0;
}

static int
getulong(DwarfBuf *b, int form, ulong unit, ulong *u, int *type)
{
    static int nbad;
    uvlong uv;

    switch(form){
    default:
        return -1;

    /* addresses */
    case FormAddr:
        *type = TAddress;
        *u = dwarfgetaddr(b);
        return 0;

    /* references */
    case FormRefAddr:
        /* absolute ref in .debug_info */
        *type = TReference;
        *u = dwarfgetaddr(b);
        return 0;
    case FormRef1:
        *u = dwarfget1(b);
        goto relativeref;
    case FormRef2:
        *u = dwarfget2(b);
        goto relativeref;
    case FormRef4:
        *u = dwarfget4(b);
        goto relativeref;
    case FormRef8:
        *u = dwarfget8(b);
        goto relativeref;
    case FormRefUdata:
        *u = dwarfget128(b);
    relativeref:
        *u += unit;
        *type = TReference;
        return 0;

    /* constants */
    case FormData1:
        *u = dwarfget1(b);
        goto constant;
    case FormData2:
        *u = dwarfget2(b);
        goto constant;
    case FormData4:
        *u = dwarfget4(b);
        goto constant;
    case FormData8:
        uv = dwarfget8(b);
        *u = uv;
        if(uv != *u && ++nbad == 1)
            werrstr("dwarf: truncating 64-bit attribute constants");
        goto constant;
    case FormSdata:
        *u = dwarfget128s(b);
        goto constant;
    case FormUdata:
        *u = dwarfget128(b);
    constant:
        *type = TConstant;
        return 0;
    }
}

static int
getuchar(DwarfBuf *b, int form, uchar *u)
{
    switch(form){
    default:
        return -1;

    case FormFlag:
        *u = dwarfget1(b);
        return 0;
    }
}

static int
getstring(DwarfBuf *b, int form, char **s)
{
    static int nbad;
    ulong u;

    switch(form){
    default:
        return -1;

    case FormString:
        *s = dwarfgetstring(b);
        return 0;

    case FormStrp:
        u = dwarfget4(b);
        if(u >= b->d->str.len){
            if(++nbad == 1)
                werrstr("dwarf: bad string pointer 0x%lux in attribute", u);
            /* don't return error - maybe can proceed */
            *s = nil;
        }else
            *s = (char*)b->d->str.data + u;
        return 0;

    }
}

static int
getblock(DwarfBuf *b, int form, DwarfBlock *bl)
{
    ulong n;

    switch(form){
    default:
        return -1;
    case FormDwarfBlock:
        n = dwarfget128(b);
        goto copyn;
    case FormDwarfBlock1:
        n = dwarfget1(b);
        goto copyn;
    case FormDwarfBlock2:
        n = dwarfget2(b);
        goto copyn;
    case FormDwarfBlock4:
        n = dwarfget4(b);
    copyn:
        bl->data = dwarfgetnref(b, n);
        bl->len = n;
        if(bl->data == nil)
            return -1;
        return 0;
    }
}

static int
constblock(Dwarf *d, DwarfBlock *bl, ulong *pval)
{
    DwarfBuf b;

    memset(&b, 0, sizeof b);
    b.p = bl->data;
    b.ep = bl->data+bl->len;
    b.d = d;

    switch(dwarfget1(&b)){
    case OpAddr:
        *pval = dwarfgetaddr(&b);
        return TConstant;
    case OpConst1u:
        *pval = dwarfget1(&b);
        return TConstant;
    case OpConst1s:
        *pval = (schar)dwarfget1(&b);
        return TConstant;
    case OpConst2u:
        *pval = dwarfget2(&b);
        return TConstant;
    case OpConst2s:
        *pval = (s16int)dwarfget2(&b);
        return TConstant;
    case OpConst4u:
        *pval = dwarfget4(&b);
        return TConstant;
    case OpConst4s:
        *pval = (s32int)dwarfget4(&b);
        return TConstant;
    case OpConst8u:
        *pval = (u64int)dwarfget8(&b);
        return TConstant;
    case OpConst8s:
        *pval = (s64int)dwarfget8(&b);
        return TConstant;
    case OpConstu:
        *pval = dwarfget128(&b);
        return TConstant;
    case OpConsts:
        *pval = dwarfget128s(&b);
        return TConstant;
    case OpPlusUconst:
        *pval = dwarfget128(&b);
        return TConstant;
    default:
        return TBlock;
    }
}

/* last resort */
static int
skipform(DwarfBuf *b, int form)
{
    int type;
    DwarfVal val;

    if(getulong(b, form, 0, &val.c, &type) < 0
    && getuchar(b, form, (uchar*)&val) < 0
    && getstring(b, form, &val.s) < 0
    && getblock(b, form, &val.b) < 0)
        return -1;
    return 0;
}