units.cpp

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#include <../../nrnconf.h>
 
#include <algorithm>
#include <string>
#include <string_view>
#include <fstream>
 
/* /local/src/master/nrn/src/modlunit/units.c,v 1.5 1997/11/24 16:19:13 hines Exp */
/* Mostly from Berkeley */
#include "model.h"
#include "nrnassrt.h"
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <string.h>
#include "units.h"
#include <assert.h>
 
#include <cstring>
 
#ifdef MINGW
#include "../mswin/extra/d2upath.h"
#endif
 
#if defined(WIN32)
#include <windows.h>
#endif
 
#ifndef _WIN32
#include <unistd.h>
#include <fcntl.h>
#endif
 
int unitonflag = 1;
static int UnitsOn = 0;
extern "C" {
extern double fabs(double);
}  // extern "C"
extern void diag(const char*, const char*);
#define IFUNITS       \
    {                 \
        if (!UnitsOn) \
            return;   \
    }
#define OUTTOLERANCE(arg1, arg2) (fabs(arg2 / arg1 - 1.) > 1.e-5)
 
#define NTAB 601
 
/* if MODLUNIT environment variable not set then look in the following places*/
#if defined(NEURON_DATA_DIR)
static char const* const dfile = NEURON_DATA_DIR "/lib/nrnunits.lib";
#else
static char const* const dfile = "/usr/lib/units";
#endif
static char const* const dfilealt = "../../share/lib/nrnunits.lib";
static char* unames[NDIM];
double getflt();
void fperr(int);
int lookup(char* name, unit* up, int den, int c);
struct table* hash_table(const char*);
 
void chkfperror();
void units(unit*);
int pu(int, int, int);
int convr(unit*);
void units_cpp_init();
int get();
 
extern void Unit_push(const char*);
 
static struct table {
    double factor;
#if - 1 == '\377'
    char dim[NDIM];
#else
    signed char dim[NDIM];
#endif
    char* name;
} * table;
 
static char* names;
 
static struct prefix {
    double factor;
    const char* pname;
} prefix[] = {{1e-18, "atto"},
              {1e-15, "femto"},
              {1e-12, "pico"},
              {1e-9, "nano"},
              {1e-6, "micro"},
              {1e-3, "milli"},
              {1e-2, "centi"},
              {1e-1, "deci"},
              {1e1, "deka"},
              {1e2, "hecta"},
              {1e2, "hecto"},
              {1e3, "kilo"},
              {1e6, "mega"},
              {1e6, "meg"},
              {1e9, "giga"},
              {1e12, "tera"},
              {0.0, nullptr}};
static FILE* inpfile;
static int fperrc;
static int peekc;
static int dumpflg;
 
static const char* pc;
 
static constexpr std::string_view embedded_nrnunits =
#include "embedded_nrnunits.lib"
    ;
 
// cross-platform workaround for:
// https://github.com/neuronsimulator/nrn/issues/3470
// the API requires a FILE handle instead of a std::string or similar
// so we write a temporary file
// Note: with posix we experience
// warning: 'tmpnam' is deprecated: This function is provided for
// compatibility reasons only.  Due to security concerns inherent in the
// design of tmpnam(3), it is highly recommended that you use mkstemp(3) instead
// [-Wdeprecated-declarations]
static FILE* open_embedded_nrnunits_as_file() {
#ifdef _WIN32
    // Windows: Use GetTempPath and CreateFile for a secure temp file
    char temp_path[MAX_PATH];
    GetTempPath(MAX_PATH, temp_path);
    char temp_file[MAX_PATH];
    GetTempFileName(temp_path, "nrn", 0, temp_file);
 
    // Write embedded_nrnunits to the temp file
    std::ofstream out(temp_file, std::ios::out | std::ios::binary);
    out.write(embedded_nrnunits.data(), embedded_nrnunits.size());
    out.close();
 
    // Open the temp file for reading
    return fopen(temp_file, "r");
#else
    // POSIX: Use mkstemp for a secure temp file
    char temp_file[] = "/tmp/nrnunitsXXXXXX";
    int fd = mkstemp(temp_file);
    if (fd == -1) {
        return nullptr;  // Handle error appropriately
    }
 
    // Write embedded_nrnunits to the temp file
    std::ofstream out(temp_file, std::ios::out | std::ios::binary);
    out.write(embedded_nrnunits.data(), embedded_nrnunits.size());
    out.close();
 
    // Open the temp file for reading
    FILE* file = fdopen(fd, "r");
    if (!file) {
        close(fd);
        unlink(temp_file);  // Clean up
    }
    return file;
#endif
}
 
static int Getc(FILE* inp) {
    if (inp != stdin) {
        return getc(inp);
    } else if (pc && *pc) {
        return (int) (*pc++);
    } else {
        return (int) ('\n');
    }
}
 
#define UNIT_STK_SIZE 20
static struct unit unit_stack[UNIT_STK_SIZE], *usp{nullptr};
 
static std::string neuronhome() {
#if defined(MINGW)
    std::string buf(256, '\0');
    GetModuleFileName(nullptr, buf.data(), 256);
    // Remove neuron.exe
    auto pos = buf.find_last_of('\\');
    buf.resize(pos);
    // Remove bin
    pos = buf.find_last_of('\\');
    buf.resize(pos);
    std::replace(buf.begin(), buf.end(), '\\', '/');
    return buf;
#else
    char* buf = std::getenv("NEURONHOME");
    return (buf != nullptr) ? std::string(buf) : std::string();
#endif
}
 
 
static char* ucp;
const char* Unit_str(unit* up) {
    struct unit* p;
    int f, i;
    static char buf[256];
 
    p = up;
    Sprintf(buf, "%g ", p->factor);
    {
        int seee = 0;
        for (ucp = buf; *ucp; ucp++) {
            if (*ucp == 'e')
                seee = 1;
            if (seee)
                *ucp = ucp[1];
        }
        if (seee)
            ucp--;
    }
    f = 0;
    for (i = 0; i < NDIM; i++)
        f |= pu(p->dim[i], i, f);
    if (f & 1) {
        *ucp++ = '/';
        f = 0;
        for (i = 0; i < NDIM; i++)
            f |= pu(-p->dim[i], i, f);
    }
    *ucp = '\0';
    return buf;
}
 
void unit_pop() {
    IFUNITS
    assert(usp >= unit_stack);
    if (usp == unit_stack) {
        usp = nullptr;
    } else {
        --usp;
    }
}
 
void unit_swap() { /*exchange top two elements of stack*/
    struct unit* up;
    int i, j;
    double d;
 
    IFUNITS
    assert(usp > unit_stack);
    up = usp - 1;
 
    d = usp->factor;
    usp->factor = up->factor;
    up->factor = d;
 
    for (i = 0; i < NDIM; i++) {
        j = usp->dim[i];
        usp->dim[i] = up->dim[i];
        up->dim[i] = j;
    }
}
 
double unit_mag() { /* return unit magnitude that is on stack */
    return usp->factor;
}
 
void unit_mag_mul(double d) {
    usp->factor *= d;
}
 
void punit() {
    struct unit* i;
    for (i = usp; i != unit_stack - 1; --i) {
        printf("%s\n", Unit_str(i));
    }
}
 
void ucopypop(unit* up) {
    int i;
    for (i = 0; i < NDIM; i++) {
        up->dim[i] = usp->dim[i];
    }
    up->factor = usp->factor;
    up->isnum = usp->isnum;
    unit_pop();
}
 
void ucopypush(unit* up) {
    int i;
    Unit_push("");
    for (i = 0; i < NDIM; i++) {
        usp->dim[i] = up->dim[i];
    }
    usp->factor = up->factor;
    usp->isnum = up->isnum;
}
 
void Unit_push(const char* str) {
    IFUNITS
    assert(usp < unit_stack + (UNIT_STK_SIZE - 1));
    if (usp) {
        ++usp;
    } else {
        usp = unit_stack;
    }
    pc = str;
    if (str) {
        usp->isnum = 0;
    } else {
        pc = "";
        usp->isnum = 1;
    }
    convr(usp);
    /*printf("unit_push %s\n", str); units(usp);*/
}
 
void unit_push_num(double d) {
    Unit_push("");
    usp->factor = d;
}
 
void unitcheck(char* s) {
    Unit_push(s);
    unit_pop();
}
 
const char* unit_str() {
    /* return top of stack as units string */
    if (!UnitsOn)
        return "";
    return Unit_str(usp);
}
 
static void install_units_help(char* s1, char* s2) /* define s1 as s2 */
{
    struct table* tp;
    int i;
 
    IFUNITS
    Unit_push(s2);
    tp = hash_table(s1);
    if (tp->name) {
        printf("Redefinition of units (%s) to:", s1);
        units(usp);
        printf(" is ignored.\nThey remain:");
        Unit_push(s1);
        units(usp);
        diag("Units redefinition", (char*) 0);
    }
    tp->name = s1;
    tp->factor = usp->factor;
    for (i = 0; i < NDIM; i++) {
        tp->dim[i] = usp->dim[i];
    }
    unit_pop();
}
 
void install_units(char* s1, char* s2) {
    install_units_help(s1, s2);
}
 
void check_num() {
    struct unit* up = usp - 1;
    /*EMPTY*/
    if (up->isnum && usp->isnum) {
        ;
    } else {
        up->isnum = 0;
    }
}
 
void unit_mul() {
    /* multiply next element by top of stack and leave on stack */
    struct unit* up;
    int i;
 
    IFUNITS
    assert(usp > unit_stack);
    check_num();
    up = usp - 1;
    for (i = 0; i < NDIM; i++) {
        up->dim[i] += usp->dim[i];
    }
    up->factor *= usp->factor;
    unit_pop();
}
 
void unit_div() {
    /* divide next element by top of stack and leave on stack */
    struct unit* up;
    int i;
 
    IFUNITS
    assert(usp > unit_stack);
    check_num();
    up = usp - 1;
    for (i = 0; i < NDIM; i++) {
        up->dim[i] -= usp->dim[i];
    }
    up->factor /= usp->factor;
    unit_pop();
}
 
void Unit_exponent(int val) {
    /* multiply top of stack by val and leave on stack */
    int i;
    double d;
 
    IFUNITS
    assert(usp >= unit_stack);
    for (i = 0; i < NDIM; i++) {
        usp->dim[i] *= val;
    }
    d = usp->factor;
    for (i = 1; i < val; i++) {
        usp->factor *= d;
    }
}
 
int unit_cmp_exact() { /* returns 1 if top two units on stack are same */
    struct unit* up;
    int i;
 
    {
        if (!UnitsOn)
            return 0;
    }
    up = usp - 1;
    if (unitonflag) {
        if (up->dim[0] == 9 || usp->dim[0] == 9) {
            return 1;
        }
        for (i = 0; i < NDIM; i++) {
            if (up->dim[i] != usp->dim[i]) {
                chkfperror();
                return 0;
            }
        }
        if (OUTTOLERANCE(up->factor, usp->factor)) {
            chkfperror();
            return 0;
        }
    }
    return 1;
}
 
void Unit_cmp() {
    /*compares top two units on stack. If not conformable then
    gives error. If not same factor then gives error.
    */
    struct unit* up;
    int i;
 
    IFUNITS
    assert(usp > unit_stack);
    up = usp - 1;
    if (usp->isnum) {
        unit_pop();
        return;
    }
    if (up->isnum) {
        for (i = 0; i < NDIM; i++) {
            up->dim[i] = usp->dim[i];
        }
        up->factor = usp->factor;
        up->isnum = 0;
    }
    if (unitonflag && up->dim[0] != 9 && usp->dim[0] != 9) {
        for (i = 0; i < NDIM; i++) {
            if (up->dim[i] != usp->dim[i]) {
                chkfperror();
                fprintf(stderr, "\nunits:");
                units(usp);
                fprintf(stderr, "\nunits:");
                units(up);
                diag("The units of the previous two expressions are not conformable", (char*) "\n");
            }
        }
        if (OUTTOLERANCE(up->factor, usp->factor)) {
            chkfperror();
            fprintf(stderr,
                    "The previous primary expression with units: %s\n\
is missing a conversion factor and should read:\n  (%g)*(",
                    Unit_str(usp),
                    usp->factor / up->factor);
            diag(")\n", (char*) 0);
        }
    }
    unit_pop();
    return;
}
 
int unit_diff() {
    /*compares top two units on stack. If not conformable then
    return 1, if not same factor return 2 if same return 0
    */
    struct unit* up;
    int i;
 
    if (!UnitsOn)
        return 0;
    assert(usp > unit_stack);
    up = usp - 1;
    if (up->dim[0] == 9 || usp->dim[0] == 9) {
        unit_pop();
        return 0;
    }
    if (usp->isnum) {
        unit_pop();
        return 0;
    }
    if (up->isnum) {
        for (i = 0; i < NDIM; i++) {
            up->dim[i] = usp->dim[i];
        }
        up->factor = usp->factor;
        up->isnum = 0;
    }
    for (i = 0; i < NDIM; i++) {
        if (up->dim[i] != usp->dim[i]) {
            return 1;
        }
    }
    if (OUTTOLERANCE(up->factor, usp->factor)) {
        return 2;
    }
    unit_pop();
    return 0;
}
 
void chkfperror() {
    if (fperrc) {
        diag("underflow or overflow in units calculation", (char*) 0);
    }
}
 
void dimensionless() {
    /* ensures top element is dimensionless */
    int i;
 
    IFUNITS
    assert(usp >= unit_stack);
    if (usp->dim[0] == 9) {
        return;
    }
    for (i = 0; i < NDIM; i++) {
        if (usp->dim[i] != 0) {
            units(usp);
            diag("The previous expression is not dimensionless", (char*) 0);
        }
    }
}
 
void unit_less() {
    /* ensures top element is dimensionless  with factor 1*/
    IFUNITS
    if (unitonflag) {
        dimensionless();
        if (usp->dim[0] != 9 && OUTTOLERANCE(usp->factor, 1.0)) {
            fprintf(stderr,
                    "The previous expression needs the conversion factor (%g)\n",
                    1. / (usp->factor));
            diag("", (char*) 0);
        }
    }
    unit_pop();
}
 
void unit_stk_clean() {
    IFUNITS
    usp = nullptr;
}
 
// allow the outside world to call either modl_units() or unit_init().
static void units_alloc() {
    static int units_alloc_called = 0;
    if (!units_alloc_called) {
        units_alloc_called = 1;
        table = (struct table*) calloc(NTAB, sizeof(struct table));
        assert(table);
        names = (char*) calloc(NTAB * 10, sizeof(char));
        assert(names);
    }
}
 
extern void unit_init();
 
void modl_units() {
    static int first = 1;
    unitonflag = 1;
    if (first) {
        units_alloc();
        unit_init();
        first = 0;
    }
}
 
void unit_init() {
    char* s;
    char buf[1024];
    inpfile = (FILE*) 0;
    units_alloc();
    UnitsOn = 1;
    s = getenv("MODLUNIT");
    if (s) {
        /* note that on mingw, even if MODLUNIT set to /cygdrive/c/...
         * it ends up here as c:/... and that is good*/
        /* printf("MODLUNIT=|%s|\n", s); */
        Sprintf(buf, "%s", s);
        if ((inpfile = fopen(buf, "r")) == (FILE*) 0) {
            diag("Bad MODLUNIT environment variable. Cant open:", buf);
        }
    }
#if defined(__MINGW32__)
    if (!inpfile) {
        auto s = neuronhome();
        if (!s.empty()) {
            std::string filename = s + "/lib/nrnunits.lib";
            inpfile = fopen(filename.c_str(), "r");
        }
    }
#else
    if (!inpfile && (inpfile = fopen(dfile, "r")) == nullptr) {
        if ((inpfile = fopen(dfilealt, "r")) == nullptr) {
            auto s = neuronhome();
            if (!s.empty()) {
                std::string filename = s + "/lib/nrnunits.lib";
                inpfile = fopen(filename.c_str(), "r");
            }
        }
    }
#endif
 
    // try to load the embedded one as a last resort
    if (!inpfile) {
        inpfile = open_embedded_nrnunits_as_file();
    }
 
    if (!inpfile) {
        fprintf(stderr, "Set a MODLUNIT environment variable path to the units table file\n");
        fprintf(stderr, "Cant open units table in either of:\n%s\n", buf);
        diag(dfile, dfilealt);
    }
    signal(8, fperr);
    units_cpp_init();
    unit_stk_clean();
}
 
void units(unit* up) {
    printf("\t%s\n", Unit_str(up));
}
 
int pu(int u, int i, int f) {
    if (u > 0) {
        if (f & 2)
            *ucp++ = '-';
        if (unames[i]) {
            std::strcpy(ucp, unames[i]);
            ucp += strlen(ucp);
        } else {
            *ucp++ = '*';
            *ucp++ = 'a' + i;
            *ucp++ = '*';
        }
        if (u > 1)
            *ucp++ = (u + '0');
        return 2;
    }
    if (u < 0)
        return 1;
    return 0;
}
 
int convr(unit* up) {
    struct unit* p;
    int c;
    char* cp;
    char name[20];
    int den, err;
 
    p = up;
    for (c = 0; c < NDIM; c++)
        p->dim[c] = 0;
    p->factor = getflt();
    if (p->factor == 0.) {
        p->factor = 1.0;
    }
    err = 0;
    den = 0;
    cp = name;
 
loop:
    switch (c = get()) {
    case '1':
    case '2':
    case '3':
    case '4':
    case '5':
    case '6':
    case '7':
    case '8':
    case '9':
    case '-':
    case '/':
    case ' ':
    case '\t':
    case '\n':
        if (cp != name) {
            *cp++ = 0;
            cp = name;
            err |= lookup(cp, p, den, c);
        }
        if (c == '/')
            den++;
        if (c == '\n')
            return err;
        goto loop;
    }
    *cp++ = c;
    goto loop;
}
 
int lookup(char* name, unit* up, int den, int c) {
    struct unit* p;
    struct table* q;
    int i;
    char* cp2;
    double e;
 
    p = up;
    e = 1.0;
loop:
    q = hash_table(name);
    if (q->name) {
    l1:
        if (den) {
            p->factor /= q->factor * e;
            for (i = 0; i < NDIM; i++)
                p->dim[i] -= q->dim[i];
        } else {
            p->factor *= q->factor * e;
            for (i = 0; i < NDIM; i++)
                p->dim[i] += q->dim[i];
        }
        if (c >= '2' && c <= '9') {
            c--;
            goto l1;
        }
        return 0;
    }
    {
        const char* cp1{};
        for (i = 0; (cp1 = prefix[i].pname) != 0; i++) {
            cp2 = name;
            while (*cp1 == *cp2++)
                if (*cp1++ == 0) {
                    cp1--;
                    break;
                }
            if (*cp1 == 0) {
                e *= prefix[i].factor;
                name = cp2 - 1;
                goto loop;
            }
        }
    }
    /*EMPTY*/
    char* cp1;
    for (cp1 = name; *cp1; cp1++)
        ;
    if (cp1 > name + 1 && *--cp1 == 's') {
        *cp1 = 0;
        goto loop;
    }
    fprintf(stderr,
            "Need declaration in UNITS block of the form:\n\
    (%s)    (units)\n",
            name);
    diag("Cannot recognize the units: ", name);
    /*  printf("cannot recognize %s\n", name);*/
    return 1;
}
 
static int equal(const char* c1, const char* c2) {
    while (*c1++ == *c2)
        if (*c2++ == 0)
            return 1;
    return 0;
}
 
void units_cpp_init() {
    char* cp;
    struct table *tp, *lp;
    int c, i, f, t;
    char* np;
 
    cp = names;
    for (i = 0; i < NDIM; i++) {
        np = cp;
        *cp++ = '*';
        *cp++ = i + 'a';
        *cp++ = '*';
        *cp++ = 0;
        lp = hash_table(np);
        lp->name = np;
        lp->factor = 1.0;
        lp->dim[i] = 1;
    }
    lp = hash_table("");
    lp->name = cp - 1;
    lp->factor = 1.0;
 
l0:
    c = get();
    if (c == 0) {
        if (dumpflg)
            for (tp = table; tp < table + NTAB; tp++) {
                if (tp->name == 0)
                    continue;
                printf("%s", tp->name);
                units((struct unit*) tp);
            }
 
        fclose(inpfile);
        inpfile = stdin;
        return;
    }
    if (c == '/') {
        while (c != '\n' && c != 0)
            c = get();
        goto l0;
    }
 
    if (c == '\n')
        goto l0;
 
    np = cp;
    while (c != ' ' && c != '\t') {
        *cp++ = c;
        c = get();
        if (c == 0)
            goto l0;
        if (c == '\n') {
            *cp++ = 0;
            tp = hash_table(np);
            if (tp->name)
                goto redef;
            tp->name = np;
            tp->factor = lp->factor;
            for (c = 0; c < NDIM; c++)
                tp->dim[c] = lp->dim[c];
            i++;
            goto l0;
        }
    }
    *cp++ = 0;
    lp = hash_table(np);
    if (lp->name)
        goto redef;
    convr((struct unit*) lp);
    lp->name = np;
    f = 0;
    i++;
    if (lp->factor != 1.0)
        goto l0;
    for (c = 0; c < NDIM; c++) {
        t = lp->dim[c];
        if (t > 1 || (f > 0 && t != 0))
            goto l0;
        if (f == 0 && t == 1) {
            if (unames[c])
                goto l0;
            f = c + 1;
        }
    }
    if (f > 0)
        unames[f - 1] = np;
    goto l0;
 
redef:
    printf("redefinition %s\n", np);
    goto l0;
}
 
double getflt() {
    int c;
    char str[100];
    char* cp;
    double d_modern;
 
    cp = str;
    do
        c = get();
    while (c == ' ' || c == '\t');
 
l1:
    if (c >= '0' && c <= '9') {
        *cp++ = c;
        c = get();
        goto l1;
    }
    if (c == '.') {
        *cp++ = c;
        c = get();
        goto l1;
    }
    if (c == '+' || c == '-') {
        *cp++ = 'e';
        *cp++ = c;
        c = get();
        while (c >= '0' && c <= '9') {
            *cp++ = c;
            c = get();
        }
    }
    *cp = '\0';
    d_modern = atof(str);
    if (c == '|') {
        d_modern /= getflt();
        return d_modern;
    }
    peekc = c;
    return d_modern;
}
 
int get() {
    int c;
 
    /*SUPPRESS 560*/
    if ((c = peekc) != 0) {
        peekc = 0;
        return c;
    }
    c = Getc(inpfile);
    if (c == '\r') {
        c = Getc(inpfile);
    }
    if (c == EOF) {
        if (inpfile == stdin) {
            printf("\n");
            exit(0);
        }
        return 0;
    }
    return c;
}
 
struct table* hash_table(const char* name) {
    struct table* tp;
    const char* np;
    unsigned h;
 
    h = 0;
    np = name;
    while (*np)
        h = h * 57 + *np++ - '0';
    if (((int) h) < 0)
        h = -(int) h;
    h %= NTAB;
    tp = &table[h];
l0:
    if (tp->name == 0)
        return tp;
    if (equal(name, tp->name))
        return tp;
    tp++;
    if (tp >= table + NTAB)
        tp = table;
    goto l0;
}
 
void fperr(int sig) {
    signal(8, fperr);
    fperrc++;
}
 
void nrnunit_str(char (&buf)[NRN_BUFSIZE], const char* name, const char* u1, const char* u2) {
    Unit_push(u1);
    Unit_push(u2);
    unit_div();
    Sprintf(buf, "static double %s = %a;\n", name, unit_mag());
    unit_pop();
}