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test: fix expression parser

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The old parser code was rubbish and only worked for trivial
expressions.  The new code properly handles complex expressions,
including short circuit evaluation.

As such, the BUGS section has been removed from the test(1) man page.
The description of an unimplemented feature has also been removed.
This commit is contained in:
Alex Musolino 2021-02-06 15:51:09 +10:30
parent 4ec97f73ee
commit b562b269ce
2 changed files with 128 additions and 87 deletions
Download patch file Download diff file Expand all files Collapse all files

203
sys/src/cmd/test.c
View file

@ -30,7 +30,7 @@ int isolderthan(char *, char *);
int isnewerthan(char *, char *);
int hasmode(char *, ulong);
int tio(char *, int);
int e(void), e1(void), e2(void), e3(void);
int e(int), e1(int), e2(int), e3(int);
char *nxtarg(int);
void
@ -47,12 +47,8 @@ main(int argc, char *argv[])
argv[ac] = 0;
if (ac<=1)
exits("usage");
r = e();
/*
* nice idea but short-circuit -o and -a operators may have
* not consumed their right-hand sides.
*/
if(0 && (c = nxtarg(1)) != nil)
r = e(1);
if((c = nxtarg(1)) != nil)
synbad("unexpected operator/operand: ", c);
exits(r?0:"false");
}
@ -81,78 +77,128 @@ nxtintarg(int *pans)
}
int
e(void)
e(int eval)
{
char *op;
int p1;
p1 = e1();
if (EQ(nxtarg(1), "-o"))
return(p1 || e());
ap--;
return(p1);
p1 = e1(eval);
for(;;){
op = nxtarg(1);
if(op == nil)
break;
if(!EQ(op, "-o")){
ap--;
return p1;
}
if(!p1 && eval)
p1 |= e1(1);
else
e1(0);
}
return p1;
}
int
e1(void)
e1(int eval)
{
char *op;
int p1;
p1 = e2();
if (EQ(nxtarg(1), "-a"))
return (p1 && e1());
ap--;
return(p1);
p1 = e2(eval);
for(;;){
op = nxtarg(1);
if(op == nil)
break;
if(!EQ(op, "-a")){
ap--;
return p1;
}
if(p1 && eval)
p1 &= e2(1);
else
e2(0);
}
return p1;
}
int
e2(void)
e2(int eval)
{
if (EQ(nxtarg(0), "!"))
return(!e2());
char *op;
int p1;
p1 = 0;
for(;;){
op = nxtarg(1);
if(op == nil)
return p1 ^ 1;
if(!EQ(op, "!"))
break;
p1 ^= 1;
}
ap--;
return(e3());
return(p1^e3(eval));
}
int
e3(void)
e3(int eval)
{
int p1, int1, int2;
char *a, *p2;
char *a, *b, *p2;
a = nxtarg(0);
if(EQ(a, "(")) {
p1 = e();
p1 = e(eval);
if(!EQ(nxtarg(0), ")"))
synbad(") expected","");
return(p1);
}
if(EQ(a, "-A"))
return(hasmode(nxtarg(0), DMAPPEND));
if(EQ(a, "-A")){
b = nxtarg(0);
return(eval && hasmode(b, DMAPPEND));
}
if(EQ(a, "-L"))
return(hasmode(nxtarg(0), DMEXCL));
if(EQ(a, "-L")){
b = nxtarg(0);
return(eval && hasmode(b, DMEXCL));
}
if(EQ(a, "-T"))
return(hasmode(nxtarg(0), DMTMP));
if(EQ(a, "-T")){
b = nxtarg(0);
return(eval && hasmode(b, DMTMP));
}
if(EQ(a, "-f"))
return(isreg(nxtarg(0)));
if(EQ(a, "-f")){
b = nxtarg(0);
return(eval && isreg(b));
}
if(EQ(a, "-d"))
return(isdir(nxtarg(0)));
if(EQ(a, "-d")){
b = nxtarg(0);
return(eval && isdir(b));
}
if(EQ(a, "-r"))
return(tio(nxtarg(0), AREAD));
if(EQ(a, "-r")){
b = nxtarg(0);
return(eval && tio(b, AREAD));
}
if(EQ(a, "-w"))
return(tio(nxtarg(0), AWRITE));
if(EQ(a, "-w")){
b = nxtarg(0);
return(eval && tio(b, AWRITE));
}
if(EQ(a, "-x"))
return(tio(nxtarg(0), AEXEC));
if(EQ(a, "-x")){
b = nxtarg(0);
return(eval && tio(b, AEXEC));
}
if(EQ(a, "-e"))
return(tio(nxtarg(0), AEXIST));
if(EQ(a, "-e")){
b = nxtarg(0);
return(eval && tio(b, AEXIST));
}
if(EQ(a, "-c"))
return(0);
@ -166,14 +212,16 @@ e3(void)
if(EQ(a, "-g"))
return(0);
if(EQ(a, "-s"))
return(fsizep(nxtarg(0)));
if(EQ(a, "-s")){
b = nxtarg(0);
return(eval && fsizep(b));
}
if(EQ(a, "-t"))
if(ap>=ac)
return(isatty(1));
return(eval && isatty(1));
else if(nxtintarg(&int1))
return(isatty(int1));
return(eval && isatty(int1));
else
synbad("not a valid file descriptor number ", "");
@ -191,35 +239,40 @@ e3(void)
if(EQ(p2, "!="))
return(!EQ(nxtarg(0), a));
if(EQ(p2, "-older"))
return(isolder(nxtarg(0), a));
if(EQ(p2, "-ot"))
return(isolderthan(nxtarg(0), a));
if(EQ(p2, "-nt"))
return(isnewerthan(nxtarg(0), a));
if(!isint(a, &int1))
synbad("unexpected operator/operand: ", p2);
if(nxtintarg(&int2)){
if(EQ(p2, "-eq"))
return(int1==int2);
if(EQ(p2, "-ne"))
return(int1!=int2);
if(EQ(p2, "-gt"))
return(int1>int2);
if(EQ(p2, "-lt"))
return(int1<int2);
if(EQ(p2, "-ge"))
return(int1>=int2);
if(EQ(p2, "-le"))
return(int1<=int2);
if(EQ(p2, "-older")){
b = nxtarg(0);
return(eval && isolder(b, a));
}
synbad("unknown operator ",p2);
return 0; /* to shut ken up */
if(EQ(p2, "-ot")){
b = nxtarg(0);
return(eval && isolderthan(b, a));
}
if(EQ(p2, "-nt")){
b = nxtarg(0);
return(eval && isnewerthan(b, a));
}
if(isint(a, &int1)){
if(nxtintarg(&int2)){
if(EQ(p2, "-eq"))
return(int1==int2);
if(EQ(p2, "-ne"))
return(int1!=int2);
if(EQ(p2, "-gt"))
return(int1>int2);
if(EQ(p2, "-lt"))
return(int1<int2);
if(EQ(p2, "-ge"))
return(int1>=int2);
if(EQ(p2, "-le"))
return(int1<=int2);
ap--;
}
}
ap--;
return !EQ(a, "");
}
int