gc: make sure path names are canonical

R=ken2
CC=golang-dev
https://golang.org/cl/2209042

diff --git a/src/cmd/gc/lex.c b/src/cmd/gc/lex.c
index 726cab7533b370398150f3fdbaf6cfd1c8c3dbce..a01da962c6ac90e21b31ed7907ad43dbc086c20c 100644 (file)
--- a/src/cmd/gc/lex.c
+++ b/src/cmd/gc/lex.c
@@ -353,8 +353,11 @@ static int
 findpkg(Strlit *name)
 {
        Idir *p;
+       char *q;
 
        if(islocalname(name)) {
+               if(debug['u'])
+                       return 0;
                // try .a before .6.  important for building libraries:
                // if there is an array.6 in the array.a library,
                // want to find all of array.a, not just array.6.
@@ -367,6 +370,18 @@ findpkg(Strlit *name)
                return 0;
        }
 
+       // local imports should be canonicalized already.
+       // don't want to see "container/../container/vector"
+       // as different from "container/vector".
+       q = mal(name->len+1);
+       memmove(q, name->s, name->len);
+       q[name->len] = '\0';
+       cleanname(q);
+       if(strlen(q) != name->len || memcmp(q, name->s, name->len) != 0) {
+               yyerror("non-canonical import name %Z (%s)", name->s, q);
+               return 0;
+       }
+
        for(p = idirs; p != nil; p = p->link) {
                snprint(namebuf, sizeof(namebuf), "%s/%Z.a", p->dir, name);
                if(access(namebuf, 0) >= 0)