ld: detect all import cycles

Fixes #2052.

R=r
CC=golang-dev
https://golang.org/cl/4812053

diff --git a/src/cmd/ld/go.c b/src/cmd/ld/go.c
index 05d1cc136c2e32e1ecd9eebde6b60e1ebe274afe..1c77cca1a8382596f82a54bc1505e84b633e90da 100644 (file)
--- a/src/cmd/ld/go.c
+++ b/src/cmd/ld/go.c
@@ -32,6 +32,7 @@ enum {
 };
 static Import *ihash[NIHASH];
 static int nimport;
+static void imported(char *pkg, char *import);
 
 static int
 hashstr(char *name)
@@ -308,12 +309,23 @@ loop:
                p += 6;
        else if(strncmp(p, "import ", 7) == 0) {
                p += 7;
+               while(p < ep && *p != ' ')
+                       p++;
+               p++;
+               name = p;
                while(p < ep && *p != '\n')
                        p++;
+               if(p >= ep) {
+                       fprint(2, "%s: %s: confused in import line\n", argv0, file);
+                       nerrors++;
+                       return -1;
+               }
+               *p++ = '\0';
+               imported(pkg, name);
                goto loop;
        }
        else {
-               fprint(2, "%s: confused in pkg data near <<%.40s>>\n", argv0, prefix);
+               fprint(2, "%s: %s: confused in pkg data near <<%.40s>>\n", argv0, file, prefix);
                nerrors++;
                return -1;
        }
@@ -708,3 +720,150 @@ addexport(void)
        for(i=0; i<ndynexp; i++)
                adddynsym(dynexp[i]);
 }
+
+/* %Z from gc, for quoting import paths */
+int
+Zconv(Fmt *fp)
+{
+       Rune r;
+       char *s, *se;
+       int n;
+
+       s = va_arg(fp->args, char*);
+       if(s == nil)
+               return fmtstrcpy(fp, "<nil>");
+
+       se = s + strlen(s);
+       while(s < se) {
+               n = chartorune(&r, s);
+               s += n;
+               switch(r) {
+               case Runeerror:
+                       if(n == 1) {
+                               fmtprint(fp, "\\x%02x", (uchar)*(s-1));
+                               break;
+                       }
+                       // fall through
+               default:
+                       if(r < ' ') {
+                               fmtprint(fp, "\\x%02x", r);
+                               break;
+                       }
+                       fmtrune(fp, r);
+                       break;
+               case '\t':
+                       fmtstrcpy(fp, "\\t");
+                       break;
+               case '\n':
+                       fmtstrcpy(fp, "\\n");
+                       break;
+               case '\"':
+               case '\\':
+                       fmtrune(fp, '\\');
+                       fmtrune(fp, r);
+                       break;
+               }
+       }
+       return 0;
+}
+
+
+typedef struct Pkg Pkg;
+struct Pkg
+{
+       uchar mark;
+       uchar checked;
+       Pkg *next;
+       char *path;
+       Pkg **impby;
+       int nimpby;
+       int mimpby;
+       Pkg *all;
+};
+
+static Pkg *phash[1024];
+static Pkg *pkgall;
+
+static Pkg*
+getpkg(char *path)
+{
+       Pkg *p;
+       int h;
+       
+       h = hashstr(path) % nelem(phash);
+       for(p=phash[h]; p; p=p->next)
+               if(strcmp(p->path, path) == 0)
+                       return p;
+       p = mal(sizeof *p);
+       p->path = strdup(path);
+       p->next = phash[h];
+       phash[h] = p;
+       p->all = pkgall;
+       pkgall = p;
+       return p;
+}
+
+static void
+imported(char *pkg, char *import)
+{
+       Pkg *p, *i;
+       
+       // everyone imports runtime, even runtime.
+       if(strcmp(import, "\"runtime\"") == 0)
+               return;
+
+       pkg = smprint("\"%Z\"", pkg);  // turn pkg path into quoted form, freed below
+       p = getpkg(pkg);
+       i = getpkg(import);
+       if(i->nimpby >= i->mimpby) {
+               i->mimpby *= 2;
+               if(i->mimpby == 0)
+                       i->mimpby = 16;
+               i->impby = realloc(i->impby, i->mimpby*sizeof i->impby[0]);
+       }
+       i->impby[i->nimpby++] = p;
+       free(pkg);
+}
+
+static Pkg*
+cycle(Pkg *p)
+{
+       int i;
+       Pkg *bad;
+
+       if(p->checked)
+               return 0;
+
+       if(p->mark) {
+               nerrors++;
+               print("import cycle:\n");
+               print("\t%s\n", p->path);
+               return p;
+       }
+       p->mark = 1;
+       for(i=0; i<p->nimpby; i++) {
+               if((bad = cycle(p->impby[i])) != nil) {
+                       p->mark = 0;
+                       p->checked = 1;
+                       print("\timports %s\n", p->path);
+                       if(bad == p)
+                               return nil;
+                       return bad;
+               }
+       }
+       p->checked = 1;
+       p->mark = 0;
+       return 0;
+}
+
+void
+importcycles(void)
+{
+       Pkg *p;
+       
+       for(p=pkgall; p; p=p->all)
+               cycle(p);
+}
+
+
+       
\ No newline at end of file

diff --git a/src/cmd/ld/lib.c b/src/cmd/ld/lib.c
index ebc4b0bf7fdaea214de255edd27bf65afa5ec7c9..86ed8476aa3d0c839e6f4b8311f4673ce7e981c3 100644 (file)
--- a/src/cmd/ld/lib.c
+++ b/src/cmd/ld/lib.c
@@ -62,6 +62,7 @@ libinit(void)
 {
        fmtinstall('i', iconv);
        fmtinstall('Y', Yconv);
+       fmtinstall('Z', Zconv);
        mywhatsys();    // get goroot, goarch, goos
        if(strcmp(goarch, thestring) != 0)
                print("goarch is not known: %s\n", goarch);
@@ -281,6 +282,8 @@ loadlib(void)
        // binaries, so leave it enabled on OS X (Mach-O) binaries.
        if(!havedynamic && HEADTYPE != Hdarwin)
                debug['d'] = 1;
+       
+       importcycles();
 }
 
 /*

diff --git a/src/cmd/ld/lib.h b/src/cmd/ld/lib.h
index ee7eb87c006a5890f53d82c457a593ac790d67ed..03a1d5806dbd3777b33455d5b2a63a3593ee999b 100644 (file)
--- a/src/cmd/ld/lib.h
+++ b/src/cmd/ld/lib.h
@@ -302,3 +302,5 @@ vlong       cpos(void);
 void   cseek(vlong);
 void   cseekend(void);
 void   cwrite(void*, int);
+void   importcycles(void);
+int    Zconv(Fmt*);