Merge pull request #5220 from WalterBright/asciiz2

reduce internal dependency on 0 terminated strings
dlang · Oct 23, 2015 · 1fe51af · 1fe51af
2 parents 5db650f + a8b1f56
commit 1fe51af
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Showing 7 changed files with 44 additions and 24 deletions.
diff --git a/src/attrib.d b/src/attrib.d
@@ -413,7 +413,7 @@ public:
         char* depmsg = null;
         StringExp se = msg.toStringExp();
         if (se)
-            depmsg = cast(char*)se.string;
+            depmsg = se.toStringz();
         else
             msg.error("string expected, not '%s'", msg.toChars());
         Scope* scx = sc.push();
@@ -1266,7 +1266,8 @@ public:
             {
                 se = se.toUTF8(sc);
                 uint errors = global.errors;
-                scope Parser p = new Parser(loc, sc._module, cast(char*)se.string, se.len, 0);
+                auto cstr = se.toStringz();
+                scope Parser p = new Parser(loc, sc._module, cstr, se.len, 0);
                 p.nextToken();
                 decl = p.parseDeclDefs(0);
                 if (p.token.value != TOKeof)

diff --git a/src/backend/dt.c b/src/backend/dt.c
@@ -175,23 +175,25 @@ dt_t ** dtnbytes(dt_t **pdtend,unsigned size,const char *ptr)
  * Construct a DTabytes record, and return it.
  */
 
-dt_t **dtabytes(dt_t **pdtend, unsigned offset, unsigned size, const char *ptr)
+dt_t **dtabytes(dt_t **pdtend, unsigned offset, unsigned size, const char *ptr, unsigned nbytes)
 {
-    return dtabytes(pdtend, TYnptr, offset, size, ptr);
+    return dtabytes(pdtend, TYnptr, offset, size, ptr, nbytes);
 }
 
-dt_t **dtabytes(dt_t **pdtend,tym_t ty, unsigned offset, unsigned size, const char *ptr)
+dt_t **dtabytes(dt_t **pdtend,tym_t ty, unsigned offset, unsigned size, const char *ptr, unsigned nbytes)
 {   dt_t *dt;
 
     while (*pdtend)
         pdtend = &((*pdtend)->DTnext);
 
     dt = dt_calloc(DT_abytes);
-    dt->DTnbytes = size;
-    dt->DTpbytes = (char *) MEM_PH_MALLOC(size);
+    dt->DTnbytes = size + nbytes;
+    dt->DTpbytes = (char *) MEM_PH_MALLOC(size + nbytes);
     dt->Dty = ty;
     dt->DTabytes = offset;
     memcpy(dt->DTpbytes,ptr,size);
+    if (size)
+        memset(dt->DTpbytes + size, 0, nbytes);
 
     *pdtend = dt;
     pdtend = &dt->DTnext;

diff --git a/src/backend/dt.h b/src/backend/dt.h
@@ -11,8 +11,8 @@ void dt_free(dt_t *);
 void dt_term();
 
 dt_t **dtnbytes(dt_t **,unsigned,const char *);
-dt_t **dtabytes(dt_t **pdtend,tym_t ty, unsigned offset, unsigned size, const char *ptr);
-dt_t **dtabytes(dt_t **pdtend, unsigned offset, unsigned size, const char *ptr);
+dt_t **dtabytes(dt_t **pdtend,tym_t ty, unsigned offset, unsigned size, const char *ptr, unsigned nzeros);
+dt_t **dtabytes(dt_t **pdtend, unsigned offset, unsigned size, const char *ptr, unsigned nzeros);
 dt_t **dtdword(dt_t **, int value);
 dt_t **dtsize_t(dt_t **, unsigned long long value);
 dt_t **dtnzeros(dt_t **pdtend,unsigned size);

diff --git a/src/e2ir.c b/src/e2ir.c
@@ -1391,9 +1391,11 @@ elem *toElem(Expression *e, IRState *irs)
                 e = el_calloc();
                 e->Eoper = OPstring;
                 // freed in el_free
-                e->EV.ss.Vstring = (char *)mem_malloc((se->len + 1) * se->sz);
-                memcpy(e->EV.ss.Vstring, se->string, (se->len + 1) * se->sz);
-                e->EV.ss.Vstrlen = (se->len + 1) * se->sz;
+                unsigned len = se->len * se->sz;
+                e->EV.ss.Vstring = (char *)mem_malloc(len + se->sz);
+                memcpy(e->EV.ss.Vstring, se->string, len);
+                memset(e->EV.ss.Vstring + len, 0, se->sz);
+                e->EV.ss.Vstrlen = len + se->sz;
                 e->Ety = TYnptr;
             }
             else
@@ -5593,7 +5595,8 @@ Symbol *toStringSymbol(const char *str, size_t len, size_t sz)
         Symbol *si = symbol_generate(SCstatic,type_static_array(len * sz, tschar));
         si->Salignment = 1;
         si->Sdt = NULL;
-        dtnbytes(&si->Sdt, (len + 1) * sz, str);
+        dt_t **pdt = dtnbytes(&si->Sdt, len * sz, str);
+        dtnzeros(pdt, sz);
         si->Sfl = FLdata;
         out_readonly(si);
         outdata(si);

diff --git a/src/expression.d b/src/expression.d
@@ -4428,6 +4428,19 @@ public:
         return value;
     }
 
+    /********************************
+     * Convert string contents to a 0 terminated string,
+     * allocated by mem.xmalloc().
+     */
+    final char* toStringz()
+    {
+        auto nbytes = len * sz;
+        char* s = cast(char*)mem.xmalloc(nbytes + sz);
+        memcpy(s, string, nbytes);
+        memset(s + nbytes, 0, sz);
+        return s;
+    }
+
     override void accept(Visitor v)
     {
         v.visit(this);
@@ -7602,12 +7615,14 @@ public:
 
     override Expression semantic(Scope* sc)
     {
-        const(char)* name;
-        StringExp se;
         static if (LOGSEMANTIC)
         {
             printf("FileExp::semantic('%s')\n", toChars());
         }
+        const(char)* name;
+        char* namez;
+        StringExp se;
+
         sc = sc.startCTFE();
         e1 = e1.semantic(sc);
         e1 = resolveProperties(sc, e1);
@@ -7620,24 +7635,24 @@ public:
         }
         se = cast(StringExp)e1;
         se = se.toUTF8(sc);
-        name = cast(char*)se.string;
+        namez = se.toStringz();
         if (!global.params.fileImppath)
         {
-            error("need -Jpath switch to import text file %s", name);
+            error("need -Jpath switch to import text file %s", namez);
             goto Lerror;
         }
         /* Be wary of CWE-22: Improper Limitation of a Pathname to a Restricted Directory
          * ('Path Traversal') attacks.
          * http://cwe.mitre.org/data/definitions/22.html
          */
-        name = FileName.safeSearchPath(global.filePath, name);
+        name = FileName.safeSearchPath(global.filePath, namez);
         if (!name)
         {
             error("file %s cannot be found or not in a path specified with -J", se.toChars());
             goto Lerror;
         }
         if (global.params.verbose)
-            fprintf(global.stdmsg, "file      %s\t(%s)\n", cast(char*)se.string, name);
+            fprintf(global.stdmsg, "file      %.*s\t(%s)\n", cast(int)se.len, se.string, name);
         if (global.params.moduleDeps !is null)
         {
             OutBuffer* ob = global.params.moduleDeps;
@@ -7650,7 +7665,7 @@ public:
             ob.writestring(") : ");
             if (global.params.moduleDepsFile)
                 ob.writestring("string : ");
-            ob.writestring(cast(char*)se.string);
+            ob.write(se.string, se.len);
             ob.writestring(" (");
             escapePath(ob, name);
             ob.writestring(")");

diff --git a/src/expression.h b/src/expression.h
@@ -380,6 +380,7 @@ class StringExp : public Expression
     Expression *modifiableLvalue(Scope *sc, Expression *e);
     unsigned charAt(uinteger_t i);
     void accept(Visitor *v) { v->visit(this); }
+    char *toStringz();
 };
 
 // Tuple

diff --git a/src/todt.c b/src/todt.c
@@ -381,7 +381,8 @@ dt_t **Expression_toDt(Expression *e, dt_t **pdt)
             {
                 case Tarray:
                     pdt = dtsize_t(pdt, e->len);
-                    pdt = dtabytes(pdt, 0, (e->len + 1) * e->sz, (char *)e->string);
+                case Tpointer:
+                    pdt = dtabytes(pdt, 0, e->len * e->sz, (const char *)e->string, (unsigned)e->sz);
                     break;
 
                 case Tsarray:
@@ -400,9 +401,6 @@ dt_t **Expression_toDt(Expression *e, dt_t **pdt)
                     }
                     break;
                 }
-                case Tpointer:
-                    pdt = dtabytes(pdt, 0, (e->len + 1) * e->sz, (char *)e->string);
-                    break;
 
                 default:
                     printf("StringExp::toDt(type = %s)\n", e->type->toChars());