[PATCH v17 7/9] vbscript: Bind global-scope Dim variables at compile time.

[Francis De Brabandere]

From: Francis De Brabandere <[e-mail]>

Extend compile-time identifier binding to global-scope code. Previously,
bind_local() unconditionally skipped binding for FUNC_GLOBAL functions,
forcing every global variable access through the string-based
lookup_identifier() path at runtime. Now, for code compiled via
ParseScriptText (skip_collisions=FALSE), global Dim variables are bound
to indexed slots at compile time, emitting OP_local/OP_assign_local
instead of OP_ident/OP_assign_ident.

At execution time, exec_script() builds a var_refs[] indirection table
that maps compile-time indices to their ScriptDisp->global_vars[]
storage. This is done once per script block (O(vars * global_vars)),
after exec_global_code() has already registered all Dim variables.

Execute/ExecuteGlobal code (skip_collisions=TRUE) is not affected: it
still skips binding in bind_local() because the destination of its Dim
variables (ScriptDisp vs caller dynamic_vars) is not known at compile
time.
---
 dlls/vbscript/compile.c | 14 ++++++++-
 dlls/vbscript/interp.c  | 66 ++++++++++++++++++++++++++++++++++-------
 2 files changed, 69 insertions(+), 11 deletions(-)

diff --git a/dlls/vbscript/compile.c b/dlls/vbscript/compile.c
index c969b9a0058..93a869e6af9 100644
--- a/dlls/vbscript/compile.c
+++ b/dlls/vbscript/compile.c
@@ -64,6 +64,13 @@ typedef struct {
     function_t *func;
     function_decl_t *func_decls;
     dim_decl_t *class_props;
+
+    /* Set for Execute/ExecuteGlobal: (1) suppresses compile-time binding of
+     * global Dim variables in bind_local(), since they may end up in the
+     * caller's dynamic_vars rather than ScriptDisp->global_vars; (2) makes
+     * check_script_collisions() non-fatal so re-declaring an existing name
+     * is silently tolerated instead of raising VBSE_NAME_REDEFINED. */
+    BOOL skip_collisions;
 } compile_ctx_t;
 
 static HRESULT compile_expression(compile_ctx_t*,expression_t*);
@@ -491,7 +498,11 @@ static BOOL bind_local(compile_ctx_t *ctx, const WCHAR *name, int *ret)
     dim_decl_t *dim_decl;
     unsigned i;
 
-    if(ctx->func->type == FUNC_GLOBAL)
+    /* Execute/Eval code may run from either global or local scope.
+     * When run from local scope, Dim vars are placed in the caller's
+     * dynamic_vars, not in ScriptDisp->global_vars.  We cannot bind
+     * them at compile time because we don't know which case it will be. */
+    if(ctx->func->type == FUNC_GLOBAL && ctx->skip_collisions)
         return FALSE;
 
     for(dim_decl = ctx->dim_decls, i = 0; dim_decl; dim_decl = dim_decl->next, i++) {
@@ -2325,6 +2336,7 @@ HRESULT compile_script(script_ctx_t *script, const WCHAR *src, const WCHAR *item
     }
 
     memset(&ctx, 0, sizeof(ctx));
+    ctx.skip_collisions = skip_collisions;
     code = ctx.code = alloc_vbscode(&ctx, src, cookie, start_line);
     if(!ctx.code)
         return E_OUTOFMEMORY;
diff --git a/dlls/vbscript/interp.c b/dlls/vbscript/interp.c
index 0196901573a..ca662e4d877 100644
--- a/dlls/vbscript/interp.c
+++ b/dlls/vbscript/interp.c
@@ -35,6 +35,9 @@ typedef struct _exec_ctx_t {
 
     VARIANT *args;
     VARIANT *vars;
+    /* For global-scope code: maps compile-time var indices to their
+     * ScriptDisp->global_vars[] VARIANT storage.  NULL for local scope. */
+    VARIANT **var_refs;
     SAFEARRAY **arrays;
 
     dynamic_var_t *dynamic_vars;
@@ -873,16 +876,20 @@ static HRESULT interp_mcallv(exec_ctx_t *ctx)
     return do_mcall(ctx, NULL);
 }
 
+static inline VARIANT *get_local_var(exec_ctx_t *ctx, int ref)
+{
+    if(ref < 0)
+        return ctx->args - ref - 1;
+    return ctx->var_refs ? ctx->var_refs[ref] : ctx->vars + ref;
+}
+
 static HRESULT interp_local(exec_ctx_t *ctx)
 {
     const int arg = ctx->instr->arg1.lng;
     VARIANT *v;
     VARIANT r;
 
-    if(arg < 0)
-        v = ctx->args - arg - 1;
-    else
-        v = ctx->vars + arg;
+    v = get_local_var(ctx, arg);
 
     TRACE("%s\n", debugstr_variant(v));
 
@@ -1093,7 +1100,7 @@ static HRESULT interp_assign_local(exec_ctx_t *ctx)
     DISPPARAMS dp;
     HRESULT hres;
 
-    v = ref < 0 ? ctx->args - ref - 1 : ctx->vars + ref;
+    v = get_local_var(ctx, ref);
 
     TRACE("%d\n", ref);
 
@@ -1114,7 +1121,7 @@ static HRESULT interp_set_local(exec_ctx_t *ctx)
     DISPPARAMS dp;
     HRESULT hres;
 
-    v = ref < 0 ? ctx->args - ref - 1 : ctx->vars + ref;
+    v = get_local_var(ctx, ref);
 
     TRACE("%d %u\n", ref, arg_cnt);
 
@@ -1776,7 +1783,7 @@ static HRESULT interp_step_local(exec_ctx_t *ctx)
 
     TRACE("%d\n", ref);
 
-    v = ref < 0 ? ctx->args - ref - 1 : ctx->vars + ref;
+    v = get_local_var(ctx, ref);
 
     if(V_VT(stack_top(ctx, 0)) == VT_EMPTY && V_VT(stack_top(ctx, 1)) == VT_EMPTY) {
         WARN("For loop not initialized\n");
@@ -2732,7 +2739,7 @@ static HRESULT interp_incc_local(exec_ctx_t *ctx)
 
     TRACE("%d\n", ref);
 
-    return do_incc(ctx, ref < 0 ? ctx->args - ref - 1 : ctx->vars + ref);
+    return do_incc(ctx, get_local_var(ctx, ref));
 }
 
 static HRESULT interp_with(exec_ctx_t *ctx)
@@ -2793,8 +2800,16 @@ static void release_exec(exec_ctx_t *ctx)
     }
 
     if(ctx->vars) {
-        for(i=0; i < ctx->func->var_cnt; i++)
-            VariantClear(ctx->vars+i);
+        if(ctx->var_refs) {
+            /* Only clear fallback slots (vars not found in ScriptDisp) */
+            for(i=0; i < ctx->func->var_cnt; i++) {
+                if(ctx->var_refs[i] == ctx->vars + i)
+                    VariantClear(ctx->vars+i);
+            }
+        }else {
+            for(i=0; i < ctx->func->var_cnt; i++)
+                VariantClear(ctx->vars+i);
+        }
     }
 
     if(ctx->arrays) {
@@ -2808,6 +2823,7 @@ static void release_exec(exec_ctx_t *ctx)
     heap_pool_free(&ctx->heap);
     free(ctx->args);
     free(ctx->vars);
+    free(ctx->var_refs);
     free(ctx->stack);
 }
 
@@ -2921,6 +2937,36 @@ HRESULT exec_script(script_ctx_t *ctx, BOOL extern_caller, function_t *func, vbd
         exec.vars = NULL;
     }
 
+    /* For global-scope code (ParseScriptText), resolve compile-time variable
+     * indices to pointers into ScriptDisp->global_vars[].  This allows OP_local
+     * and OP_assign_local to access global Dim variables by index instead of
+     * doing string-based lookup_identifier() at runtime.  exec_global_code()
+     * has already registered all Dim variables into global_vars before this. */
+    if(func->type == FUNC_GLOBAL && !exec.caller && func->var_cnt) {
+        ScriptDisp *obj = func->code_ctx->named_item
+            ? func->code_ctx->named_item->script_obj : ctx->script_obj;
+        unsigned i, j;
+
+        exec.var_refs = malloc(func->var_cnt * sizeof(VARIANT*));
+        if(!exec.var_refs) {
+            release_exec(&exec);
+            return E_OUTOFMEMORY;
+        }
+
+        for(i = 0; i < func->var_cnt; i++) {
+            exec.var_refs[i] = NULL;
+            for(j = 0; j < obj->global_vars_cnt; j++) {
+                if(!vbs_wcsicmp(func->vars[i].name, obj->global_vars[j]->name)) {
+                    exec.var_refs[i] = &obj->global_vars[j]->v;
+                    break;
+                }
+            }
+            /* If not found (e.g. shadowed by host), fall back to local storage */
+            if(!exec.var_refs[i])
+                exec.var_refs[i] = exec.vars + i;
+        }
+    }
+
     exec.stack_size = 16;
     exec.top = 0;
     exec.stack = malloc(exec.stack_size * sizeof(VARIANT));
-- 
GitLab


https://gitlab.winehq.org/wine/wine/-/merge_requests/10515