From: Petr Machata <pmachata@redhat.com>
Date: Mon, 11 Oct 2010 21:39:43 +0000 (+0200)
Subject: dwarflint: Introduce read_generic_value into checked_read
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=21c4259c2e5a76a1e33f4ab326a38c1b16d326f4;p=thirdparty%2Felfutils.git

dwarflint: Introduce read_generic_value into checked_read
- the hope being several reading operations can be expressed in terms of
  read_generic_value
---

diff --git a/dwarflint/check_debug_info.cc b/dwarflint/check_debug_info.cc
index a8877f7ef..402e8df59 100644
--- a/dwarflint/check_debug_info.cc
+++ b/dwarflint/check_debug_info.cc
@@ -770,44 +770,33 @@ namespace
 
 	    /* Attribute value.  */
 	    uint64_t value;
+	    read_ctx block;
+
 	    storage_class_t storclass = form->storage_class ();
-	    if (storclass == sc_string)
+	    if (!read_generic_value (ctx, form->width (cu), storclass,
+				     &where, &value, &block))
 	      {
-		if (!read_ctx_read_str (ctx))
-		  goto cant_read;
+		// Note that for fw_uleb and fw_sleb we report the
+		// error the second time now.
+		wr_error (where)
+		  << "can't read value of attribute "
+		  << *attribute << '.' << std::endl;
+		return -1;
 	      }
-	    else
+	    if (storclass == sc_block)
 	      {
-		if (!read_sc_value (&value, form->width (cu), ctx, &where))
-		  {
-		    // Note that for fw_uleb and fw_sleb we report the
-		    // error the second time now.
-		  cant_read:
-		    wr_error (where)
-		      << "can't read value of attribute "
-		      << *attribute << '.' << std::endl;
-		    return -1;
-		  }
-
-		if (storclass == sc_block)
+		if (cls == cl_exprloc)
 		  {
-		    // Read & validate the block body.
-		    if (cls == cl_exprloc)
-		      {
-			uint64_t expr_start
-			  = cu->head->offset + read_ctx_get_offset (ctx);
-			if (!check_location_expression
-			    (file, ctx, cu, expr_start, reloc, value, &where))
-			  return false;
-		      }
-		    else
-		      relocation_skip (reloc,
-				       read_ctx_get_offset (ctx) + value,
-				       &where, skip_mismatched);
-
-		    if (!read_ctx_skip (ctx, value))
-		      goto cant_read;
+		    uint64_t expr_start
+		      = cu->head->offset + read_ctx_get_offset (ctx) - value;
+		    if (!check_location_expression
+			(ver, file, &block, cu,
+			 expr_start, reloc, value, &where))
+		      return false;
 		  }
+		else
+		  relocation_skip (reloc, read_ctx_get_offset (ctx),
+				   &where, skip_mismatched);
 	      }
 
 	    /* Relocate the value if appropriate.  */
diff --git a/dwarflint/checked_read.cc b/dwarflint/checked_read.cc
index 4b73152dc..c6a714454 100644
--- a/dwarflint/checked_read.cc
+++ b/dwarflint/checked_read.cc
@@ -176,3 +176,41 @@ read_sc_value (uint64_t *valuep, form_width_t width,
     }
   UNREACHABLE;
 }
+
+bool
+read_generic_value (read_ctx *ctx,
+		    form_width_t width, storage_class_t storclass,
+		    where const *where, uint64_t *valuep, read_ctx *blockp)
+{
+  uint64_t value;
+  if (storclass == sc_value
+      || storclass == sc_block)
+    {
+      if (!read_sc_value (&value, width, ctx, where))
+	return false;
+      if (valuep != NULL)
+	*valuep = value;
+      if (storclass == sc_value)
+	return true;
+    }
+
+  unsigned char const *start = ctx->ptr;
+  if (storclass == sc_string)
+    {
+      if (!read_ctx_read_str (ctx))
+	return false;
+    }
+  else if (storclass == sc_block)
+    {
+      if (!read_ctx_skip (ctx, value))
+	return false;
+    }
+
+  if (blockp != NULL)
+    {
+      if (!read_ctx_init_sub (blockp, ctx, start, ctx->ptr))
+	return false;
+    }
+
+  return true;
+}
diff --git a/dwarflint/checked_read.hh b/dwarflint/checked_read.hh
index 39927e5b1..0843aaf17 100644
--- a/dwarflint/checked_read.hh
+++ b/dwarflint/checked_read.hh
@@ -51,4 +51,14 @@ bool checked_read_leb128 (read_ctx *ctx, form_width_t width, uint64_t *ret,
 bool read_sc_value (uint64_t *valuep, form_width_t width,
 		    read_ctx *ctx, where const *where);
 
+/// Read value depending on the form width and storage class.
+/// Value is returned via VALUEP, if that is non-NULL; for block
+/// forms, the value is block length.  Block context is returned via
+/// BLOCKP, in non-NULL; for string class, the block is the string
+/// itself.
+bool read_generic_value (read_ctx *ctx,
+			 form_width_t width, storage_class_t storclass,
+			 where const *where, uint64_t *valuep,
+			 read_ctx *blockp);
+
 #endif//DWARFLINT_CHECKED_READ_HH