Fix size calculations for multidimensional arrays.

The code in abg-ir.cc that calculated the memory size of an array
summed, rather than multiplied, the dimensions. It also did duplicate
work for each dimension after the first.

Existing code in abg-reader.cc asserted that array size information
read from XML match freshly calculated values.

This patch corrects the calculation, eliminates the duplicate work and
updates the XML reader validation to just emit a warning if old bad
array size information is found.

	* include/abg-ir.h (array_type_def::append_subrange): Remove
	this function.
	* src/abg-ir.cc (array_type_def::set_element_type): Add a note
	about safe usage.
	(array_type_def::append_subrange): Inline this function into
	its only caller append_subranges and remove it.
	(array_type_def::append_subranges): Do correct multiplicative
	calculation of multidimensional array sizes.
	* src/abg-reader.cc (build_array_type_def): When checking
	calculated against read array sizes, warn once if value
	matches old behaviour rather than raising an assertion.
	Otherwise, before raising an assertion, emit an informative
	error message.
	* tests/data/test-annotate/test14-pr18893.so.abi: Correct
	array sizes.
	* tests/data/test-annotate/test17-pr19027.so.abi: Ditto.
	* tests/data/test-annotate/test19-pr19023-libtcmalloc_and_profiler.so.abi:
	Ditto.
	* tests/data/test-annotate/test7.so.abi: Ditto.
	* tests/data/test-diff-dwarf/test10-report.txt: Ditto.
	* tests/data/test-diff-dwarf/test11-report.txt: Ditto.
	* tests/data/test-read-write/test25.xml: Ditto.

Reviewed-by: Matthias Maennich <maennich@google.com>
Signed-off-by: Giuliano Procida <gprocida@google.com>

diff --git a/include/abg-ir.h b/include/abg-ir.h
index 1278da9460f6c4c72169b63aa55a56e4147eb532..fda10de5c537f45c705d68fd5ff8b71789da30db 100644 (file)
--- a/include/abg-ir.h
+++ b/include/abg-ir.h
@@ -2380,9 +2380,6 @@ public:
   void
   set_element_type(const type_base_sptr& element_type);
 
-  virtual void
-  append_subrange(subrange_sptr sub);
-
   virtual void
   append_subranges(const std::vector<subrange_sptr>& subs);
 

diff --git a/src/abg-ir.cc b/src/abg-ir.cc
index 5b73abcf7d033a4e530b2630619603f8124e0965..27831352570da4c69dafe7998c34598155a2e71f 100644 (file)
--- a/src/abg-ir.cc
+++ b/src/abg-ir.cc
@@ -14558,6 +14558,10 @@ array_type_def::get_element_type() const
 /// re-compute the canonical type of the array, if one has already
 /// been computed.
 ///
+/// The intended use of this method is to permit in-place adjustment
+/// of the element type's qualifiers. In particular, the size of the
+/// element type should not be changed.
+///
 /// @param element_type the new element type to set.
 void
 array_type_def::set_element_type(const type_base_sptr& element_type)
@@ -14565,29 +14569,25 @@ array_type_def::set_element_type(const type_base_sptr& element_type)
   priv_->element_type_ = element_type;
 }
 
-// Append a single subrange @param sub.
-void
-array_type_def::append_subrange(subrange_sptr sub)
-{
-  priv_->subranges_.push_back(sub);
-  size_t s = get_size_in_bits();
-  s += sub->get_length() * get_element_type()->get_size_in_bits();
-  set_size_in_bits(s);
-  string r = get_pretty_representation();
-  const environment* env = get_environment();
-  ABG_ASSERT(env);
-  set_name(env->intern(r));
-}
-
 /// Append subranges from the vector @param subs to the current
 /// vector of subranges.
 void
 array_type_def::append_subranges(const std::vector<subrange_sptr>& subs)
 {
+  size_t s = get_element_type()->get_size_in_bits();
+
   for (std::vector<shared_ptr<subrange_type> >::const_iterator i = subs.begin();
        i != subs.end();
        ++i)
-    append_subrange(*i);
+    {
+      priv_->subranges_.push_back(*i);
+      s *= (*i)->get_length();
+    }
+
+  const environment* env = get_environment();
+  ABG_ASSERT(env);
+  set_name(env->intern(get_pretty_representation()));
+  set_size_in_bits(s);
 }
 
 /// @return true if one of the sub-ranges of the array is infinite, or

diff --git a/src/abg-reader.cc b/src/abg-reader.cc
index f14d590b0bd4110fdb0b74ea7ba19cf43ac9a4d8..340223d0edf446860a50d0bf15dddb14d9ecc63d 100644 (file)
--- a/src/abg-reader.cc
+++ b/src/abg-reader.cc
@@ -39,6 +39,8 @@
 #include "abg-suppression-priv.h"
 
 #include "abg-internal.h"
+#include "abg-tools-utils.h"
+
 // <headers defining libabigail's API go under here>
 ABG_BEGIN_EXPORT_DECLARATIONS
 
@@ -4075,13 +4077,40 @@ build_array_type_def(read_context&      ctxt,
          != ar_type->get_element_type()->get_alignment_in_bits()))
     return nil;
 
-  if (has_size_in_bits)
-    if (size_in_bits != ar_type->get_size_in_bits())
-      {
-       ABG_ASSERT(size_in_bits == (size_t) -1
-              || ar_type->get_element_type()->get_size_in_bits() == (size_t)-1
-              || ar_type->get_element_type()->get_size_in_bits() == 0);
-      }
+  if (has_size_in_bits && size_in_bits != (size_t) -1
+      && size_in_bits != ar_type->get_size_in_bits())
+    {
+      // We have a potential discrepancy between calculated and recorded sizes.
+      size_t element_size = ar_type->get_element_type()->get_size_in_bits();
+      if (element_size && element_size != (size_t)-1)
+       {
+         // Older versions miscalculated multidimensional array sizes.
+         size_t bad_count = 0;
+         for (vector<array_type_def::subrange_sptr>::const_iterator i =
+                subranges.begin();
+              i != subranges.end();
+              ++i)
+           bad_count += (*i)->get_length();
+         if (size_in_bits == bad_count * element_size)
+           {
+             static bool reported = false;
+             if (!reported)
+               {
+                 std::cerr << "notice: Found incorrectly calculated array "
+                           << "sizes in XML - this is benign.\nOlder versions "
+                           << "of libabigail miscalculated multidimensional "
+                           << "array sizes." << std::endl;
+                 reported = true;
+               }
+           }
+         else
+           {
+             std::cerr << "error: Found incorrectly calculated array size in "
+                       << "XML (id=\"" << id <<  "\")." << std::endl;
+             ABG_ASSERT_NOT_REACHED;
+           }
+       }
+    }
 
   if (ctxt.push_and_key_type_decl(ar_type, id, add_to_current_scope))
     {

diff --git a/tests/data/test-annotate/test14-pr18893.so.abi b/tests/data/test-annotate/test14-pr18893.so.abi
index d357bfbd9000564004d63cdb6c659f2bdf062c40..c7baf6adf359447f918c542035aa3ffbbb7e309a 100644 (file)
--- a/tests/data/test-annotate/test14-pr18893.so.abi
+++ b/tests/data/test-annotate/test14-pr18893.so.abi
@@ -5047,7 +5047,7 @@
 
     </array-type-def>
     <!-- REAL[40][4] -->
-    <array-type-def dimensions='2' type-id='type-id-122' size-in-bits='1408' id='type-id-156'>
+    <array-type-def dimensions='2' type-id='type-id-122' size-in-bits='5120' id='type-id-156'>
       <!-- <anonymous range>[40] -->
       <subrange length='40' type-id='type-id-32' id='type-id-126'/>
 
@@ -9621,7 +9621,7 @@
   </abi-instr>
   <abi-instr version='1.0' address-size='64' path='libnurbs/internals/backend.cc' comp-dir-path='/tmp/legendre/spack-stage/spack-stage-T0fsxk/Mesa-8.0.5/src/glu/sgi' language='LANG_C_plus_plus'>
     <!-- REAL[3][4] -->
-    <array-type-def dimensions='2' type-id='type-id-122' size-in-bits='224' id='type-id-292'>
+    <array-type-def dimensions='2' type-id='type-id-122' size-in-bits='384' id='type-id-292'>
       <!-- <anonymous range>[3] -->
       <subrange length='3' type-id='type-id-32' id='type-id-35'/>
 
@@ -10572,7 +10572,7 @@
 
     </array-type-def>
     <!-- REAL[5][5] -->
-    <array-type-def dimensions='2' type-id='type-id-122' size-in-bits='320' id='type-id-321'>
+    <array-type-def dimensions='2' type-id='type-id-122' size-in-bits='800' id='type-id-321'>
       <!-- <anonymous range>[5] -->
       <subrange length='5' type-id='type-id-32' id='type-id-320'/>
 
@@ -13394,7 +13394,7 @@
 
     </array-type-def>
     <!-- REAL[2][5] -->
-    <array-type-def dimensions='2' type-id='type-id-122' size-in-bits='224' id='type-id-379'>
+    <array-type-def dimensions='2' type-id='type-id-122' size-in-bits='320' id='type-id-379'>
       <!-- <anonymous range>[2] -->
       <subrange length='2' type-id='type-id-32' id='type-id-191'/>
 

diff --git a/tests/data/test-annotate/test17-pr19027.so.abi b/tests/data/test-annotate/test17-pr19027.so.abi
index fae390c6e4a421b36ade309b7517ae4c5b725ad3..9214a0f4553285e9acb2f6e9792c5ed74074fcbd 100644 (file)
--- a/tests/data/test-annotate/test17-pr19027.so.abi
+++ b/tests/data/test-annotate/test17-pr19027.so.abi
@@ -1296,7 +1296,7 @@
 
     </array-type-def>
     <!-- hb_codepoint_t[2][5] -->
-    <array-type-def dimensions='2' type-id='type-id-64' size-in-bits='224' id='type-id-65'>
+    <array-type-def dimensions='2' type-id='type-id-64' size-in-bits='320' id='type-id-65'>
       <!-- <anonymous range>[2] -->
       <subrange length='2' type-id='type-id-4' id='type-id-8'/>
 

diff --git a/tests/data/test-annotate/test19-pr19023-libtcmalloc_and_profiler.so.abi b/tests/data/test-annotate/test19-pr19023-libtcmalloc_and_profiler.so.abi
index 64c8c39552404f8551508efba438a44ee5fb0f30..b62486d98f2ca58d01319d86aad2dded3d19e326 100644 (file)
--- a/tests/data/test-annotate/test19-pr19023-libtcmalloc_and_profiler.so.abi
+++ b/tests/data/test-annotate/test19-pr19023-libtcmalloc_and_profiler.so.abi
@@ -38460,7 +38460,7 @@
 
     </array-type-def>
     <!-- void*[20][32] -->
-    <array-type-def dimensions='2' type-id='type-id-17' size-in-bits='3328' id='type-id-434'>
+    <array-type-def dimensions='2' type-id='type-id-17' size-in-bits='40960' id='type-id-434'>
       <!-- <anonymous range>[20] -->
       <subrange length='20' type-id='type-id-3' id='type-id-10'/>
 

diff --git a/tests/data/test-annotate/test7.so.abi b/tests/data/test-annotate/test7.so.abi
index 294bac3c2d81cce5968459df83f737bc47694e33..11bd6a3d25cf690b7a744f123fade2c7fb5cf50f 100644 (file)
--- a/tests/data/test-annotate/test7.so.abi
+++ b/tests/data/test-annotate/test7.so.abi
@@ -34,7 +34,7 @@
     <!-- double -->
     <type-decl name='double' size-in-bits='64' id='type-id-10'/>
     <!-- double[5][3] -->
-    <array-type-def dimensions='2' type-id='type-id-10' size-in-bits='512' id='type-id-11'>
+    <array-type-def dimensions='2' type-id='type-id-10' size-in-bits='960' id='type-id-11'>
       <!-- <anonymous range>[5] -->
       <subrange length='5' type-id='type-id-4' id='type-id-12'/>
 

diff --git a/tests/data/test-diff-dwarf/test10-report.txt b/tests/data/test-diff-dwarf/test10-report.txt
index ea1817b7cb15513c6ef43562af2abeda5c220b21..ea561e89a5995b6e2f915d76e14899737f48e766 100644 (file)
--- a/tests/data/test-diff-dwarf/test10-report.txt
+++ b/tests/data/test-diff-dwarf/test10-report.txt
@@ -10,7 +10,7 @@ Variables changes summary: 0 Removed, 0 Changed, 0 Added variable
         2 data member changes:
           type of 'int S::m0[5][3]' changed:
             type name changed from 'int[5][3]' to 'int[5][4]'
-            array type size changed from 256 to 288
+            array type size changed from 480 to 640
             array type subrange 2 changed length from 3 to 4
           type of 'int* S::m1[10]' changed:
             array element type 'int*' changed: 

diff --git a/tests/data/test-diff-dwarf/test11-report.txt b/tests/data/test-diff-dwarf/test11-report.txt
index 0675db657cbd9427e2a8650d56fbce96f26b512d..2f9f25a4447a0e50e57a0caf408eec775fa3b1b4 100644 (file)
--- a/tests/data/test-diff-dwarf/test11-report.txt
+++ b/tests/data/test-diff-dwarf/test11-report.txt
@@ -10,11 +10,11 @@ Variables changes summary: 0 Removed, 0 Changed, 0 Added variable
         2 data member changes:
           type of 'int S::m0[5][3]' changed:
             type name changed from 'int[5][3]' to 'int[6][3]'
-            array type size changed from 256 to 288
+            array type size changed from 480 to 576
             array type subrange 1 changed length from 5 to 6
           type of 'int S::m1[6][4]' changed:
             type name changed from 'int[6][4]' to 'int[6][5]'
-            array type size changed from 320 to 352
+            array type size changed from 768 to 960
             array type subrange 2 changed length from 4 to 5
           and offset changed from 480 to 576 (in bits) (by +96 bits)
 

diff --git a/tests/data/test-read-write/test25.xml b/tests/data/test-read-write/test25.xml
index 9be61ccef3b1b4a2bfd441da70123e50491f88fc..5be51f856aa4b3692068b9bf3071356bac4b63e7 100644 (file)
--- a/tests/data/test-read-write/test25.xml
+++ b/tests/data/test-read-write/test25.xml
@@ -26,7 +26,7 @@
     </data-member>
   </class-decl>
   <type-decl name='double' size-in-bits='64' alignment-in-bits='64' id='type-id-11'/>
-  <array-type-def dimensions='2' type-id='type-id-11' size-in-bits='512' alignment-in-bits='64' id='type-id-9'>
+  <array-type-def dimensions='2' type-id='type-id-11' size-in-bits='960' alignment-in-bits='64' id='type-id-9'>
     <subrange length='5' id='type-id-12'/>
 
     <subrange length='3' id='type-id-13'/>