commit 5c0e023c4933cff33e40a8c413cba890a3e6271f
author Olli Etuaho <oetuaho@nvidia.com> Wed Nov 11 15:55:59 2015 +0200
committer Olli Etuaho <oetuaho@nvidia.com> Thu Nov 19 08:57:00 2015 +0000
tree 3ed940ab5bbd764882c397aba24589f5671216bd
parent 36b0514accbafba86c527af8ed1e8f7587fa7b15

Qualify stored constant union data with const

This prevents accidentally changing data that may be shared between
multiple TIntermConstantUnion nodes.

Besides making the code less prone to bugs in general, this will make it
easier to implement constant folding of array constructors.

BUG=541551
TEST=angle_unittests, WebGL conformance tests

Change-Id: I4f3059f70b841d9dd0cf20fea4d37684da9cd47e
Reviewed-on: https://chromium-review.googlesource.com/312440
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Tryjob-Request: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Tested-by: Olli Etuaho <oetuaho@nvidia.com>

src/compiler/translator/ParseContext.cpp

diff --git a/src/compiler/translator/ParseContext.cpp b/src/compiler/translator/ParseContext.cpp
index fd9d2c0..8486ac0 100644
--- a/src/compiler/translator/ParseContext.cpp
+++ b/src/compiler/translator/ParseContext.cpp
@@ -1216,7 +1216,7 @@
 
     if (variable->getConstPointer())
     {
-        TConstantUnion *constArray = variable->getConstPointer();
+        const TConstantUnion *constArray = variable->getConstPointer();
         return intermediate.addConstantUnion(constArray, variable->getType(), location);
     }
     else
@@ -1353,7 +1353,7 @@
                 symbolTable.find(initializer->getAsSymbolNode()->getSymbol(), 0);
             const TVariable *tVar = static_cast<const TVariable *>(symbol);
 
-            TConstantUnion *constArray = tVar->getConstPointer();
+            const TConstantUnion *constArray = tVar->getConstPointer();
             if (constArray)
             {
                 variable->shareConstPointer(constArray);
@@ -2373,7 +2373,7 @@
         index = node->getType().getCols() - 1;
     }
 
-    TConstantUnion *unionArray = node->getUnionArrayPointer();
+    const TConstantUnion *unionArray = node->getUnionArrayPointer();
     int size = node->getType().getCols();
     return intermediate.addConstantUnion(&unionArray[size * index], node->getType(), line);
 }
@@ -2401,8 +2401,8 @@
         outOfRangeError(outOfRangeIndexIsError, line, "", "[", extraInfo.c_str());
         index = node->getType().getArraySize() - 1;
     }
-    size_t arrayElementSize    = arrayElementType.getObjectSize();
-    TConstantUnion *unionArray = node->getUnionArrayPointer();
+    size_t arrayElementSize          = arrayElementType.getObjectSize();
+    const TConstantUnion *unionArray = node->getUnionArrayPointer();
     return intermediate.addConstantUnion(&unionArray[arrayElementSize * index], node->getType(),
                                          line);
 }
@@ -2437,7 +2437,7 @@
     TIntermConstantUnion *tempConstantNode = node->getAsConstantUnion();
     if (tempConstantNode)
     {
-        TConstantUnion *constArray = tempConstantNode->getUnionArrayPointer();
+        const TConstantUnion *constArray = tempConstantNode->getUnionArrayPointer();
 
         // type will be changed in the calling function
         typedNode = intermediate.addConstantUnion(constArray + instanceSize,
@@ -2796,8 +2796,9 @@
                 safeIndex = baseExpression->getType().getNominalSize() - 1;
             }
 
-            // Don't modify the data of the previous constant union, because it can point
-            // to builtins, like gl_MaxDrawBuffers. Instead use a new sanitized object.
+            // Data of constant unions can't be changed, because it may be shared with other
+            // constant unions or even builtins, like gl_MaxDrawBuffers. Instead use a new
+            // sanitized object.
             if (safeIndex != -1)
             {
                 TConstantUnion *safeConstantUnion = new TConstantUnion();