+
+string get_unused_variable_name(const Block &block, const string &base)
+{
+ string name = base;
+
+ unsigned number = 1;
+ unsigned base_size = name.size();
+ while(1)
+ {
+ bool unused = true;
+ for(const Block *b=█ (unused && b); b=b->parent)
+ unused = !b->variables.count(name);
+ if(unused)
+ return name;
+
+ name.erase(base_size);
+ name += format("_%d", number);
+ ++number;
+ }
+}
+
+int get_layout_value(const Layout &layout, const string &name, int def_value)
+{
+ auto i = find_member(layout.qualifiers, name, &Layout::Qualifier::name);
+ return (i!=layout.qualifiers.end() ? i->value : def_value);
+}
+
+void add_to_chain(Assignment::Target &target, Assignment::Target::ChainType type, unsigned index)
+{
+ if(target.chain_len<7)
+ target.chain[target.chain_len] = type | min<unsigned>(index, 0x3F);
+ ++target.chain_len;
+}
+
+bool targets_overlap(const Assignment::Target &target1, const Assignment::Target &target2)
+{
+ bool overlap = (target1.declaration==target2.declaration);
+ for(unsigned i=0; (overlap && i<target1.chain_len && i<target2.chain_len); ++i)
+ {
+ Assignment::Target::ChainType type1 = static_cast<Assignment::Target::ChainType>(target1.chain[i]&0xC0);
+ Assignment::Target::ChainType type2 = static_cast<Assignment::Target::ChainType>(target2.chain[i]&0xC0);
+ unsigned index1 = target1.chain[i]&0x3F;
+ unsigned index2 = target2.chain[i]&0x3F;
+ if(type1==Assignment::Target::SWIZZLE || type2==Assignment::Target::SWIZZLE)
+ {
+ if(type1==Assignment::Target::SWIZZLE && type2==Assignment::Target::SWIZZLE)
+ overlap = index1&index2;
+ else if(type1==Assignment::Target::ARRAY && index1<4)
+ overlap = index2&(1<<index1);
+ else if(type2==Assignment::Target::ARRAY && index2<4)
+ overlap = index1&(1<<index2);
+ // Treat other combinations as overlapping (shouldn't happen)
+ }
+ else
+ overlap = (type1==type2 && (index1==index2 || index1==0x3F || index2==0x3F));
+ }
+
+ return overlap;
+}
+