commit 5d69db12d1944dc37b2c2a2039f6445073105934
author Olli Etuaho <oetuaho@nvidia.com> Fri Nov 24 16:51:15 2017 +0200
committer Commit Bot <commit-bot@chromium.org> Fri Dec 01 07:21:32 2017 +0000
tree 92576f16d89346e667bc46346fa96c9d01973590
parent da854a272832f486a9dc491ac24b6069d22eefd9

Reset symbol unique id counter between compilations

This guarantees identical compilation results on different
compilations using the same compiler instance, guards against
overflow, and is useful as a building block for tracking more symbol
information in the symbol table.

BUG=angleproject:2267
TEST=angle_unittests

Change-Id: Ib5a7cec2fff6712ead969d935d238d28a87fd4a7
Reviewed-on: https://chromium-review.googlesource.com/796795
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>

src/compiler/translator/Compiler.cpp

diff --git a/src/compiler/translator/Compiler.cpp b/src/compiler/translator/Compiler.cpp
index e0fd0cb..f0df223 100644
--- a/src/compiler/translator/Compiler.cpp
+++ b/src/compiler/translator/Compiler.cpp
@@ -734,6 +734,8 @@
 
     IdentifyBuiltIns(shaderType, shaderSpec, resources, symbolTable);
 
+    symbolTable.markBuiltInInitializationFinished();
+
     return true;
 }
 
@@ -868,6 +870,8 @@
     nameMap.clear();
 
     mSourcePath     = nullptr;
+
+    symbolTable.clearCompilationResults();
 }
 
 bool TCompiler::initCallDag(TIntermNode *root)

src/compiler/translator/SymbolTable.cpp

diff --git a/src/compiler/translator/SymbolTable.cpp b/src/compiler/translator/SymbolTable.cpp
index 3cfa8b7..9e7270d 100644
--- a/src/compiler/translator/SymbolTable.cpp
+++ b/src/compiler/translator/SymbolTable.cpp
@@ -291,7 +291,8 @@
                                                                const TString *name)
 {
     TInterfaceBlockName *blockNameSymbol = new TInterfaceBlockName(this, name);
-    if (insert(level, ext, blockNameSymbol))
+    blockNameSymbol->relateToExtension(ext);
+    if (insert(level, blockNameSymbol))
     {
         return blockNameSymbol;
     }
@@ -324,7 +325,8 @@
                                            const TType &type)
 {
     TVariable *var = new TVariable(this, NewPoolTString(name), type);
-    if (insert(level, ext, var))
+    var->relateToExtension(ext);
+    if (insert(level, var))
     {
         if (var->getType().getBasicType() == EbtStruct)
         {
@@ -583,6 +585,7 @@
 void TSymbolTable::insertUnmangledBuiltInName(const char *name, ESymbolLevel level)
 {
     ASSERT(level >= 0 && level < static_cast<ESymbolLevel>(table.size()));
+    ASSERT(mUserDefinedUniqueIdsStart == -1);
     table[level]->insertUnmangledBuiltInName(std::string(name));
 }
 
@@ -619,4 +622,23 @@
     return false;
 }
 
+void TSymbolTable::markBuiltInInitializationFinished()
+{
+    mUserDefinedUniqueIdsStart = mUniqueIdCounter;
+}
+
+void TSymbolTable::clearCompilationResults()
+{
+    mUniqueIdCounter = mUserDefinedUniqueIdsStart;
+
+    // User-defined scopes should have already been cleared when the compilation finished.
+    ASSERT(table.size() == LAST_BUILTIN_LEVEL + 1u);
+}
+
+int TSymbolTable::nextUniqueIdValue()
+{
+    ASSERT(mUniqueIdCounter < std::numeric_limits<int>::max());
+    return ++mUniqueIdCounter;
+}
+
 }  // namespace sh

src/compiler/translator/SymbolTable.h

diff --git a/src/compiler/translator/SymbolTable.h b/src/compiler/translator/SymbolTable.h
index b09f643..e92ac8f 100644
--- a/src/compiler/translator/SymbolTable.h
+++ b/src/compiler/translator/SymbolTable.h
@@ -287,7 +287,7 @@
 class TSymbolTable : angle::NonCopyable
 {
   public:
-    TSymbolTable() : mUniqueIdCounter(0), mEmptySymbolId(this)
+    TSymbolTable() : mUniqueIdCounter(0), mUserDefinedUniqueIdsStart(-1), mEmptySymbolId(this)
     {
         // The symbol table cannot be used until push() is called, but
         // the lack of an initial call to push() can be used to detect
@@ -358,7 +358,8 @@
         TConstantUnion *unionArray = new TConstantUnion[1];
         unionArray[0].setIConst(value);
         constant->shareConstPointer(unionArray);
-        return insert(level, ext, constant);
+        constant->relateToExtension(ext);
+        return insert(level, constant);
     }
 
     bool insertConstIvec3(ESymbolLevel level,
@@ -509,19 +510,20 @@
     // Checks whether there is a built-in accessible by a shader with the specified version.
     bool hasUnmangledBuiltInForShaderVersion(const char *name, int shaderVersion);
 
+    void markBuiltInInitializationFinished();
+    void clearCompilationResults();
+
   private:
     friend class TSymbolUniqueId;
-    int nextUniqueIdValue() { return ++mUniqueIdCounter; }
+    int nextUniqueIdValue();
 
     ESymbolLevel currentLevel() const { return static_cast<ESymbolLevel>(table.size() - 1); }
 
     TVariable *insertVariable(ESymbolLevel level, const TString *name, const TType &type);
 
-    bool insert(ESymbolLevel level, TSymbol *symbol) { return table[level]->insert(symbol); }
-
-    bool insert(ESymbolLevel level, TExtension ext, TSymbol *symbol)
+    bool insert(ESymbolLevel level, TSymbol *symbol)
     {
-        symbol->relateToExtension(ext);
+        ASSERT(level > LAST_BUILTIN_LEVEL || mUserDefinedUniqueIdsStart == -1);
         return table[level]->insert(symbol);
     }
 
@@ -537,6 +539,11 @@
 
     int mUniqueIdCounter;
 
+    // -1 before built-in init has finished, one past the last built-in id afterwards.
+    // TODO(oetuaho): Make this a compile-time constant once the symbol table is initialized at
+    // compile time. http://anglebug.com/1432
+    int mUserDefinedUniqueIdsStart;
+
     const TSymbolUniqueId mEmptySymbolId;
 };