getStringHash on string literals (#1140)

* WIP getStringHash

* Have a use.

* Add slang-string-hash.h/.cpp

* Use StringSlicePool for holding strings for StringHash.
Add outputBuffer to string-literal-hash.slang so value can be tested.
Ignore the GlobalHashedStringLiterals instruction on emit.

* Add all the hashed string literals to ProgramLayout.

* Add reflection support for hashed string literals to reflection test.

* Fix string literal hash test.

* Small fixes to pass test suite.

* Fix issue in serialization where IRUse is not correctly initialized.

* Fix problem initializing IRUse for string hash pass.
Remove hack from slang-ir-specialize - specially handling if user is not null.

* * Use shared builder when replacing getStringHash
* Comments for functions in slang-ir-string-hash
* Do not allow zero length string literals. Could be allowed, but doing so would require StringSlicePool to have a special case (or some other mechanism)

1 files changed, 23 insertions, 0 deletions

diff --git a/source/slang/slang-lower-to-ir.cpp b/source/slang/slang-lower-to-ir.cpp
index 2a04b53b2..8b8a67f1e 100644
--- a/source/slang/slang-lower-to-ir.cpp
+++ b/source/slang/slang-lower-to-ir.cpp
@@ -14,6 +14,8 @@
 #include "slang-ir-ssa.h"
 #include "slang-ir-strip.h"
 #include "slang-ir-validate.h"
+#include "slang-ir-string-hash.h"
+
 #include "slang-mangle.h"
 #include "slang-type-layout.h"
 #include "slang-visitor.h"
@@ -776,6 +778,24 @@ LoweredValInfo emitCallToDeclRef(
         }
         else
         {
+            switch (intrinsicOp)
+            {
+                case kIROp_GetStringHash:
+                {
+                    IRStringLit* stringLit = as<IRStringLit>(args[0]);
+
+                    if (stringLit == nullptr || stringLit->getStringSlice() == UnownedStringSlice())
+                    {
+                        auto sink = context->getSink();
+
+                        sink->diagnose(funcDecl, Diagnostics::getStringHashRequiresStringLiteral);
+
+                        return LoweredValInfo();
+                    }
+
+                }
+            }
+
             // The intrinsic op maps to a single IR instruction,
             // so we will emit an instruction with the chosen
             // opcode, and the arguments to the call as its operands.
@@ -6737,6 +6757,9 @@ IRModule* generateIRForTranslationUnit(
     // call graph) based on constraints imposed by different instructions.
     propagateConstExpr(module, compileRequest->getSink());
 
+    // Replace calls to getStringHash, and save all the unique string lits in a GlobalHashedStringLiterals inst
+    replaceGetStringHashWithGlobal(module, *sharedBuilder);
+    
     // TODO: give error messages if any `undefined` or
     // `unreachable` instructions remain.