1 files changed, 81 insertions, 0 deletions
diff --git a/source/compiler-core/slang-perfect-hash-codegen.cpp b/source/compiler-core/slang-perfect-hash-codegen.cpp
new file mode 100644
index 000000000..611b34c54
--- /dev/null
+++ b/source/compiler-core/slang-perfect-hash-codegen.cpp
@@ -0,0 +1,81 @@
+#include "slang-perfect-hash-codegen.h"
+#include "../core/slang-io.h"
+
+namespace Slang
+{
+    SlangResult writeHashFile(
+        String outCppPath,
+        String valueType,
+        const List<String> includes,
+        const HashParams& hashParams,
+        const List<String> values)
+    {
+        StringBuilder sb;
+        StringWriter writer(&sb, WriterFlags(0));
+        WriterHelper w(&writer);
+
+        w.print("// Hash function for %s\n", valueType.getBuffer());
+        w.print("//\n");
+        w.print("// This file was thoughtfully generated by a machine,\n");
+        w.print("// don't even think about modifying it yourself!\n");
+        w.print("//\n");
+        w.print("\n");
+        for (const auto& i : includes)
+        {
+            if (i.getLength())
+                w.print("#include \"%s\"\n", i.getBuffer());
+        }
+        w.print("\n");
+        w.print("\n");
+        w.print("namespace Slang\n");
+        w.print("{\n");
+        w.print("\n");
+
+        w.put(perfectHashToEmbeddableCpp(
+            hashParams,
+            valueType.getUnownedSlice(),
+            (String("lookup") + valueType).getUnownedSlice(),
+            values
+        ).getBuffer());
+
+        w.print("}\n");
+
+        return File::writeAllTextIfChanged(outCppPath, sb.getUnownedSlice());
+    }
+
+    SlangResult writePerfectHashLookupCppFile(String fileName, List<String> opnames, String enumName, String enumerantPrefix, String enumHeaderFile, DiagnosticSink* sink)
+    {
+        HashParams hashParams;
+        auto r = minimalPerfectHash(opnames, hashParams);
+        switch (r)
+        {
+        case HashFindResult::UnavoidableHashCollision:
+        {
+            sink->diagnoseRaw(
+                Severity::Error,
+                "Unable to find a non-overlapping hash function.\n"
+                "The hash function probably has a unavoidable "
+                "collision for some input words\n");
+            return SLANG_FAIL;
+        }
+        case HashFindResult::NonUniqueKeys:
+        {
+            sink->diagnoseRaw(Severity::Error, "Input word list has duplicates\n");
+            return SLANG_FAIL;
+        }
+        case HashFindResult::Success:;
+        }
+
+        List<String> values;
+        values.reserve(hashParams.destTable.getCount());
+        for (const auto& v : hashParams.destTable)
+            values.add(enumerantPrefix + v);
+        return writeHashFile(
+            fileName,
+            enumName,
+            { "../core/slang-common.h", "../core/slang-string.h", enumHeaderFile },
+            hashParams,
+            values);
+    }
+
+}