[Offload] Use llvm::Error throughout liboffload internals (#140879)

This removes the `ol_impl_result_t` helper class, replacing it with
`llvm::Error`. In addition, some internal functions that returned
`ol_errc_t` now return `llvm::Error` (with a fancy message).

3 files changed, 15 insertions, 5 deletions

diff --git a/offload/tools/offload-tblgen/EntryPointGen.cpp b/offload/tools/offload-tblgen/EntryPointGen.cpp
index 66b9665292e1..85c5c50bf2f2 100644
--- a/offload/tools/offload-tblgen/EntryPointGen.cpp
+++ b/offload/tools/offload-tblgen/EntryPointGen.cpp
@@ -23,7 +23,7 @@ using namespace offload::tblgen;
 static void EmitValidationFunc(const FunctionRec &F, raw_ostream &OS) {
   OS << CommentsHeader;
   // Emit preamble
-  OS << formatv("{0}_impl_result_t {1}_val(\n  ", PrefixLower, F.getName());
+  OS << formatv("llvm::Error {0}_val(\n  ", F.getName());
   // Emit arguments
   std::string ParamNameList = "";
   for (auto &Param : F.getParams()) {
@@ -42,7 +42,9 @@ static void EmitValidationFunc(const FunctionRec &F, raw_ostream &OS) {
       if (Condition.starts_with("`") && Condition.ends_with("`")) {
         auto ConditionString = Condition.substr(1, Condition.size() - 2);
         OS << formatv(TAB_2 "if ({0}) {{\n", ConditionString);
-        OS << formatv(TAB_3 "return {0};\n", Return.getValue());
+        OS << formatv(TAB_3 "return createOffloadError(error::ErrorCode::{0}, "
+                            "\"validation failure: {1}\");\n",
+                      Return.getUnprefixedValue(), ConditionString);
         OS << TAB_2 "}\n\n";
       }
     }
@@ -78,8 +80,9 @@ static void EmitEntryPointFunc(const FunctionRec &F, raw_ostream &OS) {
 
   // Perform actual function call to the validation wrapper
   ParamNameList = ParamNameList.substr(0, ParamNameList.size() - 2);
-  OS << formatv(TAB_1 "{0}_result_t Result = {1}_val({2});\n\n", PrefixLower,
-                F.getName(), ParamNameList);
+  OS << formatv(
+      TAB_1 "{0}_result_t Result = llvmErrorToOffloadError({1}_val({2}));\n\n",
+      PrefixLower, F.getName(), ParamNameList);
 
   // Emit post-call prints
   OS << TAB_1 "if (offloadConfig().TracingEnabled) {\n";
diff --git a/offload/tools/offload-tblgen/MiscGen.cpp b/offload/tools/offload-tblgen/MiscGen.cpp
index b73d70d58c23..bc3d204f78d8 100644
--- a/offload/tools/offload-tblgen/MiscGen.cpp
+++ b/offload/tools/offload-tblgen/MiscGen.cpp
@@ -61,7 +61,7 @@ void EmitOffloadImplFuncDecls(const RecordKeeper &Records, raw_ostream &OS) {
   OS << GenericHeader;
   for (auto *R : Records.getAllDerivedDefinitions("Function")) {
     FunctionRec F{R};
-    OS << formatv("{0}_impl_result_t {1}_impl(", PrefixLower, F.getName());
+    OS << formatv("Error {0}_impl(", F.getName());
     auto Params = F.getParams();
     for (auto &Param : Params) {
       OS << Param.getType() << " " << Param.getName();
diff --git a/offload/tools/offload-tblgen/RecordTypes.hpp b/offload/tools/offload-tblgen/RecordTypes.hpp
index 686634ed778a..bb7c06c643da 100644
--- a/offload/tools/offload-tblgen/RecordTypes.hpp
+++ b/offload/tools/offload-tblgen/RecordTypes.hpp
@@ -184,6 +184,13 @@ class ReturnRec {
 public:
   ReturnRec(const Record *rec) : rec(rec) {}
   StringRef getValue() const { return rec->getValueAsString("value"); }
+  // Strip the "OL_ERRC_" from the value, resulting in just "FOO" from
+  // "OL_ERRC_FOO"
+  StringRef getUnprefixedValue() const {
+    constexpr const char *ERRC = "ERRC_";
+    auto Start = getValue().find(ERRC) + strlen(ERRC);
+    return getValue().substr(Start);
+  }
   std::vector<StringRef> getConditions() const {
     return rec->getValueAsListOfStrings("conditions");
   }