Give a catch copy thunk a debug scope of its own

tslang/lib/TypeScript/MLIRGenStatements.cpp

@@ -1083,6 +1083,21 @@ namespace mlirgen
         GenContext thunkGenContext{};
         thunkGenContext.funcOp = funcOp;
 
+        // A function of its own to the debugger as well. `location` is the throw or catch
+        // statement's, and carries that statement's debug scope - a lexical block of the
+        // function around it when the statement sits in a braced block. Left on the thunk and
+        // its body, LLVM rejected the module: the thunk got a subprogram of its own while its
+        // instructions still pointed into the other function's block. Same steps as
+        // mlirGenFunctionLikeDeclaration: a subprogram for the thunk, the body scoped under it.
+        DITableScopeT debugFuncScope(debugScope);
+        if (compileOptions.generateDebugInfo)
+        {
+            MLIRDebugInfoHelper mdi(builder, debugScope);
+            auto plainLocation = stripMetadata(location);
+            funcOp->setLoc(mdi.getSubprogram(plainLocation, name, name, plainLocation));
+            location = locFuseWithScope(plainLocation);
+        }
+
         auto &entryBlock = *funcOp.addEntryBlock();
         builder.setInsertionPointToStart(&entryBlock);
 

tslang/test/tester/CMakeLists.txt

@@ -392,6 +392,7 @@ tslang_add_test(NAME test-compile-00-throw-inlined COMMAND test-runner "${PROJEC
 tslang_add_test(NAME test-compile-00-try-catch-sequence-and-nesting COMMAND test-runner "${PROJECT_SOURCE_DIR}/test/tester/tests/00try_catch_sequence_and_nesting.ts")
 tslang_add_test(NAME test-compile-00-try-in-catch-with-finally COMMAND test-runner "${PROJECT_SOURCE_DIR}/test/tester/tests/00try_in_catch_with_finally.ts")
 tslang_add_test(NAME test-compile-00-throw-number-untyped-catch COMMAND test-runner "${PROJECT_SOURCE_DIR}/test/tester/tests/00throw_number_untyped_catch.ts")
+tslang_add_test(NAME test-compile-00-throw-in-block-debug-info COMMAND test-runner "${PROJECT_SOURCE_DIR}/test/tester/tests/00throw_in_block_debug_info.ts")
 tslang_add_test(NAME test-compile-00-catch-untyped-value COMMAND test-runner "${PROJECT_SOURCE_DIR}/test/tester/tests/00catch_untyped_value.ts")
 tslang_add_test(NAME test-compile-00-throw-bool-bigint COMMAND test-runner "${PROJECT_SOURCE_DIR}/test/tester/tests/00throw_bool_bigint.ts")
 tslang_add_test(NAME test-compile-00-throw-f32 COMMAND test-runner "${PROJECT_SOURCE_DIR}/test/tester/tests/00throw_f32.ts")
@@ -825,6 +826,7 @@ tslang_add_test(NAME test-jit-00-throw-inlined COMMAND test-runner -jit "${PROJE
 tslang_add_test(NAME test-jit-00-try-catch-sequence-and-nesting COMMAND test-runner -jit "${PROJECT_SOURCE_DIR}/test/tester/tests/00try_catch_sequence_and_nesting.ts")
 tslang_add_test(NAME test-jit-00-try-in-catch-with-finally COMMAND test-runner -jit "${PROJECT_SOURCE_DIR}/test/tester/tests/00try_in_catch_with_finally.ts")
 tslang_add_test(NAME test-jit-00-throw-number-untyped-catch COMMAND test-runner -jit "${PROJECT_SOURCE_DIR}/test/tester/tests/00throw_number_untyped_catch.ts")
+tslang_add_test(NAME test-jit-00-throw-in-block-debug-info COMMAND test-runner -jit "${PROJECT_SOURCE_DIR}/test/tester/tests/00throw_in_block_debug_info.ts")
 tslang_add_test(NAME test-jit-00-catch-untyped-value COMMAND test-runner -jit "${PROJECT_SOURCE_DIR}/test/tester/tests/00catch_untyped_value.ts")
 tslang_add_test(NAME test-jit-00-throw-bool-bigint COMMAND test-runner -jit "${PROJECT_SOURCE_DIR}/test/tester/tests/00throw_bool_bigint.ts")
 tslang_add_test(NAME test-jit-00-throw-f32 COMMAND test-runner -jit "${PROJECT_SOURCE_DIR}/test/tester/tests/00throw_f32.ts")
@@ -1737,6 +1739,7 @@ set(TSLANG_CORPUS
     00throw_bool_bigint.ts
     00throw_f32.ts
     00throw_u32.ts
+    00throw_in_block_debug_info.ts
     00throw_inlined.ts
     00throw_number_untyped_catch.ts
     00to_primitive_ops.ts

tslang/test/tester/tests/00throw_in_block_debug_info.ts

@@ -0,0 +1,33 @@
+// A class thrown from inside a braced block, with debug info on (the suite runs every test with
+// --di). The block opens a lexical debug scope, and the catch copy thunk built for the throw
+// used to inherit that scope: LLVM then rejected the module ("!dbg attachment points at wrong
+// subprogram for function"). The thunk has to be a function of its own to the debugger too.
+class Err {
+    constructor(public m: string) {}
+}
+
+function f(n: number) {
+    if (n < 0) {
+        throw new Err("negative");
+    }
+
+    return n;
+}
+
+function g(n: number) {
+    let caught = "";
+    try {
+        f(n);
+    } catch (e: Err) {
+        caught = e.m;
+    }
+
+    return caught;
+}
+
+function main() {
+    assert(f(1) == 1, "f(1)");
+    assert(g(-1) == "negative", "g(-1)");
+    assert(g(2) == "", "g(2)");
+    print("done.");
+}