Add basic lowering of generic function definitions. (#5015)

Very basic (incomplete) lowering of function definitions for generics.

toolchain/lower/file_context.cpp

@@ -86,6 +86,16 @@ auto FileContext::Run() -> std::unique_ptr<llvm::Module> {
   for (auto [id, _] : sem_ir_->functions().enumerate()) {
     BuildFunctionDefinition(id);
   }
+
+  // Lower function definitions for generics.
+  // This cannot be a range-based loop, as new definitions can be added
+  // while building other definitions.
+  // NOLINTNEXTLINE
+  for (size_t i = 0; i != specific_function_definitions_.size(); ++i) {
+    auto [function_id, specific_id] = specific_function_definitions_[i];
+    BuildFunctionDefinition(function_id, specific_id);
+  }
+
   // Append `__global_init` to `llvm::global_ctors` to initialize global
   // variables.
   if (sem_ir().global_ctor_id().has_value()) {
@@ -185,8 +195,8 @@ auto FileContext::GetOrCreateFunction(SemIR::FunctionId function_id,
   // TODO: Add this function to a list of specific functions whose definitions
   // we need to emit.
   specific_functions_[specific_id.index] = result;
-  // TODO: Should this be a pair of <function_id, specific_id> ?
-  specific_function_definitions_.push_back(specific_id);
+  // TODO: Use this to generate definitions for these functions.
+  specific_function_definitions_.push_back({function_id, specific_id});
   return result;
 }
 
@@ -302,7 +312,8 @@ auto FileContext::BuildFunctionDecl(SemIR::FunctionId function_id,
   return llvm_function;
 }
 
-auto FileContext::BuildFunctionDefinition(SemIR::FunctionId function_id)
+auto FileContext::BuildFunctionDefinition(SemIR::FunctionId function_id,
+                                          SemIR::SpecificId specific_id)
     -> void {
   const auto& function = sem_ir().functions().Get(function_id);
   const auto& body_block_ids = function.body_block_ids;
@@ -311,14 +322,22 @@ auto FileContext::BuildFunctionDefinition(SemIR::FunctionId function_id)
     return;
   }
 
-  llvm::Function* llvm_function = GetFunction(function_id);
-  if (!llvm_function) {
-    // We chose not to lower this function at all, for example because it's a
-    // generic function.
-    return;
+  llvm::Function* llvm_function;
+  if (specific_id.has_value()) {
+    llvm_function = specific_functions_[specific_id.index];
+  } else {
+    llvm_function = GetFunction(function_id);
+    if (!llvm_function) {
+      // We chose not to lower this function at all, for example because it's a
+      // generic function.
+      return;
+    }
   }
 
-  BuildFunctionBody(function_id, function, llvm_function);
+  // For non-generics we do not lower. For generics, the llvm function was
+  // created via GetOrCreateFunction prior to this when building the
+  // declaration.
+  BuildFunctionBody(function_id, function, llvm_function, specific_id);
 }
 
 auto FileContext::BuildFunctionBody(SemIR::FunctionId function_id,
@@ -350,12 +369,15 @@ auto FileContext::BuildFunctionBody(SemIR::FunctionId function_id,
   auto lower_param = [&](SemIR::InstId param_id) {
     // Get the value of the parameter from the function argument.
     auto param_inst = sem_ir().insts().GetAs<SemIR::AnyParam>(param_id);
-    llvm::Value* param_value =
-        llvm::PoisonValue::get(GetType(param_inst.type_id));
+    llvm::Value* param_value;
+
     if (SemIR::ValueRepr::ForType(sem_ir(), param_inst.type_id).kind !=
         SemIR::ValueRepr::None) {
       param_value = llvm_function->getArg(param_index);
       ++param_index;
+    } else {
+      param_value = llvm::PoisonValue::get(GetType(
+          SemIR::GetTypeInSpecific(sem_ir(), specific_id, param_inst.type_id)));
     }
     // The value of the parameter is the value of the argument.
     function_lowering.SetLocal(param_id, param_value);

toolchain/lower/file_context.h

@@ -103,8 +103,12 @@ class FileContext {
                              SemIR::SpecificId::None) -> llvm::Function*;
 
   // Builds the definition for the given function. If the function is only a
-  // declaration with no definition, does nothing.
-  auto BuildFunctionDefinition(SemIR::FunctionId function_id) -> void;
+  // declaration with no definition, does nothing. If this is a generic it'll
+  // only be lowered if the specific_id is specified. During this lowering of
+  // a generic, more generic functions may be added for lowering.
+  auto BuildFunctionDefinition(
+      SemIR::FunctionId function_id,
+      SemIR::SpecificId specific_id = SemIR::SpecificId::None) -> void;
 
   // Builds a functions body. Common functionality for all functions.
   auto BuildFunctionBody(
@@ -163,7 +167,8 @@ class FileContext {
   // definitions lowered after the lowering of other definitions.
   // This list may grow while lowering generic definitions from this list.
   // The list uses the `SpecificId` to index into specific_functions_.
-  llvm::SmallVector<SemIR::SpecificId, 10> specific_function_definitions_;
+  llvm::SmallVector<std::pair<SemIR::FunctionId, SemIR::SpecificId>, 10>
+      specific_function_definitions_;
 
   // Provides lowered versions of types.
   // Vector indexes correspond to `TypeId` indexes for non-symbolic types. We

toolchain/lower/testdata/function/generic/call.carbon

@@ -18,10 +18,12 @@ fn G() {
   var c: C = {};
   var d: D = {};
   var n: i32 = 0;
+  var m: f64 = 0.0;
 
   F(c);
   F(d);
   F(n);
+  F(m);
   F(i32);
 }
 
@@ -38,18 +40,23 @@ fn G() {
 // CHECK:STDOUT:   %c.var = alloca {}, align 8, !dbg !7
 // CHECK:STDOUT:   %d.var = alloca {}, align 8, !dbg !7
 // CHECK:STDOUT:   %n.var = alloca i32, align 4, !dbg !7
+// CHECK:STDOUT:   %m.var = alloca double, align 8, !dbg !7
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(i64 0, ptr %c.var), !dbg !7
 // CHECK:STDOUT:   call void @llvm.memcpy.p0.p0.i64(ptr align 1 %c.var, ptr align 1 @C.val.loc18_3.2, i64 0, i1 false), !dbg !7
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(i64 0, ptr %d.var), !dbg !7
 // CHECK:STDOUT:   call void @llvm.memcpy.p0.p0.i64(ptr align 1 %d.var, ptr align 1 @D.val.loc19_3.2, i64 0, i1 false), !dbg !8
 // CHECK:STDOUT:   call void @llvm.lifetime.start.p0(i64 4, ptr %n.var), !dbg !7
 // CHECK:STDOUT:   store i32 0, ptr %n.var, align 4, !dbg !9
-// CHECK:STDOUT:   call void @_CF.Main.15b1f98bd9cc0c5b(ptr %c.var), !dbg !10
-// CHECK:STDOUT:   call void @_CF.Main.2cc450fc05045897(ptr %d.var), !dbg !11
-// CHECK:STDOUT:   %.loc24 = load i32, ptr %n.var, align 4, !dbg !12
-// CHECK:STDOUT:   call void @_CF.Main.b88d1103f417c6d4(i32 %.loc24), !dbg !13
-// CHECK:STDOUT:   call void @_CF.Main.5754c7a55c7cbe4a(%type zeroinitializer), !dbg !14
-// CHECK:STDOUT:   ret void, !dbg !15
+// CHECK:STDOUT:   call void @llvm.lifetime.start.p0(i64 8, ptr %m.var), !dbg !7
+// CHECK:STDOUT:   store double 0.000000e+00, ptr %m.var, align 8, !dbg !10
+// CHECK:STDOUT:   call void @_CF.Main.15b1f98bd9cc0c5b(ptr %c.var), !dbg !11
+// CHECK:STDOUT:   call void @_CF.Main.2cc450fc05045897(ptr %d.var), !dbg !12
+// CHECK:STDOUT:   %.loc25 = load i32, ptr %n.var, align 4, !dbg !13
+// CHECK:STDOUT:   call void @_CF.Main.b88d1103f417c6d4(i32 %.loc25), !dbg !14
+// CHECK:STDOUT:   %.loc26 = load double, ptr %m.var, align 8, !dbg !15
+// CHECK:STDOUT:   call void @_CF.Main.66be507887ceee78(double %.loc26), !dbg !16
+// CHECK:STDOUT:   call void @_CF.Main.5754c7a55c7cbe4a(%type zeroinitializer), !dbg !17
+// CHECK:STDOUT:   ret void, !dbg !18
 // CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
@@ -58,16 +65,33 @@ fn G() {
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
 // CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #1
 // CHECK:STDOUT:
-// CHECK:STDOUT: declare void @_CF.Main.15b1f98bd9cc0c5b(ptr)
+// CHECK:STDOUT: define void @_CF.Main.15b1f98bd9cc0c5b(ptr %x) !dbg !19 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   ret void, !dbg !20
+// CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: declare void @_CF.Main.2cc450fc05045897(ptr)
+// CHECK:STDOUT: define void @_CF.Main.2cc450fc05045897(ptr %x) !dbg !21 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   ret void, !dbg !22
+// CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: declare void @_CF.Main.b88d1103f417c6d4(i32)
+// CHECK:STDOUT: define void @_CF.Main.b88d1103f417c6d4(i32 %x) !dbg !23 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   ret void, !dbg !24
+// CHECK:STDOUT: }
 // CHECK:STDOUT:
-// CHECK:STDOUT: declare void @_CF.Main.5754c7a55c7cbe4a(%type)
+// CHECK:STDOUT: define void @_CF.Main.66be507887ceee78(double %x) !dbg !25 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   ret void, !dbg !26
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: define void @_CF.Main.5754c7a55c7cbe4a(%type %x) !dbg !27 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   ret void, !dbg !28
+// CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; uselistorder directives
-// CHECK:STDOUT: uselistorder ptr @llvm.lifetime.start.p0, { 2, 1, 0 }
+// CHECK:STDOUT: uselistorder ptr @llvm.lifetime.start.p0, { 3, 2, 1, 0 }
 // CHECK:STDOUT: uselistorder ptr @llvm.memcpy.p0.p0.i64, { 1, 0 }
 // CHECK:STDOUT:
 // CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
@@ -86,9 +110,22 @@ fn G() {
 // CHECK:STDOUT: !7 = !DILocation(line: 18, column: 3, scope: !4)
 // CHECK:STDOUT: !8 = !DILocation(line: 19, column: 3, scope: !4)
 // CHECK:STDOUT: !9 = !DILocation(line: 20, column: 3, scope: !4)
-// CHECK:STDOUT: !10 = !DILocation(line: 22, column: 3, scope: !4)
+// CHECK:STDOUT: !10 = !DILocation(line: 21, column: 3, scope: !4)
 // CHECK:STDOUT: !11 = !DILocation(line: 23, column: 3, scope: !4)
-// CHECK:STDOUT: !12 = !DILocation(line: 24, column: 5, scope: !4)
-// CHECK:STDOUT: !13 = !DILocation(line: 24, column: 3, scope: !4)
+// CHECK:STDOUT: !12 = !DILocation(line: 24, column: 3, scope: !4)
+// CHECK:STDOUT: !13 = !DILocation(line: 25, column: 5, scope: !4)
 // CHECK:STDOUT: !14 = !DILocation(line: 25, column: 3, scope: !4)
-// CHECK:STDOUT: !15 = !DILocation(line: 17, column: 1, scope: !4)
+// CHECK:STDOUT: !15 = !DILocation(line: 26, column: 5, scope: !4)
+// CHECK:STDOUT: !16 = !DILocation(line: 26, column: 3, scope: !4)
+// CHECK:STDOUT: !17 = !DILocation(line: 27, column: 3, scope: !4)
+// CHECK:STDOUT: !18 = !DILocation(line: 17, column: 1, scope: !4)
+// CHECK:STDOUT: !19 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main.15b1f98bd9cc0c5b", scope: null, file: !3, line: 11, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !20 = !DILocation(line: 11, column: 1, scope: !19)
+// CHECK:STDOUT: !21 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main.2cc450fc05045897", scope: null, file: !3, line: 11, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !22 = !DILocation(line: 11, column: 1, scope: !21)
+// CHECK:STDOUT: !23 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main.b88d1103f417c6d4", scope: null, file: !3, line: 11, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !24 = !DILocation(line: 11, column: 1, scope: !23)
+// CHECK:STDOUT: !25 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main.66be507887ceee78", scope: null, file: !3, line: 11, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !26 = !DILocation(line: 11, column: 1, scope: !25)
+// CHECK:STDOUT: !27 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main.5754c7a55c7cbe4a", scope: null, file: !3, line: 11, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !28 = !DILocation(line: 11, column: 1, scope: !27)

toolchain/lower/testdata/function/generic/call_basic.carbon

@@ -0,0 +1,123 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+// AUTOUPDATE
+// TIP: To test this file alone, run:
+// TIP:   bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/lower/testdata/function/generic/call_basic.carbon
+// TIP: To dump output, run:
+// TIP:   bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/lower/testdata/function/generic/call_basic.carbon
+
+fn F[T:! type](x: T) {
+}
+
+fn H[T:! type](x: T) {
+}
+
+fn G[T:! type](x: T) -> T {
+  // TODO: the call below is crashing because proper type resolution to
+  // use the G specific, not the G generic is not done yet.
+  // H(T);
+  return x;
+}
+
+
+fn M() {
+  var n: i32 = 0;
+  var m: i32;
+  var p: f64 = 1.0;
+  var q: f64;
+
+  F(n);
+  m = G(n);
+  F(p);
+  q = G(p);
+}
+
+// CHECK:STDOUT: ; ModuleID = 'call_basic.carbon'
+// CHECK:STDOUT: source_filename = "call_basic.carbon"
+// CHECK:STDOUT:
+// CHECK:STDOUT: define void @_CM.Main() !dbg !4 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   %n.var = alloca i32, align 4, !dbg !7
+// CHECK:STDOUT:   %m.var = alloca i32, align 4, !dbg !7
+// CHECK:STDOUT:   %p.var = alloca double, align 8, !dbg !7
+// CHECK:STDOUT:   %q.var = alloca double, align 8, !dbg !7
+// CHECK:STDOUT:   call void @llvm.lifetime.start.p0(i64 4, ptr %n.var), !dbg !7
+// CHECK:STDOUT:   store i32 0, ptr %n.var, align 4, !dbg !7
+// CHECK:STDOUT:   call void @llvm.lifetime.start.p0(i64 4, ptr %m.var), !dbg !7
+// CHECK:STDOUT:   call void @llvm.lifetime.start.p0(i64 8, ptr %p.var), !dbg !7
+// CHECK:STDOUT:   store double 1.000000e+00, ptr %p.var, align 8, !dbg !8
+// CHECK:STDOUT:   call void @llvm.lifetime.start.p0(i64 8, ptr %q.var), !dbg !7
+// CHECK:STDOUT:   %.loc31 = load i32, ptr %n.var, align 4, !dbg !9
+// CHECK:STDOUT:   call void @_CF.Main.b88d1103f417c6d4(i32 %.loc31), !dbg !10
+// CHECK:STDOUT:   %.loc32 = load i32, ptr %n.var, align 4, !dbg !11
+// CHECK:STDOUT:   %G.call.loc32 = call i32 @_CG.Main.b88d1103f417c6d4(i32 %.loc32), !dbg !12
+// CHECK:STDOUT:   store i32 %G.call.loc32, ptr %m.var, align 4, !dbg !13
+// CHECK:STDOUT:   %.loc33 = load double, ptr %p.var, align 8, !dbg !14
+// CHECK:STDOUT:   call void @_CF.Main.66be507887ceee78(double %.loc33), !dbg !15
+// CHECK:STDOUT:   %.loc34 = load double, ptr %p.var, align 8, !dbg !16
+// CHECK:STDOUT:   %G.call.loc34 = call double @_CG.Main.66be507887ceee78(double %.loc34), !dbg !17
+// CHECK:STDOUT:   store double %G.call.loc34, ptr %q.var, align 8, !dbg !18
+// CHECK:STDOUT:   ret void, !dbg !19
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
+// CHECK:STDOUT: declare void @llvm.lifetime.start.p0(i64 immarg, ptr captures(none)) #0
+// CHECK:STDOUT:
+// CHECK:STDOUT: define void @_CF.Main.b88d1103f417c6d4(i32 %x) !dbg !20 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   ret void, !dbg !21
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: define i32 @_CG.Main.b88d1103f417c6d4(i32 %x) !dbg !22 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   ret i32 %x, !dbg !23
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: define void @_CF.Main.66be507887ceee78(double %x) !dbg !24 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   ret void, !dbg !25
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: define double @_CG.Main.66be507887ceee78(double %x) !dbg !26 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   ret double %x, !dbg !27
+// CHECK:STDOUT: }
+// CHECK:STDOUT:
+// CHECK:STDOUT: ; uselistorder directives
+// CHECK:STDOUT: uselistorder ptr @llvm.lifetime.start.p0, { 3, 2, 1, 0 }
+// CHECK:STDOUT:
+// CHECK:STDOUT: attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
+// CHECK:STDOUT:
+// CHECK:STDOUT: !llvm.module.flags = !{!0, !1}
+// CHECK:STDOUT: !llvm.dbg.cu = !{!2}
+// CHECK:STDOUT:
+// CHECK:STDOUT: !0 = !{i32 7, !"Dwarf Version", i32 5}
+// CHECK:STDOUT: !1 = !{i32 2, !"Debug Info Version", i32 3}
+// CHECK:STDOUT: !2 = distinct !DICompileUnit(language: DW_LANG_C, file: !3, producer: "carbon", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug)
+// CHECK:STDOUT: !3 = !DIFile(filename: "call_basic.carbon", directory: "")
+// CHECK:STDOUT: !4 = distinct !DISubprogram(name: "M", linkageName: "_CM.Main", scope: null, file: !3, line: 25, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !5 = !DISubroutineType(types: !6)
+// CHECK:STDOUT: !6 = !{}
+// CHECK:STDOUT: !7 = !DILocation(line: 26, column: 3, scope: !4)
+// CHECK:STDOUT: !8 = !DILocation(line: 28, column: 3, scope: !4)
+// CHECK:STDOUT: !9 = !DILocation(line: 31, column: 5, scope: !4)
+// CHECK:STDOUT: !10 = !DILocation(line: 31, column: 3, scope: !4)
+// CHECK:STDOUT: !11 = !DILocation(line: 32, column: 9, scope: !4)
+// CHECK:STDOUT: !12 = !DILocation(line: 32, column: 7, scope: !4)
+// CHECK:STDOUT: !13 = !DILocation(line: 32, column: 3, scope: !4)
+// CHECK:STDOUT: !14 = !DILocation(line: 33, column: 5, scope: !4)
+// CHECK:STDOUT: !15 = !DILocation(line: 33, column: 3, scope: !4)
+// CHECK:STDOUT: !16 = !DILocation(line: 34, column: 9, scope: !4)
+// CHECK:STDOUT: !17 = !DILocation(line: 34, column: 7, scope: !4)
+// CHECK:STDOUT: !18 = !DILocation(line: 34, column: 3, scope: !4)
+// CHECK:STDOUT: !19 = !DILocation(line: 25, column: 1, scope: !4)
+// CHECK:STDOUT: !20 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main.b88d1103f417c6d4", scope: null, file: !3, line: 11, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !21 = !DILocation(line: 11, column: 1, scope: !20)
+// CHECK:STDOUT: !22 = distinct !DISubprogram(name: "G", linkageName: "_CG.Main.b88d1103f417c6d4", scope: null, file: !3, line: 17, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !23 = !DILocation(line: 21, column: 3, scope: !22)
+// CHECK:STDOUT: !24 = distinct !DISubprogram(name: "F", linkageName: "_CF.Main.66be507887ceee78", scope: null, file: !3, line: 11, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !25 = !DILocation(line: 11, column: 1, scope: !24)
+// CHECK:STDOUT: !26 = distinct !DISubprogram(name: "G", linkageName: "_CG.Main.66be507887ceee78", scope: null, file: !3, line: 17, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !27 = !DILocation(line: 21, column: 3, scope: !26)

toolchain/lower/testdata/function/generic/call_method.carbon

@@ -44,7 +44,10 @@ fn CallF() -> i32 {
 // CHECK:STDOUT: ; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
 // CHECK:STDOUT: declare void @llvm.memcpy.p0.p0.i64(ptr noalias writeonly captures(none), ptr noalias readonly captures(none), i64, i1 immarg) #1
 // CHECK:STDOUT:
-// CHECK:STDOUT: declare i32 @_CF.C.Main.b88d1103f417c6d4(ptr, i32)
+// CHECK:STDOUT: define i32 @_CF.C.Main.b88d1103f417c6d4(ptr %self, i32 %x) !dbg !12 {
+// CHECK:STDOUT: entry:
+// CHECK:STDOUT:   ret i32 %x, !dbg !13
+// CHECK:STDOUT: }
 // CHECK:STDOUT:
 // CHECK:STDOUT: ; uselistorder directives
 // CHECK:STDOUT: uselistorder ptr @llvm.lifetime.start.p0, { 1, 0 }
@@ -67,3 +70,5 @@ fn CallF() -> i32 {
 // CHECK:STDOUT: !9 = !DILocation(line: 20, column: 14, scope: !4)
 // CHECK:STDOUT: !10 = !DILocation(line: 20, column: 10, scope: !4)
 // CHECK:STDOUT: !11 = !DILocation(line: 20, column: 3, scope: !4)
+// CHECK:STDOUT: !12 = distinct !DISubprogram(name: "F", linkageName: "_CF.C.Main.b88d1103f417c6d4", scope: null, file: !3, line: 12, type: !5, spFlags: DISPFlagDefinition, unit: !2)
+// CHECK:STDOUT: !13 = !DILocation(line: 13, column: 5, scope: !12)