[SYCL] Add splitting module capabilities when compiling for NVPTX and AMDGCN (#4107)

The patch allows modules splitting for NVPTX and AMDGCN targets.

As those path needs to rely on existing tool, the approach taken here is
to generate and intercept commands so they  can be wrapped by a `llvm-foreach` tool call.

To do that, the patch adds `ForEachWrappingAction` which allows to encapsulate
a set of actions whose underlying commands will be wrapped under a llvm-foreach commands.

During the binding phases, the action will trigger the emission of jobs outside the set,
record the Jobs state then triggers the emission of the jobs inside the set.
The newly added commands are stolen from the Jobs list and
the commands are re-emitted with the llvm-foreach wrapping.

To allow standard clang tools to work properly,
SYCLPostLinkJobAction and FileTableTformJobAction reports
the underlying file type rather than TY_Tempfilelist or TY_tempfiletable
for those targets. Otherwise tools get confused as they don't know how to process the input.

To not make this patch too large, I maintained the SPIR-V path behaviour as it is, meaning the list of actions are not set up in the same way nor does it uses the `ForEachWrappingAction`. Otherwise there is a long list of test to update.

Signed-off-by: Victor Lomuller <[email protected]>

Author: Naghasan

clang/include/clang/Driver/Action.h

@@ -57,6 +57,7 @@ class Action {
     InputClass = 0,
     BindArchClass,
     OffloadClass,
+    ForEachWrappingClass,
     PreprocessJobClass,
     PrecompileJobClass,
     HeaderModulePrecompileJobClass,
@@ -737,7 +738,15 @@ class SYCLPostLinkJobAction : public JobAction {
   void anchor() override;
 
 public:
-  SYCLPostLinkJobAction(Action *Input, types::ID OutputType);
+  // The tempfiletable management relies on a shadowing the main file type by
+  // types::TY_Tempfiletable. The problem of shadowing is it prevents its
+  // integration with clang tools that relies on the file type to properly set
+  // args.
+  // We "trick" the driver by declaring the underlying file type and set a
+  // "true output type" which will be used by the SYCLPostLinkJobAction
+  // to properly set the job.
+  SYCLPostLinkJobAction(Action *Input, types::ID ShadowOutputType,
+                        types::ID TrueOutputType);
 
   static bool classof(const Action *A) {
     return A->getKind() == SYCLPostLinkJobClass;
@@ -747,8 +756,11 @@ class SYCLPostLinkJobAction : public JobAction {
 
   bool getRTSetsSpecConstants() const { return RTSetsSpecConsts; }
 
+  types::ID getTrueType() const { return TrueOutputType; }
+
 private:
   bool RTSetsSpecConsts = true;
+  types::ID TrueOutputType;
 };
 
 class BackendCompileJobAction : public JobAction {
@@ -771,6 +783,9 @@ class FileTableTformJobAction : public JobAction {
   void anchor() override;
 
 public:
+  static constexpr const char *COL_CODE = "Code";
+  static constexpr const char *COL_ZERO = "0";
+
   struct Tform {
     enum Kind {
       EXTRACT,
@@ -791,8 +806,10 @@ class FileTableTformJobAction : public JobAction {
     SmallVector<std::string, 2> TheArgs;
   };
 
-  FileTableTformJobAction(Action *Input, types::ID OutputType);
-  FileTableTformJobAction(ActionList &Inputs, types::ID OutputType);
+  FileTableTformJobAction(Action *Input, types::ID ShadowOutputType,
+                          types::ID TrueOutputType);
+  FileTableTformJobAction(ActionList &Inputs, types::ID ShadowOutputType,
+                          types::ID TrueOutputType);
 
   // Deletes all columns except the one with given name.
   void addExtractColumnTform(StringRef ColumnName, bool WithColTitle = true);
@@ -820,7 +837,10 @@ class FileTableTformJobAction : public JobAction {
 
   const ArrayRef<Tform> getTforms() const { return Tforms; }
 
+  types::ID getTrueType() const { return TrueOutputType; }
+
 private:
+  types::ID TrueOutputType;
   SmallVector<Tform, 2> Tforms; // transformation actions requested
 
   // column to copy single file from if requested
@@ -849,6 +869,30 @@ class StaticLibJobAction : public JobAction {
   }
 };
 
+/// Wrap all jobs performed between TFormInput (excluded) and Job (included)
+/// behind a `llvm-foreach` call.
+///
+/// Assumptions:
+///   - No change of toolchain, boundarch and offloading kind should occur
+///     within the sub-region;
+///   - No job should produce multiple outputs;
+///   - Results of action within the sub-region should not be used outside the
+///     wrapped region.
+/// Note: this doesn't bind to a tool directly and this need special casing
+/// anyhow. Hence why this is an Action and not a JobAction, even if there is a
+/// command behind.
+class ForEachWrappingAction : public Action {
+public:
+  ForEachWrappingAction(JobAction *TFormInput, JobAction *Job);
+
+  JobAction *getTFormInput() const;
+  JobAction *getJobAction() const;
+
+  static bool classof(const Action *A) {
+    return A->getKind() == ForEachWrappingClass;
+  }
+};
+
 } // namespace driver
 } // namespace clang
 

clang/include/clang/Driver/Job.h

@@ -319,6 +319,8 @@ class JobList {
   /// Clear the job list.
   void clear();
 
+  /// Return a mutable list of Jobs for llvm-foreach wrapping.
+  list_type &getJobsForOverride() { return Jobs; }
   const list_type &getJobs() const { return Jobs; }
 
   bool empty() const { return Jobs.empty(); }

clang/lib/Driver/Action.cpp

@@ -59,6 +59,8 @@ const char *Action::getClassName(ActionClass AC) {
     return "append-footer";
   case StaticLibJobClass:
     return "static-lib-linker";
+  case ForEachWrappingClass:
+    return "foreach";
   }
 
   llvm_unreachable("invalid class");
@@ -474,8 +476,11 @@ SPIRCheckJobAction::SPIRCheckJobAction(Action *Input, types::ID Type)
 
 void SYCLPostLinkJobAction::anchor() {}
 
-SYCLPostLinkJobAction::SYCLPostLinkJobAction(Action *Input, types::ID Type)
-    : JobAction(SYCLPostLinkJobClass, Input, Type) {}
+SYCLPostLinkJobAction::SYCLPostLinkJobAction(Action *Input,
+                                             types::ID ShadowOutputType,
+                                             types::ID TrueOutputType)
+    : JobAction(SYCLPostLinkJobClass, Input, ShadowOutputType),
+      TrueOutputType(TrueOutputType) {}
 
 void BackendCompileJobAction::anchor() {}
 
@@ -489,12 +494,17 @@ BackendCompileJobAction::BackendCompileJobAction(Action *Input,
 
 void FileTableTformJobAction::anchor() {}
 
-FileTableTformJobAction::FileTableTformJobAction(Action *Input, types::ID Type)
-    : JobAction(FileTableTformJobClass, Input, Type) {}
+FileTableTformJobAction::FileTableTformJobAction(Action *Input,
+                                                 types::ID ShadowOutputType,
+                                                 types::ID TrueOutputType)
+    : JobAction(FileTableTformJobClass, Input, ShadowOutputType),
+      TrueOutputType(TrueOutputType) {}
 
 FileTableTformJobAction::FileTableTformJobAction(ActionList &Inputs,
-                                                 types::ID Type)
-    : JobAction(FileTableTformJobClass, Inputs, Type) {}
+                                                 types::ID ShadowOutputType,
+                                                 types::ID TrueOutputType)
+    : JobAction(FileTableTformJobClass, Inputs, ShadowOutputType),
+      TrueOutputType(TrueOutputType) {}
 
 void FileTableTformJobAction::addExtractColumnTform(StringRef ColumnName,
                                                     bool WithColTitle) {
@@ -533,3 +543,15 @@ void StaticLibJobAction::anchor() {}
 
 StaticLibJobAction::StaticLibJobAction(ActionList &Inputs, types::ID Type)
     : JobAction(StaticLibJobClass, Inputs, Type) {}
+
+ForEachWrappingAction::ForEachWrappingAction(JobAction *TFormInput,
+                                             JobAction *Job)
+    : Action(ForEachWrappingClass, {TFormInput, Job}, Job->getType()) {}
+
+JobAction *ForEachWrappingAction::getTFormInput() const {
+  return llvm::cast<JobAction>(getInputs()[0]);
+}
+
+JobAction *ForEachWrappingAction::getJobAction() const {
+  return llvm::cast<JobAction>(getInputs()[1]);
+}