[mlir-c] Add getting fused loc

[jpienaar]

Summary

For creating a fused loc using array of locations and metadata. I think this follows the convention of passing arrays.

[jpienaar]

Updated post change for param order (uploaded snapshot mid change by accident)

mlir/include/mlir-c/IR.h

 /// Creates an File/Line/Column location owned by the given context.
 MLIR_CAPI_EXPORTED MlirLocation mlirLocationFileLineColGet(
     MlirContext context, MlirStringRef filename, unsigned line, unsigned col);
 
 /// Creates a call site location with a callee and a caller.
 MLIR_CAPI_EXPORTED MlirLocation mlirLocationCallSiteGet(MlirLocation callee,
                                                         MlirLocation caller);
 
+/// Creates a fused location with an array of locations and metadata.
+MLIR_CAPI_EXPORTED MlirLocation
+mlirLocationFusedGet(MlirContext ctx, intptr_t nLocations,
+                     MlirLocation const *locations, MlirAttribute metadata);
+
 /// Creates a name location owned by the given context. Providing null location
 /// for childLoc is allowed and if childLoc is null location, then the behavior
 /// is the same as having unknown child location.
 MLIR_CAPI_EXPORTED MlirLocation mlirLocationNameGet(MlirContext context,
                                                     MlirStringRef name,
                                                     MlirLocation childLoc);
 
 /// Creates a location with unknown position owned by the given context.

mlir/lib/CAPI/IR/IR.cpp

MlirLocation mlirLocationFileLineColGet(MlirContext context,
   return wrap(Location(
       FileLineColLoc::get(unwrap(context), unwrap(filename), line, col)));
 }
 
 MlirLocation mlirLocationCallSiteGet(MlirLocation callee, MlirLocation caller) {
   return wrap(Location(CallSiteLoc::get(unwrap(callee), unwrap(caller))));
 }
 
+MlirLocation mlirLocationFusedGet(MlirContext ctx, MlirAttribute metadata,
+                                  intptr_t nLocations,
+                                  MlirLocation const *locations) {
+  SmallVector<Location, 4> locs;
+  ArrayRef<Location> unwrappedLocs = unwrapList(nLocations, locations, locs);
+  return wrap(FusedLoc::get(unwrappedLocs, unwrap(metadata), unwrap(ctx)));
+}
+
 MlirLocation mlirLocationNameGet(MlirContext context, MlirStringRef name,
                                  MlirLocation childLoc) {
   if (mlirLocationIsNull(childLoc))
     return wrap(
         Location(NameLoc::get(Identifier::get(unwrap(name), unwrap(context)))));
   return wrap(Location(NameLoc::get(
       Identifier::get(unwrap(name), unwrap(context)), unwrap(childLoc))));
 }

mlir/test/CAPI/ir.c

MlirLocation callSiteLoc = mlirLocationCallSiteGet(
       mlirLocationFileLineColGet(
           ctx, mlirStringRefCreateFromCString("other-file.c"), 2, 3),
       fileLineColLoc);
   mlirEmitError(callSiteLoc, "test diagnostics");
   MlirLocation null = {0};
   MlirLocation nameLoc =
       mlirLocationNameGet(ctx, mlirStringRefCreateFromCString("named"), null);
   mlirEmitError(nameLoc, "test diagnostics");
+  MlirLocation locs[2] = {nameLoc, callSiteLoc};
+  MlirAttribute nullAttr = {0};
+  MlirLocation fusedLoc = mlirLocationFusedGet(ctx, 2, locs, nullAttr);
+  mlirEmitError(fusedLoc, "test diagnostics");
   mlirContextDetachDiagnosticHandler(ctx, id);
   mlirEmitError(unknownLoc, "more test diagnostics");
   // CHECK-LABEL: @test_diagnostics
   // CHECK: processing diagnostic (userData: 42) <<
   // CHECK:   test diagnostics
   // CHECK:   loc(unknown)
   // CHECK: >> end of diagnostic (userData: 42)
   // CHECK: processing diagnostic (userData: 42) <<
   // CHECK:   test diagnostics
   // CHECK:   loc("file.c":1:2)
   // CHECK: >> end of diagnostic (userData: 42)
   // CHECK: processing diagnostic (userData: 42) <<
   // CHECK:   test diagnostics
   // CHECK:   loc(callsite("other-file.c":2:3 at "file.c":1:2))
   // CHECK: >> end of diagnostic (userData: 42)
   // CHECK: processing diagnostic (userData: 42) <<
   // CHECK:   test diagnostics
   // CHECK:   loc("named")
   // CHECK: >> end of diagnostic (userData: 42)
+  // CHECK: processing diagnostic (userData: 42) <<
+  // CHECK:   test diagnostics
+  // CHECK:   loc(fused["named", callsite("other-file.c":2:3 at "file.c":1:2)])
   // CHECK: deleting user data (userData: 42)
   // CHECK-NOT: processing diagnostic
   // CHECK:     more test diagnostics
 }
 
 int main() {
   MlirContext ctx = mlirContextCreate();
   mlirRegisterAllDialects(ctx);