main: switch to LLVM 10

This commit also adds a bit of version independence, in particular for
external commands. It also adds the LLVM version to the `tinygo version`
command, which might help while debugging.

transform/transform_test.go

@@ -6,6 +6,8 @@ import (
 	"flag"
 	"io/ioutil"
 	"os"
+	"regexp"
+	"strconv"
 	"strings"
 	"testing"
 
@@ -82,6 +84,12 @@ func fuzzyEqualIR(s1, s2 string) bool {
 // stripped out.
 func filterIrrelevantIRLines(lines []string) []string {
 	var out []string
+	llvmVersion, err := strconv.Atoi(strings.Split(llvm.Version, ".")[0])
+	if err != nil {
+		// Note: this should never happen and if it does, it will always happen
+		// for a particular build because llvm.Version is a constant.
+		panic(err)
+	}
 	for _, line := range lines {
 		line = strings.Split(line, ";")[0]    // strip out comments/info
 		line = strings.TrimRight(line, "\r ") // drop '\r' on Windows and remove trailing spaces from comments
@@ -91,6 +99,19 @@ func filterIrrelevantIRLines(lines []string) []string {
 		if strings.HasPrefix(line, "source_filename = ") {
 			continue
 		}
+		if llvmVersion < 10 && strings.HasPrefix(line, "attributes ") {
+			// Ignore attribute groups. These may change between LLVM versions.
+			// Right now test outputs are for LLVM 10.
+			continue
+		}
+		if llvmVersion < 10 && strings.HasPrefix(line, "define ") {
+			// Remove parameter values such as %0 in function definitions. These
+			// were added in LLVM 10 so to get the tests to pass on older
+			// versions, ignore them there (there are other tests that verify
+			// correct behavior).
+			re := regexp.MustCompile(` %[0-9]+(\)|,)`)
+			line = re.ReplaceAllString(line, "$1")
+		}
 		out = append(out, line)
 	}
 	return out