1. New build system

Reviewed-on: #1

cmd/cli/main.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"encoding/json"
 	"fmt"
 	"os"
 	"strings"
@@ -20,11 +21,16 @@ Flags:
   --json             output as JSON instead of text
   --wrapper <cmd>    exec wrapper (e.g. "valgrind --error-exitcode=99")
   --binary <name>    name of executable produced by build (overrides .jdg)
+  --build <name>     run only the named structured build (use with matrix CI)
+  --list-builds      print the names of structured builds in the suite as JSON
+  --list-matrix      print the full (build, toolchain, platform) matrix as JSON
   --help             show help
 
 Example:
   judge lab1.jdg ./student-solution
   judge lab1.jdg ./student-solution --json
+  judge lab1.jdg ./student-solution --build=sanitized
+  judge --list-builds lab1.jdg
   judge aggregate reports/
 `
 
@@ -41,9 +47,20 @@ func main() {
 		return
 	}
 
+	if hasFlag(args, "--list-builds") {
+		runListBuilds(args)
+		return
+	}
+
+	if hasFlag(args, "--list-matrix") {
+		runListMatrix(args)
+		return
+	}
+
 	jsonOutput := hasFlag(args, "--json")
 	wrapper := flagValue(args, "--wrapper")
 	binary := flagValue(args, "--binary")
+	targetBuild := flagValue(args, "--build")
 	positional := positionalArgs(args)
 
 	if len(positional) < 2 {
@@ -54,27 +71,17 @@ func main() {
 	testFile := positional[0]
 	solutionDir := positional[1]
 
-	src, err := os.ReadFile(testFile)
-	if err != nil {
-		fatalf("cannot read %q: %v", testFile, err)
-	}
-
-	f, warns, err := dsl.Parse(string(src))
-	if err != nil {
-		fatalf("parse error in %q:\n  %v", testFile, err)
-	}
-	for _, w := range warns {
-		fmt.Fprintf(os.Stderr, "warning: %s\n", w)
-	}
+	f := parseSuite(testFile)
 
 	if _, err := os.Stat(solutionDir); err != nil {
 		fatalf("solution dir %q not found: %v", solutionDir, err)
 	}
 
 	r := runner.New(f, runner.Config{
-		WorkDir:    solutionDir,
-		BinaryName: binary,
-		Wrapper:    wrapper,
+		WorkDir:     solutionDir,
+		BinaryName:  binary,
+		Wrapper:     wrapper,
+		TargetBuild: targetBuild,
 	})
 	result := r.Run()
 
@@ -91,6 +98,91 @@ func main() {
 	}
 }
 
+func parseSuite(path string) *dsl.File {
+	f, warns, err := dsl.ParseFile(path)
+	if err != nil {
+		fatalf("parse error in %q:\n  %v", path, err)
+	}
+	for _, w := range warns {
+		fmt.Fprintf(os.Stderr, "warning: %s\n", w)
+	}
+	return f
+}
+
+func runListBuilds(args []string) {
+	positional := positionalArgs(args)
+	if len(positional) < 1 {
+		fatalf("--list-builds requires the path to a .jdg file")
+	}
+	f := parseSuite(positional[0])
+
+	var names []string
+	if len(f.Builds) == 0 {
+		names = []string{"default"}
+	} else {
+		for _, b := range f.Builds {
+			names = append(names, b.Name)
+		}
+	}
+	enc := json.NewEncoder(os.Stdout)
+	if err := enc.Encode(names); err != nil {
+		fatalf("encode list-builds: %v", err)
+	}
+}
+
+type matrixEntry struct {
+	Build     string `json:"build"`
+	Toolchain string `json:"toolchain"`
+	Platform  string `json:"platform"`
+	Wrapper   string `json:"wrapper,omitempty"`
+}
+
+func runListMatrix(args []string) {
+	positional := positionalArgs(args)
+	if len(positional) < 1 {
+		fatalf("--list-matrix requires the path to a .jdg file")
+	}
+	f := parseSuite(positional[0])
+
+	var entries []matrixEntry
+
+	if len(f.Builds) == 0 {
+		if len(f.Toolchains) == 0 {
+			entries = append(entries, matrixEntry{Build: "default", Toolchain: "default", Platform: "linux"})
+		} else {
+			for _, tc := range f.Toolchains {
+				for _, platform := range tc.Platforms {
+					entries = append(entries, matrixEntry{Build: "default", Toolchain: tc.Name, Platform: platform})
+				}
+			}
+		}
+	} else if len(f.Toolchains) == 0 {
+		fatalf("suite has structured builds but no `toolchains { ... }` block; add one to use --list-matrix")
+	} else {
+		for _, b := range f.Builds {
+			for _, tc := range f.Toolchains {
+				for _, platform := range tc.Platforms {
+					eff := b.Resolve(f.BuildDefaults, platform)
+					if !eff.AppliesTo(platform, tc.Name) {
+						continue
+					}
+					entries = append(entries, matrixEntry{
+						Build:     b.Name,
+						Toolchain: tc.Name,
+						Platform:  platform,
+						Wrapper:   eff.Wrapper,
+					})
+				}
+			}
+		}
+	}
+
+	enc := json.NewEncoder(os.Stdout)
+	if err := enc.Encode(entries); err != nil {
+		fatalf("encode list-matrix: %v", err)
+	}
+}
+
 func runAggregate(args []string) {
 	if len(args) < 1 {
 		fatalf("usage: judge aggregate <reports-dir>")
@@ -128,8 +220,18 @@ func flagValue(args []string, name string) string {
 }
 
 func positionalArgs(args []string) []string {
-	known := map[string]bool{"--json": true, "--help": true, "-h": true}
-	withValue := map[string]bool{"--wrapper": true, "--binary": true}
+	known := map[string]bool{
+		"--json":        true,
+		"--help":        true,
+		"-h":            true,
+		"--list-builds": true,
+		"--list-matrix": true,
+	}
+	withValue := map[string]bool{
+		"--wrapper": true,
+		"--binary":  true,
+		"--build":   true,
+	}
 
 	var out []string
 	skip := false
@@ -145,7 +247,7 @@ func positionalArgs(args []string) []string {
 			skip = true
 			continue
 		}
-		if strings.HasPrefix(a, "--wrapper=") || strings.HasPrefix(a, "--binary=") {
+		if strings.HasPrefix(a, "--wrapper=") || strings.HasPrefix(a, "--binary=") || strings.HasPrefix(a, "--build=") {
 			continue
 		}
 		out = append(out, a)