v: support -show-depgraph in addition to -show-callgraph

vlib/v/builder/builder.v

@@ -8,9 +8,10 @@ import v.ast
 import v.vmod
 import v.checker
 import v.parser
-import v.depgraph
 import v.markused
+import v.depgraph
 import v.callgraph
+import v.dotgraph
 
 pub struct Builder {
 pub:
@@ -52,6 +53,9 @@ pub fn new_builder(pref &pref.Preferences) Builder {
 		}
 	}
 	util.timing_set_should_print(pref.show_timings || pref.is_verbose)
+	if pref.show_callgraph || pref.show_depgraph {
+		dotgraph.start_digraph()
+	}
 	return Builder{
 		pref: pref
 		table: table
@@ -180,6 +184,9 @@ pub fn (mut b Builder) resolve_deps() {
 		eprintln(deps_resolved.display())
 		eprintln('------------------------------------------')
 	}
+	if b.pref.show_depgraph {
+		depgraph.show(deps_resolved, b.pref.path)
+	}
 	cycles := deps_resolved.display_cycles()
 	if cycles.len > 1 {
 		verror('error: import cycle detected between the following modules: \n' + cycles)

vlib/v/callgraph/callgraph.v

@@ -3,7 +3,7 @@ module callgraph
 import v.ast
 import v.ast.walker
 import v.pref
-import strings
+import v.dotgraph
 
 // callgraph.show walks the AST, starting at main() and prints a DOT output describing the calls
 // that function make transitively
@@ -11,18 +11,14 @@ pub fn show(mut table ast.Table, pref &pref.Preferences, ast_files []&ast.File)
 	mut mapper := &Mapper{
 		pref: pref
 		table: table
+		dg: dotgraph.new('CallGraph', 'CallGraph for $pref.path', 'green')
 	}
-	mapper.sb.writeln('digraph G {')
-	mapper.sb.writeln('\tedge [fontname="Helvetica",fontsize="10",labelfontname="Helvetica",labelfontsize="10",style="solid",color="black"];')
-	mapper.sb.writeln('\tnode [fontname="Helvetica",fontsize="10",style="filled",fontcolor="black",fillcolor="white",color="black",shape="box"];')
-	mapper.sb.writeln('\trankdir="LR";')
 	// Node14 [shape="box",label="PrivateBase",URL="$classPrivateBase.html"];
 	// Node15 -> Node9 [dir=back,color="midnightblue",fontsize=10,style="solid"];
 	for afile in ast_files {
 		walker.walk(mapper, afile)
 	}
-	mapper.sb.writeln('}')
+	mapper.dg.finish()
-	println(mapper.sb.str())
 }
 
 [heap]
@@ -37,7 +33,7 @@ mut:
 	caller_name     string
 	dot_caller_name string
 	is_caller_used  bool
-	sb              strings.Builder = strings.new_builder(1024)
+	dg              dotgraph.DotGraph
 }
 
 fn (mut m Mapper) dot_normalise_node_name(name string) string {
@@ -104,11 +100,10 @@ fn (mut m Mapper) visit(node &ast.Node) ? {
 					m.caller_name = m.fn_name(node.name, node.receiver.typ, node.is_method)
 					m.dot_caller_name = m.dot_fn_name(node.name, node.receiver.typ, node.is_method)
 					if m.is_caller_used {
-						if m.caller_name == 'main.main' {
+						m.dg.new_node(m.caller_name,
-							m.sb.writeln('\t$m.dot_caller_name [label="fn main()",color="blue",height=0.2,width=0.4,fillcolor="#00FF00",tooltip="The main program entry point.",shape=oval];')
+							node_name: m.dot_caller_name
-						} else {
+							should_highlight: m.caller_name == 'main.main'
-							m.sb.writeln('\t$m.dot_caller_name [shape="box",label="$m.caller_name"];')
+						)
-						}
 					}
 				}
 				else {}
@@ -121,11 +116,9 @@ fn (mut m Mapper) visit(node &ast.Node) ? {
 						dot_called_name := m.dot_fn_name(node.name, node.receiver_type,
 							node.is_method)
 						// Node15 -> Node9 [dir=back,color="midnightblue",fontsize=10,style="solid"];
-						if m.caller_name == 'main.main' {
+						m.dg.new_edge(m.dot_caller_name, dot_called_name,
-							m.sb.writeln('\t$m.dot_caller_name -> $dot_called_name [color="blue"];')
+							should_highlight: m.caller_name == 'main.main'
-						} else {
+						)
-							m.sb.writeln('\t$m.dot_caller_name -> $dot_called_name')
-						}
 					}
 				}
 				else {}
@@ -134,13 +127,3 @@ fn (mut m Mapper) visit(node &ast.Node) ? {
 		else {}
 	}
 }
-
-/*
-mut fpath := ''
-	if m.file != 0 {
-		fpath = m.file.path
-	}
-	node_pos := node.position()
-	fpos := '$fpath:$node_pos.line_nr:$node_pos.col:'
-	println('$fpos $node.type_name() | $node')
-*/

vlib/v/depgraph/depgraph.v

@@ -5,6 +5,8 @@
 // this implementation is specifically suited to ordering dependencies
 module depgraph
 
+import v.dotgraph
+
 struct DepGraphNode {
 pub mut:
 	name string
@@ -197,3 +199,20 @@ fn (mut nn NodeNames) is_part_of_cycle(name string, already_seen []string) (bool
 	nn.is_cycle[name] = false
 	return false, new_already_seen
 }
+
+pub fn show(graph &DepGraph, path string) {
+	mut dg := dotgraph.new('ModGraph', 'ModGraph for $path', 'blue')
+	mbuiltin := 'builtin'
+	for node in graph.nodes {
+		is_main := node.name == 'main'
+		dg.new_node(node.name, should_highlight: is_main)
+		mut deps := node.deps.clone()
+		if node.name != mbuiltin && mbuiltin !in deps {
+			deps << mbuiltin
+		}
+		for dep in deps {
+			dg.new_edge(node.name, dep, should_highlight: is_main)
+		}
+	}
+	dg.finish()
+}

vlib/v/dotgraph/dotgraph.c.v

@@ -0,0 +1,8 @@
+module dotgraph
+
+pub fn start_digraph() {
+	println('digraph G {')
+	C.atexit(fn () {
+		println('}')
+	})
+}

vlib/v/dotgraph/dotgraph.v

@@ -0,0 +1,81 @@
+module dotgraph
+
+import strings
+
+[heap]
+struct DotGraph {
+mut:
+	sb strings.Builder
+}
+
+pub fn new(name string, label string, color string) &DotGraph {
+	mut res := &DotGraph{
+		sb: strings.new_builder(1024)
+	}
+	res.writeln('  subgraph cluster_$name {')
+	res.writeln('\tedge [fontname="Helvetica",fontsize="10",labelfontname="Helvetica",labelfontsize="10",style="solid",color="black"];')
+	res.writeln('\tnode [fontname="Helvetica",fontsize="10",style="filled",fontcolor="black",fillcolor="white",color="black",shape="box"];')
+	res.writeln('\trankdir="LR";')
+	res.writeln('\tcolor="$color";')
+	res.writeln('\tlabel="$label";')
+	// Node14 [shape="box",label="PrivateBase",URL="$classPrivateBase.html"];
+	// Node15 -> Node9 [dir=back,color="midnightblue",fontsize=10,style="solid"];
+	return res
+}
+
+pub fn (mut d DotGraph) writeln(line string) {
+	d.sb.writeln(line)
+}
+
+pub fn (mut d DotGraph) finish() {
+	d.sb.writeln('  }')
+	println(d.sb.str())
+}
+
+//
+
+pub struct NewNodeConfig {
+	node_name        string
+	should_highlight bool
+	tooltip          string
+	ctx              voidptr = voidptr(0)
+	name2node_fn     FnLabel2NodeName = node_name
+}
+
+pub fn (mut d DotGraph) new_node(nlabel string, cfg NewNodeConfig) {
+	mut nname := cfg.name2node_fn(nlabel, cfg.ctx)
+	if cfg.node_name != '' {
+		nname = cfg.node_name
+	}
+	if cfg.should_highlight {
+		d.writeln('\t$nname [label="$nlabel",color="blue",height=0.2,width=0.4,fillcolor="#00FF00",tooltip="$cfg.tooltip",shape=oval];')
+	} else {
+		d.writeln('\t$nname [shape="box",label="$nlabel"];')
+	}
+}
+
+//
+
+pub struct NewEdgeConfig {
+	should_highlight bool
+	ctx              voidptr = voidptr(0)
+	name2node_fn     FnLabel2NodeName = node_name
+}
+
+pub fn (mut d DotGraph) new_edge(source string, target string, cfg NewEdgeConfig) {
+	nsource := cfg.name2node_fn(source, cfg.ctx)
+	ntarget := cfg.name2node_fn(target, cfg.ctx)
+	if cfg.should_highlight {
+		d.writeln('\t$nsource -> $ntarget [color="blue"];')
+	} else {
+		d.writeln('\t$nsource -> $ntarget;')
+	}
+}
+
+//
+
+pub type FnLabel2NodeName = fn (string, voidptr) string
+
+pub fn node_name(name string, context voidptr) string {
+	return name.replace('.', '_')
+}

vlib/v/pref/pref.v

@@ -112,21 +112,20 @@ pub mut:
 	obfuscate         bool   // `v -obf program.v`, renames functions to "f_XXX"
 	is_repl           bool
 	is_run            bool
+	is_debug          bool // turned on by -g or -cg, it tells v to pass -g to the C backend compiler.
+	is_vlines         bool // turned on by -g (it slows down .tmp.c generation slightly).
+	// NB: passing -cg instead of -g will set is_vlines to false and is_debug to true, thus making v generate cleaner C files,
+	// which are sometimes easier to debug / inspect manually than the .tmp.c files by plain -g (when/if v line number generation breaks).
 	sanitize               bool   // use Clang's new "-fsanitize" option
-	is_debug               bool // false by default, turned on by -g or -cg, it tells v to pass -g to the C backend compiler.
 	sourcemap              bool   // JS Backend: -sourcemap will create a source map - default false
 	sourcemap_inline       bool = true // JS Backend: -sourcemap-inline will embed the source map in the generated JaaScript file -  currently default true only implemented
 	sourcemap_src_included bool   // JS Backend: -sourcemap-src-included includes V source code in source map -  default false
-	is_vlines              bool // turned on by -g, false by default (it slows down .tmp.c generation slightly).
 	show_cc                bool   // -showcc, print cc command
 	show_c_output          bool   // -show-c-output, print all cc output even if the code was compiled correctly
 	show_callgraph         bool   // -show-callgraph, print the program callgraph, in a Graphviz DOT format to stdout
-	// NB: passing -cg instead of -g will set is_vlines to false and is_debug to true, thus making v generate cleaner C files,
+	show_depgraph          bool   // -show-depgraph, print the program module dependency graph, in a Graphviz DOT format to stdout
-	// which are sometimes easier to debug / inspect manually than the .tmp.c files by plain -g (when/if v line number generation breaks).
+	dump_c_flags           string // `-dump-c-flags file.txt` - let V store all C flags, passed to the backend C compiler in `file.txt`, one C flag/value per line.
-	// use cached modules to speed up compilation.
+	use_cache              bool   // when set, use cached modules to speed up subsequent compilations, at the cost of slower initial ones (while the modules are cached)
-	dump_c_flags string // `-dump-c-flags file.txt` - let V store all C flags, passed to the backend C compiler
-	// in `file.txt`, one C flag/value per line.
-	use_cache         bool // = true
 	retry_compilation      bool = true // retry the compilation with another C compiler, if tcc fails.
 	is_stats               bool   // `v -stats file_test.v` will produce more detailed statistics for the tests that were run
 	// TODO Convert this into a []string
@@ -141,7 +140,7 @@ pub mut:
 	building_v         bool
 	autofree           bool // `v -manualfree` => false, `v -autofree` => true; false by default for now.
 	// Disabling `free()` insertion results in better performance in some applications (e.g. compilers)
-	compress bool
+	compress bool // when set, use `upx` to compress the generated executable
 	// skip_builtin     bool   // Skips re-compilation of the builtin module
 	// to increase compilation time.
 	// This is on by default, since a vast majority of users do not
@@ -444,6 +443,9 @@ pub fn parse_args(known_external_commands []string, args []string) (&Preferences
 			'-show-callgraph' {
 				res.show_callgraph = true
 			}
+			'-show-depgraph' {
+				res.show_depgraph = true
+			}
 			'-dump-c-flags' {
 				res.dump_c_flags = cmdline.option(current_args, arg, '-')
 				i++