From b6d089b6053e44115b286329f1f63477d5c27815 Mon Sep 17 00:00:00 2001
From: Delyan Angelov <delian66@gmail.com>
Date: Sun, 14 Mar 2021 16:12:18 +0200
Subject: [PATCH] v.depgraph: ensure `v -d debug_realloc -o v cmd/v` works

---
 .github/workflows/ci.yml   |  4 ++--
 vlib/builtin/builtin.c.v   |  8 +++++---
 vlib/v/depgraph/depgraph.v | 19 ++++++++++++-------
 3 files changed, 19 insertions(+), 12 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 1318b9e8d1..edfab0f0a8 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -87,8 +87,8 @@ jobs:
       - name: Build v
         run: |
           echo $VFLAGS
-          sudo ln -s $PWD/thirdparty/tcc/tcc.exe /usr/local/bin/tcc ## TODO: remove
-          make -j4
+          make
+          ./v -d debug_realloc -o v cmd/v
           ./v -cg -cflags -Werror -o v cmd/v
       - name: Test v->c
         run: |
diff --git a/vlib/builtin/builtin.c.v b/vlib/builtin/builtin.c.v
index 4f205740c1..30fb869f7d 100644
--- a/vlib/builtin/builtin.c.v
+++ b/vlib/builtin/builtin.c.v
@@ -230,7 +230,8 @@ pub fn realloc_data(old_data byteptr, old_size int, new_size int) byteptr {
 	$if prealloc {
 		unsafe {
 			new_ptr := malloc(new_size)
-			C.memcpy(new_ptr, old_data, old_size)
+			min_size := if old_size < new_size { old_size } else { new_size }
+			C.memcpy(new_ptr, old_data, min_size)
 			return new_ptr
 		}
 	}
@@ -245,7 +246,8 @@ pub fn realloc_data(old_data byteptr, old_size int, new_size int) byteptr {
 		//    it will point to memory that is now filled with 0x57.
 		unsafe {
 			new_ptr := malloc(new_size)
-			C.memcpy(new_ptr, old_data, old_size)
+			min_size := if old_size < new_size { old_size } else { new_size }
+			C.memcpy(new_ptr, old_data, min_size)
 			C.memset(old_data, 0x57, old_size)
 			C.free(old_data)
 			return new_ptr
@@ -253,7 +255,7 @@ pub fn realloc_data(old_data byteptr, old_size int, new_size int) byteptr {
 	}
 	nptr := unsafe { C.realloc(old_data, new_size) }
 	if nptr == 0 {
-		panic('realloc_data($new_size) failed')
+		panic('realloc_data($old_data, $old_size, $new_size) failed')
 	}
 	return nptr
 }
diff --git a/vlib/v/depgraph/depgraph.v b/vlib/v/depgraph/depgraph.v
index e927bd836b..d7bdb4a46c 100644
--- a/vlib/v/depgraph/depgraph.v
+++ b/vlib/v/depgraph/depgraph.v
@@ -31,7 +31,7 @@ pub fn (mut o OrderedDepMap) set(name string, deps []string) {
 }
 
 pub fn (mut o OrderedDepMap) add(name string, deps []string) {
-	mut d := o.data[name]
+	mut d := o.get(name)
 	for dep in deps {
 		if dep !in d {
 			d << dep
@@ -42,7 +42,8 @@ pub fn (mut o OrderedDepMap) add(name string, deps []string) {
 }
 
 pub fn (o &OrderedDepMap) get(name string) []string {
-	return o.data[name]
+	res := o.data[name] or { []string{} }
+	return res
 }
 
 pub fn (mut o OrderedDepMap) delete(name string) {
@@ -60,7 +61,8 @@ pub fn (mut o OrderedDepMap) delete(name string) {
 
 pub fn (mut o OrderedDepMap) apply_diff(name string, deps []string) {
 	mut diff := []string{}
-	for dep in o.data[name] {
+	deps_of_name := o.get(name)
+	for dep in deps_of_name {
 		if dep !in deps {
 			diff << dep
 		}
@@ -75,14 +77,16 @@ pub fn (o &OrderedDepMap) size() int {
 pub fn new_dep_graph() &DepGraph {
 	return &DepGraph{
 		acyclic: true
+		nodes: []DepGraphNode{cap: 1024}
 	}
 }
 
 pub fn (mut graph DepGraph) add(mod string, deps []string) {
-	graph.nodes << DepGraphNode{
+	new_node := DepGraphNode{
 		name: mod
 		deps: deps.clone()
 	}
+	graph.nodes << new_node
 }
 
 pub fn (graph &DepGraph) resolve() &DepGraph {
@@ -96,7 +100,7 @@ pub fn (graph &DepGraph) resolve() &DepGraph {
 	for node_deps.size() != 0 {
 		mut ready_set := []string{}
 		for name in node_deps.keys {
-			deps := node_deps.data[name]
+			deps := node_deps.get(name)
 			if deps.len == 0 {
 				ready_set << name
 			}
@@ -105,13 +109,14 @@ pub fn (graph &DepGraph) resolve() &DepGraph {
 			mut g := new_dep_graph()
 			g.acyclic = false
 			for name in node_deps.keys {
-				g.add(name, node_names.data[name])
+				g.add(name, node_names.get(name))
 			}
 			return g
 		}
 		for name in ready_set {
 			node_deps.delete(name)
-			resolved.add(name, node_names.data[name])
+			resolved_deps := node_names.get(name)
+			resolved.add(name, resolved_deps)
 		}
 		for name in node_deps.keys {
 			node_deps.apply_diff(name, ready_set)