From c0db47487cd1bc5cd1fd39068d4c2838138b27d3 Mon Sep 17 00:00:00 2001
From: Ofek <ofekshilon@gmail.com>
Date: Mon, 27 Nov 2023 17:33:03 +0200
Subject: [PATCH] Fix #5784 (#5793)

Fix the name of the entry block in an IR control flow graph.
---
 lib/cfg/cfg-parsers/llvm-ir.ts        | 16 ++++++++++------
 test/cfg-cases/cfg-llvmir.invoke.json |  8 ++++----
 test/cfg-cases/cfg-llvmir.loop.json   |  6 +++---
 3 files changed, 17 insertions(+), 13 deletions(-)

diff --git a/lib/cfg/cfg-parsers/llvm-ir.ts b/lib/cfg/cfg-parsers/llvm-ir.ts
index 9dbb93a29a5..00c630dbf0a 100644
--- a/lib/cfg/cfg-parsers/llvm-ir.ts
+++ b/lib/cfg/cfg-parsers/llvm-ir.ts
@@ -27,6 +27,7 @@ import {BaseInstructionSetInfo} from '../instruction-sets/base.js';
 import {assert, unwrap} from '../../assert.js';
 
 export type BBRange = {
+    namePrefix: string; // used to encode the function name in the first block
     nameId: string;
     start: number;
     end: number;
@@ -79,29 +80,32 @@ export class LlvmIrCfgParser extends BaseCFGParser {
         const result: BBRange[] = [];
         let i = fn.start + 1;
         let bbStart = i;
-        let currentName = fnName;
+        let currentName: string = '';
+        let namePrefix: string = fnName + '\n\n';
         while (i < fn.end) {
             const match = code[i].text.match(this.labelRe);
             if (match) {
+                const label = match[1];
                 if (bbStart === i) {
-                    // for -emit-llvm the first basic block doesn't have a label, for the ir viewer it does though
                     assert(result.length === 0);
-                    bbStart = i + 1;
+                    currentName = label;
                 } else {
-                    const label = match[1];
                     // start is the fn / label define, end is exclusive
                     result.push({
+                        namePrefix: namePrefix,
                         nameId: currentName,
                         start: bbStart,
                         end: i,
                     });
                     currentName = label;
-                    bbStart = i + 1;
+                    namePrefix = '';
                 }
+                bbStart = i + 1;
             }
             i++;
         }
         result.push({
+            namePrefix: '',
             nameId: currentName,
             start: bbStart,
             end: i,
@@ -118,7 +122,7 @@ export class LlvmIrCfgParser extends BaseCFGParser {
             }
             return {
                 id: e.nameId,
-                label: `${e.nameId}${e.nameId.includes(':') ? '' : ':'}\n${this.concatInstructions(
+                label: `${e.namePrefix}${e.nameId}${e.nameId.includes(':') ? '' : ':'}\n${this.concatInstructions(
                     asms,
                     e.start,
                     end,
diff --git a/test/cfg-cases/cfg-llvmir.invoke.json b/test/cfg-cases/cfg-llvmir.invoke.json
index 0ac2fb5e69c..8e115dca0aa 100644
--- a/test/cfg-cases/cfg-llvmir.invoke.json
+++ b/test/cfg-cases/cfg-llvmir.invoke.json
@@ -304,8 +304,8 @@
     "f(int)(i32 noundef %n) personality i8* bitcast (i32 ": {
       "nodes": [
         {
-          "id": "f(int)(i32 noundef %n) personality i8* bitcast (i32 ",
-          "label": "f(int)(i32 noundef %n) personality i8* bitcast (i32 :\n  %retval = alloca i32, align 4\n  %n.addr = alloca i32, align 4\n  %a = alloca i32, align 4\n  %exn.slot = alloca i8*, align 8\n  %ehselector.slot = alloca i32, align 4\n  store i32 %n, i32* %n.addr, align 4\n  %0 = load i32, i32* %n.addr, align 4\n  %call = invoke noundef i32 @g(int)(i32 noundef %0)\n          to label %invoke.cont unwind label %lpad"
+          "id": "entry",
+          "label": "f(int)(i32 noundef %n) personality i8* bitcast (i32 \n\nentry:\n  %retval = alloca i32, align 4\n  %n.addr = alloca i32, align 4\n  %a = alloca i32, align 4\n  %exn.slot = alloca i8*, align 8\n  %ehselector.slot = alloca i32, align 4\n  store i32 %n, i32* %n.addr, align 4\n  %0 = load i32, i32* %n.addr, align 4\n  %call = invoke noundef i32 @g(int)(i32 noundef %0)\n          to label %invoke.cont unwind label %lpad"
         },
         {
           "id": "invoke.cont",
@@ -330,13 +330,13 @@
       ],
       "edges": [
         {
-          "from": "f(int)(i32 noundef %n) personality i8* bitcast (i32 ",
+          "from": "entry",
           "to": "invoke.cont",
           "arrows": "to",
           "color": "green"
         },
         {
-          "from": "f(int)(i32 noundef %n) personality i8* bitcast (i32 ",
+          "from": "entry",
           "to": "lpad",
           "arrows": "to",
           "color": "grey"
diff --git a/test/cfg-cases/cfg-llvmir.loop.json b/test/cfg-cases/cfg-llvmir.loop.json
index 0bb0edfc420..e6ac8e799ef 100644
--- a/test/cfg-cases/cfg-llvmir.loop.json
+++ b/test/cfg-cases/cfg-llvmir.loop.json
@@ -295,8 +295,8 @@
     "foo(int*, int*, int)": {
       "nodes": [
         {
-          "id": "foo(int*, int*, int)",
-          "label": "foo(int*, int*, int):\n  %a.addr = alloca i32*, align 8\n  %b.addr = alloca i32*, align 8\n  %size.addr = alloca i32, align 4\n  %i = alloca i32, align 4\n  store i32* %a, i32** %a.addr, align 8\n  store i32* %b, i32** %b.addr, align 8\n  store i32 %size, i32* %size.addr, align 4\n  store i32 0, i32* %i, align 4\n  br label %for.cond"
+          "id": "entry",
+          "label": "foo(int*, int*, int)\n\nentry:\n  %a.addr = alloca i32*, align 8\n  %b.addr = alloca i32*, align 8\n  %size.addr = alloca i32, align 4\n  %i = alloca i32, align 4\n  store i32* %a, i32** %a.addr, align 8\n  store i32* %b, i32** %b.addr, align 8\n  store i32 %size, i32* %size.addr, align 4\n  store i32 0, i32* %i, align 4\n  br label %for.cond"
         },
         {
           "id": "for.cond",
@@ -317,7 +317,7 @@
       ],
       "edges": [
         {
-          "from": "foo(int*, int*, int)",
+          "from": "entry",
           "to": "for.cond",
           "arrows": "to",
           "color": "blue"