From a735d6eae2847b039d12c75d4c794862dad59bc1 Mon Sep 17 00:00:00 2001
From: Simon Pilgrim <llvm-dev@redking.me.uk>
Date: Sun, 20 Sep 2020 13:55:04 +0100
Subject: [PATCH] JSONCompilationDatabase.cpp - cleanup key parsing error
 checks. NFCI.

Merge the key + sequence/value checks with the key handling code.

Reduces the number of key string comparisons and avoids a number of clang static analyzer null dereference warnings.
---
 clang/lib/Tooling/JSONCompilationDatabase.cpp | 43 ++++++++++++++-------------
 1 file changed, 23 insertions(+), 20 deletions(-)

diff --git a/clang/lib/Tooling/JSONCompilationDatabase.cpp b/clang/lib/Tooling/JSONCompilationDatabase.cpp
index 4af361f..67a42d3 100644
--- a/clang/lib/Tooling/JSONCompilationDatabase.cpp
+++ b/clang/lib/Tooling/JSONCompilationDatabase.cpp
@@ -369,16 +369,11 @@ bool JSONCompilationDatabase::parse(std::string &ErrorMessage) {
       }
       auto *ValueString = dyn_cast<llvm::yaml::ScalarNode>(Value);
       auto *SequenceString = dyn_cast<llvm::yaml::SequenceNode>(Value);
-      if (KeyValue == "arguments" && !SequenceString) {
-        ErrorMessage = "Expected sequence as value.";
-        return false;
-      } else if (KeyValue != "arguments" && !ValueString) {
-        ErrorMessage = "Expected string as value.";
-        return false;
-      }
-      if (KeyValue == "directory") {
-        Directory = ValueString;
-      } else if (KeyValue == "arguments") {
+      if (KeyValue == "arguments") {
+        if (!SequenceString) {
+          ErrorMessage = "Expected sequence as value.";
+          return false;
+        }
         Command = std::vector<llvm::yaml::ScalarNode *>();
         for (auto &Argument : *SequenceString) {
           auto *Scalar = dyn_cast<llvm::yaml::ScalarNode>(&Argument);
@@ -388,17 +383,25 @@ bool JSONCompilationDatabase::parse(std::string &ErrorMessage) {
           }
           Command->push_back(Scalar);
         }
-      } else if (KeyValue == "command") {
-        if (!Command)
-          Command = std::vector<llvm::yaml::ScalarNode *>(1, ValueString);
-      } else if (KeyValue == "file") {
-        File = ValueString;
-      } else if (KeyValue == "output") {
-        Output = ValueString;
       } else {
-        ErrorMessage = ("Unknown key: \"" +
-                        KeyString->getRawValue() + "\"").str();
-        return false;
+        if (!ValueString) {
+          ErrorMessage = "Expected string as value.";
+          return false;
+        }
+        if (KeyValue == "directory") {
+          Directory = ValueString;
+        } else if (KeyValue == "command") {
+          if (!Command)
+            Command = std::vector<llvm::yaml::ScalarNode *>(1, ValueString);
+        } else if (KeyValue == "file") {
+          File = ValueString;
+        } else if (KeyValue == "output") {
+          Output = ValueString;
+        } else {
+          ErrorMessage =
+              ("Unknown key: \"" + KeyString->getRawValue() + "\"").str();
+          return false;
+        }
       }
     }
     if (!File) {
-- 
2.7.4