From 4eed29502cdb962ac715f4a6740197abc5fadf0f Mon Sep 17 00:00:00 2001
From: Paul Fultz II <pfultz2@yahoo.com>
Date: Fri, 22 Apr 2022 23:18:55 -0500
Subject: [PATCH] ValueFlow: Set values to parameters to longjmp and setjmp
 (#4040)

* ValueFlow: Set values to parameters to longjmp and setjmp

* Format
---
 lib/forwardanalyzer.cpp | 8 ++++++--
 test/testvalueflow.cpp  | 6 ++++++
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/lib/forwardanalyzer.cpp b/lib/forwardanalyzer.cpp
index 5c726daa4..07460af58 100644
--- a/lib/forwardanalyzer.cpp
+++ b/lib/forwardanalyzer.cpp
@@ -123,9 +123,13 @@ struct ForwardTraversal {
 
     template<class T, class F, REQUIRES("T must be a Token class", std::is_convertible<T*, const Token*> )>
     Progress traverseTok(T* tok, F f, bool traverseUnknown, T** out = nullptr) {
-        if (Token::Match(tok, "asm|goto|setjmp|longjmp"))
+        if (Token::Match(tok, "asm|goto"))
             return Break(Analyzer::Terminate::Bail);
-        else if (Token::simpleMatch(tok, "continue")) {
+        else if (Token::Match(tok, "setjmp|longjmp (")) {
+            // Traverse the parameters of the function before escaping
+            traverseRecursive(tok->next()->astOperand2(), f, traverseUnknown);
+            return Break(Analyzer::Terminate::Bail);
+        } else if (Token::simpleMatch(tok, "continue")) {
             if (loopEnds.empty())
                 return Break(Analyzer::Terminate::Escape);
             // If we are in a loop then jump to the end
diff --git a/test/testvalueflow.cpp b/test/testvalueflow.cpp
index b6b3f4bed..404c00a5a 100644
--- a/test/testvalueflow.cpp
+++ b/test/testvalueflow.cpp
@@ -3486,6 +3486,12 @@ private:
                "    exit(x);\n"
                "}\n";
         ASSERT_EQUALS(true, testValueOfXKnown(code, 3U, 1));
+
+        code = "void f(jmp_buf env) {\n"
+               "    int x = 1;\n"
+               "    longjmp(env, x);\n"
+               "}\n";
+        ASSERT_EQUALS(true, testValueOfXKnown(code, 3U, 1));
     }
 
     void valueFlowForwardTernary() {