[clang] [clang][analyzer] FixedAddressChecker: no warning if system macro is used (PR #108993)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-clang-static-analyzer-1

@llvm/pr-subscribers-clang

Author: Balázs Kéri (balazske)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/108993.diff


3 Files Affected:

- (modified) clang/lib/StaticAnalyzer/Checkers/FixedAddressChecker.cpp (+3) 
- (modified) clang/test/Analysis/Inputs/system-header-simulator.h (+8) 
- (modified) clang/test/Analysis/ptr-arith.c (+13) 


``````````diff
diff --git a/clang/lib/StaticAnalyzer/Checkers/FixedAddressChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/FixedAddressChecker.cpp
index 7aefcdc6d358aa..e7fde3edc7f9ee 100644
--- a/clang/lib/StaticAnalyzer/Checkers/FixedAddressChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/FixedAddressChecker.cpp
@@ -48,6 +48,9 @@ void FixedAddressChecker::checkPreStmt(const BinaryOperator *B,
   if (!RV.isConstant() || RV.isZeroConstant())
     return;
 
+  if (C.getSourceManager().isInSystemMacro(B->getRHS()->getBeginLoc()))
+    return;
+
   if (ExplodedNode *N = C.generateNonFatalErrorNode()) {
     // FIXME: improve grammar in the following strings:
     constexpr llvm::StringLiteral Msg =
diff --git a/clang/test/Analysis/Inputs/system-header-simulator.h b/clang/test/Analysis/Inputs/system-header-simulator.h
index 8fd51449ecc0a4..fadc09f65d5365 100644
--- a/clang/test/Analysis/Inputs/system-header-simulator.h
+++ b/clang/test/Analysis/Inputs/system-header-simulator.h
@@ -154,3 +154,11 @@ void _Exit(int status) __attribute__ ((__noreturn__));
 #define EOF (-1)
 
 #define offsetof(t, d) __builtin_offsetof(t, d)
+
+struct sigaction {
+  void (*sa_handler)(int);
+};
+#define SIGINT 2
+#define	SIG_IGN (void (*)(int))1
+
+int sigaction(int, const struct sigaction *restrict, struct sigaction *restrict);
diff --git a/clang/test/Analysis/ptr-arith.c b/clang/test/Analysis/ptr-arith.c
index f99dfabb073666..020a5006292306 100644
--- a/clang/test/Analysis/ptr-arith.c
+++ b/clang/test/Analysis/ptr-arith.c
@@ -1,6 +1,8 @@
 // RUN: %clang_analyze_cc1 -analyzer-checker=alpha.core.FixedAddr,alpha.core.PointerArithm,debug.ExprInspection -Wno-pointer-to-int-cast -verify -triple x86_64-apple-darwin9 -Wno-tautological-pointer-compare -analyzer-config eagerly-assume=false %s
 // RUN: %clang_analyze_cc1 -analyzer-checker=alpha.core.FixedAddr,alpha.core.PointerArithm,debug.ExprInspection -Wno-pointer-to-int-cast -verify -triple i686-apple-darwin9 -Wno-tautological-pointer-compare -analyzer-config eagerly-assume=false %s
 
+#include "Inputs/system-header-simulator.h"
+
 void clang_analyzer_eval(int);
 void clang_analyzer_dump(int);
 
@@ -35,9 +37,20 @@ domain_port (const char *domain_b, const char *domain_e,
   return port;
 }
 
+#define FIXED_VALUE (int*) 0x1111
+
 void f4(void) {
   int *p;
   p = (int*) 0x10000; // expected-warning{{Using a fixed address is not portable because that address will probably not be valid in all environments or platforms}}
+  long x = 0x10100;
+  x += 10;
+  p = (int*) x; // expected-warning{{Using a fixed address is not portable because that address will probably not be valid in all environments or platforms}}
+
+  struct sigaction sa;
+  sa.sa_handler = SIG_IGN; // no warning (exclude macros defined in system header)
+  sigaction(SIGINT, &sa, NULL);
+
+  p = FIXED_VALUE; // expected-warning{{Using a fixed address is not portable because that address will probably not be valid in all environments or platforms}}
 }
 
 void f5(void) {

``````````

</details>


https://github.com/llvm/llvm-project/pull/108993