[llvm] [clang] [Sema] Implement support for -Wformat-signedness (PR #74440)

[via cfe-commits]

github-actions[bot] wrote:

<!--LLVM CODE FORMAT COMMENT: {clang-format}-->


:warning: C/C++ code formatter, clang-format found issues in your code. :warning:

<details>
<summary>
You can test this locally with the following command:
</summary>

``````````bash
git-clang-format --diff 383e35048e16c85ab26bc46822d3ceb11fd4d3f2 a80bf9d03f19d48c0aca4af7758dc49516da8825 -- format-strings-signedness.c clang/include/clang/AST/FormatString.h clang/lib/AST/FormatString.cpp clang/lib/Driver/ToolChains/Clang.cpp clang/lib/Sema/SemaChecking.cpp
``````````

</details>

<details>
<summary>
View the diff from clang-format here.
</summary>

``````````diff
diff --git a/format-strings-signedness.c b/format-strings-signedness.c
index 02964def10..876094ea4f 100644
--- a/format-strings-signedness.c
+++ b/format-strings-signedness.c
@@ -1,65 +1,68 @@
-// RUN: %clang_cc1 -std=c11 -fsyntax-only -verify -Wformat -Wformat-signedness %s
+// RUN: %clang_cc1 -std=c11 -fsyntax-only -verify -Wformat -Wformat-signedness
+// %s
 
 int printf(const char *restrict format, ...);
-int scanf(const char * restrict, ...);
+int scanf(const char *restrict, ...);
 
-void test_printf_bool(_Bool x)
-{
-    printf("%d", x); // no-warning
-    printf("%u", x); // expected-warning{{format specifies type 'unsigned int' but the argument has type '_Bool'}}
-    printf("%x", x); // expected-warning{{format specifies type 'unsigned int' but the argument has type '_Bool'}}
+void test_printf_bool(_Bool x) {
+  printf("%d", x); // no-warning
+  printf("%u", x); // expected-warning{{format specifies type 'unsigned int' but
+                   // the argument has type '_Bool'}}
+  printf("%x", x); // expected-warning{{format specifies type 'unsigned int' but
+                   // the argument has type '_Bool'}}
 }
 
-void test_printf_char(char x)
-{
-    printf("%c", x); // no-warning
+void test_printf_char(char x) {
+  printf("%c", x); // no-warning
 }
 
-void test_printf_unsigned_char(unsigned char x)
-{
-    printf("%c", x); // no-warning
+void test_printf_unsigned_char(unsigned char x) {
+  printf("%c", x); // no-warning
 }
 
-void test_printf_int(int x)
-{
-    printf("%d", x); // no-warning
-    printf("%u", x); // expected-warning{{format specifies type 'unsigned int' but the argument has type 'int'}}
-    printf("%x", x); // expected-warning{{format specifies type 'unsigned int' but the argument has type 'int'}}
+void test_printf_int(int x) {
+  printf("%d", x); // no-warning
+  printf("%u", x); // expected-warning{{format specifies type 'unsigned int' but
+                   // the argument has type 'int'}}
+  printf("%x", x); // expected-warning{{format specifies type 'unsigned int' but
+                   // the argument has type 'int'}}
 }
 
-void test_printf_unsigned(unsigned x)
-{
-    printf("%d", x); // expected-warning{{format specifies type 'int' but the argument has type 'unsigned int'}}
-    printf("%u", x); // no-warning
-    printf("%x", x); // no-warning
+void test_printf_unsigned(unsigned x) {
+  printf("%d", x); // expected-warning{{format specifies type 'int' but the
+                   // argument has type 'unsigned int'}}
+  printf("%u", x); // no-warning
+  printf("%x", x); // no-warning
 }
 
-void test_printf_long(long x)
-{
-    printf("%ld", x); // no-warning
-    printf("%lu", x); // expected-warning{{format specifies type 'unsigned long' but the argument has type 'long'}}
-    printf("%lx", x); // expected-warning{{format specifies type 'unsigned long' but the argument has type 'long'}}
+void test_printf_long(long x) {
+  printf("%ld", x); // no-warning
+  printf("%lu", x); // expected-warning{{format specifies type 'unsigned long'
+                    // but the argument has type 'long'}}
+  printf("%lx", x); // expected-warning{{format specifies type 'unsigned long'
+                    // but the argument has type 'long'}}
 }
 
-void test_printf_unsigned_long(unsigned long x)
-{
-    printf("%ld", x); // expected-warning{{format specifies type 'long' but the argument has type 'unsigned long'}}
-    printf("%lu", x); // no-warning
-    printf("%lx", x); // no-warning
+void test_printf_unsigned_long(unsigned long x) {
+  printf("%ld", x); // expected-warning{{format specifies type 'long' but the
+                    // argument has type 'unsigned long'}}
+  printf("%lu", x); // no-warning
+  printf("%lx", x); // no-warning
 }
 
-void test_printf_long_long(long long x)
-{
-    printf("%lld", x); // no-warning
-    printf("%llu", x); // expected-warning{{format specifies type 'unsigned long long' but the argument has type 'long long'}}
-    printf("%llx", x); // expected-warning{{format specifies type 'unsigned long long' but the argument has type 'long long'}}
+void test_printf_long_long(long long x) {
+  printf("%lld", x); // no-warning
+  printf("%llu", x); // expected-warning{{format specifies type 'unsigned long
+                     // long' but the argument has type 'long long'}}
+  printf("%llx", x); // expected-warning{{format specifies type 'unsigned long
+                     // long' but the argument has type 'long long'}}
 }
 
-void test_printf_unsigned_long_long(unsigned long long x)
-{
-    printf("%lld", x); // expected-warning{{format specifies type 'long long' but the argument has type 'unsigned long long'}}
-    printf("%llu", x); // no-warning
-    printf("%llx", x); // no-warning
+void test_printf_unsigned_long_long(unsigned long long x) {
+  printf("%lld", x); // expected-warning{{format specifies type 'long long' but
+                     // the argument has type 'unsigned long long'}}
+  printf("%llu", x); // no-warning
+  printf("%llx", x); // no-warning
 }
 
 void test_scanf_char(char *y) {
@@ -72,36 +75,45 @@ void test_scanf_unsigned_char(unsigned char *y) {
 
 void test_scanf_int(int *x) {
   scanf("%d", x); // no-warning
-  scanf("%u", x); // expected-warning{{format specifies type 'unsigned int *' but the argument has type 'int *'}}
-  scanf("%x", x); // expected-warning{{format specifies type 'unsigned int *' but the argument has type 'int *'}}
+  scanf("%u", x); // expected-warning{{format specifies type 'unsigned int *'
+                  // but the argument has type 'int *'}}
+  scanf("%x", x); // expected-warning{{format specifies type 'unsigned int *'
+                  // but the argument has type 'int *'}}
 }
 
 void test_scanf_unsigned(unsigned *x) {
-  scanf("%d", x); // expected-warning{{format specifies type 'int *' but the argument has type 'unsigned int *'}}
+  scanf("%d", x); // expected-warning{{format specifies type 'int *' but the
+                  // argument has type 'unsigned int *'}}
   scanf("%u", x); // no-warning
   scanf("%x", x); // no-warning
 }
 
 void test_scanf_long(long *x) {
   scanf("%ld", x); // no-warning
-  scanf("%lu", x); // expected-warning{{format specifies type 'unsigned long *' but the argument has type 'long *'}}
-  scanf("%lx", x); // expected-warning{{format specifies type 'unsigned long *' but the argument has type 'long *'}}
+  scanf("%lu", x); // expected-warning{{format specifies type 'unsigned long *'
+                   // but the argument has type 'long *'}}
+  scanf("%lx", x); // expected-warning{{format specifies type 'unsigned long *'
+                   // but the argument has type 'long *'}}
 }
 
 void test_scanf_unsigned_long(unsigned long *x) {
-  scanf("%ld", x); // expected-warning{{format specifies type 'long *' but the argument has type 'unsigned long *'}}
+  scanf("%ld", x); // expected-warning{{format specifies type 'long *' but the
+                   // argument has type 'unsigned long *'}}
   scanf("%lu", x); // no-warning
   scanf("%lx", x); // no-warning
 }
 
 void test_scanf_longlong(long long *x) {
   scanf("%lld", x); // no-warning
-  scanf("%llu", x); // expected-warning{{format specifies type 'unsigned long long *' but the argument has type 'long long *'}}
-  scanf("%llx", x); // expected-warning{{format specifies type 'unsigned long long *' but the argument has type 'long long *'}}
+  scanf("%llu", x); // expected-warning{{format specifies type 'unsigned long
+                    // long *' but the argument has type 'long long *'}}
+  scanf("%llx", x); // expected-warning{{format specifies type 'unsigned long
+                    // long *' but the argument has type 'long long *'}}
 }
 
 void test_scanf_unsigned_longlong(unsigned long long *x) {
-  scanf("%lld", x); // expected-warning{{format specifies type 'long long *' but the argument has type 'unsigned long long *'}}
+  scanf("%lld", x); // expected-warning{{format specifies type 'long long *' but
+                    // the argument has type 'unsigned long long *'}}
   scanf("%llu", x); // no-warning
   scanf("%llx", x); // no-warning
 }

``````````

</details>


https://github.com/llvm/llvm-project/pull/74440