Patch about Bug 119222 - Conversion of inf to integer is not diagnosed [Classifier] a single patch [Tags] conversion warning ;c++; inf to integer [Brief Summary ]Add a judgement in the RDIV_EXPR case

[Gwen Fu]

Patch about Bug 119222 - Conversion of inf to integer is not diagnosed
[Classifier] a single patch
[Tags] conversion warning ;c++; inf to integer
[Brief Summary] Add a judgement in the RDIV_EXPR case
[Remark]
      This patch does not support -Wall -Wextra to capture inf to integer
warnings .
 The -Wall -Wextra options do not check this conversion (and do not allow
the conversion_warning function to be executed completely), instead you
need to add           -Wfloat-conversion or -Wconversion》
[Pontential problem]
     Is there a case where the conversion result type is not limited to
INTEGER_TYPE?

From 6924ad5d1a3a96ed46b728a47462a7a054613326 Mon Sep 17 00:00:00 2001
From: Gwen Fu <gwen3293940...@gmail.com>
Date: Tue, 18 Mar 2025 11:37:28 +0800
Subject: [PATCH] fix bug119222 Conversion of inf to integer is not diagnosed

---
 gcc/c-family/c-common.cc |  5 +++--
 gcc/c-family/c-warn.cc   | 11 +++++++++++
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/gcc/c-family/c-common.cc b/gcc/c-family/c-common.cc
index 587d76461e9..dfd5c3d673c 100644
--- a/gcc/c-family/c-common.cc
+++ b/gcc/c-family/c-common.cc
@@ -1652,11 +1652,12 @@ unsafe_conversion_p (tree type, tree expr, tree result, bool check_sign)
   else
     {
       /* Warn for real types converted to integer types.  */
-      if (SCALAR_FLOAT_TYPE_P (expr_type)
+      if ((SCALAR_FLOAT_TYPE_P (expr_type)
+        ||TREE_CODE(expr_type) ==REAL_TYPE)
 	  && (TREE_CODE (type) == INTEGER_TYPE
 	      || TREE_CODE (type) == BITINT_TYPE))
 	give_warning = UNSAFE_REAL;
-
+      
       else if ((TREE_CODE (expr_type) == INTEGER_TYPE
 		|| TREE_CODE (expr_type) == BITINT_TYPE)
 	       && (TREE_CODE (type) == INTEGER_TYPE
diff --git a/gcc/c-family/c-warn.cc b/gcc/c-family/c-warn.cc
index d547b08f55d..406b591bfa0 100644
--- a/gcc/c-family/c-warn.cc
+++ b/gcc/c-family/c-warn.cc
@@ -1283,6 +1283,17 @@ conversion_warning (location_t loc, tree type, tree expr, tree result)
     case CEIL_DIV_EXPR:
     case EXACT_DIV_EXPR:
     case RDIV_EXPR:
+      /*Issue a warning about infinity conversion to int*/
+      if( TREE_CODE(type) == INTEGER_TYPE
+        && TREE_CODE (TREE_OPERAND(expr,1)) == REAL_CST && real_zerop (TREE_OPERAND(expr,1)))
+        {
+        bool ret = warning_at(loc , OPT_Wfloat_conversion ,
+              "conversion from %qT to %qT changes infinity to maximum or minimum integer value",
+              expr_type , type) ;      
+        if(!ret) warning_at(loc , OPT_Wconversion ,
+              "conversion from %qT to %qT changes infinity to maximum or minimum integer value",
+              expr_type , type) ;   
+        }
       arith_ops = 2;
       goto default_;
 
-- 
2.45.2


int fooo()
{
    return 1/static_cast<double>(0) ; 
}

int main()
{
    int a = 1/static_cast<double>(0) ; 
    int b = static_cast<float>(1) / 0 ;

    
    return 0 ;  
}