[Fixed Point Arithmetic] Fix for bug where integer literals could be treated as fixed point literals

[leonardchan]

Summary

This addresses a bug brought up in https://bugs.llvm.org/show_bug.cgi?id=38161 where integer literals could be treated as fixed point types and throw errors related to fixed point types when the 'k' or 'r' suffix used. The fix also addresses the second issue brought up with the assertion by not treating integers as fixed point types in the first place.

Integers that have suffixes 'k' and 'r' now throw the error invalid suffix 'k/r' on integer constant.

A few more tests were also added to ensure that fixed point types, and any errors/warnings related to them, are limited to C for now.

Prior discussion also at https://reviews.llvm.org/D46915.

lib/Lex/LiteralSupport.cpp

if (s == ThisTokEnd) {
         return;
     }
   }
 
   SuffixBegin = s;
   checkSeparator(TokLoc, s, CSK_AfterDigits);
 
   // Initial scan to lookahead for fixed point suffix.
+  if (PP.getLangOpts().FixedPoint) {
     for (const char *c = s; c != ThisTokEnd; ++c) {
       if (*c == 'r' || *c == 'k' || *c == 'R' || *c == 'K') {
         saw_fixed_point_suffix = true;
         break;
       }
     }
+  }
 
   // Parse the suffix.  At this point we can classify whether we have an FP or
   // integer constant.
   bool isFPConstant = isFloatingLiteral();
 
   // Loop over all of the characters of the suffix.  If we see something bad,
   // we break out of the loop.
   for (; s != ThisTokEnd; ++s) {
     switch (*s) {
     case 'R':
     case 'r':
+      if (!PP.getLangOpts().FixedPoint) break;
       if (isFract || isAccum) break;
+      if (!(saw_period || saw_exponent)) break;
       isFract = true;
       continue;
     case 'K':
     case 'k':
+      if (!PP.getLangOpts().FixedPoint) break;
       if (isFract || isAccum) break;
+      if (!(saw_period || saw_exponent)) break;
       isAccum = true;
       continue;
     case 'h':      // FP Suffix for "half".
     case 'H':
       // OpenCL Extension v1.2 s9.5 - h or H suffix for half type.
       if (!(PP.getLangOpts().Half || PP.getLangOpts().FixedPoint)) break;
       if (isIntegerLiteral()) break;  // Error for integer constant.
       if (isHalf || isFloat || isLong) break; // HH, FH, LH invalid.
if (s != ThisTokEnd) {
               diag::err_invalid_suffix_constant)
           << StringRef(SuffixBegin, ThisTokEnd - SuffixBegin) << isFPConstant;
       hadError = true;
     }
   }
 
   if (!hadError && saw_fixed_point_suffix) {
     assert(isFract || isAccum);
-    //assert(radix == 16 || radix == 10);
   }
 }
 
 /// ParseDecimalOrOctalCommon - This method is called for decimal or octal
 /// numbers. It issues an error for illegal digits, and handles floating point
 /// parsing. If it detects a floating point number, the radix is set to 10.
 void NumericLiteralParser::ParseDecimalOrOctalCommon(SourceLocation TokLoc){
   assert((radix == 8 || radix == 10) && "Unexpected radix");

test/Frontend/fixed_point_errors.c

 _Accum rk = 1.0rr;    // expected-error{{invalid suffix 'rr' on integer constant}}
 _Accum qk = 1.0qr;    // expected-error{{invalid suffix 'qr' on integer constant}}
 
 /* Using wrong exponent notation */
 _Accum dec_with_hex_exp1 = 0.1p10k;    // expected-error{{invalid suffix 'p10k' on integer constant}}
 _Accum dec_with_hex_exp2 = 0.1P10k;    // expected-error{{invalid suffix 'P10k' on integer constant}}
 _Accum hex_with_dex_exp1 = 0x0.1e10k;  // expected-error{{hexadecimal floating constant requires an exponent}}
 _Accum hex_with_dex_exp2 = 0x0.1E10k;  // expected-error{{hexadecimal floating constant requires an exponent}}
+
+void CheckSuffixOnIntegerLiterals() {
+  _Accum short_acc_int;
+  _Accum acc_int;
+  _Accum long_acc_int;
+
+  _Accum u_short_acc_int;
+  _Accum u_acc_int;
+  _Accum u_long_acc_int;
+
+  _Fract short_fract_int;
+  _Fract fract_int;
+  _Fract long_fract_int;
+
+  _Fract u_short_fract_int;
+  _Fract u_fract_int;
+  _Fract u_long_fract_int;
+
+  // Decimal integer literals (non-zero)
+  short_acc_int = 10hk; // expected-error{{invalid suffix 'hk' on integer constant}}
+  acc_int = 10k;        // expected-error{{invalid suffix 'k' on integer constant}}
+  long_acc_int = 10lk;  // expected-error{{invalid suffix 'lk' on integer constant}}
+
+  u_short_acc_int = 10uhk; // expected-error{{invalid suffix 'uhk' on integer constant}}
+  u_acc_int = 10uk;        // expected-error{{invalid suffix 'uk' on integer constant}}
+  u_long_acc_int = 10ulk;  // expected-error{{invalid suffix 'ulk' on integer constant}}
+
+  short_fract_int = 10hr; // expected-error{{invalid suffix 'hr' on integer constant}}
+  fract_int = 10r;        // expected-error{{invalid suffix 'r' on integer constant}}
+  long_fract_int = 10lr;  // expected-error{{invalid suffix 'lr' on integer constant}}
+
+  u_short_fract_int = 10uhr; // expected-error{{invalid suffix 'uhr' on integer constant}}
+  u_fract_int = 10ur;        // expected-error{{invalid suffix 'ur' on integer constant}}
+  u_long_fract_int = 10ulr;  // expected-error{{invalid suffix 'ulr' on integer constant}}
+
+  // Decimal integer literals (0)
+  short_acc_int = 0hk; // expected-error{{invalid suffix 'hk' on integer constant}}
+  acc_int = 0k;        // expected-error{{invalid suffix 'k' on integer constant}}
+  long_acc_int = 0lk;  // expected-error{{invalid suffix 'lk' on integer constant}}
+
+  // Decimal integer literals (large number)
+  acc_int = 999999999999999999k;   // expected-error{{invalid suffix 'k' on integer constant}}
+  fract_int = 999999999999999999r; // expected-error{{invalid suffix 'r' on integer constant}}
+
+  // Octal integer literals
+  short_acc_int = 010hk; // expected-error{{invalid suffix 'hk' on integer constant}}
+  acc_int = 010k;        // expected-error{{invalid suffix 'k' on integer constant}}
+  long_acc_int = 010lk;  // expected-error{{invalid suffix 'lk' on integer constant}}
+
+  u_short_acc_int = 010uhk; // expected-error{{invalid suffix 'uhk' on integer constant}}
+  u_acc_int = 010uk;        // expected-error{{invalid suffix 'uk' on integer constant}}
+  u_long_acc_int = 010ulk;  // expected-error{{invalid suffix 'ulk' on integer constant}}
+
+  short_fract_int = 010hr; // expected-error{{invalid suffix 'hr' on integer constant}}
+  fract_int = 010r;        // expected-error{{invalid suffix 'r' on integer constant}}
+  long_fract_int = 010lr;  // expected-error{{invalid suffix 'lr' on integer constant}}
+
+  u_short_fract_int = 010uhr; // expected-error{{invalid suffix 'uhr' on integer constant}}
+  u_fract_int = 010ur;        // expected-error{{invalid suffix 'ur' on integer constant}}
+  u_long_fract_int = 010ulr;  // expected-error{{invalid suffix 'ulr' on integer constant}}
+
+  // Hexadecimal integer literals
+  short_acc_int = 0x10hk; // expected-error{{invalid suffix 'hk' on integer constant}}
+  acc_int = 0x10k;        // expected-error{{invalid suffix 'k' on integer constant}}
+  long_acc_int = 0x10lk;  // expected-error{{invalid suffix 'lk' on integer constant}}
+
+  u_short_acc_int = 0x10uhk; // expected-error{{invalid suffix 'uhk' on integer constant}}
+  u_acc_int = 0x10uk;        // expected-error{{invalid suffix 'uk' on integer constant}}
+  u_long_acc_int = 0x10ulk;  // expected-error{{invalid suffix 'ulk' on integer constant}}
+
+  short_fract_int = 0x10hr; // expected-error{{invalid suffix 'hr' on integer constant}}
+  fract_int = 0x10r;        // expected-error{{invalid suffix 'r' on integer constant}}
+  long_fract_int = 0x10lr;  // expected-error{{invalid suffix 'lr' on integer constant}}
+
+  u_short_fract_int = 0x10uhr; // expected-error{{invalid suffix 'uhr' on integer constant}}
+  u_fract_int = 0x10ur;        // expected-error{{invalid suffix 'ur' on integer constant}}
+  u_long_fract_int = 0x10ulr;  // expected-error{{invalid suffix 'ulr' on integer constant}}
+
+  // Using auto
+  auto auto_fract = 0r;  // expected-error{{invalid suffix 'r' on integer constant}}
+                         // expected-warning@-1{{type specifier missing, defaults to 'int'}}
+  auto auto_accum = 0k;  // expected-error{{invalid suffix 'k' on integer constant}}
+                         // expected-warning@-1{{type specifier missing, defaults to 'int'}}
+}

test/Frontend/fixed_point_errors.cpp

 // RUN: %clang_cc1 -x c++ %s -verify
 // RUN: %clang_cc1 -x c++ -ffixed-point %s -verify
 
 // Name namgling is not provided for fixed point types in c++
 
 _Accum accum;                           // expected-error{{unknown type name '_Accum'}}
 _Fract fract;                           // expected-error{{unknown type name '_Fract'}}
 _Sat _Accum sat_accum;                  // expected-error{{unknown type name '_Sat'}}
                                         // expected-error@-1{{expected ';' after top level declarator}}
+
+int accum_int = 10k;     // expected-error{{invalid suffix 'k' on integer constant}}
+int fract_int = 10r;     // expected-error{{invalid suffix 'r' on integer constant}}
+float accum_flt = 10.0k; // expected-error{{invalid suffix 'k' on floating constant}}
+float fract_flt = 10.0r; // expected-error{{invalid suffix 'r' on floating constant}}

test/Frontend/fixed_point_not_enabled.c

 // RUN: %clang_cc1 -x c -verify %s
 
 // Primary fixed point types
 signed short _Accum s_short_accum;    // expected-error{{compile with '-ffixed-point' to enable fixed point types}}
 signed _Accum s_accum;                // expected-error{{compile with '-ffixed-point' to enable fixed point types}}
 signed long _Accum s_long_accum;      // expected-error{{compile with '-ffixed-point' to enable fixed point types}}
 unsigned short _Accum u_short_accum;  // expected-error{{compile with '-ffixed-point' to enable fixed point types}}
 unsigned _Accum u_accum;              // expected-error{{compile with '-ffixed-point' to enable fixed point types}}
 unsigned long _Accum u_long_accum;    // expected-error{{compile with '-ffixed-point' to enable fixed point types}}
 
 // Aliased fixed point types
 short _Accum short_accum;             // expected-error{{compile with '-ffixed-point' to enable fixed point types}}
 _Accum accum;                         // expected-error{{compile with '-ffixed-point' to enable fixed point types}}
                                       // expected-warning@-1{{type specifier missing, defaults to 'int'}}
 long _Accum long_accum;               // expected-error{{compile with '-ffixed-point' to enable fixed point types}}
+
+// Cannot use fixed point suffixes
+int accum_int = 10k;     // expected-error{{invalid suffix 'k' on integer constant}}
+int fract_int = 10r;     // expected-error{{invalid suffix 'r' on integer constant}}
+float accum_flt = 10.0k; // expected-error{{invalid suffix 'k' on floating constant}}
+float fract_flt = 10.0r; // expected-error{{invalid suffix 'r' on floating constant}}