1 //===- OptEmitter.cpp - Helper for emitting options.----------- -----------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "OptEmitter.h"
10 #include "llvm/ADT/Twine.h"
11 #include "llvm/TableGen/Error.h"
12 #include "llvm/TableGen/Record.h"
13 #include <cctype>
14 #include <cstring>
15 
16 namespace llvm {
17 
18 // Ordering on Info. The logic should match with the consumer-side function in
19 // llvm/Option/OptTable.h.
20 // FIXME: Make this take StringRefs instead of null terminated strings to
21 // simplify callers.
22 static int StrCmpOptionName(const char *A, const char *B) {
23   const char *X = A, *Y = B;
24   char a = tolower(*A), b = tolower(*B);
25   while (a == b) {
26     if (a == '\0')
27       return strcmp(A, B);
28 
29     a = tolower(*++X);
30     b = tolower(*++Y);
31   }
32 
33   if (a == '\0') // A is a prefix of B.
34     return 1;
35   if (b == '\0') // B is a prefix of A.
36     return -1;
37 
38   // Otherwise lexicographic.
39   return (a < b) ? -1 : 1;
40 }
41 
42 int CompareOptionRecords(Record *const *Av, Record *const *Bv) {
43   const Record *A = *Av;
44   const Record *B = *Bv;
45 
46   // Sentinel options precede all others and are only ordered by precedence.
47   bool ASent = A->getValueAsDef("Kind")->getValueAsBit("Sentinel");
48   bool BSent = B->getValueAsDef("Kind")->getValueAsBit("Sentinel");
49   if (ASent != BSent)
50     return ASent ? -1 : 1;
51 
52   // Compare options by name, unless they are sentinels.
53   if (!ASent)
54     if (int Cmp = StrCmpOptionName(A->getValueAsString("Name").str().c_str(),
55                                    B->getValueAsString("Name").str().c_str()))
56       return Cmp;
57 
58   if (!ASent) {
59     std::vector<StringRef> APrefixes = A->getValueAsListOfStrings("Prefixes");
60     std::vector<StringRef> BPrefixes = B->getValueAsListOfStrings("Prefixes");
61 
62     for (std::vector<StringRef>::const_iterator APre = APrefixes.begin(),
63                                                 AEPre = APrefixes.end(),
64                                                 BPre = BPrefixes.begin(),
65                                                 BEPre = BPrefixes.end();
66          APre != AEPre && BPre != BEPre; ++APre, ++BPre) {
67       if (int Cmp = StrCmpOptionName(APre->str().c_str(), BPre->str().c_str()))
68         return Cmp;
69     }
70   }
71 
72   // Then by the kind precedence;
73   int APrec = A->getValueAsDef("Kind")->getValueAsInt("Precedence");
74   int BPrec = B->getValueAsDef("Kind")->getValueAsInt("Precedence");
75   if (APrec == BPrec && A->getValueAsListOfStrings("Prefixes") ==
76                             B->getValueAsListOfStrings("Prefixes")) {
77     PrintError(A->getLoc(), Twine("Option is equivalent to"));
78     PrintError(B->getLoc(), Twine("Other defined here"));
79     PrintFatalError("Equivalent Options found.");
80   }
81   return APrec < BPrec ? -1 : 1;
82 }
83 
84 } // namespace llvm
85