https://github.com/PiJoules created https://github.com/llvm/llvm-project/pull/83071
Clang was incorrectly finding the start of the exponent in a fixed point hex literal. It would unconditionally find the first `e/E/p/P` in a constant regardless of if it were hex or not and parser the remaining digits as an APInt. In a debug build, this would be caught by an assertion, but in a release build, the assertion is removed and we'd end up in an infinite loop. >From 26b6f600f8ebe7751f68af78f714f8b4ae24071c Mon Sep 17 00:00:00 2001 From: Leonard Chan <leonardc...@google.com> Date: Mon, 26 Feb 2024 14:11:45 -0800 Subject: [PATCH] [clang] Add fix for GH issue 83050 Clang was incorrectly finding the start of the exponent in a fixed point hex literal. It would unconditionally find the first `e/E/p/P` in a constant regardless of if it were hex or not and parser the remaining digits as an APInt. In a debug build, this would be caught by an assertion, but in a release build, the assertion is removed and we'd end up in an infinite loop. --- clang/lib/Lex/LiteralSupport.cpp | 9 ++++++--- clang/test/Frontend/GH83050.cpp | 11 +++++++++++ clang/test/Frontend/fixed_point_declarations.c | 18 ++++++++++++++++++ 3 files changed, 35 insertions(+), 3 deletions(-) create mode 100644 clang/test/Frontend/GH83050.cpp diff --git a/clang/lib/Lex/LiteralSupport.cpp b/clang/lib/Lex/LiteralSupport.cpp index 571a984884029d..438c6d772e6e04 100644 --- a/clang/lib/Lex/LiteralSupport.cpp +++ b/clang/lib/Lex/LiteralSupport.cpp @@ -1513,8 +1513,10 @@ NumericLiteralParser::GetFloatValue(llvm::APFloat &Result) { : APFloat::opInvalidOp; } -static inline bool IsExponentPart(char c) { - return c == 'p' || c == 'P' || c == 'e' || c == 'E'; +static inline bool IsExponentPart(char c, bool isHex) { + if (isHex) + return c == 'p' || c == 'P'; + return c == 'e' || c == 'E'; } bool NumericLiteralParser::GetFixedPointValue(llvm::APInt &StoreVal, unsigned Scale) { @@ -1533,7 +1535,8 @@ bool NumericLiteralParser::GetFixedPointValue(llvm::APInt &StoreVal, unsigned Sc if (saw_exponent) { const char *Ptr = DigitsBegin; - while (!IsExponentPart(*Ptr)) ++Ptr; + while (!IsExponentPart(*Ptr, radix == 16)) + ++Ptr; ExponentBegin = Ptr; ++Ptr; NegativeExponent = *Ptr == '-'; diff --git a/clang/test/Frontend/GH83050.cpp b/clang/test/Frontend/GH83050.cpp new file mode 100644 index 00000000000000..df55d848a5fd5f --- /dev/null +++ b/clang/test/Frontend/GH83050.cpp @@ -0,0 +1,11 @@ +/// This is the regression test for https://github.com/llvm/llvm-project/issues/83050. +/// This just needs to compile. +// RUN: %clang_cc1 -x c++ -ffixed-point -S %s -o /dev/null -triple=x86_64-linux -ffixed-point +static constexpr unsigned short _Fract SQRT_FIRST_APPROX[12][2] = { + {0x1.e8p-1uhr, 0x1.0cp-2uhr}, {0x1.bap-1uhr, 0x1.28p-2uhr}, + {0x1.94p-1uhr, 0x1.44p-2uhr}, {0x1.74p-1uhr, 0x1.6p-2uhr}, + {0x1.6p-1uhr, 0x1.74p-2uhr}, {0x1.4ep-1uhr, 0x1.88p-2uhr}, + {0x1.3ep-1uhr, 0x1.9cp-2uhr}, {0x1.32p-1uhr, 0x1.acp-2uhr}, + {0x1.22p-1uhr, 0x1.c4p-2uhr}, {0x1.18p-1uhr, 0x1.d4p-2uhr}, + {0x1.08p-1uhr, 0x1.fp-2uhr}, {0x1.04p-1uhr, 0x1.f8p-2uhr}, +}; diff --git a/clang/test/Frontend/fixed_point_declarations.c b/clang/test/Frontend/fixed_point_declarations.c index 04ed25d227ca52..c8045767442739 100644 --- a/clang/test/Frontend/fixed_point_declarations.c +++ b/clang/test/Frontend/fixed_point_declarations.c @@ -125,3 +125,21 @@ long _Fract long_fract_zero = 0.0lr; // CHECK-DAG: @long_fract_ unsigned short _Fract u_short_fract_zero = 0.0uhr; // CHECK-DAG: @u_short_fract_zero = {{.*}}global i8 0, align 1 unsigned _Fract u_fract_zero = 0.0ur; // CHECK-DAG: @u_fract_zero = {{.*}}global i16 0, align 2 unsigned long _Fract u_long_fract_zero = 0.0ulr; // CHECK-DAG: @u_long_fract_zero = {{.*}}global i32 0, align 4 + +// Hex exponent suffix with E in hex digit sequence. +unsigned short _Fract e1 = 0x1.e8p-1uhr; // CHECK-DAG: @e1 = {{.*}}global i8 -12 +unsigned short _Fract e2 = 0x1.8ep-1uhr; // CHECK-DAG: @e2 = {{.*}}global i8 -57 +unsigned short _Fract e3 = 0x1.ep-1uhr; // CHECK-DAG: @e3 = {{.*}}global i8 -16 +unsigned _Accum e4 = 0xep-1uk; // CHECK-DAG: @e4 = {{.*}}global i32 458752 +unsigned _Accum e5 = 0xe.1p-1uk; // CHECK-DAG: @e5 = {{.*}}global i32 460800 +unsigned _Accum e6 = 0xe.ep-1uk; // CHECK-DAG: @e6 = {{.*}}global i32 487424 +unsigned _Accum e7 = 0xe.e8p-1uk; // CHECK-DAG: @e7 = {{.*}}global i32 488448 +unsigned _Accum e8 = 0xe.8ep-1uk; // CHECK-DAG: @e8 = {{.*}}global i32 476928 +unsigned short _Fract E1 = 0x1.E8p-1uhr; // CHECK-DAG: @E1 = {{.*}}global i8 -12 +unsigned short _Fract E2 = 0x1.8Ep-1uhr; // CHECK-DAG: @E2 = {{.*}}global i8 -57 +unsigned short _Fract E3 = 0x1.Ep-1uhr; // CHECK-DAG: @E3 = {{.*}}global i8 -16 +unsigned _Accum E4 = 0xEp-1uk; // CHECK-DAG: @E4 = {{.*}}global i32 458752 +unsigned _Accum E5 = 0xE.1p-1uk; // CHECK-DAG: @E5 = {{.*}}global i32 460800 +unsigned _Accum E6 = 0xE.Ep-1uk; // CHECK-DAG: @E6 = {{.*}}global i32 487424 +unsigned _Accum E7 = 0xE.E8p-1uk; // CHECK-DAG: @E7 = {{.*}}global i32 488448 +unsigned _Accum E8 = 0xE.8Ep-1uk; // CHECK-DAG: @E8 = {{.*}}global i32 476928 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits