[clang] 3d2a918 - [clang] Fixes inf loop parsing fixed point literal (#83071)
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Mon Feb 26 14:47:19 PST 2024
Author: PiJoules
Date: 2024-02-26T14:47:16-08:00
New Revision: 3d2a918831e7bcf1285641ee446ac1640819819f
URL: https://github.com/llvm/llvm-project/commit/3d2a918831e7bcf1285641ee446ac1640819819f
DIFF: https://github.com/llvm/llvm-project/commit/3d2a918831e7bcf1285641ee446ac1640819819f.diff
LOG: [clang] Fixes inf loop parsing fixed point literal (#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.
Fixes #83050
Added:
Modified:
clang/lib/Lex/LiteralSupport.cpp
clang/test/Frontend/fixed_point_declarations.c
Removed:
################################################################################
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/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
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