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HLSL: allow "sample" in expressions.

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Unlike other qualifiers, HLSL allows "sample" to be either a qualifier keyword or an
identifier (e.g, a variable or function name).

A fix to allow this was made a while ago, but that fix was insufficient when 'sample'
was used in an expression.  The problem was around the initial ambiguity between:

   sample float a; // "sample" is part of a fully specified type
and
   sample.xyz;     // sample is a keyword in a dot expression

Both start the same.  The "sample" was being accepted as a qualifier before enough
further parsing was done to determine we were not a declaration after all.  This
consumed the token, causing it to fail for its real purpose.

Now, when accepting a fully specified type, the token is pushed back onto the stack if
the thing is not a fully specified type.  This leaves it available for subsequent
purposes.

Changed the "hlsl.identifier.sample.frag" test to exercise this situation, distilled
down from a production shaders.
This commit is contained in:
steve-lunarg 2016-12-18 17:51:14 -07:00
parent abf5057948
commit a64ed3eba0
3 changed files with 71 additions and 41 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

88
Test/baseResults/hlsl.identifier.sample.frag.out
View File

@ -12,18 +12,27 @@ gl_FragCoord origin is upper left
0:12 Function Parameters:
0:? Sequence
0:15 Sequence
0:15 move second child to first child (temp int)
0:15 'sample' (temp int)
0:15 Constant:
0:15 3 (const int)
0:15 move second child to first child (temp 4-component vector of float)
0:15 'sample' (temp 4-component vector of float)
0:? Constant:
0:? 3.000000
0:? 4.000000
0:? 5.000000
0:? 6.000000
0:17 Sequence
0:17 move second child to first child (temp 4-component vector of float)
0:? '@entryPointOutput' (layout(location=0 ) out 4-component vector of float)
0:? Constant:
0:? 0.000000
0:? 0.000000
0:? 0.000000
0:? 0.000000
0:17 vector swizzle (temp 4-component vector of float)
0:17 'sample' (temp 4-component vector of float)
0:17 Sequence
0:17 Constant:
0:17 0 (const int)
0:17 Constant:
0:17 1 (const int)
0:17 Constant:
0:17 2 (const int)
0:17 Constant:
0:17 3 (const int)
0:17 Branch: Return
0:? Linker Objects
0:? '@entryPointOutput' (layout(location=0 ) out 4-component vector of float)
@ -45,54 +54,67 @@ gl_FragCoord origin is upper left
0:12 Function Parameters:
0:? Sequence
0:15 Sequence
0:15 move second child to first child (temp int)
0:15 'sample' (temp int)
0:15 Constant:
0:15 3 (const int)
0:15 move second child to first child (temp 4-component vector of float)
0:15 'sample' (temp 4-component vector of float)
0:? Constant:
0:? 3.000000
0:? 4.000000
0:? 5.000000
0:? 6.000000
0:17 Sequence
0:17 move second child to first child (temp 4-component vector of float)
0:? '@entryPointOutput' (layout(location=0 ) out 4-component vector of float)
0:? Constant:
0:? 0.000000
0:? 0.000000
0:? 0.000000
0:? 0.000000
0:17 vector swizzle (temp 4-component vector of float)
0:17 'sample' (temp 4-component vector of float)
0:17 Sequence
0:17 Constant:
0:17 0 (const int)
0:17 Constant:
0:17 1 (const int)
0:17 Constant:
0:17 2 (const int)
0:17 Constant:
0:17 3 (const int)
0:17 Branch: Return
0:? Linker Objects
0:? '@entryPointOutput' (layout(location=0 ) out 4-component vector of float)
// Module Version 10000
// Generated by (magic number): 80001
// Id's are bound by 24
// Id's are bound by 28
Capability Shader
1: ExtInstImport "GLSL.std.450"
MemoryModel Logical GLSL450
EntryPoint Fragment 4 "main" 20
EntryPoint Fragment 4 "main" 25
ExecutionMode 4 OriginUpperLeft
Name 4 "main"
Name 10 "sample(i1;"
Name 9 "x"
Name 15 "sample"
Name 20 "@entryPointOutput"
Decorate 20(@entryPointOutput) Location 0
Name 18 "sample"
Name 25 "@entryPointOutput"
Decorate 25(@entryPointOutput) Location 0
2: TypeVoid
3: TypeFunction 2
6: TypeInt 32 1
7: TypePointer Function 6(int)
8: TypeFunction 6(int) 7(ptr)
16: 6(int) Constant 3
17: TypeFloat 32
18: TypeVector 17(float) 4
19: TypePointer Output 18(fvec4)
20(@entryPointOutput): 19(ptr) Variable Output
21: 17(float) Constant 0
22: 18(fvec4) ConstantComposite 21 21 21 21
15: TypeFloat 32
16: TypeVector 15(float) 4
17: TypePointer Function 16(fvec4)
19: 15(float) Constant 1077936128
20: 15(float) Constant 1082130432
21: 15(float) Constant 1084227584
22: 15(float) Constant 1086324736
23: 16(fvec4) ConstantComposite 19 20 21 22
24: TypePointer Output 16(fvec4)
25(@entryPointOutput): 24(ptr) Variable Output
4(main): 2 Function None 3
5: Label
15(sample): 7(ptr) Variable Function
Store 15(sample) 16
Store 20(@entryPointOutput) 22
18(sample): 17(ptr) Variable Function
Store 18(sample) 23
26: 16(fvec4) Load 18(sample)
Store 25(@entryPointOutput) 26
Return
FunctionEnd
10(sample(i1;): 6(int) Function None 8

4
Test/hlsl.identifier.sample.frag
View File

@ -12,7 +12,7 @@ float4 main() : SV_Target0
{
// HLSL allows this as an identifier as well.
// However, this is not true of other qualifier keywords such as "linear".
int sample = 3;
float4 sample = float4(3,4,5,6);
return float4(0,0,0,0);
return sample.rgba; // 'sample' can participate in an expression.
}

20
hlsl/hlslGrammar.cpp
View File

@ -90,10 +90,11 @@ bool HlslGrammar::acceptIdentifier(HlslToken& idToken)
// as "linear" or "centroid" NOT valid identifiers. This code special cases "sample",
// so e.g, "int sample;" is accepted.
if (peekTokenClass(EHTokSample)) {
idToken.string = NewPoolTString("sample");
idToken.tokenClass = EHTokIdentifier;
idToken.symbol = nullptr;
idToken.loc = token.loc;
token.string = NewPoolTString("sample");
token.tokenClass = EHTokIdentifier;
token.symbol = nullptr;
idToken = token;
advanceToken();
return true;
}
@ -475,8 +476,15 @@ bool HlslGrammar::acceptFullySpecifiedType(TType& type)
TSourceLoc loc = token.loc;
// type_specifier
if (! acceptType(type))
if (! acceptType(type)) {
// If this is not a type, we may have inadvertently gone down a wrong path
// py parsing "sample", which can be treated like either an identifier or a
// qualifier. Back it out, if we did.
if (qualifier.sample)
recedeToken();
return false;
}
if (type.getBasicType() == EbtBlock) {
// the type was a block, which set some parts of the qualifier
parseContext.mergeQualifiers(type.getQualifier(), qualifier);
@ -2203,7 +2211,7 @@ bool HlslGrammar::acceptPostfixExpression(TIntermTyped*& node)
} else if (acceptIdentifier(idToken)) {
// identifier or function_call name
if (! peekTokenClass(EHTokLeftParen)) {
node = parseContext.handleVariable(idToken.loc, idToken.symbol, token.string);
node = parseContext.handleVariable(idToken.loc, idToken.symbol, idToken.string);
} else if (acceptFunctionCall(idToken, node)) {
// function_call (nothing else to do yet)
} else {