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Preprocessor: Implement skipping of macros that evaluate to nothing while evaluating expressions. They had been causing early termination of an expression's evaluation.

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Also includes some unrelated updates of documentation.


git-svn-id: https://cvs.khronos.org/svn/repos/ogl/trunk/ecosystem/public/sdk/tools/glslang@24420 e7fa87d3-cd2b-0410-9028-fcbf551c1848
This commit is contained in:
John Kessenich 2013-12-10 00:25:14 +00:00
parent c719481d43
commit 2d2f31625d
10 changed files with 120 additions and 50 deletions
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54
README.txt
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@ -66,22 +66,54 @@ shell.
Note: Despite appearances, the use of a DLL is currently disabled; it
simply makes a standalone executable from a statically linked library.
Basic external programmatic interface
-------------------------------------
Programmatic Interfaces
-----------------------
Another piece of software can programmatically translate shaders to an AST
using the C-style ShInitialize(), ShCompile(), et. al. interface. The main() in
StandAlone/StandAlone.cpp shows an example way of using these.
using one of two different interfaces:
- A new C++ class-oriented interface, or
- The original C functional interface
The Sh*() interface takes a "compiler" call-back object, which it calls after
building call back that is passed the AST and can then execute a backend on it.
The main() in StandAlone/StandAlone.cpp shows examples using both styles.
The following is a simplified resulting run-time call stack:
C++ Class Interface (new, preferred):
ShCompile(shader, compiler) -> compiler(AST) -> <back end>
This interface is in roughly the last 1/3 of ShaderLang.h. It is in the
glslang namespace and contains the following.
In practice, ShCompile() takes shader strings, default version, and
warning/error and other options for controling compilation.
const char* GetEsslVersionString();
const char* GetGlslVersionString();
bool InitializeProcess();
void FinalizeProcess();
class TShader
bool parse(...);
void setStrings(...);
const char* getInfoLog();
class TProgram
void addShader(...);
bool link(...);
const char* getInfoLog();
Reflection queries
See ShaderLang.h and the usage of it in StandAlone/StandAlone.cpp for more
details.
C Functional Interface (orginal):
This interface is in roughly the first 2/3 of ShaderLang.h, and referred to
as the Sh*() interface, as all the entry points start "Sh".
The Sh*() interface takes a "compiler" call-back object, which it calls after
building call back that is passed the AST and can then execute a backend on it.
The following is a simplified resulting run-time call stack:
ShCompile(shader, compiler) -> compiler(AST) -> <back end>
In practice, ShCompile() takes shader strings, default version, and
warning/error and other options for controling compilation.
Testing
-------
@ -100,7 +132,7 @@ missing, those tests just won't run.
Basic Internal Operation
------------------------
- Initial lexical analysis is done be the preprocessor in
- Initial lexical analysis is done by the preprocessor in
MachineIndependent/Preprocessor, and then refined by a GLSL scanner
in MachineIndependent/Scan.cpp. There is currently no use of flex.