diff options
Diffstat (limited to 'mesalib/src/glsl/glcpp/README')
-rw-r--r-- | mesalib/src/glsl/glcpp/README | 87 |
1 files changed, 32 insertions, 55 deletions
diff --git a/mesalib/src/glsl/glcpp/README b/mesalib/src/glsl/glcpp/README index 9cc00e927..735b27d44 100644 --- a/mesalib/src/glsl/glcpp/README +++ b/mesalib/src/glsl/glcpp/README @@ -1,55 +1,32 @@ -glcpp -- GLSL "C" preprocessor - -This is a simple preprocessor designed to provide the preprocessing -needs of the GLSL language. The requirements for this preprocessor are -specified in the GLSL 1.30 specification availble from: - -http://www.opengl.org/registry/doc/GLSLangSpec.Full.1.30.10.pdf - -This specification is not precise on some semantics, (for example, -#define and #if), defining these merely "as is standard for C++ -preprocessors". To fill in these details, I've been using a draft of -the C99 standard as available from: - -http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1256.pdf - -Any downstream compiler accepting output from glcpp should be prepared -to encounter and deal with the following preprocessor macros: - - #line - #pragma - #extension - -All other macros will be handles according to the GLSL specification -and will not appear in the output. - -Known limitations ------------------ -The __LINE__ and __FILE__ macros are not yet supported. - -A file that ends with a function-like macro name as the last -non-whitespace token will result in a parse error, (where it should be -passed through as is). - -Known deviations from the specification ---------------------------------------- -As mentoned above, the GLSL specification (as of 1.30.10) is fairly -vague on some aspects of the preprocessor, and we've been using C99 to -fill in details. Here is a list of cases where we have deviated from -the behavior specified in C99 to obtain better compatibility with -other GLSL implementations: - - * Redefining a macro with a different value - - C89 says that a macro "may be redefined ... provided that the - second definition [is equivalent]" (Section 3.8.3 Macro - Replacement/constraints) - - C99 is even more explicit, saying tthat a macro "shall not be - redefined by another #define preprocessing directive unless the - second definition [is equivalent]" (Section 6.10.3 Macro - Replacement/Constraints) - - In spite of this, glcpp emits a warning rather than an error for - non-equivalent redefinition of macros since this matches the - behavior of other, widely-used implementations. +glcpp -- GLSL "C" preprocessor
+
+This is a simple preprocessor designed to provide the preprocessing
+needs of the GLSL language. The requirements for this preprocessor are
+specified in the GLSL 1.30 specification availble from:
+
+http://www.opengl.org/registry/doc/GLSLangSpec.Full.1.30.10.pdf
+
+This specification is not precise on some semantics, (for example,
+#define and #if), defining these merely "as is standard for C++
+preprocessors". To fill in these details, I've been using a draft of
+the C99 standard as available from:
+
+http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1256.pdf
+
+Any downstream compiler accepting output from glcpp should be prepared
+to encounter and deal with the following preprocessor macros:
+
+ #line
+ #pragma
+ #extension
+
+All other macros will be handles according to the GLSL specification
+and will not appear in the output.
+
+Known limitations
+-----------------
+The __LINE__ and __FILE__ macros are not yet supported.
+
+A file that ends with a function-like macro name as the last
+non-whitespace token will result in a parse error, (where it should be
+passed through as is).
\ No newline at end of file |