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Diffstat (limited to 'debian/uncrustify-trinity/uncrustify-trinity-0.76.0/documentation/paren_stack.txt')
| -rw-r--r-- | debian/uncrustify-trinity/uncrustify-trinity-0.76.0/documentation/paren_stack.txt | 221 |
1 files changed, 0 insertions, 221 deletions
diff --git a/debian/uncrustify-trinity/uncrustify-trinity-0.76.0/documentation/paren_stack.txt b/debian/uncrustify-trinity/uncrustify-trinity-0.76.0/documentation/paren_stack.txt deleted file mode 100644 index 109709dc..00000000 --- a/debian/uncrustify-trinity/uncrustify-trinity-0.76.0/documentation/paren_stack.txt +++ /dev/null @@ -1,221 +0,0 @@ - -=-----------------------------------------------------------------------------= -* * -* Paren Stack * -* * -=-----------------------------------------------------------------------------= - -At the heart of this algorithm are two stacks. -There is the Paren Stack (PS) and the Frame stack. - -The PS (pse in the code) keeps track of braces, parens, -if/else/switch/do/while/etc items -- anything that is nestable. - -Complex statements go through some of these BS_ stages: - BS_PAREN1 - paren on if/for/switch/while, etc - BS_PAREN2 - paren on do{}while() - BS_BRACE_DO - brace set on do{} - BS_BRACE2 - brace on if/else/for/switch/while - BS_ELSE - expecting 'else' after 'if' - BS_ELSEIF - expecting 'if' after 'else' - BS_WHILE - expecting 'while' after 'do' - -The file is processed one token at a time to support #if/#else/#endif -preprocessors at any point. - -Take this simple if statement as an example: - - if ( x ) - { - x--; - } - -The stack would look like so: -The format is first the token processed and then the PSE stack as it appears -AFTER the token is processed. - -'if' [IF - PAREN1] -'(' [IF - PAREN1] [SPAREN OPEN] -'x' [IF - PAREN1] [SPAREN OPEN] -')' [IF - BRACE2] <- note that the stage was changed on SPAREN_CLOSE -'{' [IF - BRACE2] [BRACE OPEN] -'x' [IF - BRACE2] [BRACE OPEN] -'--' [IF - BRACE2] [BRACE OPEN] -';' [IF - BRACE2] [BRACE OPEN] -'}' [IF - ELSE] - <- lack of else kills the ELSE, closes statement - -Virtual brace example: - if ( x ) - x--; - else if (y) - y--; - else - z++; - -'if' [IF - PAREN1] -'(' [IF - PAREN1] [SPAREN OPEN] -'x' [IF - PAREN1] [SPAREN OPEN] -')' [IF - BRACE2] -'x' [IF - BRACE2] [VBRACE OPEN] <- VBrace open inserted before because - the token was not '{' -'--' [IF - BRACE2] [VBRACE OPEN] -';' [IF - ELSE] <- Semicolon causes a VBrace close to be - inserted after the semicolon -'else' [ELSE - ELSEIF] <- IF changed into ELSE, expect IF or BRACE -'x' [ELSE - BRACE2] [VBRACE OPEN] <- lack of '{' -> VBrace -'++' [ELSE - BRACE2] [VBRACE OPEN] -';' <- VBrace close inserted after semicolon - ELSE removed after statement close - -Nested virtual brace example: (EOF represents the end of the file) - if ( x ) - if (y) - y--; - else - z++; - EOF - -'if' [IF - PAREN1] -'(' [IF - PAREN1] [PAREN OPEN] -'x' [IF - PAREN1] [PAREN OPEN] -')' [IF - BRACE2] -'if' [IF - BRACE2] [VBRACE OPEN] [IF - PAREN1] <- VBrace on BRACE2, IF opened -'(' [IF - BRACE2] [VBRACE OPEN] [IF - PAREN1] [SPAREN OPEN] -'y' [IF - BRACE2] [VBRACE OPEN] [IF - PAREN1] [SPAREN OPEN] -')' [IF - BRACE2] [VBRACE OPEN] [IF - BRACE2] -'y' [IF - BRACE2] [VBRACE OPEN] [IF - BRACE2] [VBRACE OPEN] -'--' [IF - BRACE2] [VBRACE OPEN] [IF - BRACE2] [VBRACE OPEN] -';' [IF - BRACE2] [VBRACE OPEN] [IF - ELSE] -'else' [IF - BRACE2] [VBRACE OPEN] [ELSE - ELSEIF] -'z' [IF - BRACE2] [VBRACE OPEN] [ELSE - BRACE2] [VBRACE OPEN] -'++' [IF - BRACE2] [VBRACE OPEN] [ELSE - BRACE2] [VBRACE OPEN] -';' [IF - BRACE2] [VBRACE OPEN] [ELSE - BRACE2] - step1 - [IF - BRACE2] [VBRACE OPEN] - step2 - [IF - ELSE] - step3 -EOF - --- this last semi is more complicated - first it terminates the VBRACE and then - the else, which then, since it is the end of a statement, terminates the - VBRACE. That bumps the IF stage to ELSE. - The EOF kills that off (since it is not an else) - -Order of operation: -1) if TOS=VBRACE && PC=SEMI, insert VBRACE close, PC=>VBRACE close -2) if PC=VBRACE close or PC=BRACE close, and TOS is complex (if/else/etc) - then advance complex stage. If statement ends, pop and advance - - -Stages for each complex statement: -if -IF-PAREN1, IF-BRACE2, IF-ELSE - -if/else -IF-PAREN1, IF-BRACE2, IF-ELSE, ELSE-ELSEIF, ELSE-BRACE2 - -if/else if/else -IF-PAREN1, IF-BRACE2, IF-ELSE, ELSE-ELSEIF, IF-PAREN1, IF-BRACE2, IF-ELSE, ELSE-ELSEIF, ELSE-BRACE2 - -for -FOR-PAREN1, FOR-BRACE2 - -while -WHILE-PAREN1, WHILE-BRACE2 - -switch -SWITCH-PAREN1, SWITCH-BRACE2 - -synchronized -SYNCHRONIZED-PAREN1 - -do/while -DO-BRACE_DO, DO-WHILE, WHILE-PAREN2 - - -Another less-interesting example: - -{ - if (x) - volatile - { - y++; - } - return y; -} - -'{' [BRACE OPEN] -'if' [BRACE OPEN] [IF - PAREN1] -'(' [BRACE OPEN] [IF - PAREN1] [PAREN OPEN] -'x' [BRACE OPEN] [IF - PAREN1] [PAREN OPEN] -')' [BRACE OPEN] [IF - BRACE2] -'volatile' [BRACE OPEN] [IF - BRACE2] [VBRACE OPEN] [VOLATILE - BRACE2] -'{' [BRACE OPEN] [IF - BRACE2] [VBRACE OPEN] [VOLATILE - BRACE2] [BRACE OPEN] -'y' [BRACE OPEN] [IF - BRACE2] [VBRACE OPEN] [VOLATILE - BRACE2] [BRACE OPEN] -'++' [BRACE OPEN] [IF - BRACE2] [VBRACE OPEN] [VOLATILE - BRACE2] [BRACE OPEN] -';' [BRACE OPEN] [IF - BRACE2] [VBRACE OPEN] [VOLATILE - BRACE2] [BRACE OPEN] -'}' [BRACE OPEN] [IF - ELSE] <- the brace close ends brace-open, - volatile-brace2 and vbrace-open -'return' [BRACE OPEN] <- not else -'y' [BRACE OPEN] -';' [BRACE OPEN] -'}' <- empties the stack - - -=-----------------------------------------------------------------------------= -* * -* Parse Frames * -* * -=-----------------------------------------------------------------------------= - -The pse stack is kept on a frame stack. -The frame stack is need for languages that support preprocessors (C, C++, C#) -that can arbitrarily change code flow. It also isolates #define macros so -that they are indented independently and do not affect the rest of the program. - -When an #if is hit, a copy of the current frame is push on the frame stack. -When an #else/#elif is hit, a copy of the current stack is pushed under the -#if frame and the original (pre-#if) frame is copied to the current frame. -When #endif is hit, the top frame is popped. -This has the following effects: - - a simple #if / #endif does not affect program flow - - #if / #else /#endif - continues from the #if clause - -When a #define is entered, the current frame is pushed and cleared. -When a #define is exited, the frame is popped. - - -Take this example, which isn't very exciting, as both the #if and #else parts -end up with the same paren stack. This is the usual case. - -{ - foo(param1, -#ifdef DEBUG - "debug"); -#else - "release"); -#endif -} - -Right before the #ifdef, we have this for the paren stack: - Top> [BRACE OPEN] [PAREN OPEN] - -The #ifdef pushes a copy of the current stack, so we have this: - Top> [BRACE OPEN] [PAREN OPEN] - [BRACE OPEN] [PAREN OPEN] - -The close paren after "debug" closes out the PAREN-OPEN on the top of the stack. - Top> [BRACE OPEN] - [BRACE OPEN] [PAREN OPEN] - -The #else swaps the top two frames. - Top> [BRACE OPEN] [PAREN OPEN] - [BRACE OPEN] - -Right after the #else, we hit another close paren after the "release". - Top> [BRACE OPEN] - [BRACE OPEN] - -At the #endif, the top of stack is thrown out, which restores us to the #if path. - Top> [BRACE OPEN] - - |